Mouse transition support

include/ftxui/component/mouse.hpp

@@ -23,6 +23,11 @@ struct Mouse {
     Pressed = 1,
   };
 
+  // Utility function to check the variations of the mouse state.
+  bool IsPressed(Button button = Left) const;
+  bool IsHeld(Button button = Left) const;
+  bool IsReleased(Button button = Left) const;
+
   // Button
   Button button = Button::None;
 
@@ -37,6 +42,9 @@ struct Mouse {
   // Coordinates:
   int x = 0;
   int y = 0;
+
+  // Previous mouse event, if any.
+  Mouse* previous = nullptr;
 };
 
 }  // namespace ftxui

include/ftxui/component/screen_interactive.hpp

@@ -112,6 +112,7 @@ class ScreenInteractive : public Screen {
 
   bool frame_valid_ = false;
 
+  Mouse latest_mouse_event_;
   friend class Loop;
 
  public: