Fix cursor missing in tabCapture on OSX Sierra

content/browser/media/capture/cursor_renderer_mac.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/media/capture/cursor_renderer_mac.h"
 
-#include <ApplicationServices/ApplicationServices.h>
 #include <Cocoa/Cocoa.h>
 #include <CoreFoundation/CoreFoundation.h>
-#include <stdint.h>
 
-#include <cmath>
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/mac/mac_util.h"
+#include "base/memory/ptr_util.h"
+#include "skia/ext/skia_utils_mac.h"
+#include "ui/gfx/image/image.h"
 
-#include "base/logging.h"
+@implementation CursorRendererMouseTracker
+
+- (instancetype)initWithView:(NSView*)nsView {
+  if ((self = [super init])) {
+    NSTrackingAreaOptions trackingOptions =
+        NSTrackingMouseMoved | NSTrackingMouseEnteredAndExited |
+        NSTrackingActiveInKeyWindow | NSTrackingInVisibleRect;
+    trackingArea_.reset([[CrTrackingArea alloc] initWithRect:NSZeroRect
+                                                     options:trackingOptions
+                                                       owner:self
+                                                    userInfo:nil]);
+    [nsView addTrackingArea:trackingArea_.get()];
+    capturedView_ = nsView;
+  }
+  return self;
+}
+
+- (void)stopTracking {
+  if (trackingArea_.get()) {
+    [capturedView_ removeTrackingArea:trackingArea_.get()];

[miu, 2017/01/05 01:26:57]

It seems possible for |capturedView_| could sometimes be invalid at this point.
I'd suggest making it a scoped_nsobject to retain it so this method call doesn't
cause a crash.

[braveyao, 2017/01/05 22:34:49]

Done.

+    trackingArea_.reset();
+  }
+}
+
+- (void)registerMouseInteractionObserver:(const base::Closure&)observer {
+  mouseInteractionObserver_ = observer;
+}
+
+- (void)mouseMoved:(NSEvent*)theEvent {
+  mouseInteractionObserver_.Run();
+}
+
+- (void)mouseEntered:(NSEvent*)theEvent {
+  mouseInteractionObserver_.Run();
+}
+
+- (void)mouseExited:(NSEvent*)theEvent {
+}
+
+@end
 
 namespace content {
 
-namespace {
-
-// RGBA format on cursor bitmap
-const int kBytesPerPixel = 4;
-
-inline int clip_byte(int x) {
-  return std::max(0, std::min(x, 255));
+// static
+std::unique_ptr<CursorRenderer> CursorRenderer::Create(gfx::NativeView view) {
+  return base::MakeUnique<CursorRendererMac>(view);
 }
 
-inline int alpha_blend(int alpha, int src, int dst) {
-  return (src * alpha + dst * (255 - alpha)) / 255;
+CursorRendererMac::CursorRendererMac(gfx::NativeView view)
+    : CursorRenderer(view, kCursorEnabledOnMouseMovement), view_(view) {
+  mouse_tracker_.reset([[CursorRendererMouseTracker alloc] initWithView:view]);
+  [mouse_tracker_ registerMouseInteractionObserver:
+      base::Bind(&CursorRendererMac::OnMouseEvent, base::Unretained(this))];
 }
 
-}  // namespace
-
-// static
-std::unique_ptr<CursorRenderer> CursorRenderer::Create(gfx::NativeView view) {
-  return std::unique_ptr<CursorRenderer>(new CursorRendererMac(view));
+CursorRendererMac::~CursorRendererMac() {
+  [mouse_tracker_ stopTracking];
 }
 
-CursorRendererMac::CursorRendererMac(NSView* view)
-    : view_(view), weak_factory_(this) {
-  Clear();
-}
-
-CursorRendererMac::~CursorRendererMac() {}
-
-base::WeakPtr<CursorRenderer> CursorRendererMac::GetWeakPtr() {
-  return weak_factory_.GetWeakPtr();
-}
-
-void CursorRendererMac::Clear() {
-  last_cursor_data_.reset();
-  last_cursor_width_ = 0;
-  last_cursor_height_ = 0;
-  last_mouse_location_x_ = 0;
-  last_mouse_location_y_ = 0;
-  last_mouse_movement_timestamp_ = base::TimeTicks();
-}
-
-// Polls mouse cursor location and image and returns whether the mouse
-// cursor should be rendered on the frame.
-bool CursorRendererMac::SnapshotCursorState(const gfx::Rect& region_in_frame) {
-  // Mouse location in window co-ordinates.
-  NSPoint mouse_window_location =
-      [view_ window].mouseLocationOutsideOfEventStream;
-  // Mouse location with respect to the web contents.
-  NSPoint mouse_tab_location =
-      [view_ convertPoint:mouse_window_location fromView:nil];
-
-  // Mouse co-ordinates directly comparable against frame co-ordinates
-  // after translation.
-  if (mouse_tab_location.x < 0 || mouse_tab_location.y < 0 ||
-      mouse_tab_location.x > region_in_frame.width() ||
-      mouse_tab_location.y > region_in_frame.height()) {
-    VLOG(2) << "Mouse outside content region";
+bool CursorRendererMac::IsCapturedViewActive() {
+  if (![[view_ window] isKeyWindow]) {
     return false;
   }
-
-  if (![[view_ window] isKeyWindow]) {
-    VLOG(2) << "Window currently inactive";
-    return false;
-  }
-
-  if ((base::TimeTicks::Now() - last_mouse_movement_timestamp_).InSeconds() >
-          MAX_IDLE_TIME_SECONDS &&
-      std::abs(mouse_tab_location.x - last_mouse_location_x_) <
-          MIN_MOVEMENT_PIXELS &&
-      std::abs(mouse_tab_location.y - last_mouse_location_y_) <
-          MIN_MOVEMENT_PIXELS) {
-    VLOG(2) << "No mouse movement in a while";
-    return false;
-  }
-
-  // Mouse cursor position within the frame.
-  cursor_position_in_frame_ =
-      gfx::Point(region_in_frame.x() + mouse_tab_location.x,
-                 region_in_frame.y() + mouse_tab_location.y);
-
-  // Grab system cursor.
-  NSCursor* nscursor = [NSCursor currentSystemCursor];
-  NSPoint nshotspot = [nscursor hotSpot];
-  NSImage* nsimage = [nscursor image];
-  NSSize nssize = [nsimage size];
-
-  // The cursor co-ordinates in the window and the video frame co-ordinates are
-  // inverted along y-axis. We render the cursor inverse vertically on the
-  // frame. Hence the inversion on hotspot offset here.
-  cursor_position_in_frame_.Offset(-nshotspot.x,
-                                   -(nssize.height - nshotspot.y));
-  last_cursor_width_ = nssize.width;
-  last_cursor_height_ = nssize.height;
-
-  CGImageRef cg_image =
-      [nsimage CGImageForProposedRect:NULL context:nil hints:nil];
-  if (!cg_image)
-    return false;
-
-  if (CGImageGetBitsPerPixel(cg_image) != kBytesPerPixel * 8 ||
-      CGImageGetBytesPerRow(cg_image) !=
-          static_cast<size_t>(kBytesPerPixel * nssize.width) ||
-      CGImageGetBitsPerComponent(cg_image) != 8) {
-    return false;
-  }
-
-  CGDataProviderRef provider = CGImageGetDataProvider(cg_image);
-  CFDataRef image_data_ref = CGDataProviderCopyData(provider);
-  if (!image_data_ref)
-    return false;
-  last_cursor_data_.reset(image_data_ref, base::scoped_policy::ASSUME);
-
-  if (std::abs(mouse_tab_location.x - last_mouse_location_x_) >
-          MIN_MOVEMENT_PIXELS ||
-      std::abs(mouse_tab_location.y - last_mouse_location_y_) >
-          MIN_MOVEMENT_PIXELS) {
-    last_mouse_movement_timestamp_ = base::TimeTicks::Now();
-    last_mouse_location_x_ = mouse_tab_location.x;
-    last_mouse_location_y_ = mouse_tab_location.y;
-  }
   return true;
 }
 
-// Helper function to composite a RGBA cursor bitmap on a YUV420 video frame.
-void CursorRendererMac::RenderOnVideoFrame(
-    const scoped_refptr<media::VideoFrame>& target) const {
-  DCHECK(target);
-  DCHECK(last_cursor_data_);
-  const uint8_t* cursor_data_ =
-      reinterpret_cast<const uint8_t*>(CFDataGetBytePtr(last_cursor_data_));
+gfx::Size CursorRendererMac::GetCapturedViewSize() {
+  NSRect frame_rect = [view_ bounds];
+  return gfx::Size(frame_rect.size.width, frame_rect.size.height);
+}
 
-  gfx::Rect visible_rect = target->visible_rect();
-  gfx::Rect rect =
-      gfx::IntersectRects(gfx::Rect(last_cursor_width_, last_cursor_height_) +
-                              gfx::Vector2d(cursor_position_in_frame_.x(),
-                                            cursor_position_in_frame_.y()),
-                          visible_rect);
+gfx::Point CursorRendererMac::GetCursorPositionInView() {
+  // Mouse location in window co-ordinates.
+  NSPoint mouse_window_location =
+      [view_ window].mouseLocationOutsideOfEventStream;
+  // Mouse location with respect to the view within the window.
+  NSPoint mouse_view_location =
+      [view_ convertPoint:mouse_window_location fromView:nil];
 
-  for (int y = rect.y() + 1; y <= rect.bottom(); ++y) {
-    int cursor_y = rect.bottom() - y;
-    int inverted_y = visible_rect.bottom() - y;
-    uint8_t* yplane =
-        target->data(media::VideoFrame::kYPlane) +
-        inverted_y * target->row_bytes(media::VideoFrame::kYPlane);
-    uint8_t* uplane =
-        target->data(media::VideoFrame::kUPlane) +
-        (inverted_y / 2) * target->row_bytes(media::VideoFrame::kUPlane);
-    uint8_t* vplane =
-        target->data(media::VideoFrame::kVPlane) +
-        (inverted_y / 2) * target->row_bytes(media::VideoFrame::kVPlane);
-    for (int x = rect.x(); x < rect.right(); ++x) {
-      int cursor_x = x - rect.x();
-      int byte_pos = cursor_y * last_cursor_width_ * kBytesPerPixel +
-                     cursor_x * kBytesPerPixel;
-      int color_r = cursor_data_[byte_pos];
-      int color_g = cursor_data_[byte_pos + 1];
-      int color_b = cursor_data_[byte_pos + 2];
-      int alpha = cursor_data_[byte_pos + 3];
-      int color_y = clip_byte(
-          ((color_r * 66 + color_g * 129 + color_b * 25 + 128) >> 8) + 16);
-      yplane[x] = alpha_blend(alpha, color_y, yplane[x]);
+  // Invert y coordinate to unify with Aura.
+  gfx::Point cursor_position_in_view(
+      mouse_view_location.x,
+      GetCapturedViewSize().height() - mouse_view_location.y);
 
-      // Only sample U and V at even coordinates.
-      if ((x % 2 == 0) && (y % 2 == 0)) {
-        int color_u = clip_byte(
-            ((color_r * -38 + color_g * -74 + color_b * 112 + 128) >> 8) + 128);
-        int color_v = clip_byte(
-            ((color_r * 112 + color_g * -94 + color_b * -18 + 128) >> 8) + 128);
-        uplane[x / 2] = alpha_blend(alpha, color_u, uplane[x / 2]);
-        vplane[x / 2] = alpha_blend(alpha, color_v, vplane[x / 2]);
-      }
-    }
-  }
+  return cursor_position_in_view;
+}
+
+gfx::NativeCursor CursorRendererMac::GetLastKnownCursor() {
+  // Grab system cursor.
+  return [NSCursor currentSystemCursor];
+}
+
+SkBitmap CursorRendererMac::GetLastKnownCursorImage(gfx::Point* hot_point) {
+  // Grab system cursor.
+  NSCursor* nscursor = [NSCursor currentSystemCursor];
+  NSImage* nsimage = [nscursor image];
+  NSPoint nshotspot = [nscursor hotSpot];
+
+  *hot_point = gfx::Point(nshotspot.x, nshotspot.y);
+  return skia::NSImageToSkBitmapWithColorSpace(
+      nsimage, /*is_opaque=*/false, base::mac::GetSystemColorSpace());
+}
+
+void CursorRendererMac::OnMouseEvent() {
+  // Update cursor movement info to CursorRenderer.
+  OnMouseMoved(GetCursorPositionInView(), base::TimeTicks::Now());
 }
 
 }  // namespace content