Move drag event to InputDispatcher (2/n)

This CL adds the ability to receive a DRAG event through the
InputChannel, and adds the appropriate processing logic to
InputEventReceiver.

Bug: 158242495
Test: atest libinput_tests
Change-Id: I94d5fa545d920be52e03702d0d24712fd11c497c

core/java/android/view/InputEventReceiver.java

@@ -158,6 +158,16 @@ public abstract class InputEventReceiver {
     public void onPointerCaptureEvent(boolean pointerCaptureEnabled) {
     }
 
+    /**
+     * Called when a drag event is received, from native code.
+     *
+     * @param isExiting if false, the window associated with this input channel has just received
+     *                 drag
+     *                 if true, the window associated with this input channel has just lost drag
+     */
+    public void onDragEvent(boolean isExiting, float x, float y) {
+    }
+
     /**
      * Called when a batched input event is pending.
      *

core/jni/android_view_InputEventReceiver.cpp

@@ -57,6 +57,7 @@ static struct {
     jmethodID dispatchInputEvent;
     jmethodID onFocusEvent;
     jmethodID onPointerCaptureEvent;
+    jmethodID onDragEvent;
     jmethodID onBatchedInputEventPending;
 } gInputEventReceiverClassInfo;
 
@@ -400,6 +401,18 @@ status_t NativeInputEventReceiver::consumeEvents(JNIEnv* env,
                 finishInputEvent(seq, true /* handled */);
                 continue;
             }
+            case AINPUT_EVENT_TYPE_DRAG: {
+                const DragEvent* dragEvent = static_cast<DragEvent*>(inputEvent);
+                if (kDebugDispatchCycle) {
+                    ALOGD("channel '%s' ~ Received drag event: isExiting=%s",
+                          getInputChannelName().c_str(), toString(dragEvent->isExiting()));
+                }
+                env->CallVoidMethod(receiverObj.get(), gInputEventReceiverClassInfo.onDragEvent,
+                                    jboolean(dragEvent->isExiting()), dragEvent->getX(),
+                                    dragEvent->getY());
+                finishInputEvent(seq, true /* handled */);
+                continue;
+            }
 
             default:
                 assert(false); // InputConsumer should prevent this from ever happening
@@ -547,6 +560,8 @@ int register_android_view_InputEventReceiver(JNIEnv* env) {
     gInputEventReceiverClassInfo.onPointerCaptureEvent =
             GetMethodIDOrDie(env, gInputEventReceiverClassInfo.clazz, "onPointerCaptureEvent",
                              "(Z)V");
+    gInputEventReceiverClassInfo.onDragEvent =
+            GetMethodIDOrDie(env, gInputEventReceiverClassInfo.clazz, "onDragEvent", "(ZFF)V");
     gInputEventReceiverClassInfo.onBatchedInputEventPending =
             GetMethodIDOrDie(env, gInputEventReceiverClassInfo.clazz, "onBatchedInputEventPending",
                              "(I)V");