Bug 1644212 - reintroduce an attribute to limit which windows allow full screen, r=xidorn,haik

Differential Revision: https://phabricator.services.mozilla.com/D79109

browser/base/content/browser.xhtml

@@ -55,6 +55,7 @@
         tabsintitlebar="true"
         windowtype="navigator:browser"
         macanimationtype="document"
+        macnativefullscreen="true"
         screenX="4" screenY="4"
         sizemode="normal"
         retargetdocumentfocus="urlbar-input"

widget/cocoa/nsCocoaWindow.h

@@ -304,6 +304,7 @@ class nsCocoaWindow final : public nsBaseWidget, public nsPIWidgetCocoa {
   virtual void SetWindowTransform(const mozilla::gfx::Matrix& aTransform) override;
   virtual void SetWindowMouseTransparent(bool aIsTransparent) override;
   virtual void SetShowsToolbarButton(bool aShow) override;
+  virtual void SetSupportsNativeFullscreen(bool aShow) override;
   virtual void SetWindowAnimationType(WindowAnimationType aType) override;
   virtual void SetDrawsTitle(bool aDrawTitle) override;
   virtual void SetUseBrightTitlebarForeground(bool aBrightForeground) override;

widget/cocoa/nsCocoaWindow.mm

@@ -509,9 +509,6 @@ nsresult nsCocoaWindow::CreateNativeWindow(const NSRect& aRect, nsBorderStyle aB
     [mWindow setLevel:NSFloatingWindowLevel];
     newBehavior |= NSWindowCollectionBehaviorCanJoinAllSpaces;
   }
-  if ((features & NSResizableWindowMask)) {
-    newBehavior |= NSWindowCollectionBehaviorFullScreenPrimary;
-  }
   [mWindow setCollectionBehavior:newBehavior];
 
   [mWindow setContentMinSize:NSMakeSize(60, 60)];
@@ -1612,6 +1609,14 @@ void nsCocoaWindow::UpdateFullscreenState(bool aFullScreen, bool aNativeMode) {
 
 inline bool nsCocoaWindow::ShouldToggleNativeFullscreen(bool aFullScreen,
                                                         bool aUseSystemTransition) {
+  // First check if this window supports entering native fullscreen.
+  // This is set based on the macnativefullscreen attribute on the window's
+  // document element.
+  NSWindowCollectionBehavior colBehavior = [mWindow collectionBehavior];
+  if (!(colBehavior & NSWindowCollectionBehaviorFullScreenPrimary)) {
+    return false;
+  }
+
   if (mInNativeFullScreenMode) {
     // If we are using native fullscreen, go ahead to exit it.
     return true;
@@ -2329,6 +2334,28 @@ void nsCocoaWindow::SetShowsToolbarButton(bool aShow) {
   NS_OBJC_END_TRY_ABORT_BLOCK;
 }
 
+void nsCocoaWindow::SetSupportsNativeFullscreen(bool aSupportsNativeFullscreen) {
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
+
+  if (mWindow) {
+    // This determines whether we tell cocoa that the window supports native
+    // full screen. If we do so, and another window is in native full screen,
+    // this window will also appear in native full screen. We generally only
+    // want to do this for primary application windows. We'll set the
+    // relevant macnativefullscreen attribute on those, which will lead to us
+    // being called with aSupportsNativeFullscreen set to `true` here.
+    NSWindowCollectionBehavior newBehavior = [mWindow collectionBehavior];
+    if (aSupportsNativeFullscreen) {
+      newBehavior |= NSWindowCollectionBehaviorFullScreenPrimary;
+    } else {
+      newBehavior &= ~NSWindowCollectionBehaviorFullScreenPrimary;
+    }
+    [mWindow setCollectionBehavior:newBehavior];
+  }
+
+  NS_OBJC_END_TRY_ABORT_BLOCK;
+}
+
 void nsCocoaWindow::SetWindowAnimationType(nsIWidget::WindowAnimationType aType) {
   mAnimationType = aType;
 }

widget/nsBaseWidget.h

@@ -183,6 +183,8 @@ class nsBaseWidget : public nsIWidget, public nsSupportsWeakReference {
   virtual void SetWindowShadowStyle(
       mozilla::StyleWindowShadow aStyle) override {}
   virtual void SetShowsToolbarButton(bool aShow) override {}
+  virtual void SetSupportsNativeFullscreen(
+      bool aSupportsNativeFullscreen) override {}
   virtual void SetWindowAnimationType(WindowAnimationType aType) override {}
   virtual void HideWindowChrome(bool aShouldHide) override {}
   virtual bool PrepareForFullscreenTransition(nsISupports** aData) override {

widget/nsIWidget.h

@@ -1141,6 +1141,17 @@ class nsIWidget : public nsISupports {
    */
   virtual void SetShowsToolbarButton(bool aShow) = 0;
 
+  /*
+   * On macOS, this method determines whether we tell cocoa that the window
+   * supports native full screen. If we do so, and another window is in
+   * native full screen, this window will also appear in native full screen.
+   *
+   * We generally only want to do this for primary application windows.
+   *
+   * Ignored on child widgets and on non-Mac platforms.
+   */
+  virtual void SetSupportsNativeFullscreen(bool aSupportsNativeFullscreen) = 0;
+
   enum WindowAnimationType {
     eGenericWindowAnimation,
     eDocumentWindowAnimation

xpfe/appshell/AppWindow.cpp

@@ -1668,6 +1668,12 @@ void AppWindow::SyncAttributesToWidget() {
 
   NS_ENSURE_TRUE_VOID(mWindow);
 
+  // "macnativefullscreen" attribute
+  windowElement->GetAttribute(NS_LITERAL_STRING("macnativefullscreen"), attr);
+  mWindow->SetSupportsNativeFullscreen(attr.LowerCaseEqualsLiteral("true"));
+
+  NS_ENSURE_TRUE_VOID(mWindow);
+
   // "macanimationtype" attribute
   windowElement->GetAttribute(NS_LITERAL_STRING("macanimationtype"), attr);
   if (attr.EqualsLiteral("document")) {