Adding keyboard handling to QsbHostView similar to a normal appwidget view

Bug: 116842846
Change-Id: Ibab2dc1793561998f81710301d9ce0ca3d77e7b4

src/com/android/launcher3/widget/NavigableAppWidgetHostView.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2018 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 com.android.launcher3.widget;
+
+import android.appwidget.AppWidgetHostView;
+import android.content.Context;
+import android.graphics.Rect;
+import android.view.KeyEvent;
+import android.view.View;
+import android.view.ViewDebug;
+import android.view.ViewGroup;
+
+import java.util.ArrayList;
+
+/**
+ * Extension of AppWidgetHostView with support for controlled keyboard navigation.
+ */
+public abstract class NavigableAppWidgetHostView extends AppWidgetHostView {
+
+    @ViewDebug.ExportedProperty(category = "launcher")
+    private boolean mChildrenFocused;
+
+    public NavigableAppWidgetHostView(Context context) {
+        super(context);
+    }
+
+    @Override
+    public int getDescendantFocusability() {
+        return mChildrenFocused ? ViewGroup.FOCUS_BEFORE_DESCENDANTS
+                : ViewGroup.FOCUS_BLOCK_DESCENDANTS;
+    }
+
+    @Override
+    public boolean dispatchKeyEvent(KeyEvent event) {
+        if (mChildrenFocused && event.getKeyCode() == KeyEvent.KEYCODE_ESCAPE
+                && event.getAction() == KeyEvent.ACTION_UP) {
+            mChildrenFocused = false;
+            requestFocus();
+            return true;
+        }
+        return super.dispatchKeyEvent(event);
+    }
+
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        if (!mChildrenFocused && keyCode == KeyEvent.KEYCODE_ENTER) {
+            event.startTracking();
+            return true;
+        }
+        return super.onKeyDown(keyCode, event);
+    }
+
+    @Override
+    public boolean onKeyUp(int keyCode, KeyEvent event) {
+        if (event.isTracking()) {
+            if (!mChildrenFocused && keyCode == KeyEvent.KEYCODE_ENTER) {
+                mChildrenFocused = true;
+                ArrayList<View> focusableChildren = getFocusables(FOCUS_FORWARD);
+                focusableChildren.remove(this);
+                int childrenCount = focusableChildren.size();
+                switch (childrenCount) {
+                    case 0:
+                        mChildrenFocused = false;
+                        break;
+                    case 1: {
+                        if (shouldAllowDirectClick()) {
+                            focusableChildren.get(0).performClick();
+                            mChildrenFocused = false;
+                            return true;
+                        }
+                        // continue;
+                    }
+                    default:
+                        focusableChildren.get(0).requestFocus();
+                        return true;
+                }
+            }
+        }
+        return super.onKeyUp(keyCode, event);
+    }
+
+    /**
+     * For a widget with only a single interactive element, return true if whole widget should act
+     * as a single interactive element, and clicking 'enter' should activate the child element
+     * directly. Otherwise clicking 'enter' will only move the focus inside the widget.
+     */
+    protected abstract boolean shouldAllowDirectClick();
+
+    @Override
+    protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) {
+        if (gainFocus) {
+            mChildrenFocused = false;
+            dispatchChildFocus(false);
+        }
+        super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
+    }
+
+    @Override
+    public void requestChildFocus(View child, View focused) {
+        super.requestChildFocus(child, focused);
+        dispatchChildFocus(mChildrenFocused && focused != null);
+        if (focused != null) {
+            focused.setFocusableInTouchMode(false);
+        }
+    }
+
+    @Override
+    public void clearChildFocus(View child) {
+        super.clearChildFocus(child);
+        dispatchChildFocus(false);
+    }
+
+    @Override
+    public boolean dispatchUnhandledMove(View focused, int direction) {
+        return mChildrenFocused;
+    }
+
+    private void dispatchChildFocus(boolean childIsFocused) {
+        // The host view's background changes when selected, to indicate the focus is inside.
+        setSelected(childIsFocused);
+    }
+}