ViewfinderView.java 文件源码

/**
 * 绘制移动扫描线
 * @param canvas
 * @param frame
 */
private void drawLaserScanner(Canvas canvas, Rect frame) {
     linePaint.setColor(laserColor);
     radialGradient = new RadialGradient(
            (float)(frame.left + frame.width() / 2),
            (float)(scannerStart + SCANNER_LINE_HEIGHT / 2),
            360f,
            laserColor,
            shadeColor(laserColor),
            Shader.TileMode.MIRROR);
    linePaint.setShader(radialGradient);
    if(scannerStart < scannerEnd) {
        rectF.set(frame.left + 2 * SCANNER_LINE_HEIGHT,
                scannerStart, frame.right - 2 * SCANNER_LINE_HEIGHT,
                scannerStart + SCANNER_LINE_HEIGHT);
        canvas.drawOval(rectF, linePaint);
        scannerStart += SCANNER_LINE_MOVE_DISTANCE;
    } else {
        scannerStart = frame.top;
    }
    linePaint.setShader(null);
    radialGradient=null;
}