Android drawing an animated line

Question

I\'m currently working with graphics and paths, and I can successufully display whatever I want.

But instead of drawing a line directly on my SurfaceView, I\'d like

Answer 1

I just have resolve this problem, here what I do:

private float[] mIntervals = { 0f, 0f };
private float drawSpeed = 2f;
private int currentPath = -1;
private PathMeasure mPathMeasure = new PathMeasure();
private ArrayList mListPath = new ArrayList(this.pathCount);


@Override
protected void onDraw(Canvas canvas) {
   if (mIntervals[1] <= 0f && currentPath < (pathCount - 1)) {
     // Set the current path to draw
     // getPath(int num) a function to return a path.
     Path newPath = this.getPath(mListPath.size());
     this.mListPath.add(newPath);
     this.mPathMeasure.setPath(newPath, false);
     mIntervals[0] = 0;
     mIntervals[1] = this.mPathMeasure.getLength();
   }

  if (mIntervals[1] > 0) {
     // draw the previous path
     int last = this.mListPath.size();
     for (int i = 0; i < last; i++) {
        canvas.drawPath(this.mListPath.get(i), mPaint);
     }
     // partially draw the last path
     this.mPaint.setPathEffect(new DashPathEffect(mIntervals, 0f));

     canvas.drawPath(this.mListPath.get(last), mPaint);

     // Update the path effects values, to draw a little more
     // on the path.
     mIntervals[0] += drawSpeed;
     mIntervals[1] -= drawSpeed;

     super.invalidate();
  } else {
     // The drawing have been done, draw it entirely
     for (int i = 0; i < this.mListPath.size(); i++) {
        canvas.drawPath(this.mListPath.get(i), mPaint);
     }
  }
}

This example, is an adaptation of what I've done (to simplify the example). Hope you will understand it. Since I've just made this function working, It lacks of optimizations and things like that.

Hope it will help ;-)