GridItemExercise.java

/*
 * Copyright (C) 2015 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.talkback.tutorial.exercise;

import android.view.LayoutInflater;
import android.view.View;
import android.view.View.AccessibilityDelegate;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.widget.TextView;
import com.android.talkback.R;
import com.android.talkback.tutorial.GridView;

public class GridItemExercise extends Exercise implements View.OnClickListener {

    protected View mView;
    private GridView mGridView;

    @Override
    public View getContentView(final LayoutInflater inflater, ViewGroup parent) {
        mGridView = new GridView(inflater.getContext(), new GridView.ItemProvider() {
            @Override
            public View getView(ViewGroup parent, final int index) {
                View view = inflater.inflate(R.layout.tutorial_content_grid_item, parent, false);
                TextView title = (TextView) view.findViewById(R.id.title);
                String text = inflater.getContext().getString(R.string.tutorial_template_item,
                        index + 1);
                title.setText(text);
                view.setContentDescription(text);
                view.setOnClickListener(GridItemExercise.this);
                view.setAccessibilityDelegate(new GridItemAccessibilityDelegate(index + 1));
                return view;
            }
        });
        int horizontalPadding = inflater.getContext().getResources().getDimensionPixelSize(
                R.dimen.tutorial_grid_horizontal_offset);
        mGridView.setPadding(horizontalPadding, 0, horizontalPadding, 0);
        mView = mGridView;
        return mView;
    }

    @Override
    public void onClick(View view) {
        clearSelection();
        view.findViewById(R.id.circle).setSelected(true);
    }

    private void clearSelection() {
        int childrenCount = mGridView.getChildCount();
        for (int i = 0; i < childrenCount; i++) {
            View view = mGridView.getChildAt(i);
            if (view != null) {
                view.findViewById(R.id.circle).setSelected(false);
            }
        }
    }

    protected View getView() {
        return mView;
    }

    protected void onAccessibilityFocused(int index) {}

    protected void onAccessibilityClicked(int index) {}

    private class GridItemAccessibilityDelegate extends AccessibilityDelegate {
        private final int mIndex;

        /**
         * @param index the index the user sees; use 1-based indexing, not 0-based indexing
         */
        GridItemAccessibilityDelegate(int index) {
            mIndex = index;
        }

        @Override
        public void sendAccessibilityEvent(View host, int eventType) {
            super.sendAccessibilityEvent(host, eventType);

            if (eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED) {
                onAccessibilityFocused(mIndex);
            } else if (eventType == AccessibilityEvent.TYPE_VIEW_CLICKED) {
                onAccessibilityClicked(mIndex);
            }
        }
    }
}