pandroid: allow to bind volume keys (#814)

* allow to bind volume keys

* fix mapping

* pass false instead of null

src/pandroid/app/src/main/java/com/panda3ds/pandroid/app/GameActivity.java

@@ -152,11 +152,7 @@ public class GameActivity extends BaseActivity implements EmulatorCallback, Sens
 
 	@Override
 	public boolean dispatchKeyEvent(KeyEvent event) {	
-		if (event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_UP || event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_DOWN) {
-                    return super.dispatchKeyEvent(event);
-		}
-		
-		if ((!drawerFragment.isOpened()) && InputHandler.processKeyEvent(event)) {
+		if ((!drawerFragment.isOpened()) && InputHandler.processKeyEvent(event, true)) {
 			return true;
 		}
 

src/pandroid/app/src/main/java/com/panda3ds/pandroid/app/preferences/InputMapActivity.java

@@ -47,7 +47,7 @@ public class InputMapActivity extends BaseActivity {
 
     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
-        return InputHandler.processKeyEvent(event);
+        return InputHandler.processKeyEvent(event, false);
     }
 
     private void onInputEvent(InputEvent event) {

src/pandroid/app/src/main/java/com/panda3ds/pandroid/input/InputHandler.java

@@ -90,7 +90,7 @@ public class InputHandler {
         return true;
     }
 
-    public static boolean processKeyEvent(KeyEvent event) {
+    public static boolean processKeyEvent(KeyEvent event, Boolean playing) {
         if (!isSourceValid(event.getSource())) {
             return false;
         }
@@ -110,6 +110,13 @@ public class InputHandler {
             }
         }
         String code = KeyEvent.keyCodeToString(event.getKeyCode());
+
+        if (playing == true) {
+            if (InputMap.relative(code) == KeyName.NULL) {
+                return false;
+            }
+        }
+
         if (event.getAction() == KeyEvent.ACTION_UP) {
             keyDownEvents.remove(code);
             handleEvent(new InputEvent(code, 0.0f));