Hi Robert,

Great Website!!

I've started programming for Android two weeks ago.
I've read an awful lot about java & android (I had much experience with other languages but not java and not game development).

After the "Hello Android" example I started my own Tetris clone as a practice.
I have created the game as SplashActivity -> MenuActivity -> GameActivity -> GameView -> GameThread. (start with a splash screen, than show a menu with a button for starting the game)

The game itself went fairly smooth but I run into problems now that I want to improve it. I tun into problem openeing an AlertDialog from my GameThread. E.g. used for entering your name when you have a high-score, or just selection if you want to restart / quit the game.

The first issue I ran into is the error message about the looper:

E/AndroidRuntime( 1359): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

I can bypass / solve(?) this by using the following statements because it is an additional Thread besides the UI thread (inside my 'run' method just as a test):
Looper.prepare();

Looper.loop();
Looper.myLooper().quit();

After adding those looper lines I'm able able to open a dialog by using alertdialog.builder. Unfortunately as soon as I select a positive/negative/neutral button my dialog disappears but nothing happens anymore and I see the following line in the logcat output:

W/InputManagerService( 570): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@436c6bf8

After that I can go 'BACK' to my MenuActivity, but that one is not responding either. And pretty fast a 'Force Close' is shown.

I though I had to do with my initial Activity -> View -> Thread setup and made a modified version based on your maxFPS Activity->View->Thread code as a start. The issue remains.

Below the output of logcat, I added log entries with the names of the functions as soon as they are started. This way you can see the 'flow'.

====> My MenuActivity is currently active
====> I press 'start game'to start the GameActivity

I/ActivityManager( 570): Starting activity: Intent { comp={my.android/my.android.game.GameActivity} }
D/GameActivity( 1503): onCreate();
D/GameView( 1503): init();
D/GameEngine( 1503): init();
D/GameEngine( 1503): fillBitmapCache();
D/GameEngine( 1503): createInputObjectPool();
D/GameActivity( 1503): onStart();
D/GameActivity( 1503): startGame();
D/GameView( 1503): getThread();
D/GameView( 1503): create new Thread;
D/GameThread( 1503): -- CONSTRUCTOR --
D/GameView( 1503): updateThreadSurfaceState();
D/GameThread( 1503): setRunning(true);
D/GameThread( 1503): run();
D/GameActivity( 1503): onResume();
D/GameActivity( 1503): onWindowFocusChanged();
D/GameView( 1503): onWindowFOcusChanged();
D/GameThread( 1503): setPaused(false);
D/GameView( 1503): surfaceCreated();
D/GameView( 1503): updateThreadSurfaceState();
D/GameView( 1503): surfaceChanged();
D/GameThread( 1503): -- LOOP --
D/GameEngine( 1503): processInput();
D/GameEngine( 1503): update();
D/GameEngine( 1503): draw();
I/ActivityManager( 570): Displayed activity my.android/.game.GameActivity: 1023 ms
D/GameActivity( 1503): onWindowFocusChanged();
D/GameView( 1503): onWindowFOcusChanged();
D/GameThread( 1503): setPaused(true);

====> Over here an AlertDialog is shown with a positive & negative button
====> I click the positive button

D/GameActivity( 1503): onWindowFocusChanged();
D/GameView( 1503): onWindowFOcusChanged();
D/GameThread( 1503): setPaused(false);
W/InputManagerService( 570): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@436f6a08

====> I click the back button because AlertDialog disappered and that's it
====> I go back to the previous activity, but no responses and pretty fast I
====> have to choose a 'Force close' to terminate the application completely

W/KeyCharacterMap( 1503): No keyboard for id 0
W/KeyCharacterMap( 1503): Using default keymap: /system/usr/keychars/qwerty.kcm.
bin
D/GameEngine( 1503): onKeyDown();
D/GameThread( 1503): setRunning(false);
D/GameActivity( 1503): onPause();
D/GameActivity( 1503): onWindowFocusChanged();
D/GameView( 1503): onWindowFOcusChanged();
D/GameThread( 1503): setPaused(true);
D/GameView( 1503): surfaceDestroyed();
D/GameView( 1503): updateThreadSurfaceState();
D/GameView( 1503): stopThread();
D/GameView( 1503): Stopping Thread
D/GameThread( 1503): setRunning(false);
W/ActivityManager( 570): Launch timeout has expired, giving up wake lock!
W/ActivityManager( 570): Activity idle timeout for HistoryRecord{4362ce18 {my.android/my.android.menu.MenuActivity}}
W/ActivityManager( 570): Activity destroy timeout for HistoryRecord{43640820 {my.android/my.android.game.GameActivity}}

====> No I'm back in my previous activity which does not repond on keys / touches
====> After 20 seconds a 'Force Close'has to be selected

W/WindowManager( 570): Key dispatching timed out sending to my.android/my.android.menu.MenuActivity
W/WindowManager( 570): Dispatch state: {{KeyEvent{action=1 code=4 repeat=0 meta=0 scancode=158 mFlags=8} to Window{43611e78 my.android/my.android.menu.MenuActivity paused=false} @ 1262717403783 lw=Window{43611e78 my.android/my.android.menu.MenuActivity paused=false} lb=android.os.BinderProxy@436122b8 fin=false gfw=true ed=true tts=0 wf=false fp=false mcf=Window{43611e78 my.android/my.android.menu.MenuActivity paused=false}}}
W/WindowManager( 570): Current state: {{null to Window{43611e78 my.android/my.android.menu.MenuActivity paused=false} @ 1262717469025 lw=Window{43611e78 my.android/my.android.menu.MenuActivity paused=false} lb=android.os.BinderProxy@436122b8 fin=false gfw=true ed=true tts=0 wf=false fp=false mcf=Window{43611e78 my.android/my.android.menu.MenuActivity paused=false}}}
I/ActivityManager( 570): ANR (application not responding) in process: my.android
I/ActivityManager( 570): Annotation: keyDispatchingTimedOut
I/ActivityManager( 570): CPU usage:
I/ActivityManager( 570): Load: 0.01 / 0.07 / 0.08
I/ActivityManager( 570): CPU usage from 9131ms to 76ms ago:
I/ActivityManager( 570): system_server: 7% = 5% user + 2% kernel
I/ActivityManager( 570): qemud: 3% = 0% user + 3% kernel
I/ActivityManager( 570): com.android.phone: 0% = 0% user + 0% kernel
I/ActivityManager( 570): events/0: 0% = 0% user + 0% kernel
I/ActivityManager( 570): adbd: 0% = 0% user + 0% kernel
I/ActivityManager( 570): android.process.acore: 0% = 0% user + 0% kernel
I/ActivityManager( 570): TOTAL: 8% = 4% user + 3% kernel + 0% softirq
I/ActivityManager( 570): Removing old ANR trace file from /data/anr/traces.txt
I/Process ( 570): Sending signal. PID: 1503 SIG: 3
I/dalvikvm( 1503): threadid=7: reacting to signal 3
I/Process ( 570): Sending signal. PID: 612 SIG: 3
I/dalvikvm( 612): threadid=7: reacting to signal 3
I/dalvikvm( 612): Wrote stack trace to '/data/anr/traces.txt'
I/Process ( 570): Sending signal. PID: 715 SIG: 3
I/dalvikvm( 715): threadid=7: reacting to signal 3
I/Process ( 570): Sending signal. PID: 640 SIG: 3
I/dalvikvm( 640): threadid=7: reacting to signal 3
I/Process ( 570): Sending signal. PID: 668 SIG: 3
I/dalvikvm( 668): threadid=7: reacting to signal 3
I/Process ( 570): Sending signal. PID: 570 SIG: 3
I/dalvikvm( 570): threadid=7: reacting to signal 3
I/dalvikvm( 640): Wrote stack trace to '/data/anr/traces.txt'
I/dalvikvm( 715): Wrote stack trace to '/data/anr/traces.txt'
I/dalvikvm( 570): Wrote stack trace to '/data/anr/traces.txt'
I/Process ( 570): Sending signal. PID: 610 SIG: 3
I/dalvikvm( 610): threadid=7: reacting to signal 3
I/dalvikvm( 668): Wrote stack trace to '/data/anr/traces.txt'
I/dalvikvm( 610): Wrote stack trace to '/data/anr/traces.txt'
W/WindowManager( 570): No window to dispatch pointer action 1
I/dalvikvm( 1503): Wrote stack trace to '/data/anr/traces.txt'
W/WindowManager( 570): No window to dispatch pointer action 1
W/WindowManager( 570): No window to dispatch pointer action 0
W/WindowManager( 570): No window to dispatch pointer action 1
W/WindowManager( 570): No window to dispatch pointer action 0
W/WindowManager( 570): No window to dispatch pointer action 1
W/WindowManager( 570): No window to dispatch pointer action 0
W/WindowManager( 570): No window to dispatch pointer action 1

====> Select 'Force Close'

I/ActivityManager( 570): Killing process my.android (pid=1503) at user's request
I/Process ( 570): Sending signal. PID: 1503 SIG: 9
I/WindowManager( 570): WIN DEATH: Window{436b4930 SurfaceView paused=false}
I/WindowManager( 570): WIN DEATH: Window{43652728 my.android/my.android.game.GameActivity paused=false}
I/WindowManager( 570): WIN DEATH: Window{43611e78 my.android/my.android.menu.MenuActivity paused=false}
I/ActivityManager( 570): Process my.android (pid 1503) has died.
W/InputManagerService( 570): Got RemoteException sending setActive(false) notification to pid 1503 uid 10019

I hope you can point me in a direction for fixing this. The last four days I have been looking for clues about a possible workaround / cause. Maybe I'm even using the wrong approach for such a dialog box.
(Sorry for the long post I tried to give you as much detail as possible without just listing all code and asking for a fix.)