Added multi-touch, added on press down

src/UiManager.cpp

@@ -769,6 +769,16 @@ namespace ZL {
 		return true;
 	}
 
+	bool UiManager::setButtonPressCallback(const std::string& name, std::function<void(const std::string&)> cb) {
+		auto b = findButton(name);
+		if (!b) {
+			std::cerr << "UiManager: setButtonPressCallback failed, button not found: " << name << std::endl;
+			return false;
+		}
+		b->onPress = std::move(cb);
+		return true;
+	}
+
 	bool UiManager::addSlider(const std::string& name, const UiRect& rect, Renderer& renderer, const std::string& zipFile,
 		const std::string& trackPath, const std::string& knobPath, float initialValue, bool vertical) {
 
@@ -855,8 +865,8 @@ namespace ZL {
 		prev.sliders = sliders;
 		prev.textFields = textFields;
 		prev.staticImages = staticImages;
-		prev.pressedButton = pressedButton;
-		prev.pressedSlider = pressedSlider;
+		prev.pressedButtons = pressedButtons;
+		prev.pressedSliders = pressedSliders;
 		prev.focusedTextField = focusedTextField;
 		prev.path = "";
 
@@ -906,8 +916,8 @@ namespace ZL {
 		sliders = s.sliders;
 		textFields = s.textFields;
 		staticImages = s.staticImages;
-		pressedButton = s.pressedButton;
-		pressedSlider = s.pressedSlider;
+		pressedButtons = s.pressedButtons;
+		pressedSliders = s.pressedSliders;
 		focusedTextField = s.focusedTextField;
 
 		animCallbacks = s.animCallbacks;
@@ -1122,21 +1132,25 @@ namespace ZL {
 		}
 	}
 
-	void UiManager::onMouseMove(int x, int y) {
-		for (auto& b : buttons) {
-			if (b->state != ButtonState::Disabled)
-			{
-				if (b->rect.containsConsideringBorder((float)x, (float)y, b->border)) {
-					if (b->state != ButtonState::Pressed) b->state = ButtonState::Hover;
-				}
-				else {
-					if (b->state != ButtonState::Pressed) b->state = ButtonState::Normal;
+	void UiManager::onTouchMove(int64_t fingerId, int x, int y) {
+		// Hover state updates only make sense for mouse (single pointer)
+		if (fingerId == MOUSE_FINGER_ID) {
+			for (auto& b : buttons) {
+				if (b->state != ButtonState::Disabled)
+				{
+					if (b->rect.containsConsideringBorder((float)x, (float)y, b->border)) {
+						if (b->state != ButtonState::Pressed) b->state = ButtonState::Hover;
+					}
+					else {
+						if (b->state != ButtonState::Pressed) b->state = ButtonState::Normal;
+					}
 				}
 			}
 		}
 
-		if (pressedSlider) {
-			auto s = pressedSlider;
+		auto it = pressedSliders.find(fingerId);
+		if (it != pressedSliders.end()) {
+			auto s = it->second;
 			float t;
 			if (s->vertical) {
 				t = (y - s->rect.y) / s->rect.h;
@@ -1153,20 +1167,22 @@ namespace ZL {
 	}
 
 
-	void UiManager::onMouseDown(int x, int y) {
+	void UiManager::onTouchDown(int64_t fingerId, int x, int y) {
 		for (auto& b : buttons) {
 			if (b->state != ButtonState::Disabled)
 			{
 				if (b->rect.containsConsideringBorder((float)x, (float)y, b->border)) {
 					b->state = ButtonState::Pressed;
-					pressedButton = b;
+					pressedButtons[fingerId] = b;
+					if (b->onPress) b->onPress(b->name);
+					break; // a single finger can only press one button
 				}
 			}
 		}
 
 		for (auto& s : sliders) {
 			if (s->rect.contains((float)x, (float)y)) {
-				pressedSlider = s;
+				pressedSliders[fingerId] = s;
 				float t;
 				if (s->vertical) {
 					t = (y - s->rect.y) / s->rect.h;
@@ -1194,29 +1210,32 @@ namespace ZL {
 		}
 	}
 
-	void UiManager::onMouseUp(int x, int y) {
+	void UiManager::onTouchUp(int64_t fingerId, int x, int y) {
 		std::vector<std::shared_ptr<UiButton>> clicked;
 
-		for (auto& b : buttons) {
-			if (!b) continue;
-			bool contains = b->rect.contains((float)x, (float)y);
-
-			if (b->state == ButtonState::Pressed) {
-				if (contains && pressedButton == b) {
-					clicked.push_back(b);
+		auto btnIt = pressedButtons.find(fingerId);
+		if (btnIt != pressedButtons.end()) {
+			auto b = btnIt->second;
+			if (b) {
+				bool contains = b->rect.contains((float)x, (float)y);
+				if (b->state == ButtonState::Pressed) {
+					if (contains) {
+						clicked.push_back(b);
+					}
+					// On mouse: leave Hover if still over button. On touch: always Normal.
+				b->state = (contains && fingerId == MOUSE_FINGER_ID) ? ButtonState::Hover : ButtonState::Normal;
 				}
-				b->state = contains ? ButtonState::Hover : ButtonState::Normal;
 			}
+			pressedButtons.erase(btnIt);
 		}
 
+		pressedSliders.erase(fingerId);
+
 		for (auto& b : clicked) {
 			if (b->onClick) {
 				b->onClick(b->name);
 			}
 		}
-
-		pressedButton.reset();
-		if (pressedSlider) pressedSlider.reset();
 	}
 
 	void UiManager::onKeyPress(unsigned char key) {