Add a menu option to lock/unlock each brush

This is an alternative to lock brushes using its keyboard shortcut.

src/app/ui/brush_popup.cpp

@@ -64,10 +64,13 @@ protected:
       MouseMessage* mouseMsg = static_cast<MouseMessage*>(msg);
       if (mouseMsg->buttons() == kButtonRight) {
         Menu menu;
+        AppMenuItem lockItem(m_delegate->onIsBrushSlotLocked(m_slot) ? "Unlock Brush": "Lock Brush");
         AppMenuItem deleteItem("Delete");
         AppMenuItem deleteAllItem("Delete All");
+        lockItem.Click.connect(&Item::onLockBrush, this);
         deleteItem.Click.connect(&Item::onDeleteBrush, this);
         deleteAllItem.Click.connect(&Item::onDeleteAllBrushes, this);
+        menu.addChild(&lockItem);
         menu.addChild(&deleteItem);
         menu.addChild(new Separator("", JI_HORIZONTAL));
         menu.addChild(&deleteAllItem);
@@ -84,6 +87,13 @@ protected:
   }
 
 private:
+  void onLockBrush() {
+    if (m_delegate->onIsBrushSlotLocked(m_slot))
+      m_delegate->onUnlockBrushSlot(m_slot);
+    else
+      m_delegate->onLockBrushSlot(m_slot);
+  }
+
   void onDeleteBrush() {
     m_delegate->onDeleteBrushSlot(m_slot);
   }

src/app/ui/brush_popup.h

@@ -31,6 +31,9 @@ namespace app {
     virtual ~BrushPopupDelegate() { }
     virtual void onDeleteBrushSlot(int slot) = 0;
     virtual void onDeleteAllBrushes() = 0;
+    virtual bool onIsBrushSlotLocked(int slot) const = 0;
+    virtual void onLockBrushSlot(int slot) = 0;
+    virtual void onUnlockBrushSlot(int slot) = 0;
   };
 
   class BrushPopup : public ui::PopupWindow {

src/app/ui/context_bar.cpp

@@ -113,6 +113,18 @@ protected:
     m_owner->removeAllBrushes();
   }
 
+  bool onIsBrushSlotLocked(int slot) const override {
+    return m_owner->isBrushSlotLocked(slot);
+  }
+
+  void onLockBrushSlot(int slot) override {
+    m_owner->lockBrushSlot(slot);
+  }
+
+  void onUnlockBrushSlot(int slot) override {
+    m_owner->unlockBrushSlot(slot);
+  }
+
 private:
   // Returns a little rectangle that can be used by the popup as the
   // first brush position.
@@ -1066,6 +1078,35 @@ Brushes ContextBar::getBrushes()
   return brushes;
 }
 
+void ContextBar::lockBrushSlot(int slot)
+{
+  --slot;
+  if (slot >= 0 && slot < (int)m_brushes.size() &&
+      m_brushes[slot].brush) {
+    m_brushes[slot].locked = true;
+  }
+}
+
+void ContextBar::unlockBrushSlot(int slot)
+{
+  --slot;
+  if (slot >= 0 && slot < (int)m_brushes.size() &&
+      m_brushes[slot].brush) {
+    m_brushes[slot].locked = false;
+  }
+}
+
+bool ContextBar::isBrushSlotLocked(int slot) const
+{
+  --slot;
+  if (slot >= 0 && slot < (int)m_brushes.size() &&
+      m_brushes[slot].brush) {
+    return m_brushes[slot].locked;
+  }
+  else
+    return false;
+}
+
 void ContextBar::setActiveBrush(const doc::BrushRef& brush)
 {
   m_activeBrush = brush;

src/app/ui/context_bar.h

@@ -57,6 +57,10 @@ namespace app {
     void setActiveBrushBySlot(int slot);
     doc::Brushes getBrushes();
 
+    void lockBrushSlot(int slot);
+    void unlockBrushSlot(int slot);
+    bool isBrushSlotLocked(int slot) const;
+
     static doc::BrushRef createBrushFromSettings(
       IBrushSettings* brushSettings = nullptr);