| /* |
| * Copyright (C) 2013 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.example.android.pictureviewer; |
| |
| import android.app.Activity; |
| import android.graphics.Bitmap; |
| import android.graphics.BitmapFactory; |
| import android.graphics.Color; |
| import android.graphics.drawable.BitmapDrawable; |
| import android.os.Bundle; |
| import android.view.View; |
| import android.widget.ImageView; |
| |
| /** |
| * This example shows how to use ViewPropertyAnimator to get a cross-fade effect as new |
| * bitmaps get installed in an ImageView. |
| * |
| * Watch the associated video for this demo on the DevBytes channel of developer.android.com |
| * or on YouTube at https://www.youtube.com/watch?v=9XbKMUtVnJA. |
| */ |
| public class PictureViewer extends Activity { |
| |
| int mCurrentDrawable = 0; |
| int drawableIDs[] = { |
| R.drawable.p1, |
| R.drawable.p2, |
| R.drawable.p3, |
| R.drawable.p4, |
| }; |
| |
| @Override |
| public void onCreate(Bundle savedInstanceState) { |
| super.onCreate(savedInstanceState); |
| setContentView(R.layout.activity_picture_viewer); |
| |
| // This app works by having two views, which get faded in/out for the cross-fade effect |
| final ImageView prevImageView = (ImageView) findViewById(R.id.prevImageView); |
| final ImageView nextImageView = (ImageView) findViewById(R.id.nextImageView); |
| prevImageView.setBackgroundColor(Color.TRANSPARENT); |
| nextImageView.setBackgroundColor(Color.TRANSPARENT); |
| |
| // Setup default ViewPropertyAnimator durations for the two ImageViews |
| prevImageView.animate().setDuration(1000); |
| nextImageView.animate().setDuration(1000); |
| |
| // NOte that a real app would do this more robustly, and not just load all possible |
| // bitmaps at onCreate() time. |
| final BitmapDrawable drawables[] = new BitmapDrawable[drawableIDs.length]; |
| for (int i = 0; i < drawableIDs.length; ++i) { |
| Bitmap bitmap = BitmapFactory.decodeResource(getResources(), |
| drawableIDs[i]); |
| drawables[i] = new BitmapDrawable(getResources(), bitmap); |
| } |
| prevImageView.setImageDrawable(drawables[0]); |
| nextImageView.setImageDrawable(drawables[1]); |
| |
| prevImageView.setOnClickListener(new View.OnClickListener() { |
| |
| @Override |
| public void onClick(View v) { |
| // Use ViewPropertyAnimator to fade the previous imageView out and the next one in |
| prevImageView.animate().alpha(0).withLayer(); |
| nextImageView.animate().alpha(1).withLayer(). |
| withEndAction(new Runnable() { |
| // When the animation ends, set up references to change the prev/next |
| // associations |
| @Override |
| public void run() { |
| mCurrentDrawable = |
| (mCurrentDrawable + 1) % drawables.length; |
| int nextDrawableIndex = |
| (mCurrentDrawable + 1) % drawables.length; |
| prevImageView.setImageDrawable(drawables[mCurrentDrawable]); |
| nextImageView.setImageDrawable(drawables[nextDrawableIndex]); |
| nextImageView.setAlpha(0f); |
| prevImageView.setAlpha(1f); |
| } |
| }); |
| } |
| }); |
| } |
| |
| } |