Android 自定义View修炼-高仿猎豹清理大师自定义内存开口圆环比例进度View

public XCArcProgressBar(Context context, AttributeSet attrs,
            int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        // TODO Auto-generated constructor stub
        
        
        degrees =  0;
        paint  =  new Paint();
        //从attrs.xml中获取自定义属性和默认值
        TypedArray typedArray  = context.obtainStyledAttributes(attrs, R.styleable.XCRoundProgressBar);
        textColor  =typedArray.getColor(R.styleable.XCRoundProgressBar_textColor, Color.RED);
        textSize = typedArray.getDimension(R.styleable.XCRoundProgressBar_textSize, 15);
        max = typedArray.getInteger(R.styleable.XCRoundProgressBar_max, 100);
        isDisplayText  =typedArray.getBoolean(R.styleable.XCRoundProgressBar_textIsDisplayable, true);
        typedArray.recycle();
        
    }

@Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        int width = getWidth();
        int height = getHeight();
        int centerX = getWidth() / 2;// 获取中心点X坐标
        int centerY = getHeight() / 2;// 获取中心点Y坐标

        Bitmap bitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
        Canvas can = new Canvas(bitmap);
        // 绘制底部背景图
        bmpTemp = Utils.decodeCustomRes(getContext(), R.drawable.arc_bg);
        float dstWidth = (float) width;
        float dstHeight = (float) height;
        int srcWidth = bmpTemp.getWidth();
        int srcHeight = bmpTemp.getHeight();

        can.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG
                | Paint.FILTER_BITMAP_FLAG));// 抗锯齿

        Bitmap bmpBg = Bitmap.createScaledBitmap(bmpTemp, width, height, true);
        can.drawBitmap(bmpBg, 0, 0, null);

        // 绘制进度前景图
        Matrix matrixProgress = new Matrix();
        matrixProgress.postScale(dstWidth / srcWidth, dstHeight / srcWidth);
        bmpTemp = Utils.decodeCustomRes(getContext(), R.drawable.arc_progress);

        Bitmap bmpProgress = Bitmap.createBitmap(bmpTemp, 0, 0, srcWidth,
                srcHeight, matrixProgress, true);
        degrees = progress * 270 / max - 270;
        //遮罩处理前景图和背景图
        can.save();
        can.rotate(degrees, centerX, centerY);
        paint.setAntiAlias(true);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
        can.drawBitmap(bmpProgress, 0, 0, paint);
        can.restore();
        
        if ((-degrees) >= 85) {
            int posX = 0;
            int posY = 0;
            if ((-degrees) >= 270) {
                posX = 0;
                posY = 0;
            } else if ((-degrees) >= 225) {
                posX = centerX / 2;
                posY = 0;
            } else if ((-degrees) >= 180) {
                posX = centerX;
                posY = 0;
            } else if ((-degrees) >= 135) {
                posX = centerX;
                posY = 0;
            } else if ((-degrees) >= 85) {
                posX = centerX;
                posY = centerY;
            }
            
            if ((-degrees) >= 225) {

                can.save();
                Bitmap dst = bitmap
                        .createBitmap(bitmap, 0, 0, centerX, centerX);
                paint.setAntiAlias(true);
                paint.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
                Bitmap src = bmpBg.createBitmap(bmpBg, 0, 0, centerX, centerX);
                can.drawBitmap(src, 0, 0, paint);
                can.restore();

                can.save();
                dst = bitmap.createBitmap(bitmap, centerX, 0, centerX, height);
                paint.setAntiAlias(true);
                paint.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
                src = bmpBg.createBitmap(bmpBg, centerX, 0, centerX, height);
                can.drawBitmap(src, centerX, 0, paint);
                can.restore();

            } else {
                can.save();
                Bitmap dst = bitmap.createBitmap(bitmap, posX, posY, width
                        - posX, height - posY);
                paint.setAntiAlias(true);
                paint.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
                Bitmap src = bmpBg.createBitmap(bmpBg, posX, posY,
                        width - posX, height - posY);
                can.drawBitmap(src, posX, posY, paint);
                can.restore();
            }
        }
        //绘制遮罩层位图
        canvas.drawBitmap(bitmap, 0, 0, null);
        
        // 画中间进度百分比字符串
        paint.reset();
        paint.setStrokeWidth(0);
        paint.setColor(textColor);
        paint.setTextSize(textSize);
        paint.setTypeface(Typeface.DEFAULT_BOLD);
        int percent = (int) (((float) progress / (float) max) * 100);// 计算百分比
        float textWidth = paint.measureText(percent + "%");// 测量字体宽度，需要居中显示

        if (isDisplayText && percent != 0) {
            canvas.drawText(percent + "%", centerX - textWidth / 2, centerX
                    + textSize / 2 - 25, paint);
        }
        //画底部开口处标题文字
        paint.setTextSize(textSize/2);
        textWidth = paint.measureText(title);
        canvas.drawText(title, centerX-textWidth/2, height-textSize/2, paint);
    }

/**
     * 设置进度，此为线程安全控件，由于考虑多线的问题，需要同步
     * 刷新界面调用postInvalidate()能在非UI线程刷新
     * @author caizhiming
     */ 
    public synchronized void setProgress(int progress) {
        if(progress < 0){
            throw new IllegalArgumentException("progress must more than 0");
        }
        if(progress > max){
            this.progress = progress;
        }
        if(progress <= max){
            this.progress = progress;
            postInvalidate();
        }
    }