ui/cocoa: Fix absolute input device grabbing issue on Mojave

On Mojave, absolute input device, i.e. tablet, had trouble re-grabbing
the cursor in re-entry into the virtual screen area. In some cases,
the `window` property of NSEvent object was nil after cursor exiting from
window, hinting that the `-locationInWindow` method would return value in
screen coordinates. The current implementation used raw locations from
NSEvent without considering whether the value was for the window coordinates
or the macOS screen coordinates, nor the zooming factor for Zoom-to-Fit in
fullscreen mode.

In fullscreen mode, the fullscreen cocoa window might not be the key
window, therefore the location of event in virtual coordinates should
suffice.

This patches fixed boundary check methods for cursor in normal
and fullscreen with/without Zoom-to-Fit in Mojave.

Note: CGRect, -convertRectToScreen: and -convertRectFromScreen: were
used in coordinates conversion for compatibility reason.

Signed-off-by: Chen Zhang <tgfbeta@me.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: FA3FBC4F-5379-4118-B997-58FE05CC58F9@me.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 41 insertions, 2 deletions

diff --git a/ui/cocoa.m b/ui/cocoa.m
index 89b16e0e44..73cfafa524 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -406,6 +406,41 @@ QemuCocoaView *cocoaView;
     return (p.x > -1 && p.x < screen.width && p.y > -1 && p.y < screen.height);
 }
 
+/* Get location of event and convert to virtual screen coordinate */
+- (CGPoint) screenLocationOfEvent:(NSEvent *)ev
+{
+    NSWindow *eventWindow = [ev window];
+    // XXX: Use CGRect and -convertRectFromScreen: to support macOS 10.10
+    CGRect r = CGRectZero;
+    r.origin = [ev locationInWindow];
+    if (!eventWindow) {
+        if (!isFullscreen) {
+            return [[self window] convertRectFromScreen:r].origin;
+        } else {
+            CGPoint locationInSelfWindow = [[self window] convertRectFromScreen:r].origin;
+            CGPoint loc = [self convertPoint:locationInSelfWindow fromView:nil];
+            if (stretch_video) {
+                loc.x /= cdx;
+                loc.y /= cdy;
+            }
+            return loc;
+        }
+    } else if ([[self window] isEqual:eventWindow]) {
+        if (!isFullscreen) {
+            return r.origin;
+        } else {
+            CGPoint loc = [self convertPoint:r.origin fromView:nil];
+            if (stretch_video) {
+                loc.x /= cdx;
+                loc.y /= cdy;
+            }
+            return loc;
+        }
+    } else {
+        return [[self window] convertRectFromScreen:[eventWindow convertRectToScreen:r]].origin;
+    }
+}
+
 - (void) hideCursor
 {
     if (!cursor_hide) {
@@ -705,7 +740,8 @@ QemuCocoaView *cocoaView;
     int keycode = 0;
     bool mouse_event = false;
     static bool switched_to_fullscreen = false;
-    NSPoint p = [event locationInWindow];
+    // Location of event in virtual screen coordinates
+    NSPoint p = [self screenLocationOfEvent:event];
 
     switch ([event type]) {
         case NSEventTypeFlagsChanged:
@@ -816,7 +852,10 @@ QemuCocoaView *cocoaView;
             break;
         case NSEventTypeMouseMoved:
             if (isAbsoluteEnabled) {
-                if (![self screenContainsPoint:p] || ![[self window] isKeyWindow]) {
+                // Cursor re-entered into a window might generate events bound to screen coordinates
+                // and `nil` window property, and in full screen mode, current window might not be
+                // key window, where event location alone should suffice.
+                if (![self screenContainsPoint:p] || !([[self window] isKeyWindow] || isFullscreen)) {
                     if (isMouseGrabbed) {
                         [self ungrabMouse];
                     }