1 files changed, 178 insertions, 0 deletions
diff --git a/widget/cocoa/ScreenHelperCocoa.mm b/widget/cocoa/ScreenHelperCocoa.mm
new file mode 100644
index 0000000000..27c18bbfdf
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+++ b/widget/cocoa/ScreenHelperCocoa.mm
@@ -0,0 +1,178 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ScreenHelperCocoa.h"
+
+#import <Cocoa/Cocoa.h>
+
+#include "mozilla/Logging.h"
+#include "nsCocoaUtils.h"
+#include "nsObjCExceptions.h"
+
+using namespace mozilla;
+
+static LazyLogModule sScreenLog("WidgetScreen");
+
+@interface ScreenHelperDelegate : NSObject {
+ @private
+  mozilla::widget::ScreenHelperCocoa* mHelper;
+}
+
+- (id)initWithScreenHelper:(mozilla::widget::ScreenHelperCocoa*)aScreenHelper;
+- (void)didChangeScreenParameters:(NSNotification*)aNotification;
+@end
+
+@implementation ScreenHelperDelegate
+- (id)initWithScreenHelper:(mozilla::widget::ScreenHelperCocoa*)aScreenHelper {
+  if ((self = [self init])) {
+    mHelper = aScreenHelper;
+
+    [[NSNotificationCenter defaultCenter]
+        addObserver:self
+           selector:@selector(didChangeScreenParameters:)
+               name:NSApplicationDidChangeScreenParametersNotification
+             object:nil];
+  }
+
+  return self;
+}
+
+- (void)dealloc {
+  [[NSNotificationCenter defaultCenter] removeObserver:self];
+  [super dealloc];
+}
+
+- (void)didChangeScreenParameters:(NSNotification*)aNotification {
+  MOZ_LOG(sScreenLog, LogLevel::Debug,
+          ("Received NSApplicationDidChangeScreenParametersNotification"));
+
+  mHelper->RefreshScreens();
+}
+@end
+
+namespace mozilla {
+namespace widget {
+
+ScreenHelperCocoa::ScreenHelperCocoa() {
+  NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
+
+  MOZ_LOG(sScreenLog, LogLevel::Debug, ("ScreenHelperCocoa created"));
+
+  mDelegate = [[ScreenHelperDelegate alloc] initWithScreenHelper:this];
+
+  RefreshScreens();
+
+  NS_OBJC_END_TRY_IGNORE_BLOCK;
+}
+
+ScreenHelperCocoa::~ScreenHelperCocoa() {
+  NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
+
+  [mDelegate release];
+
+  NS_OBJC_END_TRY_IGNORE_BLOCK;
+}
+
+static already_AddRefed<Screen> MakeScreen(NSScreen* aScreen) {
+  NS_OBJC_BEGIN_TRY_BLOCK_RETURN;
+
+  DesktopToLayoutDeviceScale contentsScaleFactor(nsCocoaUtils::GetBackingScaleFactor(aScreen));
+  CSSToLayoutDeviceScale defaultCssScaleFactor(contentsScaleFactor.scale);
+  NSRect frame = [aScreen frame];
+  LayoutDeviceIntRect rect =
+      nsCocoaUtils::CocoaRectToGeckoRectDevPix(frame, contentsScaleFactor.scale);
+  frame = [aScreen visibleFrame];
+  LayoutDeviceIntRect availRect =
+      nsCocoaUtils::CocoaRectToGeckoRectDevPix(frame, contentsScaleFactor.scale);
+
+  // aScreen may be capable of displaying multiple pixel depths, for example by
+  // transitioning to an HDR-capable depth when required by a window displayed on
+  // the screen. We want to note the maximum capabilities of the screen, so we use
+  // the largest depth it offers.
+  uint32_t pixelDepth = 0;
+  const NSWindowDepth* depths = [aScreen supportedWindowDepths];
+  for (size_t d = 0; NSWindowDepth depth = depths[d]; d++) {
+    uint32_t bpp = NSBitsPerPixelFromDepth(depth);
+    if (bpp > pixelDepth) {
+      pixelDepth = bpp;
+    }
+  }
+
+  // But it confuses content if we return too-high a value here. Cap depth with
+  // a value that matches what Chrome returns for high bpp screens.
+  static const uint32_t MAX_REPORTED_PIXEL_DEPTH = 30;
+  if (pixelDepth > MAX_REPORTED_PIXEL_DEPTH) {
+    pixelDepth = MAX_REPORTED_PIXEL_DEPTH;
+  }
+
+  float dpi = 96.0f;
+  CGDirectDisplayID displayID =
+      [[[aScreen deviceDescription] objectForKey:@"NSScreenNumber"] intValue];
+  CGFloat heightMM = ::CGDisplayScreenSize(displayID).height;
+  if (heightMM > 0) {
+    dpi = rect.height / (heightMM / MM_PER_INCH_FLOAT);
+  }
+  MOZ_LOG(sScreenLog, LogLevel::Debug,
+          ("New screen [%d %d %d %d (%d %d %d %d) %d %f %f %f]", rect.x, rect.y, rect.width,
+           rect.height, availRect.x, availRect.y, availRect.width, availRect.height, pixelDepth,
+           contentsScaleFactor.scale, defaultCssScaleFactor.scale, dpi));
+
+  // Getting the refresh rate is a little hard on OS X. We could use
+  // CVDisplayLinkGetNominalOutputVideoRefreshPeriod, but that's a little
+  // involved. Ideally we could query it from vsync. For now, we leave it out.
+  RefPtr<Screen> screen =
+      new Screen(rect, availRect, pixelDepth, pixelDepth, 0, contentsScaleFactor,
+                 defaultCssScaleFactor, dpi, Screen::IsPseudoDisplay::No);
+  return screen.forget();
+
+  NS_OBJC_END_TRY_BLOCK_RETURN(nullptr);
+}
+
+void ScreenHelperCocoa::RefreshScreens() {
+  NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
+
+  MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refreshing screens"));
+
+  AutoTArray<RefPtr<Screen>, 4> screens;
+
+  for (NSScreen* screen in [NSScreen screens]) {
+    NSDictionary* desc = [screen deviceDescription];
+    if ([desc objectForKey:NSDeviceIsScreen] == nil) {
+      continue;
+    }
+    screens.AppendElement(MakeScreen(screen));
+  }
+
+  ScreenManager::Refresh(std::move(screens));
+
+  NS_OBJC_END_TRY_IGNORE_BLOCK;
+}
+
+NSScreen* ScreenHelperCocoa::CocoaScreenForScreen(nsIScreen* aScreen) {
+  NS_OBJC_BEGIN_TRY_BLOCK_RETURN;
+
+  for (NSScreen* screen in [NSScreen screens]) {
+    NSDictionary* desc = [screen deviceDescription];
+    if ([desc objectForKey:NSDeviceIsScreen] == nil) {
+      continue;
+    }
+    LayoutDeviceIntRect rect;
+    double scale;
+    aScreen->GetRect(&rect.x, &rect.y, &rect.width, &rect.height);
+    aScreen->GetContentsScaleFactor(&scale);
+    NSRect frame = [screen frame];
+    LayoutDeviceIntRect frameRect = nsCocoaUtils::CocoaRectToGeckoRectDevPix(frame, scale);
+    if (rect == frameRect) {
+      return screen;
+    }
+  }
+  return [NSScreen mainScreen];
+
+  NS_OBJC_END_TRY_BLOCK_RETURN(nil);
+}
+
+}  // namespace widget
+}  // namespace mozilla