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图片左右滚动控件(带倒影)——重写Gallery

转http://blog.csdn.net/ryantang03/article/details/8053643

今天在网上找了些资料,做了一个图片左右滚动的Demo,类似幻灯片播放,同时,图片带倒影效果,运行效果如下图:

                                                         

实现方式是重写Gallery,使用自定义的Gallery来实现这一效果,工程一共三个文件,一个Activity,一个自定义的Gallery,还有就是一个适配器ImageAdapter,直接上代码:

ScrollGallery.java

  

public class ScrollGallery extends Gallery {      private Camera mCamera = new Camera();      //左右图片倾斜的角度      private int mMaxRotationAngle = 60;      //背景区域大小      private int mMaxZoom = -380;      private int mCoveflowCenter;        public ScrollGallery(Context context) {          super(context);          this.setStaticTransformationsEnabled(true);      }        public ScrollGallery(Context context, AttributeSet attrs) {          super(context, attrs);          this.setStaticTransformationsEnabled(true);      }        public ScrollGallery(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;      }        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;      }        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          // 在Y轴上移动,上下移动;X轴上左右移动。          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);          }          // 在Y轴上旋转,竖向向里翻转。          // 在X轴上旋转,则横向向里翻转。          mCamera.rotateY(rotationAngle);          mCamera.getMatrix(imageMatrix);          imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));          imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));          mCamera.restore();      }  }  

 

ImageAdapter.java

public class ImageAdapter extends BaseAdapter {      //倒影的缩放比例      private static final int REFLECTION = 5;            int mGalleryItemBackground;      private Context mContext;      private int[] mImageIds;      private ImageView[] mImages;        public ImageAdapter(Context c, int[] ImageIds) {          mContext = c;          mImageIds = ImageIds;          mImages = new ImageView[mImageIds.length];      }        public boolean createReflectedImages() {          final int reflectionGap = 5;          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 / REFLECTION), 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 ScrollGallery.LayoutParams(180, 240));              mImages[index++] = imageView;          }          return true;      }        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)));      }  }  

 

ScrollImageActivity.java

 

public class ScrollImageActivity extends Activity {      /** Called when the activity is first created. */            private ScrollGallery galleryFlow = null;            int images[] = {R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.f};            @Override      public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          requestWindowFeature(Window.FEATURE_NO_TITLE);          setContentView(R.layout.main);          galleryFlow = (ScrollGallery) this.findViewById(R.id.gf_images);          ImageAdapter adapter = new ImageAdapter(this, images);          adapter.createReflectedImages();          galleryFlow.setAdapter(adapter);          galleryFlow.setSelection(1);      }  }  

 

 

main.xml

  

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:layout_width="fill_parent"      android:layout_height="fill_parent"      android:orientation="vertical" >        <com.ryan.scrollimage.ScrollGallery          android:id="@+id/gf_images"          android:layout_width="fill_parent"          android:layout_height="0dip"          android:layout_weight="1" />    </LinearLayout>  

 

图片左右滚动控件(带倒影)——重写Gallery