TouchEvent (1/n): Adding TouchModeEvent to InputChannel

This CL detaches the touch mode state update from focus update. It does
that by introducing a new internal event (TouchModeEvent). This CL also
adds this event to InputChannel and related processing logic to
InputPublisher and InputConsumer. InputDispatcher will process two
different events now: FocusEvent when gaining/losing focus and
TouchModeEvent when entering/leaving touch mode.

Test: atest libinput_tests
Bug: 193718270
Change-Id: Ie4e5b6e8e798f12d7203127b4559fa40d38788de
diff --git a/libs/input/Input.cpp b/libs/input/Input.cpp
index 9390467..30d82b6 100644
--- a/libs/input/Input.cpp
+++ b/libs/input/Input.cpp
@@ -163,6 +163,9 @@
         case AINPUT_EVENT_TYPE_DRAG: {
             return "DRAG";
         }
+        case AINPUT_EVENT_TYPE_TOUCH_MODE: {
+            return "TOUCH_MODE";
+        }
     }
     return "UNKNOWN";
 }
@@ -882,6 +885,19 @@
     mY = from.mY;
 }
 
+// --- TouchModeEvent ---
+
+void TouchModeEvent::initialize(int32_t id, bool isInTouchMode) {
+    InputEvent::initialize(id, ReservedInputDeviceId::VIRTUAL_KEYBOARD_ID, AINPUT_SOURCE_UNKNOWN,
+                           ADISPLAY_ID_NONE, INVALID_HMAC);
+    mIsInTouchMode = isInTouchMode;
+}
+
+void TouchModeEvent::initialize(const TouchModeEvent& from) {
+    InputEvent::initialize(from);
+    mIsInTouchMode = from.mIsInTouchMode;
+}
+
 // --- PooledInputEventFactory ---
 
 PooledInputEventFactory::PooledInputEventFactory(size_t maxPoolSize) :
@@ -936,6 +952,15 @@
     return event;
 }
 
+TouchModeEvent* PooledInputEventFactory::createTouchModeEvent() {
+    if (mTouchModeEventPool.empty()) {
+        return new TouchModeEvent();
+    }
+    TouchModeEvent* event = mTouchModeEventPool.front().release();
+    mTouchModeEventPool.pop();
+    return event;
+}
+
 void PooledInputEventFactory::recycle(InputEvent* event) {
     switch (event->getType()) {
     case AINPUT_EVENT_TYPE_KEY: