自定义Gallery实现3D立体,倒影的效果(一)

自定义的gallery：

package com.cogent.gallery;

import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;

public class MyGallery extends Gallery {

private Camera mCamera = new Camera();
/** 最大转动角度 */
private int mMaxRotationAngle = 30;
/** 最大缩放值 */
private int mMaxZoom = -300;
/** 半径值 */
private int mRadius;

public MyGallery(Context context){
super(context);
this.setStaticTransformationsEnabled(true);
}

public MyGallery(Context context, AttributeSet attrs) {
super(context, attrs);
this.setStaticTransformationsEnabled(true);
}

public MyGallery(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.setStaticTransformationsEnabled(true);
}

public int getmMaxRotationAngle() {
return mMaxRotationAngle;
}

public void setmMaxRotationAngle(int mMaxRotationAngle) {
this.mMaxRotationAngle = mMaxRotationAngle;
}

public int getmMaxZoom() {
return mMaxZoom;
}

public void setmMaxZoom(int mMaxZoom) {
this.mMaxZoom = mMaxZoom;
}

private int getCenterOfCoverflow() {
return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2
+ getPaddingLeft();
}

private static int getCenterOfView(View view) {
return view.getLeft() + view.getWidth() / 2;
}

// 重写gallery中的方法，控制gallery中的每个图片的旋转
@Override
protected boolean getChildStaticTransformation(View child, Transformation t) {
// TODO Auto-generated method stub
// 取得当前子view的半径值
int childCenter = getCenterOfView(child);
// 取得当前子view的宽度
int childWidth = child.getWidth();
// 旋转的角度
int rotationAngle = 0;
// 重置转换状态
t.clear();
// 设置转换类型
t.setTransformationType(Transformation.TYPE_MATRIX);
//如果图片位于中心位置不需要进行转换
if (childCenter == mRadius) {
transformImageBitmap((ImageView) child, t, 0);
} else {
// 根据图片在gallery中的位置来计算图片的旋转角度
rotationAngle = (int) (((float) (mRadius - childCenter) / childWidth) * mMaxRotationAngle);
if (Math.abs(rotationAngle) > mMaxRotationAngle) {
rotationAngle = (rotationAngle < 0) -mMaxRotationAngle
: mMaxRotationAngle;
}
transformImageBitmap((ImageView) child, t, rotationAngle);
}
return true;
}

protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mRadius = getCenterOfCoverflow();
super.onSizeChanged(w, h, oldw, oldh);
}

private void transformImageBitmap(ImageView child, Transformation t,
int rotationAngle) {
// 对效果进行保存
mCamera.save();
Matrix imageMatrix = t.getMatrix();
// 图片的高度
int imageHeight = child.getLayoutParams().height;
// 图片的宽度
int imageWidth = child.getLayoutParams().width;
// 返回旋转角度的绝对值
int rotation = Math.abs(rotationAngle);

// 在Z轴上正向移动camera的视角，实际效果为放大图片。
// 如果在Y轴上移动，则图片上下移动；X轴上对应图片左右移动。
mCamera.translate(0.0f, 0.0f, 100.0f);
if (rotation < mMaxRotationAngle) {
float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));
mCamera.translate(0.0f, 0.0f, zoomAmount);
}