Btw forgot to say thanks Romain for your help. I have another question (see forum) which I'm sure you are very capable of answering :D
On Jun 24, 10:56 am, rukiman <[email protected]> wrote: > Found the issue is because I have to clear the bitmap first before > rendering the view onto it, the edges are transparent and its showing > through to what was drawn before. > Question is how would I know what color to clear the bitmap with? > > On Jun 24, 10:14 am, Romain Guy <[email protected]> wrote: > > > > > > > > > The drawing cache is per view, so if you need to capture several views > > (sibling, and not a subtree like you are doing in your example) if > > would be better to allocate a single bitmap. This works of course only > > if all the views have the same size. > > > On Thu, Jun 23, 2011 at 5:06 PM, rukiman <[email protected]> wrote: > > > I am suspecting using the view cache system causes the view system to > > > allocate memory for the view. > > > Now lets say I can to capture 3 views, does that mean memory is > > > allocated for 3 views worth of caches if I don't destroy the cache? > > > > Also I noticed through profiling that this code runs around 100ms > > > view.setDrawingCacheEnabled(true); > > > view.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH); > > > view.setDrawingCacheBackgroundColor(Color.BLACK); > > > Bitmap bitmap = view.getDrawingCache(); > > > Bitmap retVal = bitmap == null ? null : > > > bitmap.copy(bitmap.getConfig(), false); > > > view.destroyDrawingCache(); > > > view.setDrawingCacheEnabled(false); > > > return retVal; > > > > while this runs at around 60ms > > > mCanvas.setBitmap(mBitmapCapture); > > > view.draw(mCanvas); > > > Bitmap retVal = mBitmapCapture; > > > > I have to capture a few views and trying to speed them as quick as > > > possible and at the same time not use much memory. I guess the slight > > > speed difference is in enabling and destroying the view drawing cache? > > > What is the effect of not destroying it? Does that mean it will suffer > > > from my approach above that is double the workload on each frame as > > > well? > > > > Going back to my approach my code is just as I pasted it, should I be > > > saving the canvas and restoring it in the dispatchDraw? Any help is > > > appreciated. Thanks. > > > > On Jun 24, 9:47 am, Romain Guy <[email protected]> wrote: > > >> It's either because you don't properly save/restore the state of your > > >> offline Canvas or maybe because of the bitmap config (although it > > >> should work just fine in 565.) > > > >> What I don't understand however is why you refuse to use the drawing > > >> cache API that already exists for this purpose? Using this API will > > >> not necessarily force another redraw of the view. With the drawing > > >> cache, the cache is automatically redrawn whenever the view changes. > > >> Your approach however doubles the workload on *every* frame. > > > >> On Thu, Jun 23, 2011 at 4:23 PM, rukiman <[email protected]> > > >> wrote: > > >> > I am trying to understand which this code which works perfectly for > > >> > capturing almost any view except if there is a ScrollView in the > > >> > framelayout, in this case there is a slight issue with the top and > > >> > bottom areas where scrollview fades its contents. There is some > > >> > corruption occurring. > > > >> > public class FrameLayoutWithOfflineBitmap extends FrameLayout { > > > >> > private Bitmap mOfflineBitmap; > > >> > private Canvas mOfflineCanvas; > > > >> > public FrameLayoutWithOfflineBitmap(Context context) { > > >> > super(context); > > >> > } > > > >> > @Override > > >> > public void onSizeChanged(int w, int h, int oldw, int oldh) { > > >> > // just in case we already had the bitmap allocated > > >> > before > > >> > if(mOfflineBitmap != null) { > > >> > mOfflineBitmap.recycle(); > > >> > } > > >> > mOfflineBitmap = Bitmap.createBitmap(w, h, > > >> > Bitmap.Config.RGB_565); > > >> > mOfflineCanvas = new Canvas(); > > >> > mOfflineCanvas.setBitmap(mOfflineBitmap); > > >> > } > > > >> > @Override > > >> > public void dispatchDraw(Canvas canvas) { > > >> > // draw to our offline bitmap > > >> > super.dispatchDraw(mOfflineCanvas); > > >> > // now draw our offline bitmap to the system canvas > > >> > canvas.drawBitmap(mOfflineBitmap, 0, 0, null); > > >> > } > > > >> > public Bitmap getScreenSnapshot() { > > >> > return mOfflineBitmap; > > >> > } > > >> > } > > > >> > I understand there are other ways to capture the view such as using > > >> > the View's drawing cache, but I am not interested in this method. Can > > >> > someone explain to me what is going on here and if there is way to > > >> > address this issue? Basically I am trying to get access to a snapshot > > >> > of a view as quick as possible. My idea is that the view is already > > >> > drawn onto the screen, we should be able to get access to this without > > >> > having to force another redundant redraw of the view. > > > >> > I am also very keen to understand the flaw with the above code in > > >> > terms of the scrollview. Thanks. > > > >> > -- > > >> > You received this message because you are subscribed to the Google > > >> > Groups "Android Developers" group. > > >> > To post to this group, send email to > > >> > [email protected] > > >> > To unsubscribe from this group, send email to > > >> > [email protected] > > >> > For more options, visit this group at > > >> >http://groups.google.com/group/android-developers?hl=en > > > >> -- > > >> Romain Guy > > >> Android framework engineer > > >> [email protected] > > > >> Note: please don't send private questions to me, as I don't have time > > >> to provide private support. All such questions should be posted on > > >> public forums, where I and others can see and answer them > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "Android Developers" group. > > > To post to this group, send email to [email protected] > > > To unsubscribe from this group, send email to > > > [email protected] > > > For more options, visit this group at > > >http://groups.google.com/group/android-developers?hl=en > > > -- > > Romain Guy > > Android framework engineer > > [email protected] > > > Note: please don't send private questions to me, as I don't have time > > to provide private support. All such questions should be posted on > > public forums, where I and others can see and answer them -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
