Select the initial ColorButton color when we go back to the button

If start dragging from the ColorButton, we go outside the button, and
then we go back to the same button, we should select the original
color when the whole drag-and-drop process started.

We have also improved the look of the button in that case: the
original color is displayed (instead of the inverted color, which is
when the button is selected, in this way is less confusing).

src/app/ui/color_button.cpp

@@ -160,9 +160,12 @@ bool ColorButton::onProcessMessage(Message* msg)
 
         Widget* picked = manager()->pickFromScreenPos(screenPos);
         if (picked == this) {
-          // Do nothing
+          setColor(m_startDragColor);
           break;
         }
+        else {
+          m_mouseLeft = true;
+        }
 
         IColorSource* colorSource = dynamic_cast<IColorSource*>(picked);
         if (colorSource) {
@@ -302,6 +305,20 @@ void ColorButton::onClick(Event& ev)
   }
 }
 
+void ColorButton::onStartDrag()
+{
+  m_startDragColor = m_color;
+  m_mouseLeft = false;
+}
+
+void ColorButton::onSelectWhenDragging()
+{
+  if (m_mouseLeft)
+    setSelected(false);
+  else
+    ButtonBase::onSelectWhenDragging();
+}
+
 void ColorButton::onLoadLayout(ui::LoadLayoutEvent& ev)
 {
   if (canPin()) {

src/app/ui/color_button.h

@@ -58,6 +58,8 @@ namespace app {
     void onSizeHint(ui::SizeHintEvent& ev) override;
     void onPaint(ui::PaintEvent& ev) override;
     void onClick(ui::Event& ev) override;
+    void onStartDrag() override;
+    void onSelectWhenDragging() override;
     void onLoadLayout(ui::LoadLayoutEvent& ev) override;
     void onSaveLayout(ui::SaveLayoutEvent& ev) override;
 
@@ -75,12 +77,14 @@ namespace app {
     gfx::Rect convertBounds(const gfx::Rect& bounds) const;
 
     app::Color m_color;
+    app::Color m_startDragColor;
     PixelFormat m_pixelFormat;
     ColorPopup* m_window;
     gfx::Rect m_windowDefaultBounds;
     gfx::Rect m_hiddenPopupBounds;
     bool m_desktopCoords;       // True if m_windowDefault/hiddenPopupBounds are screen coordinates
     bool m_dependOnLayer;
+    bool m_mouseLeft;
     ColorButtonOptions m_options;
   };
 

src/ui/button.cpp

@@ -1,5 +1,5 @@
 // Aseprite UI Library
-// Copyright (C) 2019  Igara Studio S.A.
+// Copyright (C) 2019-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -165,6 +165,8 @@ bool ButtonBase::onProcessMessage(Message* msg)
 
             m_pressedStatus = isSelected();
             captureMouse();
+
+            onStartDrag();
           }
           return true;
 
@@ -174,6 +176,8 @@ bool ButtonBase::onProcessMessage(Message* msg)
 
             m_pressedStatus = isSelected();
             captureMouse();
+
+            onStartDrag();
           }
           return true;
 
@@ -186,6 +190,8 @@ bool ButtonBase::onProcessMessage(Message* msg)
 
               m_pressedStatus = isSelected();
               captureMouse();
+
+              onStartDrag();
             }
           }
           return true;
@@ -231,19 +237,8 @@ bool ButtonBase::onProcessMessage(Message* msg)
 
     case kMouseMoveMessage:
       if (isEnabled() && hasCapture()) {
-        bool hasMouse = hasMouseOver();
-
         m_handleSelect = false;
-
-        // Switch state when the mouse go out
-        if ((hasMouse && isSelected() != m_pressedStatus) ||
-            (!hasMouse && isSelected() == m_pressedStatus)) {
-          if (hasMouse)
-            setSelected(m_pressedStatus);
-          else
-            setSelected(!m_pressedStatus);
-        }
-
+        onSelectWhenDragging();
         m_handleSelect = true;
       }
       break;
@@ -269,6 +264,25 @@ void ButtonBase::generateButtonSelectSignal()
   onClick(ev);
 }
 
+void ButtonBase::onStartDrag()
+{
+  // Do nothing
+}
+
+void ButtonBase::onSelectWhenDragging()
+{
+  bool hasMouse = hasMouseOver();
+
+  // Switch state when the mouse go out
+  if ((hasMouse && isSelected() != m_pressedStatus) ||
+      (!hasMouse && isSelected() == m_pressedStatus)) {
+    if (hasMouse)
+      setSelected(m_pressedStatus);
+    else
+      setSelected(!m_pressedStatus);
+  }
+}
+
 // ======================================================================
 // Button class
 // ======================================================================

src/ui/button.h

@@ -1,4 +1,5 @@
 // Aseprite UI Library
+// Copyright (C) 2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -40,6 +41,8 @@ namespace ui {
 
     // New events
     virtual void onClick(Event& ev);
+    virtual void onStartDrag();
+    virtual void onSelectWhenDragging();
 
   private:
     void generateButtonSelectSignal();