How to wait until the path is drawn on canvas in android?

Question

I have different Path's in my List and I want to draw one Path on Canvas at a time but I am executing a for loop and while drawing one path another path starts to be drawn on Canvas. What can I do to stop the for loop or wait until the path is drawn. for loop is given below.

                   for ( i = 0; i < mPaths.size(); i++) {
                        SvgHelper.SvgPath svgPath = mPaths.get(i);
                        svgPath.paint.setAlpha(255);
                        canvas.drawPath(svgPath.path, svgPath.paint);                           
                    }

onDraw(Canvas canvas) method code. Size of mPaths List variable is 24. The thing is want to draw one path at a time but when i keep it in for loop all 24 paths are drawn simultaneously.

@Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // Log.w("On draw", "Executing Ondraw");

        synchronized (mSvgLock) {

            canvas.save();

            canvas.translate(getPaddingLeft(), getPaddingTop()
                    - getPaddingBottom());

                canvas.save();

                canvas.translate(getPaddingLeft(), getPaddingTop()
                        - getPaddingBottom());

                for (i = 0; i < mPaths.size(); i++) {
                    //
                    Log.w("no of times", String.valueOf(i));
                    //
                    synchronized (Lock) {

                        SvgHelper.SvgPath svgPath = mPaths.get(i);
                        svgPath.paint.setAlpha(255);
                        canvas.drawPath(svgPath.path, svgPath.paint);
                    }

//                  break;
                }

                canvas.restore();

        }

        canvas.save();
        canvas.translate(0.0f, getHeight() - getPaddingBottom() - mRadius
                * 3.0f);
    }

If I understand it right - you need to animate drawing, so in draw loop you should not use list.size() but variable from 1 to list.size() and variable increases at the end of onDraw and calls invalidate or postdelayed method with invalidate task — curioushikhov, Aug 10 '14 at 06:00
Sorry @curioushikhov but can you please explain what you saying. because I am not getting that.. — Mohammed Rampurawala, Aug 10 '14 at 12:23
No onDraw() method runs 24 times draw's the path object and until the path.close is not encountered for every Path object it is drawn. — Mohammed Rampurawala, Aug 10 '14 at 14:07
https://www.youtube.com/watch?v=-NxG3BE9QCg @MarcoAcierno as in this video all Paths are drawn simultaneously I want to draw Paths one by one.. the video is shown that how my Paths are drawn. — Mohammed Rampurawala, Aug 10 '14 at 14:11

score 0 · Answer 1 · answered Aug 08 '14 at 11:56

0

You can create a Object for lock and put you core code in Synchronized block.

Try this;

Object lock = new Object();
for ( i = 0; i < mPaths.size(); i++) {
    synchronized (lock) {
        SvgHelper.SvgPath svgPath = mPaths.get(i);
        svgPath.paint.setAlpha(255);
        canvas.drawPath(svgPath.path, svgPath.paint);
    }               
}

answered Aug 08 '14 at 11:56

callofdutyops

318
3
9

Thank you. I have tried this but it is not working. Its drawing the same. Posted my onDraw(Canvas canvas) method code. – Mohammed Rampurawala Aug 08 '14 at 12:13

How to wait until the path is drawn on canvas in android?

1 Answers1