Have TestBack manage accessibility focus.

Test: Build and run TestBack.
Change-Id: I98babde32a483f0ba86c7339bf03b0be71a35644

3 files changed, 196 insertions, 42 deletions

diff --git a/TestBack/src/foo/bar/testback/AccessibilityFocusManager.java b/TestBack/src/foo/bar/testback/AccessibilityFocusManager.java
new file mode 100644
index 0000000..c6b91ae
--- /dev/null
+++ b/TestBack/src/foo/bar/testback/AccessibilityFocusManager.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package foo.bar.testback;
+
+import static foo.bar.testback.AccessibilityNodeInfoUtils.findParent;
+
+import android.text.TextUtils;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * Helper class to manage accessibility focus
+ */
+public class AccessibilityFocusManager {
+    private static final AccessibilityAction[] IGNORED_ACTIONS_FOR_A11Y_FOCUS = {
+            AccessibilityAction.ACTION_ACCESSIBILITY_FOCUS,
+            AccessibilityAction.ACTION_CLEAR_ACCESSIBILITY_FOCUS,
+            AccessibilityAction.ACTION_SELECT,
+            AccessibilityAction.ACTION_CLEAR_SELECTION,
+            AccessibilityAction.ACTION_SHOW_ON_SCREEN
+    };
+
+    public static final boolean canTakeAccessibilityFocus(AccessibilityNodeInfo nodeInfo) {
+        if (nodeInfo.isFocusable() || nodeInfo.isScreenReaderFocusable()) {
+            return true;
+        }
+
+        List<AccessibilityAction> actions = new ArrayList<>(nodeInfo.getActionList());
+        actions.removeAll(Arrays.asList(IGNORED_ACTIONS_FOR_A11Y_FOCUS));
+
+        // Nodes with relevant actions are always focusable
+        if (!actions.isEmpty()) {
+            return true;
+        }
+
+        // If a parent is specifically marked focusable, then this node should not be.
+        if (findParent(nodeInfo,
+                (parent) -> parent.isFocusable() || parent.isScreenReaderFocusable()) != null) {
+            return false;
+        }
+
+        return !TextUtils.isEmpty(nodeInfo.getText())
+                || !TextUtils.isEmpty(nodeInfo.getContentDescription());
+    };
+}
diff --git a/TestBack/src/foo/bar/testback/AccessibilityNodeInfoUtils.java b/TestBack/src/foo/bar/testback/AccessibilityNodeInfoUtils.java
new file mode 100644
index 0000000..f4e9398
--- /dev/null
+++ b/TestBack/src/foo/bar/testback/AccessibilityNodeInfoUtils.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package foo.bar.testback;
+
+import android.view.accessibility.AccessibilityNodeInfo;
+
+import java.util.function.Predicate;
+
+/**
+ * Utility class for working with AccessibilityNodeInfo
+ */
+public class AccessibilityNodeInfoUtils {
+    public static AccessibilityNodeInfo findParent(
+            AccessibilityNodeInfo start, Predicate<AccessibilityNodeInfo> condition) {
+        AccessibilityNodeInfo parent = start.getParent();
+        if ((parent == null) || (condition.test(parent))) {
+            return parent;
+        }
+
+        return findParent(parent, condition);
+    }
+
+    public static AccessibilityNodeInfo findChildDfs(
+            AccessibilityNodeInfo start, Predicate<AccessibilityNodeInfo> condition) {
+        int numChildren = start.getChildCount();
+        for (int i = 0; i < numChildren; i++) {
+            AccessibilityNodeInfo child = start.getChild(i);
+            if (child != null) {
+                if (condition.test(child)) {
+                    return child;
+                }
+                AccessibilityNodeInfo childResult = findChildDfs(child, condition);
+                if (childResult != null) {
+                    return childResult;
+                }
+            }
+        }
+        return null;
+    }
+}
diff --git a/TestBack/src/foo/bar/testback/TestBackService.java b/TestBack/src/foo/bar/testback/TestBackService.java
index 53db125..bd5329b 100644
--- a/TestBack/src/foo/bar/testback/TestBackService.java
+++ b/TestBack/src/foo/bar/testback/TestBackService.java
@@ -1,8 +1,30 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package foo.bar.testback;
 
+import static foo.bar.testback.AccessibilityNodeInfoUtils.findChildDfs;
+import static foo.bar.testback.AccessibilityNodeInfoUtils.findParent;
+
+import static foo.bar.testback.AccessibilityFocusManager.CAN_TAKE_A11Y_FOCUS;
+
 import android.accessibilityservice.AccessibilityService;
 import android.accessibilityservice.AccessibilityServiceInfo;
 import android.content.Context;
+import android.graphics.Rect;
 import android.util.ArraySet;
 import android.util.Log;
 import android.view.WindowManager;
@@ -13,6 +35,7 @@ import android.widget.Button;
 
 import java.util.List;
 import java.util.Set;
+import java.util.function.Predicate;
 
 public class TestBackService extends AccessibilityService {
 
@@ -20,6 +43,11 @@ public class TestBackService extends AccessibilityService {
 
     private Button mButton;
 
+    int mRowIndexOfA11yFocus = -1;
+    int mColIndexOfA11yFocus = -1;
+    AccessibilityNodeInfo mCollectionWithAccessibiltyFocus;
+    AccessibilityNodeInfo mCurrentA11yFocus;
+
     @Override
     public void onCreate() {
         super.onCreate();
@@ -29,53 +57,61 @@ public class TestBackService extends AccessibilityService {
 
     @Override
     public void onAccessibilityEvent(AccessibilityEvent event) {
-//        if (event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED) {
-//            Log.i(LOG_TAG, event.getText().toString());
-//            //dumpWindows();
-//        }
-        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_HOVER_ENTER) {
-//            Log.i(LOG_TAG, "Click event.isChecked()=" + event.isChecked()
-//                    + ((event.getSource() != null) ? " node.isChecked()="
-//                    + event.getSource().isChecked() : " node=null"));
-
-            AccessibilityNodeInfo source = event.getSource();
-            dumpWindow(source);
-//            AccessibilityNodeInfo node = event.getSource();
-//            if (node != null) {
-//                node.refresh();
-//                Log.i(LOG_TAG, "Clicked: " + node.getClassName() + " clicked:" + node.isChecked());
-//            }
+        int eventType = event.getEventType();
+        AccessibilityNodeInfo source = event.getSource();
+        if (eventType == AccessibilityEvent.TYPE_VIEW_HOVER_ENTER) {
+            if (source != null) {
+                AccessibilityNodeInfo focusNode =
+                        (CAN_TAKE_A11Y_FOCUS.test(source)) ? source : findParent(
+                                source, AccessibilityFocusManager::canTakeAccessibilityFocus);
+                if (focusNode != null) {
+                    focusNode.performAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
+                }
+            }
+            return;
         }
-    }
-
-    @Override
-    protected boolean onGesture(int gestureId) {
-        switch (gestureId) {
-            case AccessibilityService.GESTURE_SWIPE_DOWN: {
-                showAccessibilityOverlay();
-            } break;
-            case AccessibilityService.GESTURE_SWIPE_UP: {
-                hideAccessibilityOverlay();
-            } break;
+        if (eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED) {
+            mCurrentA11yFocus = source;
+            AccessibilityNodeInfo.CollectionItemInfo itemInfo = source.getCollectionItemInfo();
+            if (itemInfo == null) {
+                mRowIndexOfA11yFocus = -1;
+                mColIndexOfA11yFocus = -1;
+                mCollectionWithAccessibiltyFocus = null;
+            } else {
+                mRowIndexOfA11yFocus = itemInfo.getRowIndex();
+                mColIndexOfA11yFocus = itemInfo.getColumnIndex();
+                mCollectionWithAccessibiltyFocus = findParent(source,
+                        (nodeInfo) -> nodeInfo.getCollectionInfo() != null);
+            }
+            Rect bounds = new Rect();
+            source.getBoundsInScreen(bounds);
         }
-        return super.onGesture(gestureId);
-    }
 
-    private void showAccessibilityOverlay() {
-        WindowManager.LayoutParams params = new WindowManager.LayoutParams();
-        params.flags = WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
-                | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
-                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
-                | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
-        params.type = WindowManager.LayoutParams.TYPE_ACCESSIBILITY_OVERLAY;
+        if (eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED) {
+            mCurrentA11yFocus = null;
+            return;
+        }
 
-        WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
-        windowManager.addView(mButton, params);
-    }
+        if (eventType == AccessibilityEvent.TYPE_WINDOWS_CHANGED) {
+            mRowIndexOfA11yFocus = -1;
+            mColIndexOfA11yFocus = -1;
+            mCollectionWithAccessibiltyFocus = null;
+        }
 
-    private void hideAccessibilityOverlay() {
-        WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
-        windowManager.removeView(mButton);
+        if ((mCurrentA11yFocus == null) && (mCollectionWithAccessibiltyFocus != null)) {
+            // Look for a node to re-focus
+            AccessibilityNodeInfo focusRestoreTarget = findChildDfs(
+                    mCollectionWithAccessibiltyFocus, (nodeInfo) -> {
+                        AccessibilityNodeInfo.CollectionItemInfo collectionItemInfo =
+                                nodeInfo.getCollectionItemInfo();
+                        return (collectionItemInfo != null)
+                                && (collectionItemInfo.getRowIndex() == mRowIndexOfA11yFocus)
+                                && (collectionItemInfo.getColumnIndex() == mColIndexOfA11yFocus);
+                    });
+            if (focusRestoreTarget != null) {
+                focusRestoreTarget.performAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
+            }
+        }
     }
 
     private void dumpWindows() {