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Fixed bug #719
 Mike Blaguszewski      2009-03-23 13:32:22 PDT

Patch to 1.2 HEAD that fixes the issue

Fixes bug in SDL 1.2.13 where clicking on an app's title bar to activate the
app, when cursor capturing is enabled, will cause the window to jump. This is
because SDL's handler for activate events calls a low-level Quartz function to
move the cursor. Calling this when the mouse is down in the title bar confuses
the WindowServer into thinking the title bar has been dragged. The patch defers
processing of activate events in this case.

The bottom line is that CGWarpMouseCursorPosition() is not safe to call when
the mouse in down in a window's title bar.
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slouken committed Sep 23, 2009
1 parent 6d63d7b commit ce63f67de14800b3dd95c8c0172ad2792580ff09
Showing with 28 additions and 0 deletions.
  1. +4 −0 src/video/quartz/SDL_QuartzWindow.h
  2. +24 −0 src/video/quartz/SDL_QuartzWindow.m
@@ -27,6 +27,10 @@ typedef unsigned int NSUInteger;

/* Subclass of NSWindow to fix genie effect and support resize events */
@interface SDL_QuartzWindow : NSWindow
BOOL watchForMouseUp;

- (void)miniaturize:(id)sender;
- (void)display;
- (void)setFrame:(NSRect)frameRect display:(BOOL)flag;
@@ -128,6 +128,30 @@ - (void)setFrame:(NSRect)frameRect display:(BOOL)flag

/* QZ_DoActivate() calls a low-level CoreGraphics routine to adjust
the cursor position, if input is being grabbed. If app activation is
triggered by a mouse click in the title bar, then the window manager
gets confused and thinks we're dragging the window. The solution
below postpones the activate event to avoid this scenario. */
- (void)becomeKeyWindow
NSEvent *event = [self currentEvent];
if ([event type] == NSLeftMouseDown && [event window] == self)
watchForMouseUp = YES;
[super becomeKeyWindow];

- (void)sendEvent:(NSEvent *)event
[super sendEvent:event];
if (watchForMouseUp && [event type] == NSLeftMouseUp)
watchForMouseUp = NO;
[super becomeKeyWindow];

- (void)appDidHide:(NSNotification*)note
SDL_PrivateAppActive (0, SDL_APPACTIVE);

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