Android: Basic game controller input forwarding

android/app/src/main/java/com/github/stenzek/duckstation/EmulationActivity.java

@@ -50,7 +50,7 @@ public class EmulationActivity extends AppCompatActivity implements SurfaceHolde
      */
     private static final int UI_ANIMATION_DELAY = 300;
     private final Handler mHideHandler = new Handler();
-    private SurfaceView mContentView;
+    private EmulationSurfaceView mContentView;
     private final Runnable mHidePart2Runnable = new Runnable() {
         @SuppressLint("InlinedApi")
         @Override
@@ -148,6 +148,9 @@ public class EmulationActivity extends AppCompatActivity implements SurfaceHolde
         mTouchscreenController = new TouchscreenControllerView(this);
         activityLayout.addView(mTouchscreenController);
         mTouchscreenController.init(0, "DigitalController", mHostInterface);
+
+        // Hook up controller input.
+        mContentView.initControllerKeyMapping(mHostInterface, "DigitalController");
     }
 
     @Override

android/app/src/main/java/com/github/stenzek/duckstation/EmulationSurfaceView.java

@@ -0,0 +1,92 @@
+package com.github.stenzek.duckstation;
+
+import android.content.Context;
+import android.util.ArrayMap;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.InputDevice;
+import android.view.KeyEvent;
+import android.view.SurfaceView;
+
+public class EmulationSurfaceView extends SurfaceView {
+    public EmulationSurfaceView(Context context) {
+        super(context);
+    }
+
+    public EmulationSurfaceView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public EmulationSurfaceView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    private boolean isDPadOrButtonEvent(KeyEvent event) {
+        final int source = event.getSource();
+        return (source & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD ||
+                (source & InputDevice.SOURCE_DPAD) == InputDevice.SOURCE_DPAD ||
+                (source & InputDevice.SOURCE_JOYSTICK) == InputDevice.SOURCE_JOYSTICK;
+    }
+
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        if (isDPadOrButtonEvent(event) && event.getRepeatCount() == 0 &&
+                handleControllerKey(keyCode, true)) {
+            return true;
+        }
+
+        return super.onKeyDown(keyCode, event);
+    }
+
+    @Override
+    public boolean onKeyUp(int keyCode, KeyEvent event) {
+        if (isDPadOrButtonEvent(event) && event.getRepeatCount() == 0 &&
+                handleControllerKey(keyCode, false)) {
+            return true;
+        }
+
+        return super.onKeyDown(keyCode, event);
+    }
+
+    private AndroidHostInterface mHostInterface;
+    private ArrayMap<Integer, Integer> mControllerKeyMapping;
+
+    private void addControllerKeyMapping(int keyCode, String controllerType, String buttonName) {
+        int mapping = AndroidHostInterface.getControllerButtonCode(controllerType, buttonName);
+        Log.i("EmulationSurfaceView", String.format("Map %d to %d (%s)", keyCode, mapping,
+                buttonName));
+        if (mapping >= 0)
+            mControllerKeyMapping.put(keyCode, mapping);
+    }
+
+    public void initControllerKeyMapping(AndroidHostInterface hostInterface,
+                                         String controllerType) {
+        mHostInterface = hostInterface;
+        mControllerKeyMapping = new ArrayMap<>();
+
+        // TODO: Don't hardcode...
+        addControllerKeyMapping(KeyEvent.KEYCODE_DPAD_UP, controllerType, "Up");
+        addControllerKeyMapping(KeyEvent.KEYCODE_DPAD_RIGHT, controllerType, "Right");
+        addControllerKeyMapping(KeyEvent.KEYCODE_DPAD_DOWN, controllerType, "Down");
+        addControllerKeyMapping(KeyEvent.KEYCODE_DPAD_LEFT, controllerType, "Left");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_L1, controllerType, "L1");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_L2, controllerType, "L2");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_SELECT, controllerType, "Select");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_START, controllerType, "Start");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_Y, controllerType, "Triangle");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_B, controllerType, "Circle");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_A, controllerType, "Cross");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_X, controllerType, "Square");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_R1, controllerType, "R1");
+        addControllerKeyMapping(KeyEvent.KEYCODE_BUTTON_R2, controllerType, "R2");
+    }
+
+    private boolean handleControllerKey(int keyCode, boolean pressed) {
+        if (!mControllerKeyMapping.containsKey(keyCode))
+            return false;
+
+        final int mapping = mControllerKeyMapping.get(keyCode);
+        mHostInterface.setControllerButtonState(0, mapping, pressed);
+        return true;
+    }
+}

android/app/src/main/res/layout/activity_emulation.xml

@@ -10,7 +10,7 @@
     <!-- The primary full-screen view. This can be replaced with whatever view
          is needed to present your content, e.g. VideoView, SurfaceView,
          TextureView, etc. -->
-    <SurfaceView
+    <com.github.stenzek.duckstation.EmulationSurfaceView
         android:id="@+id/fullscreen_content"
         android:layout_width="match_parent"
         android:layout_height="match_parent"