Add start frame = end frame argument to OnMouseUp

Author: cschreib

include/lxgui/gui_frame.hpp

@@ -200,9 +200,10 @@ using script_list_view = script_signal::slot_list_view;
  * last call to `OnMouseMove` (or since the last position before the mouse
  * entered this frame), and the mouse X and Y position.
  * - `OnMouseUp`: Similar to `OnMouseDown`, but triggered when the mouse button
- * is released. This event provides one extra argument compared to `OnMouseDown`:
+ * is released. This event provides two extra argument compared to `OnMouseDown`:
  * a boolean flag indicating whether the mouse was released after a drag
- * operation (true) or not (false).
+ * operation (true) or not (false), and another boolean flag indicating whether
+ * the mouse button was initially pressed on this frame (true) or not (false).
  * - `OnMouseWheel`: Triggered when the mouse wheel is moved and this frame is
  * the topmost mouse-wheel-enabled frame under the mouse pointer. Will not
  * trigger if the frame is hidden. This event provides three arguments to the
@@ -557,7 +558,6 @@ class frame : public region {
 
     /**
      * \brief Marks this frame as unable to receive keyboard input from any key.
-     * \param key_name The key to capture
      * \see enable_key_capture()
      * \see is_key_capture_enabled()
      * \see set_keyboard_enabled()

include/lxgui/gui_root.hpp

@@ -49,10 +49,10 @@ class root :
     ~root() override;
 
     // Non-copiable, non-movable
-    root(const root&) = delete;
-    root(root&&)      = delete;
+    root(const root&)            = delete;
+    root(root&&)                 = delete;
     root& operator=(const root&) = delete;
-    root& operator=(root&&) = delete;
+    root& operator=(root&&)      = delete;
 
     /**
      * \brief Returns the width and height of this renderer's main render target (e.g., screen).
@@ -327,8 +327,9 @@ class root :
     std::vector<utils::scoped_connection> connections_;
 
     // Mouse IO
-    utils::observer_ptr<frame> hovered_frame_ = nullptr;
-    utils::observer_ptr<frame> dragged_frame_ = nullptr;
+    utils::observer_ptr<frame> hovered_frame_     = nullptr;
+    utils::observer_ptr<frame> dragged_frame_     = nullptr;
+    utils::observer_ptr<frame> start_click_frame_ = nullptr;
 
     utils::observer_ptr<region> moved_object_ = nullptr;
     utils::observer_ptr<region> sized_object_ = nullptr;

src/gui_frame_glues.cpp

@@ -159,9 +159,10 @@
  * last call to `OnMouseMove` (or since the last position before the mouse
  * entered this frame), and the mouse X and Y position.
  * - `OnMouseUp`: Similar to `OnMouseDown`, but triggered when the mouse button
- * is released. This event provides one extra argument compared to `OnMouseDown`:
+ * is released. This event provides two extra argument compared to `OnMouseDown`:
  * a boolean flag indicating whether the mouse was released after a drag
- * operation (true) or not (false).
+ * operation (true) or not (false), and another boolean flag indicating whether
+ * the mouse button was initially pressed on this frame (true) or not (false).
  * - `OnMouseWheel`: Triggered when the mouse wheel is moved and this frame is
  * the topmost mouse-wheel-enabled frame under the mouse pointer. This event
  * provides three arguments to the registered callback. The first is a number

src/gui_root.cpp

@@ -789,6 +789,7 @@ bool root::on_mouse_button_state_changed_(
     bool                is_double_click,
     bool                was_dragged,
     const vector2f&     mouse_pos) {
+
     utils::observer_ptr<frame> hovered_frame = find_topmost_frame([&](const frame& frame) {
         return frame.is_in_region(mouse_pos) && frame.is_mouse_click_enabled();
     });
@@ -798,6 +799,10 @@ bool root::on_mouse_button_state_changed_(
             clear_focus();
     }
 
+    if (is_down) {
+        start_click_frame_ = hovered_frame;
+    }
+
     if (!hovered_frame) {
         // Forward to the world
         return false;
@@ -818,7 +823,9 @@ bool root::on_mouse_button_state_changed_(
         hovered_frame->fire_script("OnMouseDown", data);
     } else {
         data.add(was_dragged);
+        data.add(start_click_frame_ == hovered_frame);
         hovered_frame->fire_script("OnMouseUp", data);
+        start_click_frame_ = nullptr;
     }
 
     return true;