Change opaque/transparent selection by default depending on the layer

data/pref.xml

@@ -111,6 +111,7 @@
     <section id="selection">
       <option id="mode" type="app::tools::SelectionMode" default="app::tools::SelectionMode::DEFAULT" />
       <option id="opaque" type="bool" default="false" />
+      <option id="auto_opaque" type="bool" default="true" />
       <option id="transparent_color" type="app::Color" />
       <option id="rotation_algorithm" type="app::tools::RotationAlgorithm" default="app::tools::RotationAlgorithm::DEFAULT" />
     </section>

data/widgets/options.xml

@@ -58,9 +58,12 @@
             <label text="Cursor Color:" />
             <box id="cursor_color_box" /><!-- custom widget -->
           </hbox>
+
+          <separator text="Selection" horizontal="true" />
+          <check text="Adjust opaque/transparent mode automatically" id="auto_opaque" tooltip="Depending on the layer (background/transparent),&#10;the pasted selection will be adjusted&#10;automatically (opaque/transparent)" />
         </vbox>
 
-        <!-- Editor -->
+        <!-- Timeline -->
         <vbox id="section_timeline">
           <separator text="Timeline" horizontal="true" />
           <check text="Show timeline automatically" id="autotimeline" tooltip="Show the timeline automatically&#10;when a new frame or layer is added." />

src/app/commands/cmd_options.cpp

@@ -84,6 +84,9 @@ public:
     if (m_preferences.editor.zoomFromCenterWithKeys())
       zoomFromCenterWithKeys()->setSelected(true);
 
+    if (m_preferences.selection.autoOpaque())
+      autoOpaque()->setSelected(true);
+
     if (m_preferences.experimental.useNativeCursor())
       nativeCursor()->setSelected(true);
 
@@ -181,6 +184,7 @@ public:
     m_preferences.editor.zoomWithWheel(wheelZoom()->isSelected());
     m_preferences.editor.rightClickMode(static_cast<app::gen::RightClickMode>(rightClickBehavior()->getSelectedItemIndex()));
     m_preferences.editor.cursorColor(m_cursorColor->getColor());
+    m_preferences.selection.autoOpaque(autoOpaque()->isSelected());
 
     m_curPref->grid.color(m_gridColor->getColor());
     m_curPref->grid.opacity(gridOpacity()->getValue());

src/app/ui/context_bar.cpp

@@ -490,10 +490,14 @@ public:
     gfx::Size sz = m_icon.getItem(0)->getPreferredSize();
     sz.w += 2*guiscale();
     m_icon.getItem(0)->setMinSize(sz);
-    setOpaque(Preferences::instance().selection.opaque());
 
     m_icon.ItemChange.connect(Bind<void>(&TransparentColorField::onPopup, this));
     m_maskColor.Change.connect(Bind<void>(&TransparentColorField::onChangeColor, this));
+
+    Preferences::instance().selection.opaque.AfterChange.connect(
+      Bind<void>(&TransparentColorField::onOpaqueChange, this));
+
+    setOpaque(Preferences::instance().selection.opaque());
   }
 
 private:
@@ -525,12 +529,18 @@ private:
   }
 
   void setOpaque(bool opaque) {
+    Preferences::instance().selection.opaque(opaque);
+  }
+
+  // When the preference is changed from outside the context bar
+  void onOpaqueChange() {
+    bool opaque = Preferences::instance().selection.opaque();
+
     int part = (opaque ? PART_SELECTION_OPAQUE: PART_SELECTION_MASKED);
     m_icon.getItem(0)->setIcon(
       static_cast<SkinTheme*>(getTheme())->get_part(part));
 
     m_maskColor.setVisible(!opaque);
-    Preferences::instance().selection.opaque(opaque);
     if (!opaque) {
       Preferences::instance().selection.transparentColor(
         m_maskColor.getColor());

src/app/ui/editor/moving_pixels_state.cpp

@@ -70,7 +70,11 @@ MovingPixelsState::MovingPixelsState(Editor* editor, MouseMessage* msg, PixelsMo
     editor->captureMouse();
   }
 
-  // Setup mask color
+  // Setup transparent mode/mask color
+  if (Preferences::instance().selection.autoOpaque()) {
+    Preferences::instance().selection.opaque(
+      editor->layer()->isBackground());
+  }
   onTransparentColorChange();
 
   // Hook BeforeCommandExecution signal so we know if the user wants