[gtk/wip/chergert/macos-iosurface] macos: use input area to define tracking areas

[Christian Hergert <chergert src gnome org>]

commit d6fb235008f6ce84dfee5bcdde237e1428f5d67f
Author: Christian Hergert <christian hergert me>
Date:   Sun Feb 13 17:22:43 2022 -0800

    macos: use input area to define tracking areas
    
    These are still way too big for libadwaita apps, but it's a start.

 gdk/macos/GdkMacosBaseView.c | 18 ++++++++++++++++++
 gdk/macos/GdkMacosBaseView.h |  1 +
 gdk/macos/gdkmacossurface.c  | 11 +++++++++++
 3 files changed, 30 insertions(+)
---
diff --git a/gdk/macos/GdkMacosBaseView.c b/gdk/macos/GdkMacosBaseView.c
index ddce1241a3..79bd7d9617 100644
--- a/gdk/macos/GdkMacosBaseView.c
+++ b/gdk/macos/GdkMacosBaseView.c
@@ -57,6 +57,24 @@
   return self;
 }
 
+-(void)setInputArea:(const cairo_rectangle_int_t *)area
+{
+  NSRect rect = NSMakeRect (area->x, area->y, area->width, area->height);
+  NSTrackingAreaOptions options;
+
+  [self removeTrackingArea:trackingArea];
+
+  options = (NSTrackingMouseEnteredAndExited |
+             NSTrackingMouseMoved |
+             NSTrackingInVisibleRect |
+             NSTrackingActiveAlways);
+  trackingArea = [[NSTrackingArea alloc] initWithRect:rect
+                                              options:options
+                                                owner:(id)self
+                                             userInfo:nil];
+  [self addTrackingArea:trackingArea];
+}
+
 -(void)setOpaqueRegion:(cairo_region_t *)region
 {
   /* Do nothing */
diff --git a/gdk/macos/GdkMacosBaseView.h b/gdk/macos/GdkMacosBaseView.h
index 7fcfc7e43b..2eb6f72721 100644
--- a/gdk/macos/GdkMacosBaseView.h
+++ b/gdk/macos/GdkMacosBaseView.h
@@ -42,5 +42,6 @@
 -(void)setNeedsInvalidateShadow: (BOOL)invalidate;
 -(NSTrackingArea *)trackingArea;
 -(void)setOpaqueRegion:(cairo_region_t *)region;
+-(void)setInputArea:(const cairo_rectangle_int_t *)area;
 
 @end
diff --git a/gdk/macos/gdkmacossurface.c b/gdk/macos/gdkmacossurface.c
index 6966db7894..80fe42f387 100644
--- a/gdk/macos/gdkmacossurface.c
+++ b/gdk/macos/gdkmacossurface.c
@@ -102,6 +102,17 @@ static void
 gdk_macos_surface_set_input_region (GdkSurface     *surface,
                                     cairo_region_t *region)
 {
+  GdkMacosSurface *self = (GdkMacosSurface *)surface;
+  cairo_rectangle_int_t rect;
+
+  g_assert (GDK_IS_MACOS_SURFACE (self));
+
+  if (self->window == NULL)
+    return;
+
+  cairo_region_get_extents (region, &rect);
+
+  [(GdkMacosBaseView *)[self->window contentView] setInputArea:&rect];
 }
 
 static void