Android實現CoverFlow效果 一

先上一張效果圖：
 

上代碼，看了代碼什麼都明白

CoverFlow從Gallery繼承過來

package com.coverflow;

002

003	import android.content.Context;

004	import android.graphics.Camera;

005	import android.graphics.Matrix;

006	import android.util.AttributeSet;

007	import android.view.View;

008	import android.view.animation.Transformation;

009	import android.widget.Gallery;

010	import android.widget.ImageView;

011

012	public class CoverFlow extends Gallery {

013

014	private Camera mCamera = new Camera();

015	private int mMaxRotationAngle = 50;

016	private int mMaxZoom = -380;

017	private int mCoveflowCenter;

018	private boolean mAlphaMode = true;

019	private boolean mCircleMode = false;

020

021	public CoverFlow(Context context) {

022	super(context);

023	this.setStaticTransformationsEnabled(true);

024

}

025

026	public CoverFlow(Context context, AttributeSet attrs) {

027	super(context, attrs);

028	this.setStaticTransformationsEnabled(true);

029

}

030

031	public CoverFlow(Context context, AttributeSet attrs, int defStyle) {

032	super(context, attrs, defStyle);

033	this.setStaticTransformationsEnabled(true);

034

}

035

036	public int getMaxRotationAngle() {

037	return mMaxRotationAngle;

038

}

039

040	public void setMaxRotationAngle(int maxRotationAngle) {

041	mMaxRotationAngle = maxRotationAngle;

042

}

043

044	public boolean getCircleMode() {

045	return mCircleMode;

046

}

047

048	public void setCircleMode(boolean isCircle) {

049	mCircleMode = isCircle;

050

}

051

052	public boolean getAlphaMode() {

053	return mAlphaMode;

054

}

055

056	public void setAlphaMode(boolean isAlpha) {

057	mAlphaMode = isAlpha;

058

}

059

060	public int getMaxZoom() {

061	return mMaxZoom;

062

}

063

064	public void setMaxZoom(int maxZoom) {

065	mMaxZoom = maxZoom;

066

}

067

068	private int getCenterOfCoverflow() {

069	return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2

070	+ getPaddingLeft();

071

}

072

073	private static int getCenterOfView(View view) {

074	return view.getLeft() + view.getWidth() / 2;

075

}

076

077	protected boolean getChildStaticTransformation(View child, Transformation t) {

078	final int childCenter = getCenterOfView(child);

079	final int childWidth = child.getWidth();

080	int rotationAngle = 0;

081	t.clear();

082	t.setTransformationType(Transformation.TYPE_MATRIX);

083	if (childCenter == mCoveflowCenter) {

084	transformImageBitmap((ImageView) child, t, 0);

085

} else {

086	rotationAngle = (int) (((float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);

087	if (Math.abs(rotationAngle) > mMaxRotationAngle) {

088	rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle

089	: mMaxRotationAngle;

090

}

091	transformImageBitmap((ImageView) child, t, rotationAngle);

092

}

093	return true;

094

}

095

096

/**

097	* 這就是所謂的在大小的佈局時,這一觀點已經發生了改變。如果 你只是添加到視圖層次,有人叫你舊的觀念 價值觀爲0。

098

*

099	* @param w

100	*            Current width of this view.

101	* @param h

102	*            Current height of this view.

103	* @param oldw

104	*            Old width of this view.

105	* @param oldh

106	*            Old height of this view.

107

*/

108	protected void onSizeChanged(int w, int h, int oldw, int oldh) {

109	mCoveflowCenter = getCenterOfCoverflow();

110	super.onSizeChanged(w, h, oldw, oldh);

111

}

112

113

/**

114	* 把圖像位圖的角度通過

115

*

116	* @param imageView

117	*            ImageView the ImageView whose bitmap we want to rotate

118	* @param t

119	*            transformation

120	* @param rotationAngle

121	*            the Angle by which to rotate the Bitmap

122

*/

123	private void transformImageBitmap(ImageView child, Transformation t,

124	int rotationAngle) {

125	mCamera.save();

126	final Matrix imageMatrix = t.getMatrix();

127	final int imageHeight = child.getLayoutParams().height;

128	final int imageWidth = child.getLayoutParams().width;

129	final int rotation = Math.abs(rotationAngle);

130	mCamera.translate(0.0f, 0.0f, 100.0f);

131

132	// 如視圖的角度更少,放大

133	if (rotation <= mMaxRotationAngle) {

134	float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));

135	mCamera.translate(0.0f, 0.0f, zoomAmount);

136	if (mCircleMode) {

137	if (rotation < 40)

138	mCamera.translate(0.0f, 155, 0.0f);

139

else

140	mCamera.translate(0.0f, (255 - rotation * 2.5f), 0.0f);

141

}

142	if (mAlphaMode) {

143	((ImageView) (child)).setAlpha((int) (255 - rotation * 2.5));

144

}

145

}

146	mCamera.rotateY(rotationAngle);

147	mCamera.getMatrix(imageMatrix);

148	imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));

149	imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));

150	mCamera.restore();

151

}

152

}