Android控件开发之Gallery3D效果

package xiaosi.GalleryFlow;

import android.app.Activity;
import android.os.Bundle;

public class GalleryFlowActivity extends Activity {
	public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        
        setContentView(R.layout.main);
        
        Integer[] images = { R.drawable.a, R.drawable.b,
                R.drawable.c, R.drawable.d, R.drawable.e,
                };
        
        ImageAdapter adapter = new ImageAdapter(this, images);
        adapter.createReflectedImages();

        GalleryFlow galleryFlow = (GalleryFlow) findViewById(R.id.Gallery01);
        galleryFlow.setAdapter(adapter);
        
}
}

ImageAdapter.java

package xiaosi.GalleryFlow;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

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(250, 340));
             imageView.setScaleType(ScaleType.FIT_XY);
             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)));
     }
}

 

GalleryFlow.java

package xiaosi.GalleryFlow;

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;
    }

    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();
    }
}

 

源代码：点击打开链接