CODEWITHSUNDEEP
android
OckhamsRazor
OckhamsRazor

Reputation: 4906

Android: transform image using a Matrix

I'm looking to transform an image using a Matrix on the onDraw method of a custom class I created which extends ImageView e.g.,

@Override
public void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.save();
    canvas.setMatrix(imageMatrix);
    canvas.drawBitmap(((BitmapDrawable)mIcon).getBitmap(), imageMatrix, null);
    canvas.restore();
}

However, what I coded above does not really work. How exactly do I apply the imageMatrix on the canvas? Thanks!

Upvotes: 0

Views: 1150

Answers (2)

a.ch.
a.ch.

Reputation: 8390

Try calling Drawable.draw(Canvas) method:

@Override
public void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.save();
    canvas.setMatrix(imageMatrix);
    ((BitmapDrawable)mIcon).draw(canvas);
    canvas.restore();
}

Upvotes: 2

Ilya Gazman
Ilya Gazman

Reputation: 32271

All you did is good, just put the super call to be the last, coz there is where all the painting is done...

@Override
public void onDraw(Canvas canvas) {
    canvas.setMatrix(imageMatrix);
    super.onDraw(canvas);
}

Upvotes: -1

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