首页 > 代码库 > 【Android UI】案例01Cover Flow3D效果的实现
【Android UI】案例01Cover Flow3D效果的实现
本例主要介绍CoverFlow3D的实现。首先介绍一下Cover Flow。Cover Flow是苹果首创的将多首歌曲的封面以3D界面的形式显示出来的方式。
本案例摘自网络http://www.cnblogs.com/yyyyy5101/archive/2011/12/14/2287871.html,该案例在真机测试中,出现显示效果的差异,由此可见该演示工程存在一定的兼容性的问题,往浏览本文的有志之士,可以给以指正与修改。最后补充一下,虽然不同机器显示的效果有差异,但是显示效果的确也算优秀。
【转载使用,请注明出处:http://blog.csdn.net/mahoking】
本案例的演示工程设计三个类文件分别为:Activity(CoverFlowActivity)、Gallery(GalleryFlow)、BaseAdapter(ImageAdapter)和布局文件activity_02_gallery.xml。
CoverFlowActivity
import android.app.Activity; import android.os.Bundle; public class CoverFlowActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_02_gallery); Integer[] images = { R.drawable.image01, R.drawable.image02,R.drawable.image03}; ImageAdapter adapter = new ImageAdapter(this, images); adapter.createReflectedImages(); GalleryFlow galleryFlow = (GalleryFlow) findViewById(R.id.activity_01_galleryFlow); galleryFlow.setAdapter(adapter); } }
Gallery是android的一个浏览图片的组件(不只是图片,可以用适配器),Gallery的中文意思也是画廊的意思,就是说把图片排成一行,然后手动滑动阅览。本文只是入门介绍,如果要深入了解Gallery还需读者自行不断深入了解。
GalleryFlow gallery在拖动图片过程中,会不断调用getChildStaticTransformation 方法,在该方法中,用Camera实现Z轴旋转。
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 GalleryFlow extends Gallery { private Camera mCamera = new Camera(); private int mMaxRotationAngle = 60; private int mMaxZoom = -120; private int mCoveflowCenter; public GalleryFlow(Context context) { super(context); this.setStaticTransformationsEnabled(true); } public GalleryFlow(Context context, AttributeSet attrs) { super(context, attrs); this.setStaticTransformationsEnabled(true); } public GalleryFlow(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); this.setStaticTransformationsEnabled(true); } public int getMaxRotationAngle() { return mMaxRotationAngle; } public void setMaxRotationAngle(int maxRotationAngle) { mMaxRotationAngle = maxRotationAngle; } public int getMaxZoom() { return mMaxZoom; } public void setMaxZoom(int maxZoom) { mMaxZoom = maxZoom; } private int getCenterOfCoverflow() { return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft(); } private static int getCenterOfView(View view) { return view.getLeft() + view.getWidth() / 2; } @Override 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; } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { mCoveflowCenter = getCenterOfCoverflow(); super.onSizeChanged(w, h, oldw, oldh); } 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); // 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); // 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); } // 在Y轴上旋转,对应图片竖向向里翻转。 // 如果在X轴上旋转,则对应图片横向向里翻转。 mCamera.rotateY(rotationAngle); mCamera.getMatrix(imageMatrix); imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2)); imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2)); mCamera.restore(); } }
ImageAdapter
import android.content.Context; import android.content.res.Resources; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.LinearGradient; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.PorterDuff.Mode; import android.graphics.PorterDuffXfermode; import android.graphics.Shader.TileMode; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; public class ImageAdapter extends BaseAdapter { int mGalleryItemBackground; private Context mContext; private Integer[] mImageIds; private ImageView[] mImages; public ImageAdapter(Context c, Integer[] ImageIds) { mContext = c; mImageIds = ImageIds; mImages = new ImageView[mImageIds.length]; } public boolean createReflectedImages() { final int reflectionGap = 4; int index = 0; for (int imageId : mImageIds) { Bitmap originalImage = BitmapFactory.decodeResource(mContext .getResources(), imageId); int width = originalImage.getWidth(); int height = originalImage.getHeight(); Matrix matrix = new Matrix(); matrix.preScale(1, -1); Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2, width, height / 2, matrix, false); Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2), Config.ARGB_8888); Canvas canvas = new Canvas(bitmapWithReflection); canvas.drawBitmap(originalImage, 0, 0, null); Paint deafaultPaint = new Paint(); canvas.drawRect(0, height, width, height + reflectionGap, deafaultPaint); canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); Paint paint = new Paint(); LinearGradient shader = new LinearGradient(0, originalImage .getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP); paint.setShader(shader); paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint); ImageView imageView = new ImageView(mContext); imageView.setImageBitmap(bitmapWithReflection); imageView.setLayoutParams(new GalleryFlow.LayoutParams(180*2, 240*2)); // imageView.setLayoutParams(new GalleryFlow.LayoutParams(180*4, 240*4)); // imageView.setScaleType(ScaleType.MATRIX); mImages[index++] = imageView; } return true; } private Resources getResources() { // TODO Auto-generated method stub return null; } public int getCount() { return mImageIds.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { return mImages[position]; } public float getScale(boolean focused, int offset) { return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset))); } }
activity_02_gallery.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <com.mahaochen.app.uisharing.example02.GalleryFlow android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/activity_01_galleryFlow"/> </LinearLayout>
演示效果截图:
【Android UI】案例01Cover Flow3D效果的实现