package com.pan.util;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
/**
* 自定义圆形 ImageView
* @author 钟买能
* @version 1.0
* @since 2014-5-30
*/
public class RoundImageView extends ImageView {
public RoundImageView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public RoundImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public RoundImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
// 获取当前控件的 drawable
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
// 这里 get 回来的宽度和高度是当前控件相对应的宽度和高度（在 xml 设置）
if (getWidth() == 0 || getHeight() == 0) {
return;
}
// 画笔
Paint paint = new Paint();
// 颜色设置
paint.setColor(0xff424242);
// 抗锯齿
paint.setAntiAlias(true);
//Paint 的 Xfermode，PorterDuff.Mode.SRC_IN 取两层图像的交集部门, 只显示上层图像。
PorterDuffXfermode xfermode = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
// 获取 bitmap，即传入 imageview 的 bitmap
Bitmap bitmap = ((BitmapDrawable)drawable).getBitmap() ;
// 标志
int saveFlags = Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG;
canvas.saveLayer(0, 0, getWidth(), getHeight(), null, saveFlags);
// 画遮罩，画出来就是一个和空间大小相匹配的圆
canvas.drawCircle(getWidth()/2, getHeight()/2, getWidth()/2, paint);
paint.setXfermode(xfermode);
// 空间的大小 /bitmap 的大小 =bitmap 缩放的倍数
float scaleWidth = ((float) getWidth()) / bitmap.getWidth();
float scaleHeight = ((float) getHeight()) / bitmap.getHeight();
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
//bitmap 缩放
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
//draw 上去
canvas.drawBitmap(bitmap, 0, 0, paint);
// paint.setXfermode(null);
canvas.restore();
}
}