ecore_cocoa: fix main loop handling

Pffff... another tricky one...

-windowDidResize is actually also called when the window is not
resize by the user, leading to multiple event posting, and of
course the infamous call of ecore_main_loop_iterate() when it
was not paused at all, leading to messy events handling... the
most visible being the initial resizing of the window going rogue.

We now ensure with -windowWillStartLiveResize and -windowDidEndLiveResize
that we only send an event when the user requested it. Since the main
loop is paused at this point, calling ecore_main_loop_iterate()
becomes safe.

Fixes T3648

src/lib/ecore_cocoa/ecore_cocoa_window.h

@@ -3,6 +3,7 @@
 @interface EcoreCocoaWindow: NSWindow <NSWindowDelegate>
 {
    void *ecore_window_data;
+   int _live_resize;
 }
 
 @property (nonatomic, assign) void *ecore_window_data;

src/lib/ecore_cocoa/ecore_cocoa_window.m

@@ -34,6 +34,8 @@ static NSCursor *_cursors[__ECORE_COCOA_CURSOR_LAST];
 
    [self setCollectionBehavior:NSWindowCollectionBehaviorFullScreenPrimary];
 
+   _live_resize = 0;
+
    return self;
 }
 
@@ -72,6 +74,13 @@ static NSCursor *_cursors[__ECORE_COCOA_CURSOR_LAST];
    Ecore_Cocoa_Event_Window_Resize_Request *event;
    NSSize size = self.frame.size;
 
+   /*
+    * Only throw a resize event and manipulate the main loop when
+    * we are 100% sure we are in a live resize, and the main loop
+    * has already been paused!!
+    */
+   if (_live_resize > 0)
+     {
         event = malloc(sizeof(*event));
         if (EINA_UNLIKELY(event == NULL))
           {
@@ -94,6 +103,7 @@ static NSCursor *_cursors[__ECORE_COCOA_CURSOR_LAST];
          * live resizing of a window.
          */
         ecore_main_loop_iterate();
+     }
 }
 
 - (void)windowDidBecomeKey:(NSNotification *)notification
@@ -112,11 +122,15 @@ static NSCursor *_cursors[__ECORE_COCOA_CURSOR_LAST];
 
 - (void) windowWillStartLiveResize:(NSNotification *) EINA_UNUSED notification
 {
+   /* Live resize must be set AFTER pausing the main loop */
    [NSApp pauseNSRunLoopMonitoring];
+   _live_resize++;
 }
 
 - (void) windowDidEndLiveResize:(NSNotification *) EINA_UNUSED notification
 {
+   /* Live resize must be clear BEFORE resuming the main loop */
+   _live_resize--;
    [NSApp resumeNSRunLoopMonitoring];
 }