android.view.SurfaceHolder#setFormat ( )源码实例Demo

public SearchView(Context context, StringBuilder queryText) {
    super(context);

    mContext = context;
    mQueryText = queryText;

    mPaint = new Paint();
    mPaint.setAntiAlias(true);

    final SurfaceHolder holder = getHolder();
    holder.setFormat(PixelFormat.TRANSLUCENT);
    holder.addCallback(mSurfaceCallback);

    final Resources res = context.getResources();

    int mExtremeRadius = 128;

    // Gradient colors.
    final int gradientInnerColor = res.getColor(R.color.search_overlay);
    final int gradientOuterColor = res.getColor(R.color.search_overlay);
    final int[] colors = new int[] {gradientInnerColor, gradientOuterColor};
    mGradientBackground =
            new GradientDrawable(Orientation.TOP_BOTTOM, colors);
    mGradientBackground.setGradientType(GradientDrawable.LINEAR_GRADIENT);
}
 

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Check for the camera permission before accessing the camera.  If the
    // permission is not granted yet, request permission.
    SurfaceHolder holder = mView.getHolder();
    holder.addCallback(this);
    holder.setFormat(ImageFormat.NV21);
}
 

private void init(@SuppressWarnings("UnusedParameters") Context context) {
	SurfaceHolder holder = getHolder();
	holder.addCallback(this);
	holder.setFormat(PixelFormat.RGBA_8888);
	setKeepScreenOn(true);
	mainThreadHandler = new Handler(Looper.getMainLooper());
}
 

@Override
public void surfaceCreated(SurfaceHolder holder) {
     this.holder = holder;
     holder.setFormat(PixelFormat.TRANSLUCENT);
     isCreatedFlag = true;
     Log.d("Loading","surfaceCreated");
 }
 

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    this.holder = holder;
    holder.setFormat(PixelFormat.TRANSLUCENT);

    Log.d("Loading","surfaceChanged");
}
 

private void initPaint() {
    SurfaceHolder holder = getHolder();
    holder.addCallback(this);
    holder.setFormat(PixelFormat.TRANSPARENT);
    setZOrderOnTop(true);

    linePaint.setAntiAlias(true);
    linePaint.setColor(0xff05225C);
    linePaint.setStyle(Paint.Style.STROKE);
    linePaint.setStrokeCap(Paint.Cap.ROUND);
    linePaint.setStrokeWidth(20);

}
 

private void init() {

        setZOrderOnTop(true);
        SurfaceHolder holder = getHolder();
        holder.addCallback(this);
        holder.setFormat(PixelFormat.TRANSPARENT);

        overlayPaint = new Paint();
        overlayPaint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
        overlayPaint.setStyle(Paint.Style.STROKE);
        overlayPaint.setStrokeCap(Paint.Cap.ROUND);
        overlayPaint.setStrokeJoin(Paint.Join.ROUND);

    }