android – 填充完整的画布,但保持绑定的填充区域,因为它像圆形,矩形

final Point p1 = new Point();
                p1.x=(int) x; //x co-ordinate where the user touches on the screen
                p1.y=(int) y; //y co-ordinate where the user touches on the screen  
 new TheTask(yourbitmap,p1,sourceColor,targetColor).execute();// use asyntask for efficiency

 class TheTask extends AsyncTask<Void,Integer,Void> {

    Bitmap bmp;
    Point pt;
    int replacementColor,targetColor;
    ProgressDialog pd;
 public TheTask(Bitmap bm,Point p,int sc,int tC)
 {
this.bR_823_11845@p=bm;
this.pt=p;
this.replacementColor=tc;
this.targetColor=sc;
pd= new ProgressDialog(co@R_607_10443@t);
pd.setmessage("Filling....");
    }
    @Override
    protected void onPreExecute() {
            pd.show();

    }

    @Override
    protected void onProgressupdate(Integer... values) {

    }

    @Override
    protected Void doInBACkground(Void... params) {
        FloodFill f= new FloodFill();
        f.floodFill(bmp,pt,targetColor,replacementColor);
        return null;
    }

    @Override
    protected void onPostExecute(Void result) { 
pd.dismiss();
invalidate();
    }

最后使用FloodFill算法填充封闭区域

public class FloodFill {
public void floodFill(Bitmap  image,Point node,int targetColor,int replacementColor) {
    int width = image.getWidth();
    int height = image.getHeight();
    int target = targetColor;
    int replacement = replacementColor;
    if (target != replacement) {
        Queue<Point> queue = new LinkedList<Point>();
        do {
            int x = node.x;
            int y = node.y;
            while (x > 0 && image.getPixel(x - 1,y) == target) {
                x--;
            }
            Boolean spanUp = false;
            Boolean spanDown = false;
            while (x < width && image.getPixel(x,y) == target) {
                image.setPixel(x,y,replacement);
                if (!spanUp && y > 0 && image.getPixel(x,y - 1) == target) {
                    queue.add(new Point(x,y - 1));
                    spanUp = true;
                } else if (spanUp && y > 0
                        && image.getPixel(x,y - 1) != target) {
                    spanUp = false;
                }
                if (!spanDown && y < height - 1
                        && image.getPixel(x,y + 1) == target) {
                    queue.add(new Point(x,y + 1));
                    spanDown = true;
                } else if (spanDown && y < height - 1
                        && image.getPixel(x,y + 1) != target) {
                    spanDown = false;
                }
                x++;
            }
        } while ((node = queue.poll()) != null);
    }
}
}