summaryrefslogtreecommitdiff
path: root/ges/ges-timeline.c
blob: 241c0d187c09611b13ad279b6bdf6d3f7897fbe4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
/* GStreamer Editing Services
 * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
 *               2009 Nokia Corporation
 *               2012 Thibault Saunier <tsaunier@gnome.org>
 *               2012 Collabora Ltd.
 *                 Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/**
 * SECTION:ges-timeline
 * @short_description: Multimedia timeline
 *
 * #GESTimeline is the central object for any multimedia timeline.
 *
 * Contains a list of #GESLayer which users should use to arrange the
 * various clips through time.
 *
 * The output type is determined by the #GESTrack that are set on
 * the #GESTimeline.
 *
 * To save/load a timeline, you can use the ges_timeline_load_from_uri() and
 * ges_timeline_save_to_uri() methods to use the default format. If you wish
 *
 * Note that any change you make in the timeline will not actually be taken
 * into account until you call the #ges_timeline_commit method.
 */

#include "ges-internal.h"
#include "ges-project.h"
#include "ges-container.h"
#include "ges-timeline.h"
#include "ges-track.h"
#include "ges-layer.h"
#include "ges-auto-transition.h"
#include "ges.h"

typedef struct _MoveContext MoveContext;

static GPtrArray *select_tracks_for_object_default (GESTimeline * timeline,
    GESClip * clip, GESTrackElement * tr_obj, gpointer user_data);
static inline void init_movecontext (MoveContext * mv_ctx, gboolean first_init);
static void ges_extractable_interface_init (GESExtractableInterface * iface);
static void ges_meta_container_interface_init
    (GESMetaContainerInterface * iface);

G_DEFINE_TYPE_WITH_CODE (GESTimeline, ges_timeline, GST_TYPE_BIN,
    G_IMPLEMENT_INTERFACE (GES_TYPE_EXTRACTABLE, ges_extractable_interface_init)
    G_IMPLEMENT_INTERFACE (GES_TYPE_META_CONTAINER,
        ges_meta_container_interface_init));


GST_DEBUG_CATEGORY_STATIC (ges_timeline_debug);
#undef GST_CAT_DEFAULT
#define GST_CAT_DEFAULT ges_timeline_debug

/* lock to protect dynamic callbacks, like pad-added */
#define DYN_LOCK(timeline) (&GES_TIMELINE (timeline)->priv->dyn_mutex)
#define LOCK_DYN(timeline) G_STMT_START {                       \
    GST_INFO_OBJECT (timeline, "Getting dynamic lock from %p", \
        g_thread_self());                                       \
    g_rec_mutex_lock (DYN_LOCK (timeline));                     \
    GST_INFO_OBJECT (timeline, "Got Dynamic lock from %p",     \
        g_thread_self());         \
  } G_STMT_END

#define UNLOCK_DYN(timeline) G_STMT_START {                         \
    GST_INFO_OBJECT (timeline, "Unlocking dynamic lock from %p", \
        g_thread_self());                                         \
    g_rec_mutex_unlock (DYN_LOCK (timeline));                     \
    GST_INFO_OBJECT (timeline, "Unlocked Dynamic lock from %p",  \
        g_thread_self());         \
  } G_STMT_END

typedef struct TrackObjIters
{
  GSequenceIter *iter_start;
  GSequenceIter *iter_end;
  GSequenceIter *iter_obj;
  GSequenceIter *iter_by_layer;

  GESLayer *layer;
  GESTrackElement *trackelement;
} TrackObjIters;

static void
_destroy_obj_iters (TrackObjIters * iters)
{
  g_slice_free (TrackObjIters, iters);
}

/*  The move context is used for the timeline editing modes functions in order to
 *  + Ripple / Roll /  Slide / Move / Trim
 *
 * The context aims at avoiding to recalculate values/objects on each call of the
 * editing functions.
 */
struct _MoveContext
{
  GESClip *clip;
  GESEdge edge;
  GESEditMode mode;

  /* Ripple and Roll Objects */
  GList *moving_trackelements;

  /* We use it as a set of Clip to move between layers */
  GHashTable *toplevel_containers;
  /* Min priority of the objects currently in toplevel_containers */
  guint min_move_layer;
  /* Max priority of the objects currently in toplevel_containers */
  guint max_layer_prio;

  /* Never trim so duration would becomes < 0 */
  guint64 max_trim_pos;

  /* fields to force/avoid new context */
  /* Set to %TRUE when the track is doing updates of track element
   * properties so we don't end up always needing new move context */
  gboolean ignore_needs_ctx;
  gboolean needs_move_ctx;

  /* Last snapping  properties */
  GESTrackElement *last_snaped1;
  GESTrackElement *last_snaped2;
  GstClockTime *last_snap_ts;
};

struct _GESTimelinePrivate
{
  /* The duration of the timeline */
  gint64 duration;

  /* The auto-transition of the timeline */
  gboolean auto_transition;

  /* Timeline edition modes and snapping management */
  guint64 snapping_distance;

  /* FIXME: Should we offer an API over those fields ?
   * FIXME: Should other classes than subclasses of Source also
   * be tracked? */

  /* Snapping fields */
  GHashTable *by_start;         /* {Source: start} */
  GHashTable *by_end;           /* {Source: end} */
  GHashTable *by_object;        /* {timecode: Source} */
  GHashTable *obj_iters;        /* {Source: TrackObjIters} */
  GSequence *starts_ends;       /* Sorted list of starts/ends */
  /* We keep 1 reference to our trackelement here */
  GSequence *tracksources;      /* Source-s sorted by start/priorities */

  GRecMutex dyn_mutex;
  GList *priv_tracks;
  /* FIXME: We should definitly offer an API over this,
   * probably through a ges_layer_get_track_elements () method */
  GHashTable *by_layer;         /* {layer: GSequence of TrackElement by start/priorities} */

  /* The set of auto_transitions we control, currently the key is
   * pointerToPreviousiTrackObjAdresspointerToNextTrackObjAdress as a string,
   * ... not really optimal but it works */
  GHashTable *auto_transitions;

  MoveContext movecontext;

  /* This variable is set to %TRUE when it makes sense to update the transitions,
   * and %FALSE otherwize */
  gboolean needs_transitions_update;

  /* While we are creating and adding the TrackElements for a clip, we need to
   * ignore the child-added signal */
  GESClip *ignore_track_element_added;
  GList *groups;

  guint group_id;
};

/* private structure to contain our track-related information */

typedef struct
{
  GESTimeline *timeline;
  GESTrack *track;
  GstPad *pad;                  /* Pad from the track */
  GstPad *ghostpad;

  gulong probe_id;
} TrackPrivate;

enum
{
  PROP_0,
  PROP_DURATION,
  PROP_AUTO_TRANSITION,
  PROP_SNAPPING_DISTANCE,
  PROP_UPDATE,
  PROP_LAST
};

static GParamSpec *properties[PROP_LAST];

enum
{
  TRACK_ADDED,
  TRACK_REMOVED,
  LAYER_ADDED,
  LAYER_REMOVED,
  SNAPING_STARTED,
  SNAPING_ENDED,
  SELECT_TRACKS_FOR_OBJECT,
  COMMITED,
  LAST_SIGNAL
};

static GstBinClass *parent_class;

static guint ges_timeline_signals[LAST_SIGNAL] = { 0 };

static gint custom_find_track (TrackPrivate * tr_priv, GESTrack * track);

static guint nb_assets = 0;

/* GESExtractable implementation */
static gchar *
extractable_check_id (GType type, const gchar * id)
{
  gchar *res;

  if (id == NULL)
    res = g_strdup_printf ("%s-%i", "project", nb_assets);
  else
    res = g_strdup (id);

  nb_assets++;

  return res;
}

static gchar *
extractable_get_id (GESExtractable * self)
{
  GESAsset *asset;

  if (!(asset = ges_extractable_get_asset (self)))
    return NULL;

  return g_strdup (ges_asset_get_id (asset));
}

static void
ges_extractable_interface_init (GESExtractableInterface * iface)
{
  iface->asset_type = GES_TYPE_PROJECT;
  iface->check_id = (GESExtractableCheckId) extractable_check_id;
  iface->get_id = extractable_get_id;
}

static void
ges_meta_container_interface_init (GESMetaContainerInterface * iface)
{
}

/* GObject Standard vmethods*/
static void
ges_timeline_get_property (GObject * object, guint property_id,
    GValue * value, GParamSpec * pspec)
{
  GESTimeline *timeline = GES_TIMELINE (object);

  switch (property_id) {
    case PROP_DURATION:
      g_value_set_uint64 (value, timeline->priv->duration);
      break;
    case PROP_AUTO_TRANSITION:
      g_value_set_boolean (value, timeline->priv->auto_transition);
      break;
    case PROP_SNAPPING_DISTANCE:
      g_value_set_uint64 (value, timeline->priv->snapping_distance);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
  }
}

static void
ges_timeline_set_property (GObject * object, guint property_id,
    const GValue * value, GParamSpec * pspec)
{
  GESTimeline *timeline = GES_TIMELINE (object);

  switch (property_id) {
    case PROP_AUTO_TRANSITION:
      ges_timeline_set_auto_transition (timeline, g_value_get_boolean (value));
      break;
    case PROP_SNAPPING_DISTANCE:
      timeline->priv->snapping_distance = g_value_get_uint64 (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
  }
}

static void
ges_timeline_dispose (GObject * object)
{
  GESTimeline *tl = GES_TIMELINE (object);
  GESTimelinePrivate *priv = tl->priv;

  while (tl->layers) {
    GESLayer *layer = (GESLayer *) tl->layers->data;
    ges_timeline_remove_layer (GES_TIMELINE (object), layer);
  }

  /* FIXME: it should be possible to remove tracks before removing
   * layers, but at the moment this creates a problem because the track
   * objects aren't notified that their gnlobjects have been destroyed.
   */

  while (tl->tracks)
    ges_timeline_remove_track (GES_TIMELINE (object), tl->tracks->data);

  while (priv->groups)
    g_list_free_full (ges_container_ungroup (priv->groups->data, FALSE),
        gst_object_unref);

  g_hash_table_unref (priv->by_start);
  g_hash_table_unref (priv->by_end);
  g_hash_table_unref (priv->by_object);
  g_hash_table_unref (priv->by_layer);
  g_hash_table_unref (priv->obj_iters);
  g_sequence_free (priv->starts_ends);
  g_sequence_free (priv->tracksources);
  g_list_free (priv->movecontext.moving_trackelements);
  g_hash_table_unref (priv->movecontext.toplevel_containers);

  g_hash_table_unref (priv->auto_transitions);

  G_OBJECT_CLASS (ges_timeline_parent_class)->dispose (object);
}

static void
ges_timeline_finalize (GObject * object)
{
  G_OBJECT_CLASS (ges_timeline_parent_class)->finalize (object);
}

/* we collect the first result */
static gboolean
_gst_array_accumulator (GSignalInvocationHint * ihint,
    GValue * return_accu, const GValue * handler_return, gpointer dummy)
{
  gpointer array;

  array = g_value_get_boxed (handler_return);
  if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
    g_value_set_boxed (return_accu, array);

  return FALSE;
}

static void
ges_timeline_class_init (GESTimelineClass * klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  g_type_class_add_private (klass, sizeof (GESTimelinePrivate));

  GST_DEBUG_CATEGORY_INIT (ges_timeline_debug, "gestimeline",
      GST_DEBUG_FG_YELLOW, "ges timeline");

  parent_class = g_type_class_peek_parent (klass);

  object_class->get_property = ges_timeline_get_property;
  object_class->set_property = ges_timeline_set_property;
  object_class->dispose = ges_timeline_dispose;
  object_class->finalize = ges_timeline_finalize;

  /**
   * GESTimeline:duration:
   *
   * Current duration (in nanoseconds) of the #GESTimeline
   */
  properties[PROP_DURATION] =
      g_param_spec_uint64 ("duration", "Duration",
      "The duration of the timeline", 0, G_MAXUINT64,
      GST_CLOCK_TIME_NONE, G_PARAM_READABLE);
  g_object_class_install_property (object_class, PROP_DURATION,
      properties[PROP_DURATION]);

  /**
   * GESTimeline:auto-transition:
   *
   * Sets whether transitions are added automagically when clips overlap.
   */
  g_object_class_install_property (object_class, PROP_AUTO_TRANSITION,
      g_param_spec_boolean ("auto-transition", "Auto-Transition",
          "whether the transitions are added", FALSE, G_PARAM_READWRITE));

  /**
   * GESTimeline:snapping-distance:
   *
   * Distance (in nanoseconds) from which a moving object will snap
   * with it neighboors. 0 means no snapping.
   */
  properties[PROP_SNAPPING_DISTANCE] =
      g_param_spec_uint64 ("snapping-distance", "Snapping distance",
      "Distance from which moving an object will snap with neighboors", 0,
      G_MAXUINT64, 0, G_PARAM_READWRITE);
  g_object_class_install_property (object_class, PROP_SNAPPING_DISTANCE,
      properties[PROP_SNAPPING_DISTANCE]);

  /**
   * GESTimeline::track-added:
   * @timeline: the #GESTimeline
   * @track: the #GESTrack that was added to the timeline
   *
   * Will be emitted after the track was added to the timeline.
   */
  ges_timeline_signals[TRACK_ADDED] =
      g_signal_new ("track-added", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GESTimelineClass, track_added), NULL,
      NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GES_TYPE_TRACK);

  /**
   * GESTimeline::track-removed:
   * @timeline: the #GESTimeline
   * @track: the #GESTrack that was removed from the timeline
   *
   * Will be emitted after the track was removed from the timeline.
   */
  ges_timeline_signals[TRACK_REMOVED] =
      g_signal_new ("track-removed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GESTimelineClass, track_removed),
      NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GES_TYPE_TRACK);

  /**
   * GESTimeline::layer-added:
   * @timeline: the #GESTimeline
   * @layer: the #GESLayer that was added to the timeline
   *
   * Will be emitted after the layer was added to the timeline.
   */
  ges_timeline_signals[LAYER_ADDED] =
      g_signal_new ("layer-added", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GESTimelineClass, layer_added), NULL,
      NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GES_TYPE_LAYER);

  /**
   * GESTimeline::layer-removed:
   * @timeline: the #GESTimeline
   * @layer: the #GESLayer that was removed from the timeline
   *
   * Will be emitted after the layer was removed from the timeline.
   */
  ges_timeline_signals[LAYER_REMOVED] =
      g_signal_new ("layer-removed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GESTimelineClass, layer_removed),
      NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GES_TYPE_LAYER);

  /**
   * GESTimeline::track-elements-snapping:
   * @timeline: the #GESTimeline
   * @obj1: the first #GESTrackElement that was snapping.
   * @obj2: the second #GESTrackElement that was snapping.
   * @position: the position where the two objects finally snapping.
   *
   * Will be emitted when the 2 #GESTrackElement first snapped
   *
   * Since: 0.10.XX
   */
  ges_timeline_signals[SNAPING_STARTED] =
      g_signal_new ("snapping-started", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
      G_TYPE_NONE, 3, GES_TYPE_TRACK_ELEMENT, GES_TYPE_TRACK_ELEMENT,
      G_TYPE_UINT64);

  /**
   * GESTimeline::snapping-end:
   * @timeline: the #GESTimeline
   * @obj1: the first #GESTrackElement that was snapping.
   * @obj2: the second #GESTrackElement that was snapping.
   * @position: the position where the two objects finally snapping.
   *
   * Will be emitted when the 2 #GESTrackElement ended to snap
   *
   * Since: 0.10.XX
   */
  ges_timeline_signals[SNAPING_ENDED] =
      g_signal_new ("snapping-ended", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
      G_TYPE_NONE, 3, GES_TYPE_TRACK_ELEMENT, GES_TYPE_TRACK_ELEMENT,
      G_TYPE_UINT64);

  /**
   * GESTimeline::select-tracks-for-object:
   * @timeline: the #GESTimeline
   * @clip: The #GESClip on which @track-element will land
   * @track-element: The #GESTrackElement for which to choose the tracks it should land into
   *
   * Returns: (transfer full) (element-type GESTrack): a #GPtrArray of #GESTrack-s where that object should be added
   *
   * Since: 0.10.XX
   */
  ges_timeline_signals[SELECT_TRACKS_FOR_OBJECT] =
      g_signal_new ("select-tracks-for-object", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, _gst_array_accumulator, NULL, NULL,
      G_TYPE_PTR_ARRAY, 2, GES_TYPE_CLIP, GES_TYPE_TRACK_ELEMENT);

  /**
   * GESTimeline::commited:
   * @timeline: the #GESTimeline
   */
  ges_timeline_signals[COMMITED] =
      g_signal_new ("commited", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
}

static void
ges_timeline_init (GESTimeline * self)
{
  GESTimelinePrivate *priv = self->priv;

  self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
      GES_TYPE_TIMELINE, GESTimelinePrivate);

  priv = self->priv;
  self->layers = NULL;
  self->tracks = NULL;
  self->priv->duration = 0;
  self->priv->auto_transition = FALSE;
  priv->snapping_distance = 0;

  /* Move context initialization */
  init_movecontext (&self->priv->movecontext, TRUE);
  priv->movecontext.ignore_needs_ctx = FALSE;

  priv->priv_tracks = NULL;
  priv->by_start = g_hash_table_new (g_direct_hash, g_direct_equal);
  priv->by_end = g_hash_table_new (g_direct_hash, g_direct_equal);
  priv->by_object = g_hash_table_new (g_direct_hash, g_direct_equal);
  priv->by_layer = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL,
      (GDestroyNotify) g_sequence_free);
  priv->obj_iters = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL,
      (GDestroyNotify) _destroy_obj_iters);
  priv->starts_ends = g_sequence_new (g_free);
  priv->tracksources = g_sequence_new (gst_object_unref);

  priv->auto_transitions =
      g_hash_table_new_full (g_str_hash, g_str_equal, NULL, gst_object_unref);
  priv->needs_transitions_update = TRUE;

  priv->group_id = -1;

  g_signal_connect_after (self, "select-tracks-for-object",
      G_CALLBACK (select_tracks_for_object_default), NULL);
}

/* Private methods */

static inline GESContainer *
get_toplevel_container (GESTrackElement * element)
{
  GESTimelineElement *ret =
      ges_timeline_element_get_toplevel_parent ((GESTimelineElement
          *) (element));

  /*  We own a ref to the elements ourself */
  gst_object_unref (ret);
  return (GESContainer *) ret;
}

/* Sorting utils*/
static gint
sort_layers (gpointer a, gpointer b)
{
  GESLayer *layer_a, *layer_b;
  guint prio_a, prio_b;

  layer_a = GES_LAYER (a);
  layer_b = GES_LAYER (b);

  prio_a = ges_layer_get_priority (layer_a);
  prio_b = ges_layer_get_priority (layer_b);

  if ((gint) prio_a > (guint) prio_b)
    return 1;
  if ((guint) prio_a < (guint) prio_b)
    return -1;

  return 0;
}

static void
timeline_update_duration (GESTimeline * timeline)
{
  GstClockTime *cduration;
  GSequenceIter *it = g_sequence_get_end_iter (timeline->priv->starts_ends);

  it = g_sequence_iter_prev (it);

  if (g_sequence_iter_is_end (it)) {
    timeline->priv->duration = 0;
    g_object_notify_by_pspec (G_OBJECT (timeline), properties[PROP_DURATION]);
    return;
  }

  cduration = g_sequence_get (it);

  if (cduration && timeline->priv->duration != *cduration) {
    GST_DEBUG ("track duration : %" GST_TIME_FORMAT " current : %"
        GST_TIME_FORMAT, GST_TIME_ARGS (*cduration),
        GST_TIME_ARGS (timeline->priv->duration));

    timeline->priv->duration = *cduration;

    g_object_notify_by_pspec (G_OBJECT (timeline), properties[PROP_DURATION]);
  }
}

static gint
find_layer_by_prio (GESLayer * a, gpointer pprio)
{
  gint prio = GPOINTER_TO_INT (pprio), lprio = ges_layer_get_priority (a);

  if (lprio < prio)
    return -1;
  if (lprio > prio)
    return 1;
  return 0;
}

static void
sort_track_elements (GESTimeline * timeline, TrackObjIters * iters)
{
  g_sequence_sort_changed (iters->iter_obj,
      (GCompareDataFunc) element_start_compare, NULL);
}

static gint
compare_uint64 (guint64 * a, guint64 * b, gpointer user_data)
{
  if (*a > *b)
    return 1;
  else if (*a == *b)
    return 0;
  else
    return -1;
}

static gint
custom_find_track (TrackPrivate * tr_priv, GESTrack * track)
{
  if (tr_priv->track == track)
    return 0;
  return -1;
}

static inline void
sort_starts_ends_end (GESTimeline * timeline, TrackObjIters * iters)
{
  GESTimelineElement *obj = GES_TIMELINE_ELEMENT (iters->trackelement);
  GESTimelinePrivate *priv = timeline->priv;
  guint64 *end = g_hash_table_lookup (priv->by_end, obj);

  *end = _START (obj) + _DURATION (obj);

  g_sequence_sort_changed (iters->iter_end, (GCompareDataFunc) compare_uint64,
      NULL);
  timeline_update_duration (timeline);
}

static inline void
sort_starts_ends_start (GESTimeline * timeline, TrackObjIters * iters)
{
  GESTimelineElement *obj = GES_TIMELINE_ELEMENT (iters->trackelement);
  GESTimelinePrivate *priv = timeline->priv;
  guint64 *start = g_hash_table_lookup (priv->by_start, obj);

  *start = _START (obj);

  g_sequence_sort_changed (iters->iter_start,
      (GCompareDataFunc) compare_uint64, NULL);
  timeline_update_duration (timeline);
}

static void
_destroy_auto_transition_cb (GESAutoTransition * auto_transition,
    GESTimeline * timeline)
{
  GESTimelinePrivate *priv = timeline->priv;
  GESClip *transition = auto_transition->transition_clip;
  GESLayer *layer = ges_clip_get_layer (transition);

  ges_layer_remove_clip (layer, transition);
  g_signal_handlers_disconnect_by_func (auto_transition,
      _destroy_auto_transition_cb, timeline);

  if (!g_hash_table_remove (priv->auto_transitions, auto_transition->key))
    GST_WARNING_OBJECT (timeline, "Could not remove auto_transition %"
        GST_PTR_FORMAT, auto_transition->key);
}

static GESAutoTransition *
create_transition (GESTimeline * timeline, GESTrackElement * previous,
    GESTrackElement * next, GESClip * transition,
    GESLayer * layer, guint64 start, guint64 duration)
{
  GESAsset *asset;
  GESAutoTransition *auto_transition;

  if (transition == NULL) {
    /* TODO make it possible to specify a Transition asset in the API */
    asset = ges_asset_request (GES_TYPE_TRANSITION_CLIP, "crossfade", NULL);
    transition =
        ges_layer_add_asset (layer, asset, start, 0, duration,
        ges_track_element_get_track_type (next));
  } else {
    GST_DEBUG_OBJECT (timeline,
        "Reusing already existing transition: %" GST_PTR_FORMAT, transition);
  }

  /* We know there is only 1 TrackElement */
  auto_transition =
      ges_auto_transition_new (GES_CONTAINER_CHILDREN (transition)->data,
      previous, next);

  g_signal_connect (auto_transition, "destroy-me",
      G_CALLBACK (_destroy_auto_transition_cb), timeline);

  g_hash_table_insert (timeline->priv->auto_transitions,
      auto_transition->key, auto_transition);

  return auto_transition;
}

typedef GESAutoTransition *(*GetAutoTransitionFunc) (GESTimeline * timeline,
    GESLayer * layer, GESTrack * track, GESTrackElement * previous,
    GESTrackElement * next, GstClockTime transition_duration);

static GESAutoTransition *
_find_transition_from_auto_transitions (GESTimeline * timeline,
    GESLayer * layer, GESTrack * track, GESTrackElement * prev,
    GESTrackElement * next, GstClockTime transition_duration)
{
  GESAutoTransition *auto_transition;

  gchar *key = g_strdup_printf ("%p%p", prev, next);

  auto_transition = g_hash_table_lookup (timeline->priv->auto_transitions, key);
  g_free (key);

  return auto_transition;
}

static GESAutoTransition *
_create_auto_transition_from_transitions (GESTimeline * timeline,
    GESLayer * layer, GESTrack * track, GESTrackElement * prev,
    GESTrackElement * next, GstClockTime transition_duration)
{
  GSequenceIter *tmp_iter;
  GSequence *by_layer_sequence;

  GESTimelinePrivate *priv = timeline->priv;
  GESAutoTransition *auto_transition =
      _find_transition_from_auto_transitions (timeline, layer, track, prev,
      next, transition_duration);

  if (auto_transition)
    return auto_transition;


  /* Try to find a transition that perfectly fits with the one that
   * should be added at that place
   * optimize: Use g_sequence_search instead of going over all the
   * sequence */
  by_layer_sequence = g_hash_table_lookup (priv->by_layer, layer);
  for (tmp_iter = g_sequence_get_begin_iter (by_layer_sequence);
      tmp_iter && !g_sequence_iter_is_end (tmp_iter);
      tmp_iter = g_sequence_iter_next (tmp_iter)) {
    GESTrackElement *maybe_transition = g_sequence_get (tmp_iter);

    if (ges_track_element_get_track (maybe_transition) != track)
      continue;

    if (_START (maybe_transition) > _START (next))
      break;
    else if (_START (maybe_transition) != _START (next) ||
        _DURATION (maybe_transition) != transition_duration)
      continue;
    else if (GES_IS_TRANSITION (maybe_transition))
      /* Use that transition */
      /* TODO We should make sure that the transition contains only
       * TrackElement-s in @track and if it is not the case properly unlink the
       * object to use it */
      return create_transition (timeline, prev, next,
          GES_CLIP (GES_TIMELINE_ELEMENT_PARENT (maybe_transition)), layer,
          _START (next), transition_duration);
  }

  return NULL;
}

/* Create all transition that do not exist on @layer.
 * @get_auto_transition is called to check if a particular transition exists
 * if @ track is specified, we will create the transitions only for that particular
 * track */
static void
_create_transitions_on_layer (GESTimeline * timeline, GESLayer * layer,
    GESTrack * track, GESTrackElement * initiating_obj,
    GetAutoTransitionFunc get_auto_transition)
{
  guint32 layer_prio;
  GSequenceIter *iter;
  GESAutoTransition *transition;

  GESTrack *ctrack = track;
  GList *entered = NULL;        /* List of TrackElement for wich we walk through the
                                 * "start" but not the "end" in the starts_ends list */
  GESTimelinePrivate *priv = timeline->priv;

  if (!layer || !ges_layer_get_auto_transition (layer))
    return;

  layer_prio = ges_layer_get_priority (layer);
  for (iter = g_sequence_get_begin_iter (priv->starts_ends);
      iter && !g_sequence_iter_is_end (iter);
      iter = g_sequence_iter_next (iter)) {
    GList *tmp;
    guint *start_or_end = g_sequence_get (iter);
    GESTrackElement *next = g_hash_table_lookup (timeline->priv->by_object,
        start_or_end);
    GESTimelineElement *toplevel =
        ges_timeline_element_get_toplevel_parent (GES_TIMELINE_ELEMENT (next));

    /* Only object that are in that layer and track */
    if (_ges_track_element_get_layer_priority (next) != layer_prio ||
        (track && track != ges_track_element_get_track (next)))
      continue;

    if (track == NULL)
      ctrack = ges_track_element_get_track (next);

    if (start_or_end == g_hash_table_lookup (priv->by_end, next)) {
      if (initiating_obj == next) {
        /* We passed the objects that initiated the research
         * we are now done */
        g_list_free (entered);
        return;
      }
      entered = g_list_remove (entered, next);

      continue;
    }

    for (tmp = entered; tmp; tmp = tmp->next) {
      gint64 transition_duration;

      GESTrackElement *prev = tmp->data;

      if (ctrack != ges_track_element_get_track (prev) ||
          ges_timeline_element_get_toplevel_parent (GES_TIMELINE_ELEMENT (prev))
          == toplevel)
        continue;

      transition_duration = (_START (prev) + _DURATION (prev)) - _START (next);
      if (transition_duration > 0 && transition_duration < _DURATION (prev) &&
          transition_duration < _DURATION (next)) {
        transition =
            get_auto_transition (timeline, layer, ctrack, prev, next,
            transition_duration);
        if (!transition)
          transition = create_transition (timeline, prev, next, NULL, layer,
              _START (next), transition_duration);
      }
    }

    /* And add that object to the entered list so that it we can possibly set
     * a transition on its end edge */
    entered = g_list_append (entered, next);
  }
}

/* @track_element must be a GESSource */
static void
create_transitions (GESTimeline * timeline, GESTrackElement * track_element)
{
  GESTrack *track;
  GList *layer_node;

  GESTimelinePrivate *priv = timeline->priv;

  if (!priv->needs_transitions_update)
    return;

  GST_DEBUG_OBJECT (timeline, "Creating transitions around %p", track_element);

  track = ges_track_element_get_track (track_element);
  layer_node = g_list_find_custom (timeline->layers,
      GINT_TO_POINTER (_ges_track_element_get_layer_priority (track_element)),
      (GCompareFunc) find_layer_by_prio);

  _create_transitions_on_layer (timeline,
      layer_node ? layer_node->data : NULL, track, track_element,
      _find_transition_from_auto_transitions);

  GST_DEBUG_OBJECT (timeline, "Done updating transitions");
}

/* Timeline edition functions */
static inline void
init_movecontext (MoveContext * mv_ctx, gboolean first_init)
{
  if (G_UNLIKELY (first_init))
    mv_ctx->toplevel_containers =
        g_hash_table_new (g_direct_hash, g_direct_equal);

  mv_ctx->moving_trackelements = NULL;
  mv_ctx->max_trim_pos = G_MAXUINT64;
  mv_ctx->min_move_layer = G_MAXUINT;
  mv_ctx->max_layer_prio = 0;
  mv_ctx->last_snaped1 = NULL;
  mv_ctx->last_snaped2 = NULL;
  mv_ctx->last_snap_ts = NULL;
}

static inline void
clean_movecontext (MoveContext * mv_ctx)
{
  g_list_free (mv_ctx->moving_trackelements);
  g_hash_table_remove_all (mv_ctx->toplevel_containers);
  init_movecontext (mv_ctx, FALSE);
}

static void
stop_tracking_track_element (GESTimeline * timeline,
    GESTrackElement * trackelement)
{
  guint64 *start, *end;
  TrackObjIters *iters;
  GESTimelinePrivate *priv = timeline->priv;

  iters = g_hash_table_lookup (priv->obj_iters, trackelement);
  if (G_LIKELY (iters->iter_by_layer)) {
    g_sequence_remove (iters->iter_by_layer);
  } else {
    GST_WARNING_OBJECT (timeline, "TrackElement %p was in no layer",
        trackelement);
  }

  if (GES_IS_SOURCE (trackelement)) {
    start = g_hash_table_lookup (priv->by_start, trackelement);
    end = g_hash_table_lookup (priv->by_end, trackelement);

    g_hash_table_remove (priv->by_start, trackelement);
    g_hash_table_remove (priv->by_end, trackelement);
    g_hash_table_remove (priv->by_object, end);
    g_hash_table_remove (priv->by_object, start);
    g_sequence_remove (iters->iter_start);
    g_sequence_remove (iters->iter_end);
    g_sequence_remove (iters->iter_obj);
    timeline_update_duration (timeline);
  }
  g_hash_table_remove (priv->obj_iters, trackelement);
}

static void
start_tracking_track_element (GESTimeline * timeline,
    GESTrackElement * trackelement)
{
  guint64 *pstart, *pend;
  GSequence *by_layer_sequence;
  TrackObjIters *iters;
  GESTimelinePrivate *priv = timeline->priv;

  guint layer_prio = _ges_track_element_get_layer_priority (trackelement);
  GList *layer_node = g_list_find_custom (timeline->layers,
      GINT_TO_POINTER (layer_prio), (GCompareFunc) find_layer_by_prio);
  GESLayer *layer = layer_node ? layer_node->data : NULL;

  iters = g_slice_new0 (TrackObjIters);

  /* We add all TrackElement to obj_iters as we always follow them
   * in the by_layer Sequences */
  g_hash_table_insert (priv->obj_iters, trackelement, iters);

  /* Track all objects by layer */
  if (G_UNLIKELY (layer == NULL)) {
    /* We handle the case where we have TrackElement that are in no layer by not
     * tracking them
     *
     * FIXME: Check if we should rather try to track them in some sort of
     * dummy layer, or even refuse TrackElements to be added in Tracks if
     * they land in no layer the timeline controls.
     */
    GST_ERROR_OBJECT (timeline, "Adding a TrackElement that lands in no layer "
        "we are controlling");
  } else {
    by_layer_sequence = g_hash_table_lookup (priv->by_layer, layer);
    iters->iter_by_layer =
        g_sequence_insert_sorted (by_layer_sequence, trackelement,
        (GCompareDataFunc) element_start_compare, NULL);
    iters->layer = layer;
  }

  if (GES_IS_SOURCE (trackelement)) {
    /* Track only sources for timeline edition and snapping */
    pstart = g_malloc (sizeof (guint64));
    pend = g_malloc (sizeof (guint64));
    *pstart = _START (trackelement);
    *pend = *pstart + _DURATION (trackelement);

    iters->iter_start = g_sequence_insert_sorted (priv->starts_ends, pstart,
        (GCompareDataFunc) compare_uint64, NULL);
    iters->iter_end = g_sequence_insert_sorted (priv->starts_ends, pend,
        (GCompareDataFunc) compare_uint64, NULL);
    iters->iter_obj =
        g_sequence_insert_sorted (priv->tracksources,
        gst_object_ref (trackelement), (GCompareDataFunc) element_start_compare,
        NULL);
    iters->trackelement = trackelement;

    g_hash_table_insert (priv->by_start, trackelement, pstart);
    g_hash_table_insert (priv->by_object, pstart, trackelement);
    g_hash_table_insert (priv->by_end, trackelement, pend);
    g_hash_table_insert (priv->by_object, pend, trackelement);

    timeline->priv->movecontext.needs_move_ctx = TRUE;

    timeline_update_duration (timeline);
    create_transitions (timeline, trackelement);
  }
}

static inline void
ges_timeline_emit_snappig (GESTimeline * timeline, GESTrackElement * obj1,
    guint64 * timecode)
{
  GESTrackElement *obj2;
  MoveContext *mv_ctx = &timeline->priv->movecontext;
  GstClockTime snap_time = timecode ? *timecode : 0;
  GstClockTime last_snap_ts = mv_ctx->last_snap_ts ?
      *mv_ctx->last_snap_ts : GST_CLOCK_TIME_NONE;

  GST_DEBUG_OBJECT (timeline, "Distance: %" GST_TIME_FORMAT " snapping at %"
      GST_TIME_FORMAT, GST_TIME_ARGS (timeline->priv->snapping_distance),
      GST_TIME_ARGS (snap_time));

  if (timecode == NULL) {
    if (mv_ctx->last_snaped1 != NULL && mv_ctx->last_snaped2 != NULL) {
      g_signal_emit (timeline, ges_timeline_signals[SNAPING_ENDED], 0,
          mv_ctx->last_snaped1, mv_ctx->last_snaped2, last_snap_ts);

      /* We then need to recalculate the moving context */
      timeline->priv->movecontext.needs_move_ctx = TRUE;
    }

    return;
  }

  obj2 = g_hash_table_lookup (timeline->priv->by_object, timecode);

  if (last_snap_ts != *timecode) {
    g_signal_emit (timeline, ges_timeline_signals[SNAPING_ENDED], 0,
        mv_ctx->last_snaped1, mv_ctx->last_snaped2, (last_snap_ts));

    /* We want the snap start signal to be emited anyway */
    mv_ctx->last_snap_ts = NULL;
  }

  if (mv_ctx->last_snap_ts == NULL) {

    mv_ctx->last_snaped1 = obj1;
    mv_ctx->last_snaped2 = obj2;
    mv_ctx->last_snap_ts = timecode;

    g_signal_emit (timeline, ges_timeline_signals[SNAPING_STARTED], 0,
        obj1, obj2, *timecode);

  }
}

static guint64 *
ges_timeline_snap_position (GESTimeline * timeline,
    GESTrackElement * trackelement, guint64 * current, guint64 timecode,
    gboolean emit)
{
  GESTimelinePrivate *priv = timeline->priv;
  GSequenceIter *iter, *prev_iter, *nxt_iter;
  GESTrackElement *tmp_trackelement;
  GESContainer *tmp_container, *container;

  GstClockTime *last_snap_ts = priv->movecontext.last_snap_ts;
  guint64 snap_distance = timeline->priv->snapping_distance;
  guint64 *prev_tc, *next_tc, *ret = NULL, off = G_MAXUINT64, off1 =
      G_MAXUINT64;

  /* Avoid useless calculations */
  if (snap_distance == 0)
    return NULL;

  /* If we can just resnap as last snap... do it */
  if (last_snap_ts) {
    off = timecode > *last_snap_ts ?
        timecode - *last_snap_ts : *last_snap_ts - timecode;
    if (off <= snap_distance) {
      ret = last_snap_ts;
      goto done;
    }
  }

  container = get_toplevel_container (trackelement);

  iter = g_sequence_search (priv->starts_ends, &timecode,
      (GCompareDataFunc) compare_uint64, NULL);

  /* Getting the next/previous  values, and use the closest one if any "respects"
   * the snap_distance value */
  nxt_iter = iter;
  while (!g_sequence_iter_is_end (nxt_iter)) {
    next_tc = g_sequence_get (iter);
    tmp_trackelement = g_hash_table_lookup (timeline->priv->by_object, next_tc);
    tmp_container = get_toplevel_container (tmp_trackelement);

    off = timecode > *next_tc ? timecode - *next_tc : *next_tc - timecode;
    if (next_tc != current && off <= snap_distance
        && container != tmp_container) {

      ret = next_tc;
      break;
    }

    nxt_iter = g_sequence_iter_next (nxt_iter);
  }

  if (ret == NULL)
    off = G_MAXUINT64;

  prev_iter = g_sequence_iter_prev (iter);
  while (!g_sequence_iter_is_begin (prev_iter)) {
    prev_tc = g_sequence_get (prev_iter);
    tmp_trackelement = g_hash_table_lookup (timeline->priv->by_object, prev_tc);
    tmp_container = get_toplevel_container (tmp_trackelement);

    off1 = timecode > *prev_tc ? timecode - *prev_tc : *prev_tc - timecode;
    if (prev_tc != current && off1 < off && off1 <= snap_distance &&
        container != tmp_container) {
      ret = prev_tc;

      break;
    }

    prev_iter = g_sequence_iter_prev (prev_iter);
  }

done:
  /* We emit the snapping signal only if we snapped with a different value
   * than the current one */
  if (emit) {
    GstClockTime snap_time = ret ? *ret : GST_CLOCK_TIME_NONE;

    ges_timeline_emit_snappig (timeline, trackelement, ret);

    GST_DEBUG_OBJECT (timeline, "Snaping at %" GST_TIME_FORMAT,
        GST_TIME_ARGS (snap_time));
  }

  return ret;
}

static inline GESContainer *
add_toplevel_container (MoveContext * mv_ctx, GESTrackElement * trackelement)
{
  guint layer_prio;
  GESContainer *toplevel = get_toplevel_container (trackelement);

  /* Avoid recalculating */
  if (!g_hash_table_lookup (mv_ctx->toplevel_containers, toplevel)) {
    if (GES_IS_CLIP (toplevel)) {

      layer_prio = ges_clip_get_layer_priority (GES_CLIP (toplevel));
      if (layer_prio == (guint32) - 1) {
        GST_WARNING_OBJECT (toplevel, "Not in any layer, can not move"
            " between layers");

        return toplevel;
      }
      mv_ctx->min_move_layer = MIN (mv_ctx->min_move_layer, layer_prio);
      mv_ctx->max_layer_prio = MAX (mv_ctx->max_layer_prio, layer_prio);
    } else if GES_IS_GROUP
      (toplevel) {
      mv_ctx->min_move_layer = MIN (mv_ctx->min_move_layer,
          _PRIORITY (toplevel));
      mv_ctx->max_layer_prio = MAX (mv_ctx->max_layer_prio,
          _PRIORITY (toplevel) + GES_CONTAINER_HEIGHT (toplevel));
    } else
      g_assert_not_reached ();

    g_hash_table_insert (mv_ctx->toplevel_containers, toplevel, toplevel);

  }

  return toplevel;
}

static gboolean
ges_move_context_set_objects (GESTimeline * timeline, GESTrackElement * obj,
    GESEdge edge)
{
  TrackObjIters *iters;
  GESTrackElement *tmptrackelement;
  guint64 start, end, tmpend;
  GSequenceIter *iter, *trackelement_iter;

  MoveContext *mv_ctx = &timeline->priv->movecontext;

  iters = g_hash_table_lookup (timeline->priv->obj_iters, obj);
  trackelement_iter = iters->iter_obj;
  switch (edge) {
    case GES_EDGE_START:
      /* set it properly in the context of "trimming" */
      mv_ctx->max_trim_pos = 0;
      start = _START (obj);

      if (g_sequence_iter_is_begin (trackelement_iter))
        break;

      /* Look for the objects */
      for (iter = g_sequence_iter_prev (trackelement_iter);
          iter && !g_sequence_iter_is_end (iter);
          iter = g_sequence_iter_prev (iter)) {

        tmptrackelement = GES_TRACK_ELEMENT (g_sequence_get (iter));
        tmpend = _START (tmptrackelement) + _DURATION (tmptrackelement);

        if (tmpend <= start) {
          mv_ctx->max_trim_pos =
              MAX (mv_ctx->max_trim_pos, _START (tmptrackelement));
          mv_ctx->moving_trackelements =
              g_list_prepend (mv_ctx->moving_trackelements, tmptrackelement);
        }

        if (g_sequence_iter_is_begin (iter))
          break;
      }
      break;

    case GES_EDGE_END:
    case GES_EDGE_NONE:        /* In this case only works for ripple */
      end = _START (obj) + _DURATION (obj);
      mv_ctx->max_trim_pos = G_MAXUINT64;

      /* Look for folowing objects */
      for (iter = g_sequence_iter_next (trackelement_iter);
          iter && !g_sequence_iter_is_end (iter);
          iter = g_sequence_iter_next (iter)) {
        tmptrackelement = GES_TRACK_ELEMENT (g_sequence_get (iter));

        if (_START (tmptrackelement) >= end) {
          tmpend = _START (tmptrackelement) + _DURATION (tmptrackelement);
          mv_ctx->max_trim_pos = MIN (mv_ctx->max_trim_pos, tmpend);
          mv_ctx->moving_trackelements =
              g_list_prepend (mv_ctx->moving_trackelements, tmptrackelement);
        }
      }
      break;
    default:
      GST_DEBUG ("Edge type %d no supported", edge);
      return FALSE;
  }

  return TRUE;
}

static gboolean
ges_timeline_set_moving_context (GESTimeline * timeline, GESTrackElement * obj,
    GESEditMode mode, GESEdge edge, GList * layers)
{
  /* A TrackElement that could initiate movement for other object */
  GESTrackElement *editor_trackelement = NULL;
  MoveContext *mv_ctx = &timeline->priv->movecontext;
  GESClip *clip = GES_CLIP (GES_TIMELINE_ELEMENT_PARENT (obj));

  /* Still in the same mv_ctx */
  if ((mv_ctx->clip == clip && mv_ctx->mode == mode &&
          mv_ctx->edge == edge && !mv_ctx->needs_move_ctx)) {

    GST_DEBUG ("Keeping the same moving mv_ctx");
    return TRUE;
  }

  GST_DEBUG_OBJECT (clip,
      "Changing context:\nold: obj: %p, mode: %d, edge: %d \n"
      "new: obj: %p, mode: %d, edge: %d ! Has changed %i", mv_ctx->clip,
      mv_ctx->mode, mv_ctx->edge, clip, mode, edge, mv_ctx->needs_move_ctx);

  clean_movecontext (mv_ctx);
  mv_ctx->edge = edge;
  mv_ctx->mode = mode;
  mv_ctx->clip = clip;
  mv_ctx->needs_move_ctx = FALSE;

  /* We try to find a Source inside the Clip so we can set the
   * moving context Else we just move the selected one only */
  if (GES_IS_SOURCE (obj) == FALSE) {
    GList *tmp;

    for (tmp = GES_CONTAINER_CHILDREN (clip); tmp; tmp = tmp->next) {
      if (GES_IS_SOURCE (tmp->data)) {
        editor_trackelement = tmp->data;
        break;
      }
    }
  } else {
    editor_trackelement = obj;
  }

  if (editor_trackelement) {
    switch (mode) {
      case GES_EDIT_MODE_RIPPLE:
      case GES_EDIT_MODE_ROLL:
        if (!(ges_move_context_set_objects (timeline, editor_trackelement,
                    edge)))
          return FALSE;
      default:
        break;
    }
    add_toplevel_container (&timeline->priv->movecontext, editor_trackelement);
  } else {
    /* We add the main object to the toplevel_containers set */
    add_toplevel_container (&timeline->priv->movecontext, obj);
  }


  return TRUE;
}

gboolean
ges_timeline_trim_object_simple (GESTimeline * timeline,
    GESTimelineElement * element, GList * layers, GESEdge edge,
    guint64 position, gboolean snapping)
{
  guint64 start, inpoint, duration, max_duration, *snapped, *cur;
  gboolean ret = TRUE;
  gint64 real_dur;
  GESTrackElement *track_element;

  /* We only work with GESSource-s */
  if (GES_IS_SOURCE (element) == FALSE)
    return FALSE;

  track_element = GES_TRACK_ELEMENT (element);
  GST_DEBUG_OBJECT (track_element, "Trimming to %" GST_TIME_FORMAT
      " %s snaping, edge %i", GST_TIME_ARGS (position),
      snapping ? "Is" : "Not", edge);

  start = _START (track_element);
  g_object_get (track_element, "max-duration", &max_duration, NULL);

  switch (edge) {
    case GES_EDGE_START:
    {
      GESTimelineElement *toplevel;
      GESChildrenControlMode old_mode;
      toplevel = ges_timeline_element_get_toplevel_parent (element);

      if (position < _START (toplevel) && _START (toplevel) < _START (element)) {
        GST_DEBUG_OBJECT (toplevel, "Not trimming %p as not at begining "
            "of the container", element);

        gst_object_unref (toplevel);
        return FALSE;
      }

      old_mode = GES_CONTAINER (toplevel)->children_control_mode;
      if (GES_IS_GROUP (toplevel) && old_mode == GES_CHILDREN_UPDATE) {
        GST_DEBUG_OBJECT (toplevel, "Setting children udpate mode to"
            " UPDDATE_ALL_VALUES so we can trim without moving the contained");
        /* The container will update its values itself according to new
         * values of the children */
        GES_CONTAINER (toplevel)->children_control_mode =
            GES_CHILDREN_UPDATE_ALL_VALUES;
      }

      inpoint = _INPOINT (track_element);
      duration = _DURATION (track_element);

      if (snapping) {
        cur = g_hash_table_lookup (timeline->priv->by_start, track_element);

        snapped = ges_timeline_snap_position (timeline, track_element, cur,
            position, TRUE);
        if (snapped)
          position = *snapped;
      }

      /* Calculate new values */
      position = MIN (position, start + duration);
      inpoint =
          MAX (0, inpoint + position > start ? inpoint + position - start : 0);

      real_dur = _END (element) - position;
      /* FIXME: Why CLAMP (0, real_dur, max_duration) doesn't work? */
      duration = MAX (0, real_dur);
      duration =
          MIN (real_dur,
          max_duration > inpoint ? max_duration - inpoint : G_MAXUINT64);

      /* If we already are at max duration or duration == 0 do no useless work */
      if ((duration == _DURATION (track_element) &&
              _DURATION (track_element) == _MAXDURATION (track_element)) ||
          (duration == 0 && _DURATION (element) == 0)) {
        GST_DEBUG_OBJECT (track_element,
            "Duration already == max_duration, no triming");
        gst_object_unref (toplevel);
        return FALSE;
      }

      timeline->priv->needs_transitions_update = FALSE;
      _set_start0 (GES_TIMELINE_ELEMENT (track_element), position);
      _set_inpoint0 (GES_TIMELINE_ELEMENT (track_element), inpoint);
      timeline->priv->needs_transitions_update = TRUE;

      _set_duration0 (GES_TIMELINE_ELEMENT (track_element), duration);
      if (GES_IS_GROUP (toplevel))
        GES_CONTAINER (toplevel)->children_control_mode = old_mode;

      gst_object_unref (toplevel);
      break;
    }
    case GES_EDGE_END:
    {
      cur = g_hash_table_lookup (timeline->priv->by_end, track_element);
      snapped = ges_timeline_snap_position (timeline, track_element, cur,
          position, TRUE);
      if (snapped)
        position = *snapped;

      /* Calculate new values */
      real_dur = position - start;
      duration = MAX (0, real_dur);
      duration = MIN (duration, max_duration - _INPOINT (track_element));

      /* Not moving, avoid overhead */
      if (duration == _DURATION (track_element)) {
        GST_DEBUG_OBJECT (track_element, "No change in duration");
        return FALSE;
      }

      _set_duration0 (GES_TIMELINE_ELEMENT (track_element), duration);
      break;
    }
    default:
      GST_WARNING ("Can not trim with %i GESEdge", edge);
      return FALSE;
  }

  return ret;
}

gboolean
timeline_ripple_object (GESTimeline * timeline, GESTrackElement * obj,
    GList * layers, GESEdge edge, guint64 position)
{
  GList *tmp, *moved_clips = NULL;
  GESTrackElement *trackelement;
  GESContainer *container;
  guint64 duration, new_start, *snapped, *cur;
  gint64 offset;

  MoveContext *mv_ctx = &timeline->priv->movecontext;

  mv_ctx->ignore_needs_ctx = TRUE;

  if (!ges_timeline_set_moving_context (timeline, obj, GES_EDIT_MODE_RIPPLE,
          edge, layers))
    goto error;

  switch (edge) {
    case GES_EDGE_NONE:
      GST_DEBUG ("Simply rippling");

      /* We should be smart here to avoid recalculate transitions when possible */
      cur = g_hash_table_lookup (timeline->priv->by_end, obj);
      snapped = ges_timeline_snap_position (timeline, obj, cur, position, TRUE);
      if (snapped)
        position = *snapped;

      offset = position - _START (obj);

      for (tmp = mv_ctx->moving_trackelements; tmp; tmp = tmp->next) {
        trackelement = GES_TRACK_ELEMENT (tmp->data);
        new_start = _START (trackelement) + offset;

        container = add_toplevel_container (mv_ctx, trackelement);
        /* Make sure not to move 2 times the same Clip */
        if (g_list_find (moved_clips, container) == NULL) {
          _set_start0 (GES_TIMELINE_ELEMENT (trackelement), new_start);
          moved_clips = g_list_prepend (moved_clips, container);
        }

      }
      g_list_free (moved_clips);
      _set_start0 (GES_TIMELINE_ELEMENT (obj), position);

      break;
    case GES_EDGE_END:
      timeline->priv->needs_transitions_update = FALSE;
      GST_DEBUG ("Rippling end");

      cur = g_hash_table_lookup (timeline->priv->by_end, obj);
      snapped = ges_timeline_snap_position (timeline, obj, cur, position, TRUE);
      if (snapped)
        position = *snapped;

      duration = _DURATION (obj);

      if (!ges_timeline_trim_object_simple (timeline,
              GES_TIMELINE_ELEMENT (obj), NULL, GES_EDGE_END, position,
              FALSE)) {
        return FALSE;
      }

      offset = _DURATION (obj) - duration;
      for (tmp = mv_ctx->moving_trackelements; tmp; tmp = tmp->next) {
        trackelement = GES_TRACK_ELEMENT (tmp->data);
        new_start = _START (trackelement) + offset;

        container = add_toplevel_container (mv_ctx, trackelement);
        if (GES_IS_GROUP (container))
          container->children_control_mode = GES_CHILDREN_UPDATE_OFFSETS;
        /* Make sure not to move 2 times the same Clip */
        if (g_list_find (moved_clips, container) == NULL) {
          _set_start0 (GES_TIMELINE_ELEMENT (trackelement), new_start);
          moved_clips = g_list_prepend (moved_clips, container);
        }
        if (GES_IS_GROUP (container))
          container->children_control_mode = GES_CHILDREN_UPDATE;

      }

      g_list_free (moved_clips);
      timeline->priv->needs_transitions_update = TRUE;
      GST_DEBUG ("Done Rippling end");
      break;
    case GES_EDGE_START:
      GST_INFO ("Ripple start doesn't make sense, trimming instead");
      timeline->priv->movecontext.needs_move_ctx = TRUE;
      timeline_trim_object (timeline, obj, layers, edge, position);
      break;
    default:
      GST_DEBUG ("Can not ripple edge: %i", edge);

      break;
  }

  mv_ctx->ignore_needs_ctx = FALSE;

  return TRUE;

error:
  mv_ctx->ignore_needs_ctx = FALSE;

  return FALSE;
}

gboolean
timeline_slide_object (GESTimeline * timeline, GESTrackElement * obj,
    GList * layers, GESEdge edge, guint64 position)
{

  /* FIXME implement me! */
  GST_FIXME_OBJECT (timeline, "Slide mode editing not implemented yet");

  return FALSE;
}

gboolean
timeline_trim_object (GESTimeline * timeline, GESTrackElement * object,
    GList * layers, GESEdge edge, guint64 position)
{
  gboolean ret = FALSE;
  MoveContext *mv_ctx = &timeline->priv->movecontext;

  mv_ctx->ignore_needs_ctx = TRUE;

  if (!ges_timeline_set_moving_context (timeline, object, GES_EDIT_MODE_TRIM,
          edge, layers))
    goto end;

  ret = ges_timeline_trim_object_simple (timeline,
      GES_TIMELINE_ELEMENT (object), layers, edge, position, TRUE);

end:
  mv_ctx->ignore_needs_ctx = FALSE;

  return ret;
}

gboolean
timeline_roll_object (GESTimeline * timeline, GESTrackElement * obj,
    GList * layers, GESEdge edge, guint64 position)
{
  MoveContext *mv_ctx = &timeline->priv->movecontext;
  guint64 start, duration, end, tmpstart, tmpduration, tmpend, *snapped, *cur;
  gboolean ret = TRUE;
  GList *tmp;

  mv_ctx->ignore_needs_ctx = TRUE;

  GST_DEBUG_OBJECT (obj, "Rolling object to %" GST_TIME_FORMAT,
      GST_TIME_ARGS (position));

  if (!ges_timeline_set_moving_context (timeline, obj, GES_EDIT_MODE_ROLL,
          edge, layers))
    goto error;

  start = _START (obj);
  duration = _DURATION (obj);
  end = start + duration;

  timeline->priv->needs_transitions_update = FALSE;
  switch (edge) {
    case GES_EDGE_START:

      /* Avoid negative durations */
      if (position < mv_ctx->max_trim_pos || position > end)
        goto error;

      cur = g_hash_table_lookup (timeline->priv->by_start, obj);
      snapped = ges_timeline_snap_position (timeline, obj, cur, position, TRUE);
      if (snapped)
        position = *snapped;

      ret &= ges_timeline_trim_object_simple (timeline,
          GES_TIMELINE_ELEMENT (obj), layers, GES_EDGE_START, position, FALSE);

      /* In the case we reached max_duration we just make sure to roll
       * everything to the real new position */
      position = _START (obj);

      /* Send back changes to the neighbourhood */
      for (tmp = mv_ctx->moving_trackelements; tmp; tmp = tmp->next) {
        GESTimelineElement *tmpelement = GES_TIMELINE_ELEMENT (tmp->data);

        tmpstart = _START (tmpelement);
        tmpduration = _DURATION (tmpelement);
        tmpend = tmpstart + tmpduration;

        /* Check that the object should be resized at this position
         * even if an error accurs, we keep doing our job */
        if (tmpend == start) {
          ret &= ges_timeline_trim_object_simple (timeline, tmpelement, NULL,
              GES_EDGE_END, position, FALSE);
          break;
        }
      }
      break;
    case GES_EDGE_END:

      /* Avoid negative durations */
      if (position > mv_ctx->max_trim_pos || position < start)
        goto error;

      end = _START (obj) + _DURATION (obj);

      cur = g_hash_table_lookup (timeline->priv->by_end, obj);
      snapped = ges_timeline_snap_position (timeline, obj, cur, position, TRUE);
      if (snapped)
        position = *snapped;

      ret &= ges_timeline_trim_object_simple (timeline,
          GES_TIMELINE_ELEMENT (obj), NULL, GES_EDGE_END, position, FALSE);

      if (ret == FALSE) {
        GST_DEBUG_OBJECT (timeline, "No triming, bailing out");
        goto done;
      }

      /* In the case we reached max_duration we just make sure to roll
       * everything to the real new position */
      position = _START (obj) + _DURATION (obj);

      /* Send back changes to the neighbourhood */
      for (tmp = mv_ctx->moving_trackelements; tmp; tmp = tmp->next) {
        GESTimelineElement *tmpelement = GES_TIMELINE_ELEMENT (tmp->data);

        tmpstart = _START (tmpelement);
        tmpduration = _DURATION (tmpelement);
        tmpend = tmpstart + tmpduration;

        /* Check that the object should be resized at this position
         * even if an error accure, we keep doing our job */
        if (end == tmpstart) {
          ret &= ges_timeline_trim_object_simple (timeline, tmpelement, NULL,
              GES_EDGE_START, position, FALSE);
        }
      }
      break;
    default:
      GST_DEBUG ("Edge type %i not handled here", edge);
      break;
  }

done:
  timeline->priv->needs_transitions_update = TRUE;
  mv_ctx->ignore_needs_ctx = FALSE;

  return ret;

error:
  GST_DEBUG_OBJECT (obj, "Could not roll edge %d to %" GST_TIME_FORMAT,
      edge, GST_TIME_ARGS (position));

  ret = FALSE;
  goto done;
}

gboolean
timeline_move_object (GESTimeline * timeline, GESTrackElement * object,
    GList * layers, GESEdge edge, guint64 position)
{
  if (!ges_timeline_set_moving_context (timeline, object, GES_EDIT_MODE_NORMAL,
          edge, layers)) {
    GST_DEBUG_OBJECT (object, "Could not move to %" GST_TIME_FORMAT,
        GST_TIME_ARGS (position));

    return FALSE;
  }

  return ges_timeline_move_object_simple (timeline,
      GES_TIMELINE_ELEMENT (object), layers, edge, position);
}

gboolean
ges_timeline_move_object_simple (GESTimeline * timeline,
    GESTimelineElement * element, GList * layers, GESEdge edge,
    guint64 position)
{
  guint64 *snap_end, *snap_st, *cur, off1, off2, end;
  GESTrackElement *track_element;

  /* We only work with GESSource-s and we check that we are not already moving
   * element ourself*/
  if (GES_IS_SOURCE (element) == FALSE ||
      g_list_find (timeline->priv->movecontext.moving_trackelements, element))
    return FALSE;

  track_element = GES_TRACK_ELEMENT (element);
  end = position + _DURATION (get_toplevel_container (track_element));
  cur = g_hash_table_lookup (timeline->priv->by_end, track_element);

  GST_DEBUG_OBJECT (timeline, "Moving %" GST_PTR_FORMAT "to %"
      GST_TIME_FORMAT " (end %" GST_TIME_FORMAT ")", element,
      GST_TIME_ARGS (position), GST_TIME_ARGS (end));

  snap_end = ges_timeline_snap_position (timeline, track_element, cur, end,
      FALSE);
  if (snap_end)
    off1 = end > *snap_end ? end - *snap_end : *snap_end - end;
  else
    off1 = G_MAXUINT64;

  cur = g_hash_table_lookup (timeline->priv->by_start, track_element);
  snap_st =
      ges_timeline_snap_position (timeline, track_element, cur, position,
      FALSE);
  if (snap_st)
    off2 = position > *snap_st ? position - *snap_st : *snap_st - position;
  else
    off2 = G_MAXUINT64;

  /* In the case we could snap on both sides, we snap on the end */
  if (snap_end && off1 <= off2) {
    position = position + *snap_end - end;
    ges_timeline_emit_snappig (timeline, track_element, snap_end);
  } else if (snap_st) {
    position = position + *snap_st - position;
    ges_timeline_emit_snappig (timeline, track_element, snap_st);
  } else
    ges_timeline_emit_snappig (timeline, track_element, NULL);


  _set_start0 (GES_TIMELINE_ELEMENT (track_element), position);

  return TRUE;
}

gboolean
timeline_context_to_layer (GESTimeline * timeline, gint offset)
{
  gboolean ret = TRUE;
  MoveContext *mv_ctx = &timeline->priv->movecontext;



  /* Layer's priority is always positive */
  if (offset != 0 && (offset > 0 || mv_ctx->min_move_layer >= -offset)) {
    GHashTableIter iter;
    GESContainer *key, *value;
    GESLayer *new_layer;
    guint prio;

    mv_ctx->ignore_needs_ctx = TRUE;

    GST_DEBUG ("Moving %d object, offset %d",
        g_hash_table_size (mv_ctx->toplevel_containers), offset);

    g_hash_table_iter_init (&iter, mv_ctx->toplevel_containers);
    while (g_hash_table_iter_next (&iter, (gpointer *) & key,
            (gpointer *) & value)) {

      if (GES_IS_CLIP (value)) {
        prio = ges_clip_get_layer_priority (GES_CLIP (value));

        /* We know that the layer exists as we created it */
        new_layer =
            GES_LAYER (g_list_nth_data (timeline->layers, prio + offset));

        if (new_layer == NULL) {
          do {
            new_layer = ges_timeline_append_layer (timeline);
          } while (ges_layer_get_priority (new_layer) < prio + offset);
        }

        ret &= ges_clip_move_to_layer (GES_CLIP (key), new_layer);
      } else if (GES_IS_GROUP (value)) {
        guint32 last_prio = _PRIORITY (value) + offset +
            GES_CONTAINER_HEIGHT (value) - 1;

        new_layer = GES_LAYER (g_list_nth_data (timeline->layers, last_prio));

        if (new_layer == NULL) {
          do {
            new_layer = ges_timeline_append_layer (timeline);
          } while (ges_layer_get_priority (new_layer) < last_prio);
        }

        _set_priority0 (GES_TIMELINE_ELEMENT (value),
            _PRIORITY (value) + offset);
      }
    }

    /* Readjust min_move_layer */
    mv_ctx->min_move_layer = mv_ctx->min_move_layer + offset;

    mv_ctx->ignore_needs_ctx = FALSE;
  }

  return ret;
}

void
timeline_add_group (GESTimeline * timeline, GESGroup * group)
{
  GST_DEBUG_OBJECT (timeline, "Adding group %" GST_PTR_FORMAT, group);

  timeline->priv->movecontext.needs_move_ctx = TRUE;
  timeline->priv->groups = g_list_prepend (timeline->priv->groups,
      gst_object_ref_sink (group));

  ges_timeline_element_set_timeline (GES_TIMELINE_ELEMENT (group), timeline);
}

void
timeline_remove_group (GESTimeline * timeline, GESGroup * group)
{
  GST_DEBUG_OBJECT (timeline, "Removing group %" GST_PTR_FORMAT, group);

  timeline->priv->groups = g_list_remove (timeline->priv->groups, group);

  timeline->priv->movecontext.needs_move_ctx = TRUE;
  ges_timeline_element_set_timeline (GES_TIMELINE_ELEMENT (group), NULL);
  gst_object_unref (group);
}

static GPtrArray *
select_tracks_for_object_default (GESTimeline * timeline,
    GESClip * clip, GESTrackElement * tr_object, gpointer user_data)
{
  GPtrArray *result;
  GList *tmp;

  result = g_ptr_array_new ();

  for (tmp = timeline->tracks; tmp; tmp = tmp->next) {
    GESTrack *track = GES_TRACK (tmp->data);

    if ((track->type & ges_track_element_get_track_type (tr_object))) {
      gst_object_ref (track);
      g_ptr_array_add (result, track);
    }
  }

  return result;
}

static void
add_object_to_tracks (GESTimeline * timeline, GESClip * clip, GESTrack * track)
{
  gint i;
  GList *tmp;
  GESTrackType types, visited_type = GES_TRACK_TYPE_UNKNOWN;

  GST_DEBUG_OBJECT (timeline, "Creating %" GST_PTR_FORMAT
      " trackelements and adding them to our tracks", clip);

  types = ges_clip_get_supported_formats (clip);
  if (track) {
    if ((types & track->type) == 0)
      return;
    types = track->type;
  }

  for (i = 0, tmp = timeline->tracks; tmp; tmp = tmp->next, i++) {
    GESTrack *track = GES_TRACK (tmp->data);

    if (((track->type & types) == 0 || (track->type & visited_type)))
      continue;

    ges_clip_create_track_elements (clip, track->type);
  }
}

static void
layer_auto_transition_changed_cb (GESLayer * layer,
    GParamSpec * arg G_GNUC_UNUSED, GESTimeline * timeline)
{
  _create_transitions_on_layer (timeline, layer, NULL, NULL,
      _create_auto_transition_from_transitions);

}

static void
clip_track_element_added_cb (GESClip * clip,
    GESTrackElement * track_element, GESTimeline * timeline)
{
  guint i;
  GESTrack *track;
  GPtrArray *tracks = NULL;

  if (timeline->priv->ignore_track_element_added == clip) {
    GST_DEBUG_OBJECT (timeline, "Ignoring element added (%" GST_PTR_FORMAT
        " in %" GST_PTR_FORMAT, track_element, clip);

    return;
  }

  if (ges_track_element_get_track (track_element)) {
    GST_WARNING_OBJECT (track_element, "Already in a track");

    return;
  }

  g_signal_emit (G_OBJECT (timeline),
      ges_timeline_signals[SELECT_TRACKS_FOR_OBJECT], 0, clip, track_element,
      &tracks);

  if (!tracks || tracks->len == 0) {
    GST_WARNING_OBJECT (timeline, "Got no Track to add %p (type %s), removing"
        " from clip",
        track_element, ges_track_type_name (ges_track_element_get_track_type
            (track_element)));

    if (tracks)
      g_ptr_array_unref (tracks);

    ges_container_remove (GES_CONTAINER (clip),
        GES_TIMELINE_ELEMENT (track_element));

    return;
  }

  /* We add the current element to the first track */
  track = g_ptr_array_index (tracks, 0);
  if (!ges_track_add_element (track, track_element)) {
    GST_WARNING_OBJECT (clip, "Failed to add track element to track");
    ges_container_remove (GES_CONTAINER (clip),
        GES_TIMELINE_ELEMENT (track_element));
    gst_object_unref (track_element);
    return;
  }
  gst_object_unref (track);

  /* And create copies to add to other tracks */
  timeline->priv->ignore_track_element_added = clip;
  for (i = 1; i < tracks->len; i++) {
    GESTrack *track;
    GESTrackElement *track_element_copy;

    track = g_ptr_array_index (tracks, i);
    track_element_copy =
        GES_TRACK_ELEMENT (ges_timeline_element_copy (GES_TIMELINE_ELEMENT
            (track_element), TRUE));

    GST_LOG_OBJECT (timeline, "Trying to add %p to track %p",
        track_element_copy, track);

    if (!ges_container_add (GES_CONTAINER (clip),
            GES_TIMELINE_ELEMENT (track_element_copy))) {
      GST_WARNING_OBJECT (clip, "Failed to add track element to clip");
      gst_object_unref (track_element_copy);
      return;
    }

    if (!ges_track_add_element (track, track_element_copy)) {
      GST_WARNING_OBJECT (clip, "Failed to add track element to track");
      ges_container_remove (GES_CONTAINER (clip),
          GES_TIMELINE_ELEMENT (track_element_copy));
      gst_object_unref (track_element_copy);
      return;
    }

    gst_object_unref (track);
  }
  timeline->priv->ignore_track_element_added = NULL;
}

static void
clip_track_element_removed_cb (GESClip * clip,
    GESTrackElement * track_element, GESTimeline * timeline)
{
  GESTrack *track = ges_track_element_get_track (track_element);

  if (track)
    ges_track_remove_element (track, track_element);
}

static void
layer_object_added_cb (GESLayer * layer, GESClip * clip, GESTimeline * timeline)
{
  GESProject *project;

  /* We make sure not to be connected twice */
  g_signal_handlers_disconnect_by_func (clip, clip_track_element_added_cb,
      timeline);
  g_signal_handlers_disconnect_by_func (clip, clip_track_element_removed_cb,
      timeline);

  /* And we connect to the object */
  g_signal_connect (clip, "child-added",
      G_CALLBACK (clip_track_element_added_cb), timeline);
  g_signal_connect (clip, "child-removed",
      G_CALLBACK (clip_track_element_removed_cb), timeline);

  if (ges_clip_is_moving_from_layer (clip)) {
    GST_DEBUG ("Clip %p moving from one layer to another, not creating "
        "TrackElement", clip);
    timeline->priv->movecontext.needs_move_ctx = TRUE;
    _create_transitions_on_layer (timeline, layer, NULL, NULL,
        _find_transition_from_auto_transitions);
    return;
  }


  add_object_to_tracks (timeline, clip, NULL);

  GST_DEBUG ("Making sure that the asset is in our project");
  project =
      GES_PROJECT (ges_extractable_get_asset (GES_EXTRACTABLE (timeline)));
  ges_project_add_asset (project,
      ges_extractable_get_asset (GES_EXTRACTABLE (clip)));

  GST_DEBUG ("Done");
}

static void
layer_priority_changed_cb (GESLayer * layer,
    GParamSpec * arg G_GNUC_UNUSED, GESTimeline * timeline)
{
  timeline->layers = g_list_sort (timeline->layers, (GCompareFunc)
      sort_layers);
}

static void
layer_object_removed_cb (GESLayer * layer, GESClip * clip,
    GESTimeline * timeline)
{
  GList *trackelements, *tmp;

  if (ges_clip_is_moving_from_layer (clip)) {
    GST_DEBUG ("Clip %p is moving from a layer to another, not doing"
        " anything on it", clip);
    return;
  }

  GST_DEBUG ("Clip %p removed from layer %p", clip, layer);

  /* Go over the clip's track element and figure out which one belongs to
   * the list of tracks we control */

  trackelements = ges_container_get_children (GES_CONTAINER (clip), FALSE);
  for (tmp = trackelements; tmp; tmp = tmp->next) {
    GESTrackElement *track_element = (GESTrackElement *) tmp->data;
    GESTrack *track = ges_track_element_get_track (track_element);

    GST_DEBUG_OBJECT (timeline, "Trying to remove TrackElement %p",
        track_element);

    /* FIXME Check if we should actually check that we control the
     * track in the new management of TrackElement context */
    LOCK_DYN (timeline);
    if (G_LIKELY (g_list_find_custom (timeline->priv->priv_tracks, track,
                (GCompareFunc) custom_find_track) || track == NULL)) {
      GST_DEBUG ("Belongs to one of the tracks we control");

      ges_container_remove (GES_CONTAINER (clip),
          GES_TIMELINE_ELEMENT (track_element));
    }
    UNLOCK_DYN (timeline);
  }
  g_signal_handlers_disconnect_by_func (clip, clip_track_element_added_cb,
      timeline);
  g_signal_handlers_disconnect_by_func (clip, clip_track_element_removed_cb,
      timeline);

  g_list_free_full (trackelements, gst_object_unref);

  GST_DEBUG ("Done");
}

static void
trackelement_start_changed_cb (GESTrackElement * child,
    GParamSpec * arg G_GNUC_UNUSED, GESTimeline * timeline)
{
  GESTimelinePrivate *priv = timeline->priv;
  TrackObjIters *iters = g_hash_table_lookup (priv->obj_iters, child);

  if (G_LIKELY (iters->iter_by_layer))
    g_sequence_sort_changed (iters->iter_by_layer,
        (GCompareDataFunc) element_start_compare, NULL);

  if (GES_IS_SOURCE (child)) {
    sort_track_elements (timeline, iters);
    sort_starts_ends_start (timeline, iters);
    sort_starts_ends_end (timeline, iters);

    /* If the timeline is set to snap objects together, we
     * are sure that all movement of TrackElement-s are done within
     * the moving context, so we do not need to recalculate the
     * move context as often */
    if (timeline->priv->movecontext.ignore_needs_ctx &&
        timeline->priv->snapping_distance == 0)
      timeline->priv->movecontext.needs_move_ctx = TRUE;

    create_transitions (timeline, child);
  }
}

static void
trackelement_priority_changed_cb (GESTrackElement * child,
    GParamSpec * arg G_GNUC_UNUSED, GESTimeline * timeline)
{
  GESTimelinePrivate *priv = timeline->priv;

  GList *layer_node = g_list_find_custom (timeline->layers,
      GINT_TO_POINTER (_ges_track_element_get_layer_priority (child)),
      (GCompareFunc) find_layer_by_prio);
  GESLayer *layer = layer_node ? layer_node->data : NULL;
  TrackObjIters *iters = g_hash_table_lookup (priv->obj_iters,
      child);

  if (G_UNLIKELY (layer == NULL)) {
    GST_ERROR_OBJECT (timeline,
        "Changing a TrackElement prio, which would not "
        "land in no layer we are controlling");
    g_sequence_remove (iters->iter_by_layer);
    iters->iter_by_layer = NULL;
    iters->layer = NULL;
  } else {
    /* If it moves from layer, properly change it */
    if (layer != iters->layer) {
      GSequence *by_layer_sequence =
          g_hash_table_lookup (priv->by_layer, layer);

      GST_DEBUG_OBJECT (child, "Moved from layer %" GST_PTR_FORMAT
          "(prio %d) to" " %" GST_PTR_FORMAT " (prio %d)", layer,
          ges_layer_get_priority (layer), iters->layer,
          ges_layer_get_priority (iters->layer));

      g_sequence_remove (iters->iter_by_layer);
      iters->iter_by_layer =
          g_sequence_insert_sorted (by_layer_sequence, child,
          (GCompareDataFunc) element_start_compare, NULL);
      iters->layer = layer;
    } else {
      g_sequence_sort_changed (iters->iter_by_layer,
          (GCompareDataFunc) element_start_compare, NULL);
    }
  }

  if (GES_IS_SOURCE (child))
    sort_track_elements (timeline, iters);
}

static void
trackelement_duration_changed_cb (GESTrackElement * child,
    GParamSpec * arg G_GNUC_UNUSED, GESTimeline * timeline)
{
  GESTimelinePrivate *priv = timeline->priv;
  TrackObjIters *iters = g_hash_table_lookup (priv->obj_iters, child);

  if (GES_IS_SOURCE (child)) {
    sort_starts_ends_end (timeline, iters);

    /* If the timeline is set to snap objects together, we
     * are sure that all movement of TrackElement-s are done within
     * the moving context, so we do not need to recalculate the
     * move context as often */
    if (timeline->priv->movecontext.ignore_needs_ctx &&
        timeline->priv->snapping_distance == 0) {
      timeline->priv->movecontext.needs_move_ctx = TRUE;
    }

    create_transitions (timeline, child);
  }
}

static void
track_element_added_cb (GESTrack * track, GESTrackElement * track_element,
    GESTimeline * timeline)
{
  /* Auto transition should be updated before we receive the signal */
  g_signal_connect_after (GES_TRACK_ELEMENT (track_element), "notify::start",
      G_CALLBACK (trackelement_start_changed_cb), timeline);
  g_signal_connect_after (GES_TRACK_ELEMENT (track_element),
      "notify::duration", G_CALLBACK (trackelement_duration_changed_cb),
      timeline);
  g_signal_connect_after (GES_TRACK_ELEMENT (track_element),
      "notify::priority", G_CALLBACK (trackelement_priority_changed_cb),
      timeline);

  start_tracking_track_element (timeline, track_element);
}

static void
track_element_removed_cb (GESTrack * track,
    GESTrackElement * track_element, GESTimeline * timeline)
{

  if (GES_IS_SOURCE (track_element)) {
    /* Make sure to reinitialise the moving context next time */
    timeline->priv->movecontext.needs_move_ctx = TRUE;
  }

  /* Disconnect all signal handlers */
  g_signal_handlers_disconnect_by_func (track_element,
      trackelement_start_changed_cb, timeline);
  g_signal_handlers_disconnect_by_func (track_element,
      trackelement_duration_changed_cb, timeline);
  g_signal_handlers_disconnect_by_func (track_element,
      trackelement_priority_changed_cb, timeline);

  stop_tracking_track_element (timeline, track_element);
}

static GstPadProbeReturn
_pad_probe_cb (GstPad * mixer_pad, GstPadProbeInfo * info,
    GESTimeline * timeline)
{
  GstEvent *event = GST_PAD_PROBE_INFO_EVENT (info);
  if (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START) {
    LOCK_DYN (timeline);
    if (timeline->priv->group_id == -1) {
      if (!gst_event_parse_group_id (event, &timeline->priv->group_id))
        timeline->priv->group_id = gst_util_group_id_next ();
    }

    info->data = gst_event_make_writable (event);
    gst_event_set_group_id (GST_PAD_PROBE_INFO_EVENT (info),
        timeline->priv->group_id);
    UNLOCK_DYN (timeline);

    return GST_PAD_PROBE_REMOVE;
  }

  return GST_PAD_PROBE_OK;
}

static void
pad_added_cb (GESTrack * track, GstPad * pad, TrackPrivate * tr_priv)
{
  gchar *padname;
  gboolean no_more;
  GList *tmp;

  GST_DEBUG ("track:%p, pad:%s:%s", track, GST_DEBUG_PAD_NAME (pad));

  if (G_UNLIKELY (tr_priv->pad)) {
    GST_WARNING ("We are already controlling a pad for this track");
    return;
  }

  /* Remember the pad */
  LOCK_DYN (tr_priv->timeline);
  GST_OBJECT_LOCK (track);
  tr_priv->pad = pad;

  no_more = TRUE;
  for (tmp = tr_priv->timeline->priv->priv_tracks; tmp; tmp = g_list_next (tmp)) {
    TrackPrivate *tr_priv = (TrackPrivate *) tmp->data;

    if (!tr_priv->pad) {
      GST_LOG ("Found track without pad %p", tr_priv->track);
      no_more = FALSE;
    }
  }
  GST_OBJECT_UNLOCK (track);

  /* ghost it ! */
  GST_DEBUG ("Ghosting pad and adding it to ourself");
  padname = g_strdup_printf ("track_%p_src", track);
  tr_priv->ghostpad = gst_ghost_pad_new (padname, pad);
  g_free (padname);
  gst_pad_set_active (tr_priv->ghostpad, TRUE);
  gst_element_add_pad (GST_ELEMENT (tr_priv->timeline), tr_priv->ghostpad);

  if (no_more) {
    GST_DEBUG ("Signaling no-more-pads");
    gst_element_no_more_pads (GST_ELEMENT (tr_priv->timeline));
  }

  tr_priv->probe_id = gst_pad_add_probe (pad,
      GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM,
      (GstPadProbeCallback) _pad_probe_cb, tr_priv->timeline, NULL);

  UNLOCK_DYN (tr_priv->timeline);
}

static void
pad_removed_cb (GESTrack * track, GstPad * pad, TrackPrivate * tr_priv)
{
  GST_DEBUG ("track:%p, pad:%s:%s", track, GST_DEBUG_PAD_NAME (pad));

  if (G_UNLIKELY (tr_priv->pad != pad)) {
    GST_WARNING ("Not the pad we're controlling");
    return;
  }

  if (G_UNLIKELY (tr_priv->ghostpad == NULL)) {
    GST_WARNING ("We don't have a ghostpad for this pad !");
    return;
  }

  GST_DEBUG ("Removing ghostpad");
  gst_pad_set_active (tr_priv->ghostpad, FALSE);
  gst_element_remove_pad (GST_ELEMENT (tr_priv->timeline), tr_priv->ghostpad);
  tr_priv->ghostpad = NULL;
  tr_priv->pad = NULL;
}

/**** API *****/
/**
 * ges_timeline_new:
 *
 * Creates a new empty #GESTimeline.
 *
 * Returns: The new timeline.
 */

GESTimeline *
ges_timeline_new (void)
{
  GESProject *project = ges_project_new (NULL);

  return GES_TIMELINE (ges_asset_extract (GES_ASSET (project), NULL));
}

/**
 * ges_timeline_new_from_uri:
 * @uri: the URI to load from
 * @error: (out) (allow-none): An error to be set in case something wrong happens or %NULL
 *
 * Creates a timeline from the given URI.
 *
 * Returns: A new timeline if the uri was loaded successfully, or NULL if the
 * uri could not be loaded
 */
GESTimeline *
ges_timeline_new_from_uri (const gchar * uri, GError ** error)
{
  GESTimeline *ret;
  GESProject *project = ges_project_new (uri);

  ret = GES_TIMELINE (ges_asset_extract (GES_ASSET (project), error));
  gst_object_unref (project);

  return ret;
}

/**
 * ges_timeline_load_from_uri:
 * @timeline: an empty #GESTimeline into which to load the formatter
 * @uri: The URI to load from
 * @error: (out) (allow-none): An error to be set in case something wrong happens or %NULL
 *
 * Loads the contents of URI into the given timeline.
 *
 * Returns: TRUE if the timeline was loaded successfully, or FALSE if the uri
 * could not be loaded.
 */
gboolean
ges_timeline_load_from_uri (GESTimeline * timeline, const gchar * uri,
    GError ** error)
{
  GESProject *project;
  gboolean ret = FALSE;

  g_return_val_if_fail (GES_IS_TIMELINE (timeline), FALSE);
  g_return_val_if_fail ((ges_extractable_get_asset (GES_EXTRACTABLE
              (timeline)) == NULL), FALSE);

  project = ges_project_new (uri);
  ret = ges_project_load (project, timeline, error);
  gst_object_unref (project);

  return ret;
}

/**
 * ges_timeline_save_to_uri:
 * @timeline: a #GESTimeline
 * @uri: The location to save to
 * @formatter_asset: (allow-none): The formatter asset to use or %NULL. If %NULL,
 * will try to save in the same format as the one from which the timeline as been loaded
 * or default to the formatter with highest rank
 * @overwrite: %TRUE to overwrite file if it exists
 * @error: (out) (allow-none): An error to be set in case something wrong happens or %NULL
 *
 * Saves the timeline to the given location
 *
 * Returns: TRUE if the timeline was successfully saved to the given location,
 * else FALSE.
 */
gboolean
ges_timeline_save_to_uri (GESTimeline * timeline, const gchar * uri,
    GESAsset * formatter_asset, gboolean overwrite, GError ** error)
{
  GESProject *project;

  gboolean ret, created_proj = FALSE;

  g_return_val_if_fail (GES_IS_TIMELINE (timeline), FALSE);
  project =
      GES_PROJECT (ges_extractable_get_asset (GES_EXTRACTABLE (timeline)));

  if (project == NULL) {
    project = ges_project_new (NULL);
    created_proj = TRUE;
  }

  ret = ges_project_save (project, timeline, uri, formatter_asset, overwrite,
      error);

  if (created_proj)
    gst_object_unref (project);

  return ret;
}

/**
 * ges_timeline_append_layer:
 * @timeline: a #GESTimeline
 *
 * Append a newly created #GESLayer to @timeline
 * Note that you do not own any reference to the returned layer.
 *
 * Returns: (transfer none): The newly created #GESLayer, or the last (empty)
 * #GESLayer of @timeline.
 */
GESLayer *
ges_timeline_append_layer (GESTimeline * timeline)
{
  guint32 priority;
  GESLayer *layer;

  layer = ges_layer_new ();
  priority = g_list_length (timeline->layers);
  ges_layer_set_priority (layer, priority);

  ges_timeline_add_layer (timeline, layer);

  return layer;
}

/**
 * ges_timeline_add_layer:
 * @timeline: a #GESTimeline
 * @layer: the #GESLayer to add
 *
 * Add the layer to the timeline. The reference to the @layer will be stolen
 * by the @timeline.
 *
 * Returns: TRUE if the layer was properly added, else FALSE.
 */
gboolean
ges_timeline_add_layer (GESTimeline * timeline, GESLayer * layer)
{
  gboolean auto_transition;
  GList *objects, *tmp;

  GST_DEBUG ("timeline:%p, layer:%p", timeline, layer);

  /* We can only add a layer that doesn't already belong to another timeline */
  if (G_UNLIKELY (layer->timeline)) {
    GST_WARNING ("Layer belongs to another timeline, can't add it");
    return FALSE;
  }

  /* Add to the list of layers, make sure we don't already control it */
  if (G_UNLIKELY (g_list_find (timeline->layers, (gconstpointer) layer))) {
    GST_WARNING ("Layer is already controlled by this timeline");
    return FALSE;
  }

  auto_transition = ges_layer_get_auto_transition (layer);

  /* If the user doesn't explicitely set layer auto_transition, then set our */
  if (!auto_transition) {
    auto_transition = ges_timeline_get_auto_transition (timeline);
    ges_layer_set_auto_transition (layer, auto_transition);
  }

  gst_object_ref_sink (layer);
  timeline->layers = g_list_insert_sorted (timeline->layers, layer,
      (GCompareFunc) sort_layers);

  /* Inform the layer that it belongs to a new timeline */
  ges_layer_set_timeline (layer, timeline);

  g_hash_table_insert (timeline->priv->by_layer, layer, g_sequence_new (NULL));

  /* Connect to 'clip-added'/'clip-removed' signal from the new layer */
  g_signal_connect (layer, "clip-added", G_CALLBACK (layer_object_added_cb),
      timeline);
  g_signal_connect (layer, "clip-removed",
      G_CALLBACK (layer_object_removed_cb), timeline);
  g_signal_connect (layer, "notify::priority",
      G_CALLBACK (layer_priority_changed_cb), timeline);
  g_signal_connect (layer, "notify::auto-transition",
      G_CALLBACK (layer_auto_transition_changed_cb), timeline);

  GST_DEBUG ("Done adding layer, emitting 'layer-added' signal");
  g_signal_emit (timeline, ges_timeline_signals[LAYER_ADDED], 0, layer);

  /* add any existing clips to the timeline */
  objects = ges_layer_get_clips (layer);
  for (tmp = objects; tmp; tmp = tmp->next) {
    layer_object_added_cb (layer, tmp->data, timeline);
    gst_object_unref (tmp->data);
    tmp->data = NULL;
  }
  g_list_free (objects);

  return TRUE;
}

/**
 * ges_timeline_remove_layer:
 * @timeline: a #GESTimeline
 * @layer: the #GESLayer to remove
 *
 * Removes the layer from the timeline. The reference that the @timeline holds on
 * the layer will be dropped. If you wish to use the @layer after calling this
 * method, you need to take a reference before calling.
 *
 * Returns: TRUE if the layer was properly removed, else FALSE.
 */

gboolean
ges_timeline_remove_layer (GESTimeline * timeline, GESLayer * layer)
{
  GList *layer_objects, *tmp;

  GST_DEBUG ("timeline:%p, layer:%p", timeline, layer);

  if (G_UNLIKELY (!g_list_find (timeline->layers, layer))) {
    GST_WARNING ("Layer doesn't belong to this timeline");
    return FALSE;
  }

  /* remove objects from any private data structures */

  layer_objects = ges_layer_get_clips (layer);
  for (tmp = layer_objects; tmp; tmp = tmp->next) {
    layer_object_removed_cb (layer, GES_CLIP (tmp->data), timeline);
    gst_object_unref (G_OBJECT (tmp->data));
    tmp->data = NULL;
  }
  g_list_free (layer_objects);

  /* Disconnect signals */
  GST_DEBUG ("Disconnecting signal callbacks");
  g_signal_handlers_disconnect_by_func (layer, layer_object_added_cb, timeline);
  g_signal_handlers_disconnect_by_func (layer, layer_object_removed_cb,
      timeline);
  g_signal_handlers_disconnect_by_func (layer, layer_priority_changed_cb,
      timeline);
  g_signal_handlers_disconnect_by_func (layer,
      layer_auto_transition_changed_cb, timeline);

  g_hash_table_remove (timeline->priv->by_layer, layer);
  timeline->layers = g_list_remove (timeline->layers, layer);
  ges_layer_set_timeline (layer, NULL);

  g_signal_emit (timeline, ges_timeline_signals[LAYER_REMOVED], 0, layer);

  gst_object_unref (layer);

  return TRUE;
}

/**
 * ges_timeline_add_track:
 * @timeline: a #GESTimeline
 * @track: the #GESTrack to add
 *
 * Add a track to the timeline. The reference to the track will be stolen by the
 * pipeline.
 *
 * Returns: TRUE if the track was properly added, else FALSE.
 */

/* FIXME: create track elements for clips which have already been
 * added to existing layers.
 */

gboolean
ges_timeline_add_track (GESTimeline * timeline, GESTrack * track)
{
  TrackPrivate *tr_priv;
  GList *tmp;

  GST_DEBUG ("timeline:%p, track:%p", timeline, track);

  /* make sure we don't already control it */
  if (G_UNLIKELY (g_list_find (timeline->tracks, (gconstpointer) track))) {
    GST_WARNING ("Track is already controlled by this timeline");
    return FALSE;
  }

  /* Add the track to ourself (as a GstBin)
   * Reference is stolen ! */
  if (G_UNLIKELY (!gst_bin_add (GST_BIN (timeline), GST_ELEMENT (track)))) {
    GST_WARNING ("Couldn't add track to ourself (GST)");
    return FALSE;
  }

  tr_priv = g_new0 (TrackPrivate, 1);
  tr_priv->timeline = timeline;
  tr_priv->track = track;

  /* Add the track to the list of tracks we track */
  LOCK_DYN (timeline);
  timeline->priv->priv_tracks = g_list_append (timeline->priv->priv_tracks,
      tr_priv);
  UNLOCK_DYN (timeline);
  timeline->tracks = g_list_append (timeline->tracks, track);

  /* Listen to pad-added/-removed */
  g_signal_connect (track, "pad-added", (GCallback) pad_added_cb, tr_priv);
  g_signal_connect (track, "pad-removed", (GCallback) pad_removed_cb, tr_priv);

  /* Inform the track that it's currently being used by ourself */
  ges_track_set_timeline (track, timeline);

  GST_DEBUG ("Done adding track, emitting 'track-added' signal");

  /* emit 'track-added' */
  g_signal_emit (timeline, ges_timeline_signals[TRACK_ADDED], 0, track);

  /* ensure that each existing clip has the opportunity to create a
   * track element for this track*/

  /* We connect to the object for the timeline editing mode management */
  g_signal_connect (G_OBJECT (track), "track-element-added",
      G_CALLBACK (track_element_added_cb), timeline);
  g_signal_connect (G_OBJECT (track), "track-element-removed",
      G_CALLBACK (track_element_removed_cb), timeline);

  for (tmp = timeline->layers; tmp; tmp = tmp->next) {
    GList *objects, *obj;
    objects = ges_layer_get_clips (tmp->data);

    for (obj = objects; obj; obj = obj->next) {
      GESClip *clip = obj->data;

      add_object_to_tracks (timeline, clip, track);
      gst_object_unref (clip);
    }
    g_list_free (objects);
  }

  /* FIXME Check if we should rollback if we can't sync state */
  gst_element_sync_state_with_parent (GST_ELEMENT (track));

  return TRUE;
}

/**
 * ges_timeline_remove_track:
 * @timeline: a #GESTimeline
 * @track: the #GESTrack to remove
 *
 * Remove the @track from the @timeline. The reference stolen when adding the
 * @track will be removed. If you wish to use the @track after calling this
 * function you must ensure that you have a reference to it.
 *
 * Returns: TRUE if the @track was properly removed, else FALSE.
 */

/* FIXME: release any track elements associated with this layer. currenly this
 * will not happen if you remove the track before removing *all*
 * clips which have a track element in this track.
 */

gboolean
ges_timeline_remove_track (GESTimeline * timeline, GESTrack * track)
{
  GList *tmp;
  TrackPrivate *tr_priv;
  GESTimelinePrivate *priv;

  g_return_val_if_fail (GES_IS_TRACK (track), FALSE);
  g_return_val_if_fail (GES_IS_TIMELINE (timeline), FALSE);

  GST_DEBUG ("timeline:%p, track:%p", timeline, track);

  priv = timeline->priv;
  LOCK_DYN (timeline);
  if (G_UNLIKELY (!(tmp = g_list_find_custom (priv->priv_tracks,
                  track, (GCompareFunc) custom_find_track)))) {
    GST_WARNING ("Track doesn't belong to this timeline");
    UNLOCK_DYN (timeline);
    return FALSE;
  }

  tr_priv = tmp->data;
  priv->priv_tracks = g_list_remove (priv->priv_tracks, tr_priv);
  UNLOCK_DYN (timeline);
  timeline->tracks = g_list_remove (timeline->tracks, track);

  ges_track_set_timeline (track, NULL);

  /* Remove ghost pad */
  if (tr_priv->ghostpad) {
    GST_DEBUG ("Removing ghostpad");
    gst_pad_set_active (tr_priv->ghostpad, FALSE);
    gst_ghost_pad_set_target ((GstGhostPad *) tr_priv->ghostpad, NULL);
    gst_element_remove_pad (GST_ELEMENT (timeline), tr_priv->ghostpad);
  }

  /* Remove pad-added/-removed handlers */
  g_signal_handlers_disconnect_by_func (track, pad_added_cb, tr_priv);
  g_signal_handlers_disconnect_by_func (track, pad_removed_cb, tr_priv);
  g_signal_handlers_disconnect_by_func (track, track_element_added_cb,
      timeline);
  g_signal_handlers_disconnect_by_func (track, track_element_removed_cb,
      timeline);

  /* Signal track removal to all layers/objects */
  g_signal_emit (timeline, ges_timeline_signals[TRACK_REMOVED], 0, track);

  /* remove track from our bin */
  gst_object_ref (track);
  if (G_UNLIKELY (!gst_bin_remove (GST_BIN (timeline), GST_ELEMENT (track)))) {
    GST_WARNING ("Couldn't remove track to ourself (GST)");
    gst_object_unref (track);
    return FALSE;
  }

  /* set track state to NULL */
  gst_element_set_state (GST_ELEMENT (track), GST_STATE_NULL);

  gst_object_unref (track);

  g_free (tr_priv);

  return TRUE;
}

/**
 * ges_timeline_get_track_for_pad:
 * @timeline: The #GESTimeline
 * @pad: The #GstPad
 *
 * Search the #GESTrack corresponding to the given @timeline's @pad.
 *
 * Returns: (transfer none): The corresponding #GESTrack if it is found,
 * or %NULL if there is an error.
 */

GESTrack *
ges_timeline_get_track_for_pad (GESTimeline * timeline, GstPad * pad)
{
  GList *tmp;

  LOCK_DYN (timeline);
  for (tmp = timeline->priv->priv_tracks; tmp; tmp = g_list_next (tmp)) {
    TrackPrivate *tr_priv = (TrackPrivate *) tmp->data;
    if (pad == tr_priv->ghostpad) {
      UNLOCK_DYN (timeline);
      return tr_priv->track;
    }
  }
  UNLOCK_DYN (timeline);

  return NULL;
}

/**
 * ges_timeline_get_tracks:
 * @timeline: a #GESTimeline
 *
 * Returns the list of #GESTrack used by the Timeline.
 *
 * Returns: (transfer full) (element-type GESTrack): A list of #GESTrack.
 * The caller should unref each track once he is done with them.
 */
GList *
ges_timeline_get_tracks (GESTimeline * timeline)
{
  g_return_val_if_fail (GES_IS_TIMELINE (timeline), NULL);

  return g_list_copy_deep (timeline->tracks, (GCopyFunc) gst_object_ref, NULL);
}

/**
 * ges_timeline_get_layers:
 * @timeline: a #GESTimeline
 *
 * Get the list of #GESLayer present in the Timeline.
 *
 * Returns: (transfer full) (element-type GESLayer): the list of
 * #GESLayer present in the Timeline sorted by priority.
 * The caller should unref each Layer once he is done with them.
 */
GList *
ges_timeline_get_layers (GESTimeline * timeline)
{
  GList *tmp, *res = NULL;

  for (tmp = timeline->layers; tmp; tmp = g_list_next (tmp)) {
    res = g_list_insert_sorted (res, gst_object_ref (tmp->data),
        (GCompareFunc) sort_layers);
  }

  return res;
}

/**
 * ges_timeline_commit:
 * @timeline: a #GESTimeline
 *
 * Commits all the pending changes of the clips contained in the
 * @timeline.
 *
 * When timing changes happen in a timeline, the changes are not
 * directly done inside GNL. This method needs to be called so any changes
 * on a clip contained in the timeline actually happen at the media
 * processing level.
 *
 * Returns: %TRUE if something as been commited %FALSE if nothing needed
 * to be commited
 */
gboolean
ges_timeline_commit (GESTimeline * timeline)
{
  GList *tmp;
  gboolean res = TRUE;

  GST_DEBUG_OBJECT (timeline, "commiting changes");

  for (tmp = timeline->layers; tmp; tmp = tmp->next) {
    _create_transitions_on_layer (timeline, GES_LAYER (tmp->data),
        NULL, NULL, _find_transition_from_auto_transitions);
  }

  for (tmp = timeline->tracks; tmp; tmp = tmp->next) {
    if (!ges_track_commit (GES_TRACK (tmp->data)))
      res = FALSE;
  }

  /* Make sure we reset the context */
  timeline->priv->movecontext.needs_move_ctx = TRUE;

  if (res)
    g_signal_emit (timeline, ges_timeline_signals[COMMITED], 0);

  return res;
}

/**
 * ges_timeline_get_duration:
 * @timeline: a #GESTimeline
 *
 * Get the current duration of @timeline
 *
 * Returns: The current duration of @timeline
 */
GstClockTime
ges_timeline_get_duration (GESTimeline * timeline)
{
  g_return_val_if_fail (GES_IS_TIMELINE (timeline), GST_CLOCK_TIME_NONE);

  return timeline->priv->duration;
}

/**
 * ges_timeline_get_auto_transition:
 * @timeline: a #GESTimeline
 *
 * Gets whether transitions are automatically added when objects
 * overlap or not.
 *
 * Returns: %TRUE if transitions are automatically added, else %FALSE.
 */
gboolean
ges_timeline_get_auto_transition (GESTimeline * timeline)
{
  g_return_val_if_fail (GES_IS_TIMELINE (timeline), 0);

  return timeline->priv->auto_transition;
}

/**
 * ges_timeline_set_auto_transition:
 * @timeline: a #GESLayer
 * @auto_transition: whether the auto_transition is active
 *
 * Sets the layer to the given @auto_transition. See the documentation of the
 * property auto_transition for more information.
 */
void
ges_timeline_set_auto_transition (GESTimeline * timeline,
    gboolean auto_transition)
{
  GList *layers;
  GESLayer *layer;

  g_return_if_fail (GES_IS_TIMELINE (timeline));

  timeline->priv->auto_transition = auto_transition;
  g_object_notify (G_OBJECT (timeline), "auto-transition");

  layers = timeline->layers;
  for (; layers; layers = layers->next) {
    layer = layers->data;
    ges_layer_set_auto_transition (layer, auto_transition);
  }
}

/**
 * ges_timeline_get_snapping_distance:
 * @timeline: a #GESTimeline
 *
 * Gets the configured snapping distance of the timeline. See
 * the documentation of the property snapping_distance for more
 * information.
 *
 * Returns: The @snapping_distance property of the timeline
 */
GstClockTime
ges_timeline_get_snapping_distance (GESTimeline * timeline)
{
  g_return_val_if_fail (GES_IS_TIMELINE (timeline), GST_CLOCK_TIME_NONE);

  return timeline->priv->snapping_distance;

}

/**
 * ges_timeline_set_snapping_distance:
 * @timeline: a #GESLayer
 * @snapping_distance: whether the snapping_distance is active
 *
 * Sets the @snapping_distance of the timeline. See the documentation of the
 * property snapping_distance for more information.
 */
void
ges_timeline_set_snapping_distance (GESTimeline * timeline,
    GstClockTime snapping_distance)
{
  g_return_if_fail (GES_IS_TIMELINE (timeline));

  timeline->priv->snapping_distance = snapping_distance;
}