Allow picking up items with a single touch (#29)

* Allow handling middle click events

* Send middle click events when touch starts (Android)

* Punch objects when middle clicking (Touch only, combination with previous change)

src/client/inputhandler.h

@@ -215,6 +215,14 @@ public:
 	{
 		return m_receiver->left_active;
 	}
+	virtual bool getMiddleState()
+	{
+		return m_receiver->middle_active;
+	}
+	virtual void resetMiddleState()
+	{
+		m_receiver->middle_active = false;
+	}
 	virtual bool getRightState()
 	{
 		return m_receiver->right_active;
@@ -303,6 +311,11 @@ public:
 	{
 		return leftdown;
 	}
+	virtual bool getMiddleState()
+	{
+		return false;
+	}
+	virtual void resetMiddleState() {}
 	virtual bool getRightState()
 	{
 		return rightdown;

src/game.cpp

@@ -3670,6 +3670,8 @@ void Game::processPlayerInteraction(GameRunData *runData,
 
 	input->resetLeftReleased();
 	input->resetRightReleased();
+
+	input->resetMiddleState();
 }
 
 
@@ -3792,7 +3794,14 @@ void Game::handlePointingAtObject(GameRunData *runData,
 			runData->selected_object->debugInfoText()));
 	}
 
-	if (input->getLeftState()) {
+#ifdef HAVE_TOUCHSCREENGUI
+	// Interact with object on single touch (touchscreengui.cpp send this event)
+	bool middle_state = input->getMiddleState();
+#else
+	const bool middle_state = false;
+#endif
+
+	if (input->getLeftState() || middle_state) {
 		bool do_punch = false;
 		bool do_punch_damage = false;
 
@@ -3802,7 +3811,7 @@ void Game::handlePointingAtObject(GameRunData *runData,
 			runData->object_hit_delay_timer = object_hit_delay;
 		}
 
-		if (input->getLeftClicked())
+		if (input->getLeftClicked() || middle_state)
 			do_punch = true;
 
 		if (do_punch) {

src/game.h

@@ -114,6 +114,8 @@ public:
 	virtual void setMousePos(s32 x, s32 y) = 0;
 
 	virtual bool getLeftState() = 0;
+	virtual bool getMiddleState() = 0;
+	virtual void resetMiddleState() = 0; // TODO: handle middle button like all others
 	virtual bool getRightState() = 0;
 
 	virtual bool getLeftClicked() = 0;

src/touchscreengui.cpp

@@ -611,6 +611,23 @@ void TouchScreenGUI::translateEvent(const SEvent &event)
 				m_move_downtime            = getTimeMs();
 				m_move_downlocation        = v2s32(event.TouchInput.X, event.TouchInput.Y);
 				m_move_sent_as_mouse_event = false;
+
+				// update shootline (in case the game handles the event we send below)
+				m_shootline = m_device
+						->getSceneManager()
+						->getSceneCollisionManager()
+						->getRayFromScreenCoordinates(m_move_downlocation);
+
+				// send a middle click event so the game can handle single touches
+				SEvent *translated = new SEvent;
+				memset(translated, 0, sizeof(SEvent));
+				translated->EventType = EET_MOUSE_INPUT_EVENT;
+				translated->MouseInput.X = m_move_downlocation.X;
+				translated->MouseInput.Y = m_move_downlocation.Y;
+				translated->MouseInput.ButtonStates = EMBSM_MIDDLE; // << important!
+				translated->MouseInput.Event = EMIE_MMOUSE_LEFT_UP;
+				m_receiver->OnEvent(*translated);
+				delete translated;
 			}
 		}