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Bug 2133

Summary: SDL_AddTouch added too late for Android
Product: SDL Reporter: Martin Gerhardy <martin.gerhardy>
Component: *don't know*Assignee: Ryan C. Gordon <icculus>
Status: RESOLVED FIXED QA Contact: Sam Lantinga <slouken>
Severity: normal    
Priority: P2 CC: philipp.wiesemann
Version: HG 2.0   
Hardware: All   
OS: Android (All)   
Attachments: hg export for add touches in init with JNI

Description Martin Gerhardy 2013-10-04 07:29:22 UTC 
Is there any chance that SDL_AddTouch can get executed earlier for
Android? I'm trying to get thinks working on the OUYA and querying
SDL_GetNumTouchDevices after SDL_INIT_VIDEO call still gives me 0 on my
phone and tablet. So I can't rely on the value before I did my first touch.
This is of course too late when it's about assembling the UI dependent on
whether there is a touch device or not.

It would be great if this information could get set earlier.




Btw. There is a "Touch" component missing in the list above.
Comment 1 Philipp Wiesemann 2013-10-05 15:21:49 UTC 
Created attachment 1356 [details]
hg export for add touches in init with JNI

The time when SDL_GetNumTouchDevices() returns a valid value seems not be be consistent across platforms. On the other hand it is also not documented when this should be.

I attached a patch which may solve the problem described in the bug report. It adds an additional touch device detection with the video initialization.
Comment 2 Sam Lantinga 2013-10-06 02:04:30 UTC 
On other platforms it works the same way, touches are added as touch events come in.

However, I think it would be super useful if we were able to tell how many touch devices are available after initialization. So, I'm adding your patch, thanks!
http://hg.libsdl.org/SDL/rev/cfc1285375e1
Comment 3 Philipp Wiesemann 2013-10-06 11:15:17 UTC 
(In reply to Sam Lantinga from comment #2)
> On other platforms it works the same way, touches are added as touch events
> come in.

From looking at the source I assumed that this would not be the case on X11 and UIKit and both would call SDL_AddTouch() only during initialization.

On Windows, Cocoa and Android SDL_AddTouch() was called on touch events.
Comment 4 Martin Gerhardy 2013-10-07 22:02:00 UTC 
I'm now getting a crash at startup

signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0000001c
Stack frame #00  pc 0005fe10  /system/lib/libdvm.so (dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)+19)
Stack frame #01  pc 0004a15d  /system/lib/libdvm.so
Stack frame #02  pc 0003a691  /data/app-lib/org.foobar-1/libSDL2.so (Android_JNI_GetTouchDeviceIds+52): Routine Android_JNI_GetTouchDeviceIds in jni/SDL/src/core/android/SDL_android.c:1194
Stack frame #03  pc 0007b31d  /data/app-lib/org.foobar-1/libSDL2.so (Android_InitTouch+4): Routine Android_InitTouch in jni/SDL/src/video/android/SDL_androidtouch.c:61
Stack frame #04  pc 0007b667  /data/app-lib/org.foobar-1/libSDL2.so: Routine Android_VideoInit in jni/SDL/src/video/android/SDL_androidvideo.c:169
Stack frame #05  pc 0007acff  /data/app-lib/org.foobar-1/libSDL2.so (SDL_VideoInit+326): Routine SDL_VideoInit in jni/SDL/src/video/SDL_video.c:504
Stack frame #06  pc 0000e9e1  /data/app-lib/org.foobar-1/libSDL2.so (SDL_InitSubSystem+140): Routine SDL_InitSubSystem in jni/SDL/src/SDL.c:166
Stack frame #07  pc 0000ea83  /data/app-lib/org.foobar-1/libSDL2.so (SDL_Init+2): Routine SDL_Init in jni/SDL/src/SDL.c:237
Stack frame #08  pc 0009f48b  /data/app-lib/org.foobar-1/libmain.so (SDLFrontend::init(int, int, bool, EventHandler&)+154): Routine init in jni/src/client/SDLFrontend.cpp:501
Stack frame #09  pc 000db0f5  /data/app-lib/org.foobar-1/libmain.so (SDLBackend::init(int, char**)+528): Routine init in jni/src/server/SDLBackend.cpp:103
Stack frame #10  pc 000db207  /data/app-lib/org.foobar-1/libmain.so (SDLBackend::mainLoop(int, char**)+18): Routine mainLoop in jni/src/common/System.h:25
Stack frame #11  pc 0009977f  /data/app-lib/org.foobar-1/libmain.so (SDL_main+178): Routine SDL_main in jni/src/foobar.cpp:16
Stack frame #12  pc 00152521  /data/app-lib/org.foobar-1/libmain.so (Java_org_libsdl_app_SDLActivity_nativeInit+28): Routine Java_org_libsdl_app_SDLActivity_nativeInit in jni/src/libs/SDL/src/main/android/SDL_android_main.c:30
Stack frame #13  pc 0001dc4c  /system/lib/libdvm.so (dvmPlatformInvoke+112)
Stack frame #14  pc 0004decf  /system/lib/libdvm.so (dvmCallJNIMethod(unsigned int const*, JValue*, Method const*, Thread*)+398)
Stack frame #15  pc 0004f8bd  /system/lib/libdvm.so (dvmResolveNativeMethod(unsigned int const*, JValue*, Method const*, Thread*)+184)
Stack frame #16  pc 00027060  /system/lib/libdvm.so
Stack frame #17  pc 0002b5ec  /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+184)
Stack frame #18  pc 0005ff21  /system/lib/libdvm.so (dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)+292)
Stack frame #19  pc 0005ff4b  /system/lib/libdvm.so (dvmCallMethod(Thread*, Method const*, Object*, JValue*, ...)+20)
Stack frame #20  pc 00054ccb  /system/lib/libdvm.so
Stack frame #21  pc 0000ca58  /system/lib/libc.so (__thread_entry+72)
Stack frame #22  pc 0000cbd4  /system/lib/libc.so (pthread_create+208)
Comment 5 Philipp Wiesemann 2013-10-08 17:55:00 UTC 
(In reply to Martin Gerhardy from comment #4)
> I'm now getting a crash at startup

Thank you for testing. Which Android version was used? Real device or emulator? And have you updated the SDLActivity.java file? I tried to reproduce the crash you reported (not successful yet) but I get a similar error if I remove the new method there.
Comment 6 Martin Gerhardy 2013-10-08 21:16:44 UTC 
oh sorry for the trouble. I have forgotten to update the java file, too. Again sorry.