Add --with-ownership flag and the matching event handling

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 42 insertions, 12 deletions

diff --git a/multitouch.c b/multitouch.c
index 7adf6f0..35b4a39 100644
--- a/multitouch.c
+++ b/multitouch.c
@@ -2,6 +2,7 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
@@ -11,6 +12,8 @@
 #include <stdint.h>
 #include <math.h>
 
+#include <errno.h>
+
 #include <cairo.h>
 #include <cairo-xlib.h>
 
@@ -22,8 +25,8 @@
 
 static void usage(void)
 {
-    printf("Usage:\n");
-    printf("	Grey window: normal touch surface\n");
+    printf("Usage: %s [--with-ownership]\n", program_invocation_short_name);
+    printf("	Grey window: normal touch surface, with or without ownership\n");
     printf("	Upper black bar left: grabs the touchpoint, no ownership, accepts\n");
     printf("	Upper White bar left: grabs the touchpoint, no ownership, rejects\n");
     printf("	Lower black bar left: grabs the touchpoint, with ownership, accepts\n");
@@ -40,6 +43,7 @@ struct touchpoint {
     enum TouchState state;
     uint32_t touchid; /* 0 == unused */
     double x, y;   /* last recorded x/y position */
+    Bool owned;
 };
 
 struct grabpoint {
@@ -81,6 +85,8 @@ struct multitouch {
 
     struct grabpoint grabs[MAX_TOUCHES];
     size_t ngrabs;
+
+    Bool needs_ownership;
 };
 
 static void expose(struct multitouch *mt, int x1, int y1, int x2, int y2);
@@ -114,7 +120,7 @@ static void sighandler(int signal)
     error("signal received, shutting down\n");
 }
 
-static void init_windows(struct multitouch *mt)
+static void init_windows(struct multitouch *mt, Bool ownership)
 {
     Window win, subwin;
     XEvent event;
@@ -156,8 +162,11 @@ static void init_windows(struct multitouch *mt)
     XISetMask(mask, XI_TouchBegin);
     XISetMask(mask, XI_TouchUpdate);
     XISetMask(mask, XI_TouchEnd);
+    if (ownership)
+        XISetMask(mask, XI_TouchOwnership);
 
     XISelectEvents(mt->dpy, win, &evmask, 1);
+    XIClearMask(mask, XI_TouchOwnership);
 
     /* grab touch events on blackbar */
     modifiers.modifiers = XIAnyModifier;
@@ -201,7 +210,7 @@ static GC init_gc(struct multitouch *mt)
     return gc;
 }
 
-static int init_x11(struct multitouch *mt, int width, int height)
+static int init_x11(struct multitouch *mt, int width, int height, Bool ownership)
 {
     Display *dpy;
     int major = 2, minor = 2;
@@ -227,7 +236,7 @@ static int init_x11(struct multitouch *mt, int width, int height)
     mt->width     = width;
     mt->height    = height;
 
-    init_windows(mt);
+    init_windows(mt, ownership);
 
     mt->pixmap = init_pixmap(mt);
     mt->gc = init_gc(mt);
@@ -305,9 +314,10 @@ static void paint_touch_begin(struct multitouch *mt, XIDeviceEvent *event)
     t->x = event->event_x;
     t->y = event->event_y;
     t->state = TSTATE_BEGIN;
+    t->owned = !mt->needs_ownership;
 
     cairo_save(mt->cr);
-    cairo_set_source_rgb(mt->cr, 0, 0, 0);
+    cairo_set_source_rgba(mt->cr, 0, 0, 0, t->owned ? 1 : .5);
     cairo_arc(mt->cr, t->x, t->y, radius, 0, 2 * M_PI);
     cairo_stroke(mt->cr);
     cairo_restore(mt->cr);
@@ -331,7 +341,7 @@ static void paint_touch_update(struct multitouch *mt, XIDeviceEvent *event)
     struct touchpoint *t = find_touch(mt, event->detail);
 
     cairo_save(mt->cr);
-    cairo_set_source_rgb(mt->cr, 0, 0, 0);
+    cairo_set_source_rgba(mt->cr, 0, 0, 0, t->owned ? 1 : .5);
     cairo_move_to(mt->cr, t->x, t->y);
     cairo_line_to(mt->cr, event->event_x, event->event_y);
     cairo_stroke(mt->cr);
@@ -353,7 +363,7 @@ static void paint_touch_end(struct multitouch *mt, XIDeviceEvent *event)
     t->state = TSTATE_END;
 
     cairo_save(mt->cr);
-    cairo_set_source_rgb(mt->cr, 0, 0, 0);
+    cairo_set_source_rgba(mt->cr, 0, 0, 0, t->owned ? 1 : .5);
     cairo_rectangle(mt->cr, t->x - rsize/2, t->y - rsize/2, rsize, rsize);
     cairo_stroke(mt->cr);
     cairo_restore(mt->cr);
@@ -398,7 +408,7 @@ static void paint_grabs(struct multitouch *mt)
         } else
         {
             r = 0; g = 1; b = 1;
-            offset = 3 * mt->height/2;
+            offset = 3 * mt->height/4;
         }
 
         cairo_save(mt->cr_grabs);
@@ -475,6 +485,20 @@ static void handle_grabbed_event(struct multitouch *mt, XIDeviceEvent *event)
     }
 }
 
+static void handle_ownership(struct multitouch *mt, XITouchOwnershipEvent *event)
+{
+    const int radius = 10;
+    struct touchpoint *t = find_touch(mt, event->touchid);
+    t->owned = True;
+
+    cairo_save(mt->cr);
+    cairo_set_source_rgba(mt->cr, 1, 0, 0, t->owned ? 1 : .5);
+    cairo_arc(mt->cr, t->x, t->y, radius, 0, 2 * M_PI);
+    cairo_stroke(mt->cr);
+    cairo_restore(mt->cr);
+    expose(mt, t->x - radius/2, t->y - radius/2, t->x + radius/2, t->y + radius/2);
+}
+
 static void paint_event(struct multitouch *mt, XIDeviceEvent *event)
 {
     if (event->event == mt->blackbar || event->event == mt->whitebar ||
@@ -489,6 +513,7 @@ static void paint_event(struct multitouch *mt, XIDeviceEvent *event)
         case XI_TouchBegin: paint_touch_begin(mt, event); break;
         case XI_TouchUpdate: paint_touch_update(mt, event); break;
         case XI_TouchEnd: paint_touch_end(mt, event); break;
+        case XI_TouchOwnership: handle_ownership(mt, (XITouchOwnershipEvent*)event); break;
     }
 }
 
@@ -602,24 +627,29 @@ static int main_loop(struct multitouch *mt)
     return EXIT_SUCCESS;
 }
 
-static void init(struct multitouch *mt)
+static void init(struct multitouch *mt, Bool ownership)
 {
     memset(mt, 0, sizeof(*mt));
 
     mt->ntouches = MAX_TOUCHES;
     mt->ngrabs = MAX_TOUCHES;
+    mt->needs_ownership = ownership;
 }
 
 int main(int argc, char **argv)
 {
     int rc;
     struct multitouch mt;
+    Bool ownership = False;
 
     usage();
 
-    init(&mt);
+    if (argc > 1 && strcmp(argv[1], "--with-ownership") == 0)
+        ownership = True;
+
+    init(&mt, ownership);
 
-    rc = init_x11(&mt, 800, 600);
+    rc = init_x11(&mt, 800, 600, ownership);
     if (rc != EXIT_SUCCESS)
         return rc;