Bug 1499429 - 2. Set default GeckoEditableChild from native code; r=esawin

Set the default GeckoEditableChild from C++, so we can keep the same
GeckoEditableChild instance across session transfers, and only have a
different GeckoEditableParent instance after each transfer.

Differential Revision: https://phabricator.services.mozilla.com/D8995

mobile/android/geckoview/src/main/aidl/org/mozilla/gecko/IGeckoEditableParent.aidl

@@ -11,6 +11,9 @@ import org.mozilla.gecko.IGeckoEditableChild;
 
 // Interface for GeckoEditable calls from child to parent
 interface IGeckoEditableParent {
+    // Set the default child to forward events to, when there is no focused child.
+    void setDefaultChild(IGeckoEditableChild child);
+
     // Notify an IME event of a type defined in GeckoEditableListener.
     void notifyIME(IGeckoEditableChild child, int type);
 

mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoEditableChild.java

@@ -72,11 +72,14 @@ public final class GeckoEditableChild extends JNIObject implements IGeckoEditabl
 
     private final IGeckoEditableParent mEditableParent;
     private final IGeckoEditableChild mEditableChild;
+    private final boolean mIsDefault;
 
     private int mCurrentTextLength; // Used by Gecko thread
 
     @WrapForJNI(calledFrom = "gecko")
-    public GeckoEditableChild(final IGeckoEditableParent editableParent) {
+    private GeckoEditableChild(final IGeckoEditableParent editableParent,
+                               final boolean isDefault) {
+        mIsDefault = isDefault;
         mEditableParent = editableParent;
 
         final IBinder binder = editableParent.asBinder();
@@ -87,6 +90,15 @@ public final class GeckoEditableChild extends JNIObject implements IGeckoEditabl
             // IGeckoEditableParent is remote; i.e. we're in a content process.
             mEditableChild = new RemoteChild();
         }
+
+        if (mIsDefault) {
+            // Tell the parent we're the default child.
+            try {
+                editableParent.setDefaultChild(mEditableChild);
+            } catch (final RemoteException e) {
+                Log.e(LOGTAG, "Failed to set default child", e);
+            }
+        }
     }
 
     @WrapForJNI(dispatchTo = "proxy") @Override // IGeckoEditableChild

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoEditable.java

@@ -658,10 +658,10 @@ import android.view.inputmethod.EditorInfo;
         mIcRunHandler = mIcPostHandler = ThreadUtils.getUiHandler();
     }
 
-    public void setDefaultEditableChild(final IGeckoEditableChild child) {
+    @Override // IGeckoEditableParent
+    public void setDefaultChild(final IGeckoEditableChild child) {
         if (DEBUG) {
-            // Called by SessionTextInput.
-            ThreadUtils.assertOnUiThread();
+            // On Gecko or binder thread.
             Log.d(LOGTAG, "setDefaultEditableChild " + child);
         }
         mDefaultChild = child;

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java

@@ -730,8 +730,7 @@ public class GeckoSession extends LayerSession
                                            GeckoBundle initData);
 
         @WrapForJNI(dispatchTo = "proxy")
-        public native void attachEditable(IGeckoEditableParent parent,
-                                          GeckoEditableChild child);
+        public native void attachEditable(IGeckoEditableParent parent);
 
         @WrapForJNI(dispatchTo = "proxy")
         public native void attachAccessibility(SessionAccessibility.NativeProvider sessionAccessibility);

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/SessionTextInput.java

@@ -275,7 +275,6 @@ public final class SessionTextInput {
     private final GeckoSession mSession;
     private final NativeQueue mQueue;
     private final GeckoEditable mEditable;
-    private final GeckoEditableChild mEditableChild;
     private InputConnectionClient mInputConnection;
     private GeckoSession.TextInputDelegate mDelegate;
     // Auto-fill nodes.
@@ -289,8 +288,6 @@ public final class SessionTextInput {
         mSession = session;
         mQueue = queue;
         mEditable = new GeckoEditable(session);
-        mEditableChild = new GeckoEditableChild(mEditable);
-        mEditable.setDefaultEditableChild(mEditableChild);
 
         session.getEventDispatcher().registerUiThreadListener(
                 new BundleEventListener() {
@@ -314,11 +311,10 @@ public final class SessionTextInput {
 
     /* package */ void onWindowChanged(final GeckoSession.Window window) {
         if (mQueue.isReady()) {
-            window.attachEditable(mEditable, mEditableChild);
+            window.attachEditable(mEditable);
         } else {
             mQueue.queueUntilReady(window, "attachEditable",
-                                   IGeckoEditableParent.class, mEditable,
-                                   GeckoEditableChild.class, mEditableChild);
+                                   IGeckoEditableParent.class, mEditable);
         }
     }
 

widget/android/nsAppShell.cpp

@@ -702,7 +702,8 @@ nsAppShell::Observe(nsISupports* aSubject,
                 contentId, tabId);
         NS_ENSURE_TRUE(editableParent, NS_OK);
 
-        auto editableChild = java::GeckoEditableChild::New(editableParent);
+        auto editableChild = java::GeckoEditableChild::New(editableParent,
+                                                           /* default */ false);
         NS_ENSURE_TRUE(editableChild, NS_OK);
 
         RefPtr<widget::GeckoEditableSupport> editableSupport =

widget/android/nsWindow.cpp

@@ -361,8 +361,7 @@ public:
                   jni::Object::Param aInitData);
 
     void AttachEditable(const GeckoSession::Window::LocalRef& inst,
-                        jni::Object::Param aEditableParent,
-                        jni::Object::Param aEditableChild);
+                        jni::Object::Param aEditableParent);
 
     void AttachAccessibility(const GeckoSession::Window::LocalRef& inst,
                              jni::Object::Param aSessionAccessibility);
@@ -1362,11 +1361,10 @@ nsWindow::GeckoViewSupport::Transfer(const GeckoSession::Window::LocalRef& inst,
 
 void
 nsWindow::GeckoViewSupport::AttachEditable(const GeckoSession::Window::LocalRef& inst,
-                                           jni::Object::Param aEditableParent,
-                                           jni::Object::Param aEditableChild)
+                                           jni::Object::Param aEditableParent)
 {
-    java::GeckoEditableChild::LocalRef editableChild(inst.Env());
-    editableChild = java::GeckoEditableChild::Ref::From(aEditableChild);
+    auto editableChild = java::GeckoEditableChild::New(aEditableParent,
+                                                       /* default */ true);
 
     if (window.mEditableSupport) {
         window.mEditableSupport.Detach(