content: /*
   * 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);
      }
  }
  