Added detection of touch devices before first touch events happen on Android.

On Android available touch devices are now added with video initialization (like
the keyboard). This fixes SDL_GetNumTouchDevices() returning 0 before any touch
events happened although there is a touch screen available. The adding of touch
devices after a touch event was received is still active to allow connecting
devices later (if this is possible) and to provide a fallback if the new init
did not work somehow. For the implementation JNI was used and API level 9 is
required. There seems to be nothing in the Android NDK's input header (input.h)
to implement everything on C side without communication with Java side.
This commit is contained in:
Philipp Wiesemann
2013-10-05 17:08:19 +02:00
parent 36b759174f
commit 0db36f51aa
6 changed files with 67 additions and 0 deletions

View File

@@ -1186,6 +1186,32 @@ int Android_JNI_GetPowerInfo(int* plugged, int* charged, int* battery, int* seco
return 0;
}
/* returns number of found touch devices as return value and ids in parameter ids */
int Android_JNI_GetTouchDeviceIds(int **ids) {
JNIEnv *env = Android_JNI_GetEnv();
jint sources = 4098; /* == InputDevice.SOURCE_TOUCHSCREEN */
jmethodID mid = (*env)->GetStaticMethodID(env, mActivityClass, "inputGetInputDeviceIds", "(I)[I");
jintArray array = (jintArray) (*env)->CallStaticObjectMethod(env, mActivityClass, mid, sources);
int number = 0;
*ids = NULL;
if (array) {
number = (int) (*env)->GetArrayLength(env, array);
if (0 < number) {
jint* elements = (*env)->GetIntArrayElements(env, array, NULL);
if (elements) {
int i;
*ids = SDL_malloc(number * sizeof (*ids[0]));
for (i = 0; i < number; ++i) { /* not assuming sizeof (jint) == sizeof (int) */
*ids[i] = elements[i];
}
(*env)->ReleaseIntArrayElements(env, array, elements, JNI_ABORT);
}
}
(*env)->DeleteLocalRef(env, array);
}
return number;
}
/* sends message to be handled on the UI event dispatch thread */
int Android_JNI_SendMessage(int command, int param)
{