Merge "Support for OnBackAnimationCallback: added for 3-button navigation / hardware keys" into udc-dev

core/java/android/view/ViewRootImpl.java

@@ -200,8 +200,10 @@ import android.view.contentcapture.MainContentCaptureSession;
 import android.view.inputmethod.ImeTracker;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.Scroller;
+import android.window.BackEvent;
 import android.window.ClientWindowFrames;
 import android.window.CompatOnBackInvokedCallback;
+import android.window.OnBackAnimationCallback;
 import android.window.OnBackInvokedCallback;
 import android.window.OnBackInvokedDispatcher;
 import android.window.ScreenCapture;
@@ -6526,6 +6528,7 @@ public final class ViewRootImpl implements ViewParent,
      */
     final class NativePreImeInputStage extends AsyncInputStage
             implements InputQueue.FinishedInputEventCallback {
+
         public NativePreImeInputStage(InputStage next, String traceCounter) {
             super(next, traceCounter);
         }
@@ -6533,32 +6536,62 @@ public final class ViewRootImpl implements ViewParent,
         @Override
         protected int onProcess(QueuedInputEvent q) {
             if (q.mEvent instanceof KeyEvent) {
-                final KeyEvent event = (KeyEvent) q.mEvent;
+                final KeyEvent keyEvent = (KeyEvent) q.mEvent;
 
                 // If the new back dispatch is enabled, intercept KEYCODE_BACK before it reaches the
                 // view tree or IME, and invoke the appropriate {@link OnBackInvokedCallback}.
-                if (isBack(event)
+                if (isBack(keyEvent)
                         && mContext != null
                         && mOnBackInvokedDispatcher.isOnBackInvokedCallbackEnabled()) {
-                    OnBackInvokedCallback topCallback =
+                    return doOnBackKeyEvent(keyEvent);
-                            getOnBackInvokedDispatcher().getTopCallback();
+                }
-                    if (event.getAction() == KeyEvent.ACTION_UP) {
+
-                        if (topCallback != null) {
+                if (mInputQueue != null) {
+                    mInputQueue.sendInputEvent(q.mEvent, q, true, this);
+                    return DEFER;
+                }
+            }
+            return FORWARD;
+        }
+
+        private int doOnBackKeyEvent(KeyEvent keyEvent) {
+            OnBackInvokedCallback topCallback = getOnBackInvokedDispatcher().getTopCallback();
+            if (topCallback instanceof OnBackAnimationCallback) {
+                final OnBackAnimationCallback animationCallback =
+                        (OnBackAnimationCallback) topCallback;
+                switch (keyEvent.getAction()) {
+                    case KeyEvent.ACTION_DOWN:
+                        // ACTION_DOWN is emitted twice: once when the user presses the button,
+                        // and again a few milliseconds later.
+                        // Based on the result of `keyEvent.getRepeatCount()` we have:
+                        // - 0 means the button was pressed.
+                        // - 1 means the button continues to be pressed (long press).
+                        if (keyEvent.getRepeatCount() == 0) {
+                            animationCallback.onBackStarted(
+                                    new BackEvent(0, 0, 0f, BackEvent.EDGE_LEFT));
+                        }
+                        break;
+                    case KeyEvent.ACTION_UP:
+                        if (keyEvent.isCanceled()) {
+                            animationCallback.onBackCancelled();
+                        } else {
                             topCallback.onBackInvoked();
                             return FINISH_HANDLED;
                         }
+                        break;
+                }
+            } else if (topCallback != null) {
+                if (keyEvent.getAction() == KeyEvent.ACTION_UP) {
+                    if (!keyEvent.isCanceled()) {
+                        topCallback.onBackInvoked();
+                        return FINISH_HANDLED;
                     } else {
-                        // Drop other actions such as {@link KeyEvent.ACTION_DOWN}.
+                        Log.d(mTag, "Skip onBackInvoked(), reason: keyEvent.isCanceled=true");
-                        return FINISH_NOT_HANDLED;
                     }
                 }
             }
 
-            if (mInputQueue != null && q.mEvent instanceof KeyEvent) {
+            return FINISH_NOT_HANDLED;
-                mInputQueue.sendInputEvent(q.mEvent, q, true, this);
-                return DEFER;
-            }
-            return FORWARD;
         }
 
         @Override