src/gui/guiFormSpecMenu.cpp

@@ -4201,13 +4201,15 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 
 	/* Mouse event other than movement, or crossing the border of inventory
 	   field while holding left, right, or middle mouse button
+	   or touch event (for touch screen devices)
 	 */
-	if (event.EventType == EET_MOUSE_INPUT_EVENT &&
+	if ((event.EventType == EET_MOUSE_INPUT_EVENT &&
 			(event.MouseInput.Event != EMIE_MOUSE_MOVED ||
 				((event.MouseInput.isLeftPressed() ||
 					event.MouseInput.isRightPressed() ||
 					event.MouseInput.isMiddlePressed()) &&
-			getItemAtPos(m_pointer).i != getItemAtPos(m_old_pointer).i))) {
+				getItemAtPos(m_pointer).i != getItemAtPos(m_old_pointer).i))) ||
+			event.EventType == EET_TOUCH_INPUT_EVENT) {
 
 		// Get selected item and hovered/clicked item (s)
 
@@ -4276,6 +4278,9 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 
 		ButtonEventType button = BET_OTHER;
 		ButtonEventType updown = BET_OTHER;
+		bool mouse_shift = false;
+		if (event.EventType == EET_MOUSE_INPUT_EVENT) {
+			mouse_shift = event.MouseInput.Shift;
 			switch (event.MouseInput.Event) {
 			case EMIE_LMOUSE_PRESSED_DOWN:
 				button = BET_LEFT; updown = BET_DOWN;
@@ -4306,6 +4311,16 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 			default:
 				break;
 			}
+		}
+
+#ifdef HAVE_TOUCHSCREENGUI
+		// The second touch (see GUIModalMenu::preprocessEvent() function)
+		ButtonEventType touch = BET_OTHER;
+		if (event.EventType == EET_TOUCH_INPUT_EVENT) {
+			if (event.TouchInput.Event == ETIE_LEFT_UP)
+				touch = BET_RIGHT;
+		}
+#endif
 
 		// Set this number to a positive value to generate a move action
 		// from m_selected_item to s.
@@ -4332,6 +4347,7 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 
 			if (m_held_mouse_button != BET_OTHER)
 				break;
+
 			if (button == BET_LEFT || button == BET_RIGHT || button == BET_MIDDLE)
 				m_held_mouse_button = button;
 
@@ -4351,13 +4367,13 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 				// Craft preview has been clicked: craft
 				if (button == BET_MIDDLE)
 					craft_amount = 10;
-				else if (event.MouseInput.Shift && button == BET_LEFT)
+				else if (mouse_shift && button == BET_LEFT)
 					craft_amount = list_s->getItem(s.i).getStackMax(m_client->idef());
 				else
 					craft_amount = 1;
 
 				// Holding shift moves the crafted item to the inventory
-				m_shift_move_after_craft = event.MouseInput.Shift;
+				m_shift_move_after_craft = mouse_shift;
 
 			} else if (!m_selected_item && button != BET_WHEEL_UP && !empty) {
 				// Non-empty stack has been clicked: select or shift-move it
@@ -4371,7 +4387,7 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 				else if (button == BET_LEFT)
 					count = s_count;
 
-				if (event.MouseInput.Shift) {
+				if (mouse_shift) {
 					// Shift pressed: move item, right click moves 1
 					shift_move_amount = button == BET_RIGHT ? 1 : count;
 				} else {
@@ -4392,7 +4408,7 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 				else if (button == BET_LEFT)
 					move_amount = m_selected_amount;
 
-				if (event.MouseInput.Shift && !identical && matching) {
+				if (mouse_shift && !identical && matching) {
 					// Shift-move all items the same as the selected item to the next list
 					move_amount = 0;
 
@@ -4530,7 +4546,7 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 			if (!s.isValid() || s.listname == "craftpreview")
 				break;
 
-			if (!m_selected_item && event.MouseInput.Shift) {
+			if (!m_selected_item && mouse_shift) {
 				// Shift-move items while dragging
 				if (m_held_mouse_button == BET_RIGHT)
 					shift_move_amount = 1;
@@ -4580,7 +4596,8 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 		case BET_OTHER: {
 			// Some other mouse event has occured
 			// Currently only left-double-click should trigger this
-			if (!s.isValid() || event.MouseInput.Event != EMIE_LMOUSE_DOUBLE_CLICK)
+			if (!s.isValid() || event.EventType != EET_MOUSE_INPUT_EVENT ||
+					event.MouseInput.Event != EMIE_LMOUSE_DOUBLE_CLICK)
 				break;
 
 			// Only do the pickup all thing when putting down an item.
@@ -4648,6 +4665,28 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 			break;
 		}
 
+#ifdef HAVE_TOUCHSCREENGUI
+		if (touch == BET_RIGHT && m_selected_item && !m_left_dragging) {
+			if (!s.isValid()) {
+				// Not a valid slot
+				if (!getAbsoluteClippingRect().isPointInside(m_pointer))
+					// Is outside the menu
+					drop_amount = 1;
+			} else {
+				// Over a valid slot
+				move_amount = 1;
+				if (identical) {
+					// Change the selected amount instead of moving
+					if (move_amount >= m_selected_amount)
+						m_selected_amount = 0;
+					else
+						m_selected_amount -= move_amount;
+					move_amount = 0;
+				}
+			}
+		}
+#endif
+
 		// Update left-dragged slots
 		if (m_left_dragging && m_left_drag_stacks.size() > 1) {
 			// The split amount will always at least one, because the number
@@ -5014,6 +5053,11 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 		}
 	}
 
+#ifdef HAVE_TOUCHSCREENGUI
+	if (m_second_touch)
+		return true; // Stop propagating the event
+#endif
+
 	return Parent ? Parent->OnEvent(event) : false;
 }
 

src/gui/modalMenu.cpp

@@ -278,12 +278,9 @@ bool GUIModalMenu::preprocessEvent(const SEvent &event)
 		irr_ptr<GUIModalMenu> holder;
 		holder.grab(this); // keep this alive until return (it might be dropped downstream [?])
 
-		switch ((int)event.TouchInput.touchedCount) {
-		case 1: {
+		if (event.TouchInput.ID == 0) {
 			if (event.TouchInput.Event == ETIE_PRESSED_DOWN || event.TouchInput.Event == ETIE_MOVED)
 				m_pointer = v2s32(event.TouchInput.X, event.TouchInput.Y);
-			if (event.TouchInput.Event == ETIE_PRESSED_DOWN)
-				m_down_pos = m_pointer;
 			gui::IGUIElement *hovered = Environment->getRootGUIElement()->getElementFromPoint(core::position2d<s32>(m_pointer));
 			if (event.TouchInput.Event == ETIE_PRESSED_DOWN)
 				Environment->setFocus(hovered);
@@ -298,26 +295,19 @@ bool GUIModalMenu::preprocessEvent(const SEvent &event)
 			if (event.TouchInput.Event == ETIE_LEFT_UP)
 				leave();
 			return ret;
-		}
-		case 2: {
-			if (event.TouchInput.Event != ETIE_PRESSED_DOWN)
+		} else if (event.TouchInput.ID == 1) {
+			if (event.TouchInput.Event != ETIE_LEFT_UP)
 				return true; // ignore
 			auto focused = Environment->getFocus();
 			if (!focused)
 				return true;
-			SEvent rclick_event{};
-			rclick_event.EventType = EET_MOUSE_INPUT_EVENT;
-			rclick_event.MouseInput.Event = EMIE_RMOUSE_PRESSED_DOWN;
-			rclick_event.MouseInput.ButtonStates = EMBSM_LEFT | EMBSM_RIGHT;
-			rclick_event.MouseInput.X = m_pointer.X;
-			rclick_event.MouseInput.Y = m_pointer.Y;
-			focused->OnEvent(rclick_event);
-			rclick_event.MouseInput.Event = EMIE_RMOUSE_LEFT_UP;
-			rclick_event.MouseInput.ButtonStates = EMBSM_LEFT;
-			focused->OnEvent(rclick_event);
+			// The second-touch event is propagated as is (not converted).
+			m_second_touch = true;
+			focused->OnEvent(event);
+			m_second_touch = false;
 			return true;
-		}
-		default: // ignored
+		} else {
+			// Any other touch after the second touch is ignored.
 			return true;
 		}
 	}

src/gui/modalMenu.h

@@ -77,7 +77,8 @@ protected:
 	std::string m_jni_field_name;
 #endif
 #ifdef HAVE_TOUCHSCREENGUI
-	v2s32 m_down_pos;
+	// This is set to true if the menu is currently processing a second-touch event.
+	bool m_second_touch = false;
 	bool m_touchscreen_visible = true;
 #endif