Made the button type interactable.

private/sdl_gpu_test/6_ui/app.cpp

@@ -83,6 +83,10 @@ void UIApp::init(const AppInitArgs& args)
         .posX = 100,
         .posY = 500
     });
+    mButton->clicked.connect([&]()
+    {
+        mButton->setText("Thanks!");
+    });
 }
 
 void UIApp::update(const AppUpdateArgs& args)
@@ -173,6 +177,8 @@ void UIApp::handleKeyboardEvent(const sdlpp::KeyboardEvent& event)
 
 void UIApp::handleMouseMotionEvent(const sdlpp::MouseMotionEvent& event)
 {
+    mWidgetTree.notifyMouseMoved(event);
+
     if (event.state.left)
     {
         mRotation += 0.5f * event.xrel;
@@ -180,6 +186,12 @@ void UIApp::handleMouseMotionEvent(const sdlpp::MouseMotionEvent& event)
     }
 }
 
+void UIApp::handleMouseButtonEvent(const sdlpp::MouseButtonEvent& event)
+{
+    mWidgetTree.notifyMouseButton(event);
+}
+
+
 void UIApp::createMeshPipeline()
 {
     // create shaders

private/sdl_gpu_test/6_ui/app.hpp

@@ -39,6 +39,7 @@ public:
     void update(const AppUpdateArgs& args) override;
     void handleKeyboardEvent(const sdlpp::KeyboardEvent& event) override;
     void handleMouseMotionEvent(const sdlpp::MouseMotionEvent& event) override;
+    void handleMouseButtonEvent(const sdlpp::MouseButtonEvent&) override;
 private:
     void createMeshPipeline();
     void processInput(const AppUpdateArgs& args);

private/sdl_gpu_test/gui/button.cpp

@@ -4,7 +4,8 @@
 namespace sdl_gpu_test
 {
 Button::Button(ButtonCreateArgs args) : mText(std::move(args.text)), mTextColor(args.textColor),
-    mBackgroundColor(args.backgroundColor), mPosX(args.posX), mPosY(args.posY), mWidth(args.width), mHeight(args.height)
+    mBackgroundColor(args.backgroundColor), mHoveredColor(args.hoveredColor), mPosX(args.posX), mPosY(args.posY),
+    mWidth(args.width), mHeight(args.height)
 {
 
 }
@@ -32,7 +33,22 @@ void Button::setBackgroundColor(const glm::vec4& color)
     if (color != mBackgroundColor)
     {
         mBackgroundColor = color;
-        invalidate();
+        if (!mHovered)
+        {
+            invalidate();
+        }
+    }
+}
+
+void Button::setHoveredColor(const glm::vec4& color)
+{
+    if (color != mHoveredColor)
+    {
+        mHoveredColor = color;
+        if (mHovered)
+        {
+            invalidate();
+        }
     }
 }
 
@@ -59,6 +75,25 @@ void Button::handleEnteredTree()
     update();
 }
 
+void Button::handleMouseMotion(const sdlpp::MouseMotionEvent& event)
+{
+    const bool hovered = (event.x >= mPosX && event.x <= mPosX + mWidth)
+                        && (event.y >= mPosY && event.y <= mPosY + mHeight);
+    if (hovered != mHovered)
+    {
+        mHovered = hovered;
+        invalidate();
+    }
+}
+
+void Button::handleMouseButton(const sdlpp::MouseButtonEvent&)
+{
+    if (mHovered)
+    {
+        clicked.emit();
+    }
+}
+
 void Button::revalidate()
 {
     update();
@@ -81,7 +116,7 @@ void Button::update()
         .y = mPosY,
         .width = mWidth,
         .height = mHeight,
-        .color = mBackgroundColor
+        .color = mHovered ? mHoveredColor : mBackgroundColor
     }, &mPrimitiveID);
     mTree->getRenderer().drawTextCentered({
         .x = mPosX + (mWidth / 2),

private/sdl_gpu_test/gui/button.hpp

@@ -5,6 +5,7 @@
 #define SDL_GPU_TEST_PRIVATE_SDL_GPU_TEST_GUI_BUTTON_HPP_INCLUDED 1
 
 #include <glm/vec4.hpp>
+#include <mijin/async/signal.hpp>
 
 #include "./widget.hpp"
 
@@ -15,6 +16,7 @@ struct ButtonCreateArgs
     std::string text;
     glm::vec4 textColor = {1.f, 1.f, 1.f, 1.f};
     glm::vec4 backgroundColor = {1.f, 0.f, 0.f, 1.f};
+    glm::vec4 hoveredColor = {1.f, 0.9f, 0.9f, 1.f};
     int posX = 0;
     int posY = 0;
     int width = 256;
@@ -27,12 +29,14 @@ public:
     using create_args_t = ButtonCreateArgs;
 private:
     std::string mText;
-    glm::vec4 mTextColor = {1.f, 1.f, 1.f, 1.f};
-    glm::vec4 mBackgroundColor = {1.f, 1.f, 1.f, 1.f};
+    glm::vec4 mTextColor;
+    glm::vec4 mBackgroundColor;
+    glm::vec4 mHoveredColor;
     int mPosX = 0;
     int mPosY = 0;
     int mWidth = 0;
     int mHeight = 0;
+    bool mHovered = false;
     UIRenderer::primitive_id_t mPrimitiveID = UIRenderer::UNSET_PRIMITIVE_ID;
 public:
     explicit Button(ButtonCreateArgs args);
@@ -44,7 +48,10 @@ public:
     const glm::vec4& getTextColor() const noexcept { return mTextColor; }
 
     [[nodiscard]]
-    const glm::vec4& getBackgroundTextColor() const noexcept { return mBackgroundColor; }
+    const glm::vec4& getBackgroundColor() const noexcept { return mBackgroundColor; }
+
+    [[nodiscard]]
+    const glm::vec4& getHoveredColor() const noexcept { return mHoveredColor; }
 
     [[nodiscard]]
     int getPosX() const noexcept { return mPosX; }
@@ -55,13 +62,18 @@ public:
     void setText(std::string text);
     void setTextColor(const glm::vec4& color);
     void setBackgroundColor(const glm::vec4& color);
+    void setHoveredColor(const glm::vec4& color);
     void setPosX(int posX);
     void setPosY(int posY);
 
     void handleEnteredTree() override;
+    void handleMouseMotion(const sdlpp::MouseMotionEvent& event) override;
+    void handleMouseButton(const sdlpp::MouseButtonEvent&) override;
     void revalidate() override;
 private:
     void update();
+public:
+    mijin::Signal<> clicked;
 };
 } // namespace sdl_gpu_test
 

private/sdl_gpu_test/gui/widget.cpp

@@ -31,6 +31,22 @@ void ParentWidget::handleEnteredTree()
     }
 }
 
+void ParentWidget::handleMouseMotion(const sdlpp::MouseMotionEvent& event)
+{
+    for (widget_ptr_t& child : mChildren)
+    {
+        child->handleMouseMotion(event);
+    }
+}
+
+void ParentWidget::handleMouseButton(const sdlpp::MouseButtonEvent& event)
+{
+    for (widget_ptr_t& child : mChildren)
+    {
+        child->handleMouseButton(event);
+    }
+}
+
 Widget* ParentWidget::addChild(widget_ptr_t&& child)
 {
     mChildren.push_back(std::move(child));
@@ -60,6 +76,16 @@ void WidgetTree::revalidateWidgets()
     mInvalidWidgets.clear();
 }
 
+void WidgetTree::notifyMouseMoved(const sdlpp::MouseMotionEvent& event)
+{
+    mRootWidget.handleMouseMotion(event);
+}
+
+void WidgetTree::notifyMouseButton(const sdlpp::MouseButtonEvent& event)
+{
+    mRootWidget.handleMouseButton(event);
+}
+
 void WidgetTree::invalidateWidget(Widget* widget) noexcept
 {
     mInvalidWidgets.insert(widget);

private/sdl_gpu_test/gui/widget.hpp

@@ -9,6 +9,7 @@
 #include <unordered_set>
 
 #include "./ui_renderer.hpp"
+#include "../sdlpp/event.hpp"
 
 namespace sdl_gpu_test
 {
@@ -21,6 +22,9 @@ public:
     virtual ~Widget() noexcept = default;
 
     virtual void handleEnteredTree() {}
+    virtual void handleMouseMotion(const sdlpp::MouseMotionEvent& /* event */) {}
+    virtual void handleMouseButton(const sdlpp::MouseButtonEvent& /* event */) {}
+
     virtual void revalidate() {}
 
     void invalidate();
@@ -38,6 +42,8 @@ private:
     std::vector<widget_ptr_t> mChildren;
 public:
     void handleEnteredTree() override;
+    void handleMouseMotion(const sdlpp::MouseMotionEvent& event) override;
+    void handleMouseButton(const sdlpp::MouseButtonEvent&) override;
 
     Widget* addChild(widget_ptr_t&& child);
 
@@ -69,6 +75,9 @@ public:
     [[nodiscard]]
     ParentWidget& getRootWidget() noexcept { return mRootWidget; }
 
+    void notifyMouseMoved(const sdlpp::MouseMotionEvent& event);
+    void notifyMouseButton(const sdlpp::MouseButtonEvent& event);
+
     void invalidateWidget(Widget* widget) noexcept;
 };
 } // namespace sdl_gpu_test