1 public class ImageViewPlus extends ImageView{
  2     /**
  3      * android.widget.ImageView
  4      */
  5     public static final int TYPE_NONE = 0;
  6     /**
  7      * 圓形
  8      */
  9     public static final int TYPE_CIRCLE = 1;
 10     /**
 11      * 圓角矩形
 12      */
 13     public static final
 
 int TYPE_ROUNDED_RECT = 2;    
 14     
 15     private static final int DEFAULT_TYPE = TYPE_NONE;
 16     private static final int DEFAULT_BORDER_COLOR = Color.TRANSPARENT;
 17     private static final int DEFAULT_BORDER_WIDTH = 0;
 18     private static final int DEFAULT_RECT_ROUND_RADIUS = 0;
 19     
 20
 
     private int mType;
 21     private int mBorderColor;
 22     private int mBorderWidth;
 23     private int mRectRoundRadius;
 24     
 25     private Paint mPaintBitmap = new Paint(Paint.ANTI_ALIAS_FLAG);
 26     private Paint mPaintBorder = new Paint(Paint.ANTI_ALIAS_FLAG);
 27     
 28     private
 
 RectF mRectBorder = new RectF();
 29     private RectF mRectBitmap = new RectF();
 30     
 31     private Bitmap mRawBitmap;
 32     private BitmapShader mShader;
 33     private Matrix mMatrix = new Matrix();
 34     
 35     public ImageViewPlus(Context context, AttributeSet attrs) {
 36         super(context, attrs);
 37         //取xml檔案中設定的引數
 38         TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ImageViewPlus);
 39         mType = ta.getInt(R.styleable.ImageViewPlus_type, DEFAULT_TYPE);
 40         mBorderColor = ta.getColor(R.styleable.ImageViewPlus_borderColor, DEFAULT_BORDER_COLOR);
 41         mBorderWidth = ta.getDimensionPixelSize(R.styleable.ImageViewPlus_borderWidth, dip2px(DEFAULT_BORDER_WIDTH));
 42         mRectRoundRadius = ta.getDimensionPixelSize(R.styleable.ImageViewPlus_rectRoundRadius, dip2px(DEFAULT_RECT_ROUND_RADIUS));
 43         ta.recycle();
 44     }
 45     
 46     @Override
 47     protected void onDraw(Canvas canvas) {
 48         Bitmap rawBitmap = getBitmap(getDrawable());
 49         
 50         if (rawBitmap != null && mType != TYPE_NONE){
 51             int viewWidth = getWidth();
 52             int viewHeight = getHeight();
 53             int viewMinSize = Math.min(viewWidth, viewHeight);
 54             float dstWidth = mType == TYPE_CIRCLE ? viewMinSize : viewWidth;
 55             float dstHeight = mType == TYPE_CIRCLE ? viewMinSize : viewHeight;
 56             float halfBorderWidth = mBorderWidth / 2.0f;
 57             float doubleBorderWidth = mBorderWidth * 2;
 58             
 59             if (mShader == null || !rawBitmap.equals(mRawBitmap)){
 60                 mRawBitmap = rawBitmap;
 61                 mShader = new BitmapShader(mRawBitmap, TileMode.CLAMP, TileMode.CLAMP);
 62             }
 63             if (mShader != null){
 64                 mMatrix.setScale((dstWidth - doubleBorderWidth) / rawBitmap.getWidth(), (dstHeight - doubleBorderWidth) / rawBitmap.getHeight());
 65                 mShader.setLocalMatrix(mMatrix);
 66             }
 67             
 68             mPaintBitmap.setShader(mShader);
 69             mPaintBorder.setStyle(Paint.Style.STROKE);
 70             mPaintBorder.setStrokeWidth(mBorderWidth);
 71             mPaintBorder.setColor(mBorderWidth > 0 ? mBorderColor : Color.TRANSPARENT);
 72             
 73             if (mType == TYPE_CIRCLE){
 74                 float radius = viewMinSize / 2.0f;
 75                 canvas.drawCircle(radius, radius, radius - halfBorderWidth, mPaintBorder);
 76                 canvas.translate(mBorderWidth, mBorderWidth);
 77                 canvas.drawCircle(radius - mBorderWidth, radius - mBorderWidth, radius - mBorderWidth, mPaintBitmap);
 78             } else if (mType == TYPE_ROUNDED_RECT){
 79                 mRectBorder.set(halfBorderWidth, halfBorderWidth, dstWidth - halfBorderWidth, dstHeight - halfBorderWidth);
 80                 mRectBitmap.set(0.0f, 0.0f, dstWidth - doubleBorderWidth, dstHeight - doubleBorderWidth);
 81                 float borderRadius = mRectRoundRadius - halfBorderWidth > 0.0f ? mRectRoundRadius - halfBorderWidth : 0.0f;
 82                 float bitmapRadius = mRectRoundRadius - mBorderWidth > 0.0f ? mRectRoundRadius - mBorderWidth : 0.0f;
 83                 canvas.drawRoundRect(mRectBorder, borderRadius, borderRadius, mPaintBorder);
 84                 canvas.translate(mBorderWidth, mBorderWidth);
 85                 canvas.drawRoundRect(mRectBitmap, bitmapRadius, bitmapRadius, mPaintBitmap);
 86             }
 87         } else {
 88             super.onDraw(canvas);
 89         }
 90     }
 91 
 92     private int dip2px(int dipVal)
 93     {
 94         float scale = getResources().getDisplayMetrics().density;
 95         return (int)(dipVal * scale + 0.5f);
 96     }
 97     
 98     private Bitmap getBitmap(Drawable drawable){
 99         if (drawable instanceof BitmapDrawable){
100             return ((BitmapDrawable)drawable).getBitmap();
101         } else if (drawable instanceof ColorDrawable){
102             Rect rect = drawable.getBounds();
103             int width = rect.right - rect.left;
104             int height = rect.bottom - rect.top;
105             int color = ((ColorDrawable)drawable).getColor();
106             Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
107             Canvas canvas = new Canvas(bitmap);
108             canvas.drawARGB(Color.alpha(color), Color.red(color), Color.green(color), Color.blue(color));
109             return bitmap;
110         } else {
111             return null;
112         }
113     }
114 }