Bug 1494713 - Add `nsWindow::From`. r=jchen

Differential Revision: https://phabricator.services.mozilla.com/D11289

--HG--
extra : moz-landing-system : lando

accessible/android/SessionAccessibility.cpp

@@ -145,11 +145,9 @@ SessionAccessibility::GetInstanceFor(Accessible* aAccessible)
   nsCOMPtr<nsIWidget> rootWidget;
   vm->GetRootWidget(getter_AddRefs(rootWidget));
   // `rootWidget` can be one of several types. Here we make sure it is an
-  // android nsWindow that implemented NS_NATIVE_WIDGET to return itself.
-  if (rootWidget &&
-      rootWidget->WindowType() == nsWindowType::eWindowType_toplevel &&
-      rootWidget->GetNativeData(NS_NATIVE_WIDGET) == rootWidget) {
-    return static_cast<nsWindow*>(rootWidget.get())->GetSessionAccessibility();
+  // android nsWindow.
+  if (RefPtr<nsWindow> window = nsWindow::From(rootWidget)) {
+    return window->GetSessionAccessibility();
   }
 
   return nullptr;

widget/android/AndroidBridge.cpp

@@ -818,24 +818,10 @@ __attribute__ ((visibility("default")))
 jobject JNICALL
 Java_org_mozilla_gecko_GeckoAppShell_allocateDirectBuffer(JNIEnv *env, jclass, jlong size);
 
-static RefPtr<nsWindow>
-GetWidget(mozIDOMWindowProxy* aWindow)
-{
-    MOZ_ASSERT(aWindow);
-
-    nsCOMPtr<nsPIDOMWindowOuter> domWindow = nsPIDOMWindowOuter::From(aWindow);
-    nsCOMPtr<nsIWidget> widget =
-            widget::WidgetUtils::DOMWindowToWidget(domWindow);
-    MOZ_ASSERT(widget);
-
-    return RefPtr<nsWindow>(static_cast<nsWindow*>(widget.get()));
-}
-
 void
 AndroidBridge::ContentDocumentChanged(mozIDOMWindowProxy* aWindow)
 {
-    auto widget = GetWidget(aWindow);
-    if (widget) {
+    if (RefPtr<nsWindow> widget = nsWindow::From(nsPIDOMWindowOuter::From(aWindow))) {
         widget->SetContentDocumentDisplayed(false);
     }
 }
@@ -843,8 +829,7 @@ AndroidBridge::ContentDocumentChanged(mozIDOMWindowProxy* aWindow)
 bool
 AndroidBridge::IsContentDocumentDisplayed(mozIDOMWindowProxy* aWindow)
 {
-    auto widget = GetWidget(aWindow);
-    if (widget) {
+    if (RefPtr<nsWindow> widget = nsWindow::From(nsPIDOMWindowOuter::From(aWindow))) {
         return widget->IsContentDocumentDisplayed();
     }
     return false;

widget/android/GeckoProcessManager.h

@@ -47,10 +47,10 @@ public:
                       int64_t aContentId, int64_t aTabId)
     {
         nsCOMPtr<nsIWidget> widget = GetWidget(aContentId, aTabId);
-        if (widget && widget->GetNativeData(NS_NATIVE_WIDGET) == widget) {
+        if (RefPtr<nsWindow> window = nsWindow::From(widget)) {
             java::GeckoProcessManager::SetEditableChildParent(
                     aEditableChild,
-                    static_cast<nsWindow*>(widget.get())->GetEditableParent());
+                    window->GetEditableParent());
         }
     }
 };

widget/android/nsAppShell.cpp

@@ -618,18 +618,7 @@ nsAppShell::Observe(nsISupports* aSubject,
         // for this particular GeckoView.
         nsCOMPtr<nsIDocument> doc = do_QueryInterface(aSubject);
         MOZ_ASSERT(doc);
-        nsCOMPtr<nsIWidget> widget =
-            widget::WidgetUtils::DOMWindowToWidget(doc->GetWindow());
-
-        // `widget` may be one of several different types in the parent
-        // process, including the Android nsWindow, PuppetWidget, etc. To
-        // ensure that we only accept the Android nsWindow, we check that the
-        // widget is a top-level window and that its NS_NATIVE_WIDGET value is
-        // non-null, which is not the case for non-native widgets like
-        // PuppetWidget.
-        if (widget &&
-            widget->WindowType() == nsWindowType::eWindowType_toplevel &&
-            widget->GetNativeData(NS_NATIVE_WIDGET) == widget) {
+        if (const RefPtr<nsWindow> window = nsWindow::From(doc->GetWindow())) {
             if (jni::IsAvailable()) {
                 // When our first window has loaded, assume any JS
                 // initialization has run and set Gecko to ready.
@@ -637,7 +626,6 @@ nsAppShell::Observe(nsISupports* aSubject,
                         java::GeckoThread::State::PROFILE_READY(),
                         java::GeckoThread::State::RUNNING());
             }
-            const auto window = static_cast<nsWindow*>(widget.get());
             window->OnGeckoViewReady();
         }
     } else if (!strcmp(aTopic, "quit-application")) {

widget/android/nsWindow.cpp

@@ -1263,10 +1263,8 @@ nsWindow::GeckoViewSupport::Open(const jni::Class::LocalRef& aCls,
 
     nsCOMPtr<nsPIDOMWindowOuter> pdomWindow =
             nsPIDOMWindowOuter::From(domWindow);
-    nsCOMPtr<nsIWidget> widget = WidgetUtils::DOMWindowToWidget(pdomWindow);
-    MOZ_ASSERT(widget);
-
-    const auto window = static_cast<nsWindow*>(widget.get());
+    const RefPtr<nsWindow> window = nsWindow::From(pdomWindow);
+    MOZ_ASSERT(window);
     window->SetScreenId(aScreenId);
 
     // Attach a new GeckoView support object to the new window.
@@ -1404,6 +1402,32 @@ nsWindow::InitNatives()
     a11y::SessionAccessibility::Init();
 }
 
+/* static */ already_AddRefed<nsWindow>
+nsWindow::From(nsPIDOMWindowOuter* aDOMWindow)
+{
+    nsCOMPtr<nsIWidget> widget = WidgetUtils::DOMWindowToWidget(aDOMWindow);
+    return From(widget);
+}
+
+/* static */ already_AddRefed<nsWindow>
+nsWindow::From(nsIWidget* aWidget)
+{
+    // `widget` may be one of several different types in the parent
+    // process, including the Android nsWindow, PuppetWidget, etc. To
+    // ensure that the cast to the Android nsWindow is valid, we check that the
+    // widget is a top-level window and that its NS_NATIVE_WIDGET value is
+    // non-null, which is not the case for non-native widgets like
+    // PuppetWidget.
+    if (aWidget &&
+        aWidget->WindowType() == nsWindowType::eWindowType_toplevel &&
+        aWidget->GetNativeData(NS_NATIVE_WIDGET) == aWidget) {
+
+        RefPtr<nsWindow> window = static_cast<nsWindow*>(aWidget);
+        return window.forget();
+    }
+    return nullptr;
+}
+
 nsWindow*
 nsWindow::TopWindow()
 {

widget/android/nsWindow.h

@@ -207,6 +207,9 @@ private:
     mozilla::Atomic<bool, mozilla::ReleaseAcquire> mContentDocumentDisplayed;
 
 public:
+    static already_AddRefed<nsWindow> From(nsPIDOMWindowOuter* aDOMWindow);
+    static already_AddRefed<nsWindow> From(nsIWidget* aWidget);
+
     static nsWindow* TopWindow();
 
     static mozilla::Modifiers GetModifiers(int32_t aMetaState);