macosx: Fix incorrect mouse entry and exit tracking behaviour of VLCTrackingView around scrolling

mouseEntered and mouseExited events only seem to be sent when the mouse cursor is moved, causing issues when the VLCTrackingView is inside a scrollview and the view itself moves. This means the cursor does not move but is not hovering the item anymore, with the view unaware of this.

Fix by checking the mouse position after the tracking areas are updated inside VLCTrackingView

After fix:

Screen_Recording_2023-05-06_at_16.47.14

Before fix:

Screen_Recording_2023-05-06_at_16.48.22

Signed-off-by: Claudio Cambra developer@claudiocambra.com

modules/gui/macosx/views/VLCTrackingView.m

@@ -25,13 +25,16 @@
 @interface VLCTrackingView ()
 {
     NSTrackingArea *_trackingArea;
+    BOOL _mouseIn;
 }
 @end
 
 @implementation VLCTrackingView
 
-- (void)mouseExited:(NSEvent *)event
+- (void)handleMouseExit
 {
+    _mouseIn = NO;
+
     if (self.animatesTransition) {
         [self.viewToHide setAlphaValue:1.0];
         [self.viewToShow setAlphaValue:.0];
@@ -53,8 +56,10 @@
     }
 }
 
-- (void)mouseEntered:(NSEvent *)event
+- (void)handleMouseEnter
 {
+    _mouseIn = YES;
+
     if (self.animatesTransition) {
         [self.viewToHide setAlphaValue:.0];
         [self.viewToHide setHidden:NO];
@@ -75,6 +80,16 @@
     }
 }
 
+- (void)mouseExited:(NSEvent *)event
+{
+    [self handleMouseExit];
+}
+
+- (void)mouseEntered:(NSEvent *)event
+{
+    [self handleMouseEnter];
+}
+
 - (void)updateTrackingAreas
 {
     [super updateTrackingAreas];
@@ -88,6 +103,18 @@
                                                    owner:self
                                                 userInfo:nil];
     [self addTrackingArea:_trackingArea];
+
+    // Once tracking area updated, check if the cursor is still inside the tracking view.
+    // This prevents situations where the mouseEntered/mouseExited is not called because the view
+    // itself has moved but the cursor has not (e.g. when this view is inside a scrollview and the
+    // user scrolls)
+    const NSPoint mouseLocation = [self convertPoint:self.window.mouseLocationOutsideOfEventStream fromView:self.window.contentView];
+    const BOOL mouseInsideView = [self mouse:mouseLocation inRect:self.frame];
+    if (mouseInsideView && !_mouseIn) {
+        [self handleMouseEnter];
+    } else if (!mouseInsideView && _mouseIn) {
+        [self handleMouseExit];
+    }
 }
 
 @end