android activity切换翻转效果
Android中并没有提供直接做3D翻转的动画，所以关于3D翻转的动画效果需要我们在代码中继承android.view.animation.Animation类来实现自定义效果。
二、动画的实现原理：
通过重写Animation的 applyTransformation(float interpolatedTime, Transformation t)函数来实现自定义动画效果。
在绘制动画的过程中会反复的调用applyTransformation函数，每次调用参数interpolatedTime值都会变化，该参数从0 渐 变为1，当该参数为1时表明动画结束。通过参数Transformation 来获取变换的矩阵（matrix），通过改变矩阵就可以实现各种复杂的 效果。
1、动画的运行模式
独行模式
2、Animation类：
Animation是动画的主要接口，其中主要定义了动画的一些属性比如开始时间，持续时间，是否重复播放等的。
每个动画都重载了父类的applyTransformation方法。这个方法的主要作用是把一些属性组装成一个Transformation类，这个方法会被父类的getTransformation方法调用。另外，每个动画还要个initialize方法，完成初始化工作，动画开始前的一些准备工作。
在getTransformation中Animation会根据动画的属性来产生一系列的差值点，然后我们将这些差值点传给applyTransformation,,这个函数将根据这些点来生成不同的Transformation.
其中包括了旋转的开始和结束角度、中心点、是否扭曲和一个Camera,这里我们主要分析applyTransformation函数，其中第一个参数就是通过getTransformation函数传递的差值点，然后我们根据这个差值线性插值算法算出一个中间角度degrees,Camera类是用来实现绕Y轴旋转后透视投影的，因此我们首先通过t.getMatrix()取得当前的矩阵，然后通过camera.translate来对矩阵进行平移变换操作，camera.rotateY进行旋转。就可以实现3D旋转效果了。
3、Interpolator类
定义动画执行过程一些加速度减速度，为了我们后面Transformation来服务的。
4、Transformation类
Transformation记录了放射矩阵Matrix,动画每触发一次，会对原来的矩阵做一次运算，View的Bitmap与这个矩阵相乘就可以实现相应的操作（旋转、平移、缩放等）。
Transformation类封装了矩阵和alpha值，它有两个重要成员，一个mMatrix，一个是mAlpha(控制透明度)
三、activity切换翻转效果源码
Transition3dActivity.java（这个文件在api demo里有：http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/animation/Rotate3dAnimation.html）
/*
* Copyright (C) 2007 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.huashao.Transition3d;
import android.view.animation.Animation;
import android.view.animation.Transformation;
import android.graphics.Camera;
import android.graphics.Matrix;
/**
* An animation that rotates the view on the Y axis between two specified angles.
* This animation also adds a translation on the Z axis (depth) to improve the effect.
*/
public class Rotate3dAnimation extends Animation {
private final float mFromDegrees;
private final float mToDegrees;
private final float mCenterX;
private final float mCenterY;
private final float mDepthZ;
private final boolean mReverse;
private Camera mCamera;
/**
* Creates a new 3D rotation on the Y axis. The rotation is defined by its
* start angle and its end angle. Both angles are in degrees. The rotation
* is performed around a center point on the 2D space, definied by a pair
* of X and Y coordinates, called centerX and centerY. When the animation
* starts, a translation on the Z axis (depth) is performed. The length
* of the translation can be specified, as well as whether the translation
* should be reversed in time.
*
* @param fromDegrees the start angle of the 3D rotation
* @param toDegrees the end angle of the 3D rotation
* @param centerX the X center of the 3D rotation
* @param centerY the Y center of the 3D rotation
* @param reverse true if the translation should be reversed, false otherwise
*/
public Rotate3dAnimation(float fromDegrees, float toDegrees,
float centerX, float centerY, float depthZ, boolean reverse) {
mFromDegrees = fromDegrees;
mToDegrees = toDegrees;
mCenterX = centerX;
mCenterY = centerY;
mDepthZ = depthZ;
mReverse = reverse;
}
@Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
super.initialize(width, height, parentWidth, parentHeight);
mCamera = new Camera();
}
@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
final float fromDegrees = mFromDegrees;
float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);
final float centerX = mCenterX;
final float centerY = mCenterY;
final Camera camera = mCamera;
final Matrix matrix = t.getMatrix();
camera.save();
if (mReverse) {
camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
} else {
camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
}
camera.rotateY(degrees);
camera.getMatrix(matrix);
camera.restore();
matrix.preTranslate(-centerX, -centerY);
matrix.postTranslate(centerX, centerY);
}
}
ITabHostMenuHandler接口：
package com.huashao.Transition3d;
import java.io.Serializable;
public interface ITabHostMenuHandler extends Serializable {
public static final class TabHostSubClazzSimpleName {
public static final String TAG_MODULE1 = "ModuleView1";
public static final String TAG_MODULE2 = "ModuleView2";
}
public void applyRotation(int position, float start, float end);
}
NewsTabActivity.java（继承自ActivityGroup的类）
package com.hhf.Transition3d;
import java.io.Serializable;
import com.huashao.Transition3d.R;
import android.app.ActivityGroup;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.Window;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.DecelerateInterpolator;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class NewsTabActivity extends ActivityGroup implements ITabHostMenuHandler {
private FrameLayout container = null;
private View view;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// 隐藏标题栏
requestWindowFeature(Window.FEATURE_NO_TITLE);
// 设置视图
setContentView(R.layout.layout);
container = (FrameLayout) findViewById(R.id.container);
container.removeAllViews();
Intent Module1Intent = new Intent(this, ModuleView1.class);
Module1Intent.setFlags(Intent.FLAG_ACTIVITY_PREVIOUS_IS_TOP);
Bundle Bundle = new Bundle();
Bundle.putSerializable(ITabHostMenuHandler.TabHostSubClazzSimpleName.TAG_MODULE1, this);
Module1Intent.putExtras(Bundle);
view=getLocalActivityManager().startActivity("Module1", Module1Intent).getDecorView();
container.addView(view);
container.setPersistentDrawingCache(ViewGroup.PERSISTENT_ANIMATION_CACHE);
}
public void applyRotation(int position, float start, float end) {
System.out.println("applyRotation start......");
// Find the center of the container
final float centerX = container.getWidth() / 2.0f;
final float centerY = container.getHeight() / 2.0f;
// Create a new 3D rotation with the supplied parameter
// The animation listener is used to trigger the next animation
final Rotate3dAnimation rotation =
new Rotate3dAnimation(start, end, centerX, centerY, 310.0f, true);
rotation.setDuration(500);
rotation.setFillAfter(true);
rotation.setInterpolator(new AccelerateInterpolator());
rotation.setAnimationListener(new DisplayNextView(position));
container.startAnimation(rotation);
System.out.println("applyRotation end .....");
}
/**
* This class listens for the end of the first half of the animation.
* It then posts a new action that effectively swaps the views when the container
* is rotated 90 degrees and thus invisible.
*/
private final class DisplayNextView implements Animation.AnimationListener {
private final int mPosition;
private DisplayNextView(int position) {
mPosition = position;
}
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
container.post(new SwapViews(mPosition));
}
public void onAnimationRepeat(Animation animation) {
}
}
/**
* This class is responsible for swapping the views and start the second
* half of the animation.
*/
private final class SwapViews implements Runnable {
private final int mPosition;
public SwapViews(int position) {
mPosition = position;
}
public void run() {
final float centerX = container.getWidth() / 2.0f;
final float centerY = container.getHeight() / 2.0f;
Rotate3dAnimation rotation;
System.out.println("SwapViews start +++++++ ");
if (mPosition > -1) {
container.removeAllViews();
Intent Module1Intent = new Intent(NewsTabActivity.this, ModuleView1.class);
Module1Intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
Bundle Bundle = new Bundle();
Bundle.putSerializable(ITabHostMenuHandler.TabHostSubClazzSimpleName.TAG_MODULE1, NewsTabActivity.this);
Module1Intent.putExtras(Bundle);
view=getLocalActivityManager().startActivity("Module1", Module1Intent).getDecorView();
container.addView(view);
rotation = new Rotate3dAnimation(90, 180, centerX, centerY, 310.0f, false);
} else {
container.removeAllViews();
Intent Module1Intent = new Intent(NewsTabActivity.this, ModuleView2.class);
Module1Intent.setFlags(Intent.FLAG_ACTIVITY_PREVIOUS_IS_TOP);
Bundle Bundle = new Bundle();
Bundle.putSerializable(ITabHostMenuHandler.TabHostSubClazzSimpleName.TAG_MODULE2, NewsTabActivity.this);
Module1Intent.putExtras(Bundle);
view=getLocalActivityManager().startActivity("Module2", Module1Intent).getDecorView();
container.addView(view);
rotation = new Rotate3dAnimation(90, 0, centerX, centerY, 310.0f, false);
}
rotation.setDuration(500);
rotation.setFillAfter(true);
rotation.setInterpolator(new DecelerateInterpolator());
container.startAnimation(rotation);
System.out.println("SwapViews end ++++++ ");
}
}
}
ModuleView1.java
package com.hhf.Transition3d;
import com.hhf.Transition3d.ITabHostMenuHandler.TabHostSubClazzSimpleName;
import com.huashao.Transition3d.R;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.ListView;
public class ModuleView1 extends Activity implements View.OnClickListener {
private ITabHostMenuHandler tabHostMenuHandler;
private ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view1layout);
img=(ImageView) findViewById(R.id.picture);
img.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.d("", "ModuleView1");
tabHostMenuHandler. applyRotation(-1, 180, 90);
}
});
tabHostMenuHandler = (ITabHostMenuHandler) getIntent().getExtras().getSerializable(TabHostSubClazzSimpleName.TAG_MODULE1);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
package com.hhf.Transition3d;
import com.hhf.Transition3d.ITabHostMenuHandler.TabHostSubClazzSimpleName;
import com.huashao.Transition3d.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ImageView;
public class ModuleView2 extends Activity implements View.OnClickListener {
private ITabHostMenuHandler tabHostMenuHandler;
private ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view2layout);
img=(ImageView) findViewById(R.id.picture);
img.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.d("", "ModuleView1");
tabHostMenuHandler.applyRotation(1, 0, 90);
}
});
tabHostMenuHandler = (ITabHostMenuHandler) getIntent().getExtras().getSerializable(TabHostSubClazzSimpleName.TAG_MODULE2);
ImageView i = (ImageView) findViewById(R.id.img);
i.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.img:
Intent in = new Intent(ModuleView2.this,MainActivity.class);
startActivity(in);
break;
default:
break;
}
}
}
package com.hhf.Transition3d;
import com.huashao.Transition3d.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
public class MainActivity extends Activity{
private ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.view1layout);
img=(ImageView) findViewById(R.id.picture);
img.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent in = new Intent(MainActivity.this,NewsTabActivity.class);
startActivity(in);
}
});
}
}
Camera就像一个摄像机，一个物体在原地不动，然后我们带着这个摄像机四处移动，在摄像机里面呈现出来的画面，就会有立体感，就可以从各个角度观看这个物体。
它有旋转、平移的一系列方法，实际上都是在改变一个Matrix对象，一系列操作完毕之后，我们得到这个Matrix，然后画我们的物体，就可以了。
常用的API如下：
rotateX(float degree) 绕着x轴旋转degree个度数
rotateY(float degree) 绕着y轴旋转degree个度数
rotateZ(float degree) 绕着z轴旋转degree个度数
translate(float x,float y,float z) 平移一段距离
save()和restore() 作用跟Canvas的一样，保存原状态，操作完之后，恢复到原状态。