src/com/android/gallery3d/photoeditor/ToolbarIdleHandler.java

/*
 * Copyright (C) 2010 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.gallery3d.photoeditor;

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.ViewGroup.OnHierarchyChangeListener;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;

import com.android.gallery3d.R;

import java.util.ArrayList;
import java.util.List;

/**
 * Handler that controls idle/awake behaviors of toolbar's child views from UI thread.
 */
class ToolbarIdleHandler implements OnHierarchyChangeListener {

    private static final int MAKE_IDLE = 1;
    private static final int TIMEOUT_IDLE = 8000;

    private final List<View> childViews = new ArrayList<View>();
    private final Handler mainHandler;
    private final Animation fadeIn;
    private final Animation fadeOut;
    private boolean idle;

    public ToolbarIdleHandler(Context context) {
        mainHandler = new Handler() {

            @Override
            public void handleMessage(Message msg) {
                switch (msg.what) {
                    case MAKE_IDLE:
                        if (!idle) {
                            idle = true;
                            for (View view : childViews) {
                                view.startAnimation(fadeOut);
                            }
                        }
                        break;
                }
            }
        };

        fadeIn = AnimationUtils.loadAnimation(context, R.anim.photoeditor_fade_in);
        fadeOut = AnimationUtils.loadAnimation(context, R.anim.photoeditor_fade_out);
    }

    public void killIdle() {
        mainHandler.removeMessages(MAKE_IDLE);
        if (idle) {
            idle = false;
            for (View view : childViews) {
                view.startAnimation(fadeIn);
            }
        }
        mainHandler.sendEmptyMessageDelayed(MAKE_IDLE, TIMEOUT_IDLE);
    }

    @Override
    public void onChildViewAdded(View parent, View child) {
        // All child views, except photo-view, will fade out on inactivity timeout.
        if (child.getId() != R.id.photo_view) {
            childViews.add(child);
        }
    }

    @Override
    public void onChildViewRemoved(View parent, View child) {
        childViews.remove(child);
    }
}