Add mouse enter/leave events for pixmaps/windows.

The current "target" is the one under the mouse and also
receives mouse movements and button down events. However,
once the button has been pressed in a window, all subsequent
mouse events will be sent to that window (and no mouse leave
will be generated) until the button has been released.


Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 82 insertions, 32 deletions

diff --git a/twin.h b/twin.h
index b7fbe5b..c2603c6 100644
--- a/twin.h
+++ b/twin.h
@@ -159,9 +159,10 @@ typedef struct _twin_screen {
      */
     twin_pixmap_t	*active;
     /*
-     * pointer down for this window
+     * this pixmap is target of mouse events
      */
-    twin_pixmap_t	*pointer;
+    twin_pixmap_t	*target;
+    twin_bool_t		clicklock;
     /*
      * mouse image (optional)
      */
@@ -317,14 +318,27 @@ extern twin_font_t	twin_Default_Font_Roman;
  */
 
 typedef enum _twin_event_kind {
-    TwinEventButtonDown, TwinEventButtonUp, TwinEventMotion,
-    TwinEventKeyDown, TwinEventKeyUp, TwinEventUcs4,
-    TwinEventActivate, TwinEventDeactivate,
-    TwinEventPaint,
-    TwinEventShow,
-    TwinEventQueryGeometry,
-    TwinEventConfigure,
-    TwinEventDestroy,
+    /* Mouse */
+    TwinEventButtonDown		= 0x0001,
+    TwinEventButtonUp		= 0x0002,
+    TwinEventMotion		= 0x0003,
+    TwinEventEnter		= 0x0004,
+    TwinEventLeave		= 0x0005,
+
+    /* keyboard */
+    TwinEventKeyDown		= 0x0101,
+    TwinEventKeyUp		= 0x0102,
+    TwinEventUcs4		= 0x0103,
+
+    /* Focus */
+    TwinEventActivate		= 0x0201,
+    TwinEventDeactivate		= 0x0202,
+
+    /* Widgets */
+    TwinEventPaint		= 0x1001,
+    TwinEventQueryGeometry	= 0x1002,
+    TwinEventConfigure		= 0x1003,
+    TwinEventDestroy		= 0x1004,
 } twin_event_kind_t;
 
 typedef struct _twin_event {
diff --git a/twin_screen.c b/twin_screen.c
index 8de8007..b2cc6dd 100644
--- a/twin_screen.c
+++ b/twin_screen.c
@@ -323,44 +323,80 @@ twin_screen_update_cursor(twin_screen_t *screen,
     }
 }
 
-twin_bool_t
-twin_screen_dispatch (twin_screen_t *screen,
-		      twin_event_t  *event)
+static void _twin_adj_mouse_evt(twin_event_t *event, twin_pixmap_t *pixmap)
+{
+    event->u.pointer.x = event->u.pointer.screen_x - pixmap->x;
+    event->u.pointer.y = event->u.pointer.screen_y - pixmap->y;
+}
+
+twin_bool_t twin_screen_dispatch (twin_screen_t *screen,
+				  twin_event_t  *event)
 {
-    twin_pixmap_t   *pixmap;
+    twin_pixmap_t   *pixmap, *ntarget;
     
     switch (event->kind) {
     case TwinEventMotion:
     case TwinEventButtonDown:
     case TwinEventButtonUp:
+	/* update mouse cursor */
         twin_screen_update_cursor(screen, event->u.pointer.screen_x,
 				  event->u.pointer.screen_y);
-	pixmap = screen->pointer;
-	if (!pixmap)
-	{
-	    for (pixmap = screen->top; pixmap; pixmap = pixmap->down)
-		if (!twin_pixmap_transparent (pixmap,
-					      event->u.pointer.screen_x,
-					      event->u.pointer.screen_y))
-		{
-		    break;
-		}
-	    if (event->kind == TwinEventButtonDown)
-		screen->pointer = pixmap;
-	}
+
+	/* if target is tracking the mouse, check for mouse up, if not,
+	 * just pass the event along
+	 */
+	pixmap = screen->target;
+	if (screen->clicklock && event->kind != TwinEventButtonUp)
+	    goto mouse_passup;
+
+	/* if event is mouse up, stop tracking if any */
 	if (event->kind == TwinEventButtonUp)
-	    screen->pointer = NULL;
-	if (pixmap)
-	{
-	    event->u.pointer.x = event->u.pointer.screen_x - pixmap->x;
-	    event->u.pointer.y = event->u.pointer.screen_y - pixmap->y;
+	    screen->clicklock = 0;
+
+	/* check who the mouse is over now */
+	for (ntarget = screen->top; ntarget; ntarget = ntarget->down)
+	    if (!twin_pixmap_transparent (ntarget,
+					  event->u.pointer.screen_x,
+					  event->u.pointer.screen_y))
+		break;
+
+	/* ah, somebody new ... send leave/enter events and set new target */
+	if (pixmap != ntarget) {
+	    twin_event_t evt;
+
+	    if (pixmap) {
+		evt = *event;
+		evt.kind = TwinEventLeave;
+		_twin_adj_mouse_evt (&evt, pixmap);
+		twin_pixmap_dispatch (pixmap, &evt);
+	    }
+
+	    pixmap = screen->target = ntarget;
+
+	    if (pixmap) {
+		evt = *event;
+		_twin_adj_mouse_evt (&evt, pixmap);
+		evt.kind = TwinEventEnter;
+		twin_pixmap_dispatch (pixmap, &evt);
+	    }
 	}
+
+	/* check for new click locking */
+	if (pixmap && event->kind == TwinEventButtonDown)
+	    screen->clicklock = 1;
+
+ mouse_passup:
+	/* adjust event to pixmap coordinates before passing up */
+	if (pixmap)
+	    _twin_adj_mouse_evt (event, pixmap);
 	break;
+
     case TwinEventKeyDown:
     case TwinEventKeyUp:
     case TwinEventUcs4:
 	pixmap = screen->active;
 	break;
+
     default:
 	pixmap = NULL;
 	break;