Comments on: Playing with graphics in Android – Part I

By: Dan Norcott

Dan Norcott — Sat, 04 Sep 2010 15:43:16 +0000

Thanks – just what I needed to get me started

By: Rick Pingry

Rick Pingry — Fri, 13 Aug 2010 14:49:28 +0000

Thanks for all your great advice and tutorials, very much appreciated.
I am trying to wrap my head around the Activity-View-Thread model.
Specifically, I want to make a game menu that will allow you to choose levels, then if the user presses the back key while in a level, they could perhaps resume the level without starting over. I also want it to make it play nice with the rest of the DROID OS (like when you press Home and then return to your app). Any ideas on a menu screen architecture? I know how to fire off new Activities with a button click, I am just not sure about the back button from the level and the resume from the main menu.

After many crashes of the emulator, I am starting to realize that I cannot depend on keeping things around in the Activity, View, or Thread (Canvas?). Even turning the DROID sideways starts things over again right? I am thinking that on certain callbacks I need to dump everything and then start over. Is that right? I do get some of the Activity life-cycle mentioned in the Android dev docs, but I am not completely sure if I have it all down to handle every case. Any advice?

I guess I need to keep the game state somewhere it will not be trashed. If I make the game so that it only runs one time in the manifest, can I hold on to stuff as static variables of the Main Activity class? I have read recently that I need to be careful of keeping implicit back-references to the Activity class around as statics, because it calls a leak. I think that happens most easily through the context. I think I can get an Application context right? Am I heading in the right direction? Any Advice?

Thanks Again
– Rick

By: faisal

faisal — Tue, 27 Jul 2010 12:41:57 +0000

Hi Martin,

Just an update might be useful to other ppl viewing this, I found out what was causing the antialiasing the get messed. I wasnt drawing a background colour. I wasnt aware I needed to do this but hey ho.

Thanks
Faisal

P.S. wicked site keep up the good work!

By: faisal

faisal — Tue, 27 Jul 2010 12:16:28 +0000

Hi Martin,

I was wondering if you could give me a bit of help. I created a simple application which contains a surface view and a thread and it simply draws a rounded rectangle within the on draw method. the problem I have is that the graphic being drawn on my device/emulator still has jagged edges even though I have set antialias to true.

Any ideas?

thanks
Faisal

By: Overv

Overv — Thu, 22 Jul 2010 18:03:18 +0000

Great tutorial, but isn’t it a better idea to only call decodeResource once? It seemed to be quite a bit faster in my tests.

By: Flycomte

Flycomte — Sat, 12 Jun 2010 06:16:41 +0000

thank u for your tutorial.

By: Martin

Martin — Thu, 03 Jun 2010 17:42:47 +0000

You should use your own SurfaceView within an XML definition. You can read here more about your own Components: http://developer.android.com/guide/topics/ui/custom-components.html#modifying

By: Jaideep

Jaideep — Thu, 03 Jun 2010 17:32:33 +0000

Thanks for the quick and easy tutorial. I have a requirement to draw a small panel (smaller than the total screen size) more like a EditView that supports mutliple lines where I can draw using the Touch events.
Any help/guidance ??

By: dw

dw — Mon, 31 May 2010 19:31:23 +0000

Thank you! This is a great example for learning how to use Canvas. Looking forward to reading part II.

By: Martin

Martin — Wed, 26 May 2010 19:56:47 +0000

You can create a SurfaceView as an overlay over your SlidingDrawer, but you keep in mind to make the SurfaceView transparent. Try that