Properly integrate MouseButton enum into the GUI core:

- The previous code used enumerations for DialogContainer, and constants for everything in src/gui
 - It took me over 3 hours to determine that a '1' in the first didn't mean the same as a '1' in the second
 - If ever there was a reason for strongly named constants (enum class), this was it.

src/common/EventHandlerSDL2.cxx

@@ -60,7 +60,7 @@ void EventHandlerSDL2::pollEvent()
       case SDL_MOUSEMOTION:
       {
         handleMouseMotionEvent(myEvent.motion.x, myEvent.motion.y,
-                               myEvent.motion.xrel, myEvent.motion.yrel, 0);
+                               myEvent.motion.xrel, myEvent.motion.yrel);
         break;
       }
 

src/debugger/gui/DataGridWidget.cxx

@@ -251,7 +251,7 @@ void DataGridWidget::setRange(int lower, int upper)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void DataGridWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void DataGridWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if (!isEnabled())
     return;
@@ -277,7 +277,7 @@ void DataGridWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void DataGridWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void DataGridWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   // If this was a double click and the mouse is still over the selected item,
   // send the double click command

src/debugger/gui/DataGridWidget.hxx

@@ -97,8 +97,8 @@ class DataGridWidget : public EditableWidget
     void receivedFocusWidget() override;
     void lostFocusWidget() override;
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleText(char text) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;

src/debugger/gui/PromptWidget.cxx

@@ -106,7 +106,7 @@ void PromptWidget::drawWidget(bool hilite)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void PromptWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void PromptWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
 //  cerr << "PromptWidget::handleMouseDown\n";
 }

src/debugger/gui/PromptWidget.hxx

@@ -71,7 +71,7 @@ class PromptWidget : public Widget, public CommandSender
     void addToHistory(const char *str);
     void historyScroll(int direction);
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleText(char text) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;

src/debugger/gui/RomListSettings.cxx

@@ -123,12 +123,12 @@ void RomListSettings::loadConfig()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void RomListSettings::handleMouseDown(int x, int y, int button, int clickCount)
+void RomListSettings::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   // Close dialog if mouse click is outside it (simulates a context menu)
   // Otherwise let the base dialog class process it
   if(x >= 0 && x < _w && y >= 0 && y < _h)
-    Dialog::handleMouseDown(x, y, button, clickCount);
+    Dialog::handleMouseDown(x, y, b, clickCount);
   else
     close();
 }

src/debugger/gui/RomListSettings.hxx

@@ -52,7 +52,7 @@ class RomListSettings : public Dialog, public CommandSender
 
   private:
     void loadConfig() override;
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 
     // Following constructors and assignment operators not supported

src/debugger/gui/RomListWidget.cxx

@@ -238,13 +238,13 @@ void RomListWidget::scrollToCurrent(int item)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void RomListWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void RomListWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if (!isEnabled())
     return;
 
   // Grab right mouse button for context menu, left for selection/edit mode
-  if(button == 2)
+  if(b == MouseButton::RIGHT)
   {
     // Set selected and add menu at current x,y mouse location
     _selectedItem = findItem(x, y);
@@ -270,7 +270,7 @@ void RomListWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void RomListWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void RomListWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   // If this was a double click and the mouse is still over the selected item,
   // send the double click command

src/debugger/gui/RomListWidget.hxx

@@ -58,8 +58,8 @@ class RomListWidget : public EditableWidget
     void setHighlighted(int item);
 
   protected:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleText(char text) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;

src/debugger/gui/TiaInfoWidget.cxx

@@ -112,7 +112,7 @@ TiaInfoWidget::TiaInfoWidget(GuiObject* boss, const GUI::Font& lfont,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaInfoWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void TiaInfoWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
 //cerr << "TiaInfoWidget button press: x = " << x << ", y = " << y << endl;
 }

src/debugger/gui/TiaInfoWidget.hxx

@@ -49,7 +49,7 @@ class TiaInfoWidget : public Widget, public CommandSender
     CheckboxWidget* myVBlank;
 
   private:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 
     // Following constructors and assignment operators not supported

src/debugger/gui/TiaOutputWidget.cxx

@@ -92,10 +92,10 @@ void TiaOutputWidget::saveSnapshot(int execDepth, const string& execPrefix)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaOutputWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void TiaOutputWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   // Grab right mouse button for command context menu
-  if(button == 2)
+  if(b == MouseButton::RIGHT)
   {
     myClickX = x;
     myClickY = y;

src/debugger/gui/TiaOutputWidget.hxx

@@ -42,7 +42,7 @@ class TiaOutputWidget : public Widget, public CommandSender
 // For example, clicking an area may cause an action
 // (fill to this scanline, etc).
 /*
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;
     bool handleKeyUp(StellaKey key, StellaMod mod) override;
@@ -58,7 +58,7 @@ class TiaOutputWidget : public Widget, public CommandSender
     uInt32 myLineBuffer[320];
 
   private:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 
     void drawWidget(bool hilite) override;

src/debugger/gui/TiaZoomWidget.cxx

@@ -102,18 +102,18 @@ void TiaZoomWidget::recalc()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaZoomWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void TiaZoomWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   // Button 1 is for 'drag'/movement of the image
   // Button 2 is for context menu
-  if(button == 1)
+  if(b == MouseButton::LEFT)
   {
     // Indicate mouse drag started/in progress
     myMouseMoving = true;
     myXClick = x;
     myYClick = y;
   }
-  else if(button == 2)
+  else if(b == MouseButton::RIGHT)
   {
     // Add menu at current x,y mouse location
     myMenu->show(x + getAbsX(), y + getAbsY());
@@ -121,7 +121,7 @@ void TiaZoomWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaZoomWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void TiaZoomWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   myMouseMoving = false;
 }
@@ -136,7 +136,7 @@ void TiaZoomWidget::handleMouseWheel(int x, int y, int direction)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaZoomWidget::handleMouseMoved(int x, int y, int button)
+void TiaZoomWidget::handleMouseMoved(int x, int y)
 {
   // TODO: Not yet working - finish for next release
 #if 0
@@ -165,7 +165,7 @@ void TiaZoomWidget::handleMouseMoved(int x, int y, int button)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TiaZoomWidget::handleMouseLeft(int button)
+void TiaZoomWidget::handleMouseLeft()
 {
   myMouseMoving = false;
 }

src/debugger/gui/TiaZoomWidget.hxx

@@ -39,11 +39,11 @@ class TiaZoomWidget : public Widget, public CommandSender
     void zoom(int level);
     void recalc();
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
-    void handleMouseMoved(int x, int y, int button) override;
+    void handleMouseMoved(int x, int y) override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
     bool handleEvent(Event::Type event) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 

src/debugger/gui/ToggleWidget.cxx

@@ -41,7 +41,7 @@ ToggleWidget::ToggleWidget(GuiObject* boss, const GUI::Font& font,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ToggleWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void ToggleWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if (!isEnabled())
     return;
@@ -62,7 +62,7 @@ void ToggleWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ToggleWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void ToggleWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if (!isEnabled() || !_editable)
     return;

src/debugger/gui/ToggleWidget.hxx

@@ -66,8 +66,8 @@ class ToggleWidget : public Widget, public CommandSender
     void drawWidget(bool hilite) override = 0;
     int findItem(int x, int y);
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 

src/emucore/EventHandler.cxx

@@ -648,7 +648,7 @@ void EventHandler::handleKeyEvent(StellaKey key, StellaMod mod, bool state)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void EventHandler::handleMouseMotionEvent(int x, int y, int xrel, int yrel, int button)
+void EventHandler::handleMouseMotionEvent(int x, int y, int xrel, int yrel)
 {
   // Determine which mode we're in, then send the event to the appropriate place
   if(myState == EventHandlerState::EMULATION)
@@ -661,7 +661,7 @@ void EventHandler::handleMouseMotionEvent(int x, int y, int xrel, int yrel, int
     mySkipMouseMotion = false;
   }
   else if(myOverlay)
-    myOverlay->handleMouseMotionEvent(x, y, button);
+    myOverlay->handleMouseMotionEvent(x, y);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/EventHandler.hxx

@@ -304,7 +304,7 @@ class EventHandler
     */
     void handleTextEvent(char text);
     void handleKeyEvent(StellaKey key, StellaMod mod, bool state);
-    void handleMouseMotionEvent(int x, int y, int xrel, int yrel, int button);
+    void handleMouseMotionEvent(int x, int y, int xrel, int yrel);
     void handleMouseButtonEvent(MouseButton b, bool pressed, int x, int y);
     void handleJoyEvent(int stick, int button, uInt8 state);
     void handleJoyAxisEvent(int stick, int axis, int value);

src/emucore/EventHandlerConstants.hxx

@@ -20,21 +20,22 @@
 
 // Enumeration representing the different states of operation
 enum class EventHandlerState {
-  NONE,
   EMULATION,
   TIMEMACHINE,
   PAUSE,
   LAUNCHER,
   OPTIONSMENU,
   CMDMENU,
-  DEBUGGER
+  DEBUGGER,
+  NONE
 };
 
 enum class MouseButton {
   LEFT,
   RIGHT,
   WHEELDOWN,
-  WHEELUP
+  WHEELUP,
+  NONE
 };
 
 enum class JoyHat {

src/gui/CheckListWidget.cxx

@@ -164,7 +164,7 @@ bool CheckListWidget::handleEvent(Event::Type e)
   {
     case Event::UISelect:
       // Simulate a mouse button click
-      _checkList[ListWidget::getSelected()]->handleMouseUp(0, 0, 1, 0);
+      _checkList[ListWidget::getSelected()]->handleMouseUp(0, 0, MouseButton::LEFT, 0);
       return true;
 
     default:

src/gui/ContextMenu.cxx

@@ -233,13 +233,13 @@ bool ContextMenu::sendSelectionLast()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ContextMenu::handleMouseDown(int x, int y, int button, int clickCount)
+void ContextMenu::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   // Compute over which item the mouse is...
   int item = findItem(x, y);
 
   // Only do a selection when the left button is in the dialog
-  if(button == 1)
+  if(b == MouseButton::LEFT)
   {
     if(item != -1)
     {
@@ -252,7 +252,7 @@ void ContextMenu::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ContextMenu::handleMouseMoved(int x, int y, int button)
+void ContextMenu::handleMouseMoved(int x, int y)
 {
   // Compute over which item the mouse is...
   int item = findItem(x, y);
@@ -264,7 +264,7 @@ void ContextMenu::handleMouseMoved(int x, int y, int button)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool ContextMenu::handleMouseClicks(int x, int y, int button)
+bool ContextMenu::handleMouseClicks(int x, int y, MouseButton b)
 {
   // Let continuous mouse clicks come through, as the scroll buttons need them
   return true;

src/gui/ContextMenu.hxx

@@ -82,9 +82,9 @@ class ContextMenu : public Dialog, public CommandSender
     bool sendSelectionLast();
 
   private:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseMoved(int x, int y, int button) override;
+    void handleMouseMoved(int x, int y) override;
-    bool handleMouseClicks(int x, int y, int button) override;
+    bool handleMouseClicks(int x, int y, MouseButton b) override;
     void handleMouseWheel(int x, int y, int direction) override;
     void handleKeyDown(StellaKey key, StellaMod mod) override;
     void handleJoyDown(int stick, int button) override;

src/gui/Dialog.cxx

@@ -90,7 +90,7 @@ void Dialog::close(bool refresh)
 {
   if (_mouseWidget)
   {
-    _mouseWidget->handleMouseLeft(0);
+    _mouseWidget->handleMouseLeft();
     _mouseWidget = nullptr;
   }
 
@@ -377,7 +377,7 @@ void Dialog::handleKeyUp(StellaKey key, StellaMod mod)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Dialog::handleMouseDown(int x, int y, int button, int clickCount)
+void Dialog::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   Widget* w = findWidget(x, y);
 
@@ -386,11 +386,11 @@ void Dialog::handleMouseDown(int x, int y, int button, int clickCount)
 
   if(w)
     w->handleMouseDown(x - (w->getAbsX() - _x), y - (w->getAbsY() - _y),
-                       button, clickCount);
+                       b, clickCount);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Dialog::handleMouseUp(int x, int y, int button, int clickCount)
+void Dialog::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(_focusedWidget)
   {
@@ -402,7 +402,7 @@ void Dialog::handleMouseUp(int x, int y, int button, int clickCount)
   Widget* w = _dragWidget;
   if(w)
     w->handleMouseUp(x - (w->getAbsX() - _x), y - (w->getAbsY() - _y),
-                     button, clickCount);
+                     b, clickCount);
 
   _dragWidget = nullptr;
 }
@@ -422,7 +422,7 @@ void Dialog::handleMouseWheel(int x, int y, int direction)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Dialog::handleMouseMoved(int x, int y, int button)
+void Dialog::handleMouseMoved(int x, int y)
 {
   Widget* w;
 
@@ -438,17 +438,17 @@ void Dialog::handleMouseMoved(int x, int y, int button)
     if(mouseInFocusedWidget && _mouseWidget != w)
     {
       if(_mouseWidget)
-        _mouseWidget->handleMouseLeft(button);
+        _mouseWidget->handleMouseLeft();
       _mouseWidget = w;
-      w->handleMouseEntered(button);
+      w->handleMouseEntered();
     }
     else if (!mouseInFocusedWidget && _mouseWidget == w)
     {
       _mouseWidget = nullptr;
-      w->handleMouseLeft(button);
+      w->handleMouseLeft();
     }
 
-    w->handleMouseMoved(x - wx, y - wy, button);
+    w->handleMouseMoved(x - wx, y - wy);
   }
 
   // While a "drag" is in process (i.e. mouse is moved while a button is pressed),
@@ -461,24 +461,24 @@ void Dialog::handleMouseMoved(int x, int y, int button)
   if (_mouseWidget != w)
   {
     if (_mouseWidget)
-      _mouseWidget->handleMouseLeft(button);
+      _mouseWidget->handleMouseLeft();
     if (w)
-      w->handleMouseEntered(button);
+      w->handleMouseEntered();
     _mouseWidget = w;
   }
 
   if (w && (w->getFlags() & WIDGET_TRACK_MOUSE))
-    w->handleMouseMoved(x - (w->getAbsX() - _x), y - (w->getAbsY() - _y), button);
+    w->handleMouseMoved(x - (w->getAbsX() - _x), y - (w->getAbsY() - _y));
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Dialog::handleMouseClicks(int x, int y, int button)
+bool Dialog::handleMouseClicks(int x, int y, MouseButton b)
 {
   Widget* w = findWidget(x, y);
 
   if(w)
     return w->handleMouseClicks(x - (w->getAbsX() - _x),
-                                y - (w->getAbsY() - _y), button);
+                                y - (w->getAbsY() - _y), b);
   else
     return false;
 }

src/gui/Dialog.hxx

@@ -86,11 +86,11 @@ class Dialog : public GuiObject
     virtual void handleText(char text);
     virtual void handleKeyDown(StellaKey key, StellaMod modifiers);
     virtual void handleKeyUp(StellaKey key, StellaMod modifiers);
-    virtual void handleMouseDown(int x, int y, int button, int clickCount);
+    virtual void handleMouseDown(int x, int y, MouseButton b, int clickCount);
-    virtual void handleMouseUp(int x, int y, int button, int clickCount);
+    virtual void handleMouseUp(int x, int y, MouseButton b, int clickCount);
     virtual void handleMouseWheel(int x, int y, int direction);
-    virtual void handleMouseMoved(int x, int y, int button);
+    virtual void handleMouseMoved(int x, int y);
-    virtual bool handleMouseClicks(int x, int y, int button);
+    virtual bool handleMouseClicks(int x, int y, MouseButton b);
     virtual void handleJoyDown(int stick, int button);
     virtual void handleJoyUp(int stick, int button);
     virtual void handleJoyAxis(int stick, int axis, int value);

src/gui/DialogContainer.cxx

@@ -65,11 +65,11 @@ void DialogContainer::updateTime(uInt64 time)
   }
 
   // Mouse button still pressed
-  if(myCurrentMouseDown.button != -1 && myClickRepeatTime < myTime)
+  if(myCurrentMouseDown.b != MouseButton::NONE && myClickRepeatTime < myTime)
   {
     activeDialog->handleMouseDown(myCurrentMouseDown.x - activeDialog->_x,
                                   myCurrentMouseDown.y - activeDialog->_y,
-                                  myCurrentMouseDown.button, 1);
+                                  myCurrentMouseDown.b, 1);
     myClickRepeatTime = myTime + kRepeatSustainDelay;
   }
 
@@ -182,7 +182,7 @@ void DialogContainer::handleKeyEvent(StellaKey key, StellaMod mod, bool state)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void DialogContainer::handleMouseMotionEvent(int x, int y, int button)
+void DialogContainer::handleMouseMotionEvent(int x, int y)
 {
   if(myDialogStack.empty())
     return;
@@ -190,9 +190,7 @@ void DialogContainer::handleMouseMotionEvent(int x, int y, int button)
   // Send the event to the dialog box on the top of the stack
   Dialog* activeDialog = myDialogStack.top();
   activeDialog->surface().translateCoords(x, y);
-  activeDialog->handleMouseMoved(x - activeDialog->_x,
+  activeDialog->handleMouseMoved(x - activeDialog->_x, y - activeDialog->_y);
-                                 y - activeDialog->_y,
-                                 button);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -206,7 +204,6 @@ void DialogContainer::handleMouseButtonEvent(MouseButton b, bool pressed,
   Dialog* activeDialog = myDialogStack.top();
   activeDialog->surface().translateCoords(x, y);
 
-  int button = b == MouseButton::LEFT ? 1 : 2;
   switch(b)
   {
     case MouseButton::LEFT:
@@ -237,27 +234,26 @@ void DialogContainer::handleMouseButtonEvent(MouseButton b, bool pressed,
 
         // Now account for repeated mouse events (click and hold), but only
         // if the dialog wants them
-        if(activeDialog->handleMouseClicks(x - activeDialog->_x, y - activeDialog->_y,
+        if(activeDialog->handleMouseClicks(x - activeDialog->_x, y - activeDialog->_y, b))
-                                           button))
         {
           myCurrentMouseDown.x = x;
           myCurrentMouseDown.y = y;
-          myCurrentMouseDown.button = button;
+          myCurrentMouseDown.b = b;
           myClickRepeatTime = myTime + kRepeatInitialDelay;
         }
         else
-          myCurrentMouseDown.button = -1;
+          myCurrentMouseDown.b = MouseButton::NONE;
 
         activeDialog->handleMouseDown(x - activeDialog->_x, y - activeDialog->_y,
-                                      button, myLastClick.count);
+                                      b, myLastClick.count);
       }
       else
       {
         activeDialog->handleMouseUp(x - activeDialog->_x, y - activeDialog->_y,
-                                    button, myLastClick.count);
+                                    b, myLastClick.count);
 
-        if(button == myCurrentMouseDown.button)
+        if(b == myCurrentMouseDown.b)
-          myCurrentMouseDown.button = -1;
+          myCurrentMouseDown.b = MouseButton::NONE;
       }
       break;
 
@@ -268,6 +264,9 @@ void DialogContainer::handleMouseButtonEvent(MouseButton b, bool pressed,
     case MouseButton::WHEELDOWN:
       activeDialog->handleMouseWheel(x - activeDialog->_x, y - activeDialog->_y, 1);
       break;
+
+    case MouseButton::NONE:  // should never get here
+      break;
   }
 }
 
@@ -346,7 +345,7 @@ void DialogContainer::handleJoyHatEvent(int stick, int hat, JoyHat value)
 void DialogContainer::reset()
 {
   myCurrentKeyDown.keycode = KBDK_UNKNOWN;
-  myCurrentMouseDown.button = -1;
+  myCurrentMouseDown.b = MouseButton::NONE;
   myLastClick.x = myLastClick.y = 0;
   myLastClick.time = 0;
   myLastClick.count = 0;

src/gui/DialogContainer.hxx

@@ -77,11 +77,10 @@ class DialogContainer
     /**
       Handle a mouse motion event.
 
-      @param x      The x location
+      @param x  The x location
-      @param y      The y location
+      @param y  The y location
-      @param button The currently pressed button
     */
-    void handleMouseMotionEvent(int x, int y, int button);
+    void handleMouseMotionEvent(int x, int y);
 
     /**
       Handle a mouse button event.
@@ -174,7 +173,7 @@ class DialogContainer
     struct {
       int x;
       int y;
-      int button;
+      MouseButton b;
     } myCurrentMouseDown;
     uInt64 myClickRepeatTime;
 

src/gui/EditTextWidget.cxx

@@ -41,7 +41,7 @@ void EditTextWidget::setText(const string& str, bool changed)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void EditTextWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void EditTextWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if(!isEditable())
     return;

src/gui/EditTextWidget.hxx

@@ -42,7 +42,7 @@ class EditTextWidget : public EditableWidget
 
     GUI::Rect getEditRect() const override;
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
 
   protected:
     string _backupString;

src/gui/LauncherDialog.cxx

@@ -432,16 +432,16 @@ void LauncherDialog::handleKeyDown(StellaKey key, StellaMod mod)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void LauncherDialog::handleMouseDown(int x, int y, int button, int clickCount)
+void LauncherDialog::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   // Grab right mouse button for context menu, send left to base class
-  if(button == 2)
+  if(b == MouseButton::RIGHT)
   {
     // Add menu at current x,y mouse location
     myMenu->show(x + getAbsX(), y + getAbsY());
   }
   else
-    Dialog::handleMouseDown(x, y, button, clickCount);
+    Dialog::handleMouseDown(x, y, b, clickCount);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/gui/LauncherDialog.hxx

@@ -79,7 +79,7 @@ class LauncherDialog : public Dialog
 
   private:
     void handleKeyDown(StellaKey key, StellaMod mod) override;
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
 
     void loadConfig() override;

src/gui/ListWidget.cxx

@@ -191,7 +191,7 @@ void ListWidget::scrollBarRecalc()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ListWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void ListWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if (!isEnabled())
     return;
@@ -216,7 +216,7 @@ void ListWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ListWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void ListWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   // If this was a double click and the mouse is still over the selected item,
   // send the double click command

src/gui/ListWidget.hxx

@@ -65,8 +65,8 @@ class ListWidget : public EditableWidget
     static void setQuickSelectDelay(uInt64 time) { _QUICK_SELECT_DELAY = time; }
 
   protected:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleText(char text) override;
     bool handleKeyDown(StellaKey key, StellaMod mod) override;

src/gui/PopUpWidget.cxx

@@ -131,7 +131,7 @@ const Variant& PopUpWidget::getSelectedTag() const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void PopUpWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void PopUpWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && !myMenu->isVisible())
   {
@@ -159,14 +159,14 @@ void PopUpWidget::handleMouseWheel(int x, int y, int direction)
 
 #ifdef FLAT_UI
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void PopUpWidget::handleMouseEntered(int button)
+void PopUpWidget::handleMouseEntered()
 {
   setFlags(WIDGET_HILITED);
   setDirty();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void PopUpWidget::handleMouseLeft(int button)
+void PopUpWidget::handleMouseLeft()
 {
   clearFlags(WIDGET_HILITED);
   setDirty();
@@ -182,7 +182,7 @@ bool PopUpWidget::handleEvent(Event::Type e)
   switch(e)
   {
     case Event::UISelect:
-      handleMouseDown(0, 0, 1, 0);
+      handleMouseDown(0, 0, MouseButton::LEFT, 0);
       return true;
     case Event::UIUp:
     case Event::UILeft:

src/gui/PopUpWidget.hxx

@@ -62,11 +62,11 @@ class PopUpWidget : public Widget, public CommandSender
     bool wantsFocus() const override { return true; }
 
   protected:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
 #ifdef FLAT_UI
-    void handleMouseEntered(int button) override;
+    void handleMouseEntered() override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
 #endif
     bool handleEvent(Event::Type e) override;
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;

src/gui/RadioButtonWidget.cxx

@@ -173,7 +173,7 @@ RadioButtonWidget::RadioButtonWidget(GuiObject* boss, const GUI::Font& font,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void RadioButtonWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void RadioButtonWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && _editable && x >= 0 && x < _w && y >= 0 && y < _h)
   {

src/gui/RadioButtonWidget.hxx

@@ -34,7 +34,7 @@ class RadioButtonWidget : public CheckboxWidget
                       const string& label, RadioButtonGroup* group,
                       int cmd = 0);
 
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void setState(bool state, bool send = true);
 
   protected:

src/gui/ScrollBarWidget.cxx

@@ -74,7 +74,7 @@ ScrollBarWidget::ScrollBarWidget(GuiObject* boss, const GUI::Font& font,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ScrollBarWidget::handleMouseDown(int x, int y, int button,
+void ScrollBarWidget::handleMouseDown(int x, int y, MouseButton b,
                                       int clickCount)
 {
   // Ignore subsequent mouse clicks when the slider is being moved
@@ -118,7 +118,7 @@ void ScrollBarWidget::handleMouseDown(int x, int y, int button,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ScrollBarWidget::handleMouseUp(int x, int y, int button,
+void ScrollBarWidget::handleMouseUp(int x, int y, MouseButton b,
                                     int clickCount)
 {
   _draggingPart = kNoPart;
@@ -142,7 +142,7 @@ void ScrollBarWidget::handleMouseWheel(int x, int y, int direction)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ScrollBarWidget::handleMouseMoved(int x, int y, int button)
+void ScrollBarWidget::handleMouseMoved(int x, int y)
 {
   // Do nothing if there are less items than fit on one page
   if(_numEntries <= _entriesPerPage)
@@ -184,7 +184,7 @@ void ScrollBarWidget::handleMouseMoved(int x, int y, int button)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool ScrollBarWidget::handleMouseClicks(int x, int y, int button)
+bool ScrollBarWidget::handleMouseClicks(int x, int y, MouseButton b)
 {
   // Let continuous mouse clicks come through, as the scroll buttons need them
   return true;
@@ -206,13 +206,13 @@ void ScrollBarWidget::checkBounds(int old_pos)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ScrollBarWidget::handleMouseEntered(int button)
+void ScrollBarWidget::handleMouseEntered()
 {
   setFlags(WIDGET_HILITED);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ScrollBarWidget::handleMouseLeft(int button)
+void ScrollBarWidget::handleMouseLeft()
 {
   _part = kNoPart;
   clearFlags(WIDGET_HILITED);

src/gui/ScrollBarWidget.hxx

@@ -45,12 +45,12 @@ class ScrollBarWidget : public Widget, public CommandSender
     void drawWidget(bool hilite) override;
     void checkBounds(int old_pos);
 
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseMoved(int x, int y, int button) override;
+    void handleMouseMoved(int x, int y) override;
-    bool handleMouseClicks(int x, int y, int button) override;
+    bool handleMouseClicks(int x, int y, MouseButton b) override;
-    void handleMouseEntered(int button) override;
+    void handleMouseEntered() override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
 
   public:
     int _numEntries;

src/gui/TabWidget.cxx

@@ -171,7 +171,7 @@ void TabWidget::setParentWidget(int tabID, Widget* parent)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TabWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void TabWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
   assert(y < _tabHeight);
 
@@ -194,14 +194,14 @@ void TabWidget::handleMouseDown(int x, int y, int button, int clickCount)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TabWidget::handleMouseEntered(int button)
+void TabWidget::handleMouseEntered()
 {
   setFlags(WIDGET_HILITED);
   setDirty();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TabWidget::handleMouseLeft(int button)
+void TabWidget::handleMouseLeft()
 {
   clearFlags(WIDGET_HILITED);
   setDirty();

src/gui/TabWidget.hxx

@@ -59,9 +59,9 @@ class TabWidget : public Widget, public CommandSender
     void loadConfig() override;
 
   protected:
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseEntered(int button) override;
+    void handleMouseEntered() override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
 
     void handleCommand(CommandSender* sender, int cmd, int data, int id) override;
     bool handleEvent(Event::Type event) override;

src/gui/Widget.cxx

@@ -400,14 +400,14 @@ ButtonWidget::ButtonWidget(GuiObject* boss, const GUI::Font& font,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ButtonWidget::handleMouseEntered(int button)
+void ButtonWidget::handleMouseEntered()
 {
   setFlags(WIDGET_HILITED);
   setDirty();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ButtonWidget::handleMouseLeft(int button)
+void ButtonWidget::handleMouseLeft()
 {
   clearFlags(WIDGET_HILITED);
   setDirty();
@@ -423,7 +423,7 @@ bool ButtonWidget::handleEvent(Event::Type e)
   {
     case Event::UISelect:
       // Simulate mouse event
-      handleMouseUp(0, 0, 1, 0);
+      handleMouseUp(0, 0, MouseButton::LEFT, 0);
       return true;
     default:
       return false;
@@ -431,7 +431,7 @@ bool ButtonWidget::handleEvent(Event::Type e)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void ButtonWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void ButtonWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && x >= 0 && x < _w && y >= 0 && y < _h)
   {
@@ -572,21 +572,21 @@ CheckboxWidget::CheckboxWidget(GuiObject* boss, const GUI::Font& font,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void CheckboxWidget::handleMouseEntered(int button)
+void CheckboxWidget::handleMouseEntered()
 {
   setFlags(WIDGET_HILITED);
   setDirty();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void CheckboxWidget::handleMouseLeft(int button)
+void CheckboxWidget::handleMouseLeft()
 {
   clearFlags(WIDGET_HILITED);
   setDirty();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void CheckboxWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void CheckboxWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && _editable && x >= 0 && x < _w && y >= 0 && y < _h)
   {
@@ -728,7 +728,7 @@ void SliderWidget::setStepValue(int value)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void SliderWidget::handleMouseMoved(int x, int y, int button)
+void SliderWidget::handleMouseMoved(int x, int y)
 {
   // TODO: when the mouse is dragged outside the widget, the slider should
   // snap back to the old value.
@@ -737,17 +737,17 @@ void SliderWidget::handleMouseMoved(int x, int y, int button)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void SliderWidget::handleMouseDown(int x, int y, int button, int clickCount)
+void SliderWidget::handleMouseDown(int x, int y, MouseButton b, int clickCount)
 {
-  if(isEnabled())
+  if(isEnabled() && b == MouseButton::LEFT)
   {
     _isDragging = true;
-    handleMouseMoved(x, y, button);
+    handleMouseMoved(x, y);
   }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void SliderWidget::handleMouseUp(int x, int y, int button, int clickCount)
+void SliderWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && _isDragging)
     sendCommand(_cmd, _value, _id);

src/gui/Widget.hxx

@@ -68,13 +68,13 @@ class Widget : public GuiObject
     virtual bool handleText(char text)                        { return false; }
     virtual bool handleKeyDown(StellaKey key, StellaMod mod)  { return false; }
     virtual bool handleKeyUp(StellaKey key, StellaMod mod)    { return false; }
-    virtual void handleMouseDown(int x, int y, int button, int clickCount) { }
+    virtual void handleMouseDown(int x, int y, MouseButton b, int clickCount) { }
-    virtual void handleMouseUp(int x, int y, int button, int clickCount) { }
+    virtual void handleMouseUp(int x, int y, MouseButton b, int clickCount) { }
-    virtual void handleMouseEntered(int button) { }
+    virtual void handleMouseEntered() { }
-    virtual void handleMouseLeft(int button) { }
+    virtual void handleMouseLeft() { }
-    virtual void handleMouseMoved(int x, int y, int button) { }
+    virtual void handleMouseMoved(int x, int y) { }
     virtual void handleMouseWheel(int x, int y, int direction) { }
-    virtual bool handleMouseClicks(int x, int y, int button) { return false; }
+    virtual bool handleMouseClicks(int x, int y, MouseButton b) { return false; }
     virtual void handleJoyDown(int stick, int button) { }
     virtual void handleJoyUp(int stick, int button) { }
     virtual void handleJoyAxis(int stick, int axis, int value) { }
@@ -226,9 +226,9 @@ class ButtonWidget : public StaticTextWidget, public CommandSender
     int getCmd() const    { return _cmd; }
 
   protected:
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseEntered(int button) override;
+    void handleMouseEntered() override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
     bool handleEvent(Event::Type event) override;
 
     void drawWidget(bool hilite) override;
@@ -267,9 +267,9 @@ class CheckboxWidget : public ButtonWidget
     void toggleState()     { setState(!_state); }
     bool getState() const  { return _state;     }
 
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseEntered(int button) override;
+    void handleMouseEntered() override;
-    void handleMouseLeft(int button) override;
+    void handleMouseLeft() override;
 
     static int boxSize() { return 14; }  // box is square
 
@@ -315,9 +315,9 @@ class SliderWidget : public ButtonWidget
     int  getStepValue() const     { return _stepValue; }
 
   protected:
-    void handleMouseMoved(int x, int y, int button) override;
+    void handleMouseMoved(int x, int y) override;
-    void handleMouseDown(int x, int y, int button, int clickCount) override;
+    void handleMouseDown(int x, int y, MouseButton b, int clickCount) override;
-    void handleMouseUp(int x, int y, int button, int clickCount) override;
+    void handleMouseUp(int x, int y, MouseButton b, int clickCount) override;
     void handleMouseWheel(int x, int y, int direction) override;
     bool handleEvent(Event::Type event) override;