Better resizing

2 files changed, 24 insertions, 56 deletions

diff --git a/main.c b/main.c
index 03c1cd1..3f00fc2 100644
--- a/main.c
+++ b/main.c
@@ -71,8 +71,6 @@ on_main_paint (FooScrollArea *scroll_area,
 	cairo_stroke (cr);
 
     }
-    
-    g_print ("paint %d %d %d %d\n", extents->x, extents->y, extents->width, extents->height);
 }
 
 static void
@@ -80,44 +78,28 @@ on_viewport_size_changed (FooScrollArea *scroll_area,
 			  GdkRectangle  *viewport,
 			  GdkRectangle  *old_viewport)
 {
-#if 0
-    double ratio;
-    int th;
-    
-    g_print ("new slide height: %d, new y: %d\n", slide_height, viewport->y);
-    
-    /* FIXME: We can recurse infinitely here when the area gets
-     * narrow enough that the scrollbar disappears causing the area
-     * to widen a little causing the scrollbar to appear causing
-     * the arrow to narrow causing ...
-     *
-     * For now we work around by have POLICY_ALWAYS on the scrollbar,
-     * it needs to be thought through and fixed in the scroll area
-     */
-    
-    ratio = (double)viewport->width / old_viewport->width;
-    
-#if 0
-    g_print ("ratio: %f (%d %d)\n", ratio, old_viewport->y, (int)(old_viewport->y * ratio));
-    
-    g_print ("old, new: %f %f\n", slide_n, MARGIN + slide_n * (MARGIN + (double)slide_height));
-#endif
-    
-    foo_scroll_area_set_size_fixed_y (scroll_area, viewport->width, th,
-				      slide_n,
-				      MARGIN + slide_n * (MARGIN + slide_height));
-#endif
+    int total_height;
+    int nth_slide;
+    double old_y;
+    double new_y;
+
+    /* Compute the y-coordinate of the first visible top edge of a slide */
     
-    int th;
-    double slide_n;
+    nth_slide = 
+	(old_viewport->y - MARGIN) / (MARGIN + (double)slide_height) + 1;
+
+    old_y = nth_slide * (MARGIN + (double)slide_height) + MARGIN;
     
     slide_width = viewport->width - 2 * MARGIN;
     slide_height = slide_width / RATIO;
     
-    th = N_SLIDES * slide_height + (N_SLIDES + 1) * MARGIN;
-    foo_scroll_area_set_size (scroll_area, viewport->width, th);
+    new_y = nth_slide * (MARGIN + (double)slide_height) + MARGIN;
+    
+    total_height = N_SLIDES * slide_height + (N_SLIDES + 1) * MARGIN;
 
-    g_print ("size changed - set size %d %d\n", viewport->width, th);
+    foo_scroll_area_set_size_fixed_y (scroll_area, viewport->width,
+				      total_height,
+				      old_y + 0.5, new_y + 0.5);
     
     foo_scroll_area_invalidate (scroll_area);
 }
@@ -127,7 +109,6 @@ on_viewport_changed (FooScrollArea *scroll_area,
                      GdkRectangle  *viewport,
                      GdkRectangle  *old_viewport)
 {
-    g_print ("viewport changed\n");
 }
 
 static void
diff --git a/scrollarea.c b/scrollarea.c
index 1d88534..f626308 100644
--- a/scrollarea.c
+++ b/scrollarea.c
@@ -636,7 +636,6 @@ emit_viewport_signals (FooScrollArea *scroll_area,
 		       GdkRectangle  *new_viewport,
 		       GdkRectangle  *old_viewport)
 {
-    int px, py;
     gboolean position_changed;
     gboolean size_changed;
 
@@ -648,6 +647,8 @@ emit_viewport_signals (FooScrollArea *scroll_area,
     
     if (size_changed || position_changed)
     {
+	int px, py;
+	
 	g_signal_emit (scroll_area, signals[VIEWPORT_CHANGED], 0, 
 		       new_viewport, old_viewport);
 
@@ -656,21 +657,15 @@ emit_viewport_signals (FooScrollArea *scroll_area,
 	    g_signal_emit (scroll_area, signals[VIEWPORT_SIZE_CHANGED], 0,
 			   new_viewport, old_viewport);
 	}
-	else
-	{
-	    g_print ("old size: %d %d\n", old_viewport->width, old_viewport->height);
-	    g_print ("new size: %d %d\n", new_viewport->width, new_viewport->height);
-	}
-	    
-	gdk_window_get_pointer (GTK_WIDGET (scroll_area)->window, &px, &py, NULL);
+
+	/* Fake an event when the viewport changes
+	 * FIXME: keep track of the last position in the window
+	 */
+	gdk_window_get_pointer (GTK_WIDGET (scroll_area)->window,
+				&px, &py, NULL);
 	    
 	process_event (scroll_area, FOO_MOTION, px, py, 0);
     }
-    else
-    {
-	g_print ("old pos: %d %d\n", old_viewport->x, old_viewport->y);
-	g_print ("new pos: %d %d\n", new_viewport->x, new_viewport->y);
-    }
 }
 
 static void
@@ -1150,12 +1145,6 @@ foo_scroll_area_set_size_fixed_y (FooScrollArea	       *scroll_area,
     scroll_area->priv->width = width;
     scroll_area->priv->height = height;
     
-#if 0
-    g_print ("diff: %d\n", new_y - old_y);
-#endif
-
-    g_print ("old: %d new %d (dy %d)\n", old_y, new_y, dy);
-    
     scroll_area->priv->vadj->value += dy;
     
     set_adjustment_values (scroll_area);
@@ -1215,8 +1204,6 @@ foo_scrollbar_adjustment_changed (GtkAdjustment *adj,
     gint dy = 0;
     GdkRectangle old_viewport, new_viewport;
 
-    g_print ("adjustment changed\n");
-    
     /* FIXME: When dragging diagonally, this function will be called
      * twice, causing two separate scrolls in the backing store.
      *