【Android】Coverflow Widget

效果预览：

实现代码：

CoverFlow.java

/* * Copyright (C) 2010 Neil Davies * * 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. *  * This code is base on the Android Gallery widget and was Created  * by Neil Davies neild001 'at' gmail dot com to be a Coverflow widget *  * @author Neil Davies */package com.example.coverflow;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 CoverFlow extends Gallery {    /**     * Graphics Camera used for transforming the matrix of ImageViews     */    private Camera mCamera = new Camera();    /**     * The maximum angle the Child ImageView will be rotated by     */        private int mMaxRotationAngle = 60;        /**     * The maximum zoom on the centre Child     */    private int mMaxZoom = -120;        /**     * The Centre of the Coverflow      */       private int mCoveflowCenter;    public CoverFlow(Context context) {  super(context);  this.setStaticTransformationsEnabled(true); } public CoverFlow(Context context, AttributeSet attrs) {  super(context, attrs);        this.setStaticTransformationsEnabled(true); }   public CoverFlow(Context context, AttributeSet attrs, int defStyle) {   super(context, attrs, defStyle);   this.setStaticTransformationsEnabled(true);     }      /**     * Get the max rotational angle of the image  * @return the mMaxRotationAngle  */ public int getMaxRotationAngle() {  return mMaxRotationAngle; } /**  * Set the max rotational angle of each image  * @param maxRotationAngle the mMaxRotationAngle to set  */ public void setMaxRotationAngle(int maxRotationAngle) {  mMaxRotationAngle = maxRotationAngle; } /**  * Get the Max zoom of the centre image  * @return the mMaxZoom  */ public int getMaxZoom() {  return mMaxZoom; } /**  * Set the max zoom of the centre image  * @param maxZoom the mMaxZoom to set  */ public void setMaxZoom(int maxZoom) {  mMaxZoom = maxZoom; } /**     * Get the Centre of the Coverflow     * @return The centre of this Coverflow.     */    private int getCenterOfCoverflow() {        return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();    }        /**     * Get the Centre of the View     * @return The centre of the given view.     */    private static int getCenterOfView(View view) {        return view.getLeft() + view.getWidth() / 2;    }      /**  * {@inheritDoc}  *  * @see #setStaticTransformationsEnabled(boolean)   */     protected boolean getChildStaticTransformation(View child, Transformation t) {    final int childCenter = getCenterOfView(child);  final int childWidth = child.getWidth() ;  int rotationAngle = 0;    t.clear();  t.setTransformationType(Transformation.TYPE_MATRIX);          if (childCenter == mCoveflowCenter) {            transformImageBitmap((ImageView) child, t, 0);        } else {                  rotationAngle = (int) (((float) (mCoveflowCenter - childCenter)/ childWidth) *  mMaxRotationAngle);            if (Math.abs(rotationAngle) > mMaxRotationAngle) {             rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;               }            transformImageBitmap((ImageView) child, t, rotationAngle);                 }                   return true; } /**  * This is called during layout when the size of this view has changed. If  * you were just added to the view hierarchy, you're called with the old  * values of 0.  *  * @param w Current width of this view.  * @param h Current height of this view.  * @param oldw Old width of this view.  * @param oldh Old height of this view.     */     protected void onSizeChanged(int w, int h, int oldw, int oldh) {      mCoveflowCenter = getCenterOfCoverflow();      super.onSizeChanged(w, h, oldw, oldh);     }       /**      * Transform the Image Bitmap by the Angle passed       *       * @param imageView ImageView the ImageView whose bitmap we want to rotate      * @param t transformation       * @param rotationAngle the Angle by which to rotate the Bitmap      */     private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) {                  mCamera.save();      final Matrix imageMatrix = t.getMatrix();;      final int imageHeight = child.getLayoutParams().height;;      final int imageWidth = child.getLayoutParams().width;      final int rotation = Math.abs(rotationAngle);                           mCamera.translate(0.0f, 0.0f, 100.0f);               //As the angle of the view gets less, zoom in           if ( rotation < mMaxRotationAngle ) {       float zoomAmount = (float) (mMaxZoom +  (rotation * 1.5));       mCamera.translate(0.0f, 0.0f, zoomAmount);                }             mCamera.rotateY(rotationAngle);      mCamera.getMatrix(imageMatrix);                     imageMatrix.preTranslate(-(imageWidth/2), -(imageHeight/2));       imageMatrix.postTranslate((imageWidth/2), (imageHeight/2));      mCamera.restore(); }}

CoverFlowExample.java

/* * Copyright (C) 2010 Neil Davies * * 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. *  * This code is base on the Android Gallery widget and was Created  * by Neil Davies neild001 'at' gmail dot com to be a Coverflow widget *  * @author Neil Davies */package com.example.coverflow;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 CoverFlow extends Gallery {    /**     * Graphics Camera used for transforming the matrix of ImageViews     */    private Camera mCamera = new Camera();    /**     * The maximum angle the Child ImageView will be rotated by     */        private int mMaxRotationAngle = 60;        /**     * The maximum zoom on the centre Child     */    private int mMaxZoom = -120;        /**     * The Centre of the Coverflow      */       private int mCoveflowCenter;    public CoverFlow(Context context) {  super(context);  this.setStaticTransformationsEnabled(true); } public CoverFlow(Context context, AttributeSet attrs) {  super(context, attrs);        this.setStaticTransformationsEnabled(true); }   public CoverFlow(Context context, AttributeSet attrs, int defStyle) {   super(context, attrs, defStyle);   this.setStaticTransformationsEnabled(true);     }      /**     * Get the max rotational angle of the image  * @return the mMaxRotationAngle  */ public int getMaxRotationAngle() {  return mMaxRotationAngle; } /**  * Set the max rotational angle of each image  * @param maxRotationAngle the mMaxRotationAngle to set  */ public void setMaxRotationAngle(int maxRotationAngle) {  mMaxRotationAngle = maxRotationAngle; } /**  * Get the Max zoom of the centre image  * @return the mMaxZoom  */ public int getMaxZoom() {  return mMaxZoom; } /**  * Set the max zoom of the centre image  * @param maxZoom the mMaxZoom to set  */ public void setMaxZoom(int maxZoom) {  mMaxZoom = maxZoom; } /**     * Get the Centre of the Coverflow     * @return The centre of this Coverflow.     */    private int getCenterOfCoverflow() {        return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();    }        /**     * Get the Centre of the View     * @return The centre of the given view.     */    private static int getCenterOfView(View view) {        return view.getLeft() + view.getWidth() / 2;    }      /**  * {@inheritDoc}  *  * @see #setStaticTransformationsEnabled(boolean)   */     protected boolean getChildStaticTransformation(View child, Transformation t) {    final int childCenter = getCenterOfView(child);  final int childWidth = child.getWidth() ;  int rotationAngle = 0;    t.clear();  t.setTransformationType(Transformation.TYPE_MATRIX);          if (childCenter == mCoveflowCenter) {            transformImageBitmap((ImageView) child, t, 0);        } else {                  rotationAngle = (int) (((float) (mCoveflowCenter - childCenter)/ childWidth) *  mMaxRotationAngle);            if (Math.abs(rotationAngle) > mMaxRotationAngle) {             rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;               }            transformImageBitmap((ImageView) child, t, rotationAngle);                 }                   return true; } /**  * This is called during layout when the size of this view has changed. If  * you were just added to the view hierarchy, you're called with the old  * values of 0.  *  * @param w Current width of this view.  * @param h Current height of this view.  * @param oldw Old width of this view.  * @param oldh Old height of this view.     */     protected void onSizeChanged(int w, int h, int oldw, int oldh) {      mCoveflowCenter = getCenterOfCoverflow();      super.onSizeChanged(w, h, oldw, oldh);     }       /**      * Transform the Image Bitmap by the Angle passed       *       * @param imageView ImageView the ImageView whose bitmap we want to rotate      * @param t transformation       * @param rotationAngle the Angle by which to rotate the Bitmap      */     private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) {                  mCamera.save();      final Matrix imageMatrix = t.getMatrix();;      final int imageHeight = child.getLayoutParams().height;;      final int imageWidth = child.getLayoutParams().width;      final int rotation = Math.abs(rotationAngle);                           mCamera.translate(0.0f, 0.0f, 100.0f);               //As the angle of the view gets less, zoom in           if ( rotation < mMaxRotationAngle ) {       float zoomAmount = (float) (mMaxZoom +  (rotation * 1.5));       mCamera.translate(0.0f, 0.0f, zoomAmount);                }             mCamera.rotateY(rotationAngle);      mCamera.getMatrix(imageMatrix);                     imageMatrix.preTranslate(-(imageWidth/2), -(imageHeight/2));       imageMatrix.postTranslate((imageWidth/2), (imageHeight/2));      mCamera.restore(); }}

作者博客：

http://www.inter-fuser.com/2010/02/android-coverflow-widget-v2.html