Use custom native mouse cursor on Skia/OSX port

src/she/osx/window.h

@@ -17,6 +17,8 @@
 #include "she/native_cursor.h"
 
 namespace she {
+  class Surface;
+
   KeyScancode cocoavk_to_scancode(UInt16 vk);
 }
 
@@ -48,6 +50,9 @@ public:
 - (gfx::Size)restoredSize;
 - (void)setMousePosition:(const gfx::Point&)position;
 - (BOOL)setNativeMouseCursor:(she::NativeCursor)cursor;
+- (BOOL)setNativeMouseCursor:(const she::Surface*)surface
+                       focus:(const gfx::Point&)focus
+                       scale:(const int)scale;
 @end
 
 #endif

src/she/osx/window.mm

@@ -14,6 +14,7 @@
 #include "she/osx/event_queue.h"
 #include "she/osx/view.h"
 #include "she/osx/window_delegate.h"
+#include "she/surface.h"
 
 using namespace she;
 
@@ -107,7 +108,7 @@ using namespace she;
 
 - (BOOL)setNativeMouseCursor:(NativeCursor)cursor
 {
-  NSCursor* nsCursor = nil;
+  NSCursor* nsCursor = nullptr;
 
   switch (cursor) {
     case kArrowCursor:
@@ -149,13 +150,70 @@ using namespace she;
     case kSizeWCursor:
       nsCursor = [NSCursor resizeLeftCursor];
       break;
-    default:
-      nsCursor = nil;
-      break;
   }
 
   [self.contentView setCursor:nsCursor];
-  return (nsCursor != nil ? YES: NO);
+  return (nsCursor ? YES: NO);
+}
+
+- (BOOL)setNativeMouseCursor:(const she::Surface*)surface
+                       focus:(const gfx::Point&)focus
+                       scale:(const int)scale
+{
+  ASSERT(surface);
+  SurfaceFormatData format;
+  surface->getFormat(&format);
+  if (format.bitsPerPixel != 32)
+    return NO;
+
+  const int w = scale*surface->width();
+  const int h = scale*surface->height();
+
+  std::vector<uint32_t> buf(4*w*h);
+  uint32_t* bits = &buf[0];
+
+  for (int y=0; y<h; ++y) {
+    const uint32_t* ptr = (const uint32_t*)surface->getData(0, y/scale);
+    for (int x=0, u=0; x<w; ++x, ++bits) {
+      *bits = *ptr;
+      if (++u == scale) {
+        u = 0;
+        ++ptr;
+      }
+    }
+  }
+
+  CGDataProviderRef dataRef =
+    CGDataProviderCreateWithData(nullptr, &buf[0],
+                                 w*h*4, nullptr);
+  if (!dataRef)
+    return NO;
+
+  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+  CGImageRef img =
+    CGImageCreate(
+      w, h, 8, 32, 4*w,
+      colorSpace, kCGImageAlphaLast, dataRef,
+      nullptr, false, kCGRenderingIntentDefault);
+  CGColorSpaceRelease(colorSpace);
+
+  CGDataProviderRelease(dataRef);
+
+  NSCursor* nsCursor = nullptr;
+  if (img) {
+    NSImage* image =
+      [[NSImage new] initWithCGImage:img
+                                size:NSMakeSize(w, h)];
+    CGImageRelease(img);
+
+    nsCursor =
+      [[NSCursor new] initWithImage:image
+                            hotSpot:NSMakePoint(scale*focus.x,
+                                                scale*focus.y)];
+  }
+  if (nsCursor)
+    [self.contentView setCursor:nsCursor];
+  return (nsCursor ? YES: NO);
 }
 
 - (void)noResponderFor:(SEL)eventSelector

src/she/skia/skia_display.cpp

@@ -151,10 +151,10 @@ bool SkiaDisplay::setNativeMouseCursor(const she::Surface* surface,
                                        const gfx::Point& focus,
                                        const int scale)
 {
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__APPLE__)
   return m_window.setNativeMouseCursor(surface, focus, scale);
 #else
-  // TODO
+  // TODO impl this for Linux
   return false;
 #endif
 }

src/she/skia/skia_system.h

@@ -70,7 +70,7 @@ public:
       int(Capabilities::MultipleDisplays) |
       int(Capabilities::CanResizeDisplay) |
       int(Capabilities::DisplayScale)
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__APPLE__)
       | int(Capabilities::CustomNativeMouseCursor)
 #endif
     // TODO enable this when the GPU support is ready

src/she/skia/skia_window_osx.h

@@ -17,6 +17,7 @@ namespace she {
 
 class EventQueue;
 class SkiaDisplay;
+class Surface;
 
 class SkiaWindow {
 public:
@@ -39,6 +40,9 @@ public:
   void releaseMouse();
   void setMousePosition(const gfx::Point& position);
   bool setNativeMouseCursor(NativeCursor cursor);
+  bool setNativeMouseCursor(const Surface* surface,
+                            const gfx::Point& focus,
+                            const int scale);
   void updateWindow(const gfx::Rect& bounds);
   std::string getLayout() { return ""; }
   void setLayout(const std::string& layout) { }

src/she/skia/skia_window_osx.mm

@@ -100,6 +100,14 @@ public:
     return ([m_window setNativeMouseCursor:cursor] ? true: false);
   }
 
+  bool setNativeMouseCursor(const she::Surface* surface,
+                            const gfx::Point& focus,
+                            const int scale) {
+    return ([m_window setNativeMouseCursor:surface
+                                     focus:focus
+                                     scale:scale] ? true: false);
+  }
+
   void updateWindow(const gfx::Rect& bounds) {
     int scale = this->scale();
     NSView* view = m_window.contentView;
@@ -424,6 +432,16 @@ bool SkiaWindow::setNativeMouseCursor(NativeCursor cursor)
     return false;
 }
 
+bool SkiaWindow::setNativeMouseCursor(const Surface* surface,
+                                      const gfx::Point& focus,
+                                      const int scale)
+{
+  if (m_impl)
+    return m_impl->setNativeMouseCursor(surface, focus, scale);
+  else
+    return false;
+}
+
 void SkiaWindow::updateWindow(const gfx::Rect& bounds)
 {
   if (m_impl)

src/ui/system.cpp

@@ -45,27 +45,6 @@ static void update_mouse_overlay(Cursor* cursor)
 {
   mouse_cursor = cursor;
 
-  // Check if we can use a custom native mouse in this platform
-  if (!use_native_mouse_cursor &&
-      support_native_custom_cursor &&
-      mouse_display) {
-    if (cursor) {
-      if (mouse_display->setNativeMouseCursor(
-            // The surface is already scaled by guiscale()
-            cursor->getSurface(),
-            cursor->getFocus(),
-            // We scale the cursor by the she::Display scale
-            mouse_display->scale())) {
-        return;
-      }
-    }
-    else {
-      if (mouse_display->setNativeMouseCursor(she::kNoCursor)) {
-        return;
-      }
-    }
-  }
-
   if (mouse_cursor && mouse_scares == 0) {
     if (!mouse_cursor_overlay) {
       mouse_cursor_overlay = new Overlay(
@@ -88,10 +67,35 @@ static void update_mouse_overlay(Cursor* cursor)
   }
 }
 
+static bool update_custom_native_cursor(Cursor* cursor)
+{
+  bool result = false;
+
+  // Check if we can use a custom native mouse in this platform
+  if (!use_native_mouse_cursor &&
+      support_native_custom_cursor &&
+      mouse_display) {
+    if (cursor) {
+      result = mouse_display->setNativeMouseCursor(
+        // The surface is already scaled by guiscale()
+        cursor->getSurface(),
+        cursor->getFocus(),
+        // We scale the cursor by the she::Display scale
+        mouse_display->scale());
+    }
+    else if (mouse_cursor_type == kOutsideDisplay) {
+      result = mouse_display->setNativeMouseCursor(she::kArrowCursor);
+    }
+    else {
+      result = mouse_display->setNativeMouseCursor(she::kNoCursor);
+    }
+  }
+
+  return result;
+}
+
 static void update_mouse_cursor()
 {
-  // Use native cursor when it's possible/available/configured to do so.
-
   she::NativeCursor nativeCursor = she::kNoCursor;
   Cursor* cursor = nullptr;
 
@@ -140,15 +144,18 @@ static void update_mouse_cursor()
       nativeCursor = she::kNoCursor;
   }
 
-  // Use a software cursor with the overlay.
+  // Use a custom cursor
   if (nativeCursor == she::kNoCursor &&
       mouse_cursor_type != ui::kOutsideDisplay &&
       CurrentTheme::get()) {
     cursor = CurrentTheme::get()->getCursor(mouse_cursor_type);
   }
 
-  // Set internal overlay
-  update_mouse_overlay(cursor);
+  // Try to use a custom native cursor if it's possible
+  if (!update_custom_native_cursor(cursor)) {
+    // Or an overlay as last resource
+    update_mouse_overlay(cursor);
+  }
 }
 
 UISystem::UISystem()
@@ -171,8 +178,9 @@ UISystem::~UISystem()
 
   details::exitWidgets();
 
-  _internal_set_mouse_display(NULL);
-  update_mouse_overlay(NULL);
+  _internal_set_mouse_display(nullptr);
+  if (!update_custom_native_cursor(nullptr))
+    update_mouse_overlay(nullptr);
 }
 
 void _internal_set_mouse_display(she::Display* display)
@@ -249,7 +257,8 @@ void show_mouse_cursor()
 
 void _internal_no_mouse_position()
 {
-  update_mouse_overlay(NULL);
+  if (!update_custom_native_cursor(nullptr))
+    update_mouse_overlay(nullptr);
 }
 
 void _internal_set_mouse_position(const gfx::Point& newPos)