Slow scrolling of bitmap
<p>I have a custom view and I draw a bitmap directly onto the canvas in the onDraw method. My problem is that the first few times, it's quite slow (the bitmap is large) to respond to any scrolling interactions. Once it gets over the initial hump, its quite responsive. My questions is, 1. where is the slowness? 2. Can I get notified when whatever its doing is over so as to show a progress bar for loading or something?</p>

<p>Some more details:</p>

<p>I draw like this in my custom view:</p>

<pre><code>    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawBitmap(mBitmap, mTranslate, null);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return mGestures.onTouchEvent(event);
    }
</code></pre>

<p>Where mGestures is a class:</p>

<pre><code>private class GestureListener implements GestureDetector.OnGestureListener,
        GestureDetector.OnDoubleTapListener { ... }
</code></pre>

<p>In there I handle the scrolling. The exact point that is slow is when I change the translation matrix, and the invalidate it, the next onDraw is quite slow.</p>
