3D Shooters Episode II: Doom for Android - Pro Android Games - page 233

Key and Touch Event Handlers
Key and touch handlers can be overridden to process key and touch events. Doom handles key and
touch events as follows (see Listing 7-5):

The Android keyCode is first translated to an ASCII key symbol by calling int sym =
DoomTools.keyCodeToKeySym(keyCode) .

•

• The ASCII symbol is the sent to the DSO through the native interface class

Natives.keyEvent(EVENT_TYPE, SYMBOL) , where the event type must be either
Natives.EV_KEYUP or Natives.EV_KEYDOWN . Note that any errors in the native side
(such as a missing symbol or invalid signature) will throw an
UnsatisfiedLinkError .

Listing 7-5. Key and Touch Handlers

public boolean onKeyUp(int keyCode, KeyEvent event) {
//
if (keyCode == KeyEvent.KEYCODE_MENU) {
return false;
}

int sym = DoomTools.keyCodeToKeySym(keyCode);

try {
Natives.keyEvent(Natives.EV_KEYUP, sym);
} catch (UnsatisfiedLinkError e) {
// Should not happen
Log.e(TAG, e.toString());
}
return false;
}

public boolean onKeyDown(int keyCode, KeyEvent event) {
// Ignore menu key
if (keyCode == KeyEvent.KEYCODE_MENU) {
return false;
}
int sym = DoomTools.keyCodeToKeySym(keyCode);
try {
Natives.keyEvent(Natives.EV_KEYDOWN, sym);
}
catch (UnsatisfiedLinkError e) {
// Should not happen
Log.e(TAG, e.toString());
}
return false;
}