Merge keeps currently selected droplet

src/main.cpp

@@ -40,10 +40,18 @@ void ProcessControls() {
 	  droplet_right = GetDroplet(DropletState::kRight,
 				     left_menu->GetBufferState());
 	}
-	// Disable split
+	// Merge
 	else {
+	  if (selected_menu == left_menu) {
 	    droplet_left->UpdateState(DropletState::kFull);
 	    delete droplet_right;
+	  } else {
+	    droplet_right->UpdateState(DropletState::kFull);
+	    delete droplet_left;
+	    droplet_left = droplet_right;
+	    left_menu->SetState(right_menu->GetBufferState());
+	    selected_menu = left_menu;
+	  }
 	}
       }
       // Switch side

src/menu.cpp

@@ -109,6 +109,17 @@ MenuState Menu::GetState() {
   return highlighted->GetState();
 }
 
+void Menu::SetState(MenuState state) {
+  MenuItem* ptr = head;
+  while(ptr != NULL) {
+    if (ptr->GetState() == state) {
+      Select(ptr);
+      return;
+    }
+  ptr = ptr->GetNext();
+  }
+}
+
 MenuState Menu::GetBufferState() {
   return buffer->GetState();
 }
@@ -124,8 +135,12 @@ void Menu::UpdateMenuState() {
 }
 
 void Menu::Select() {
+  Select(highlighted);
+}
+
+void Menu::Select(MenuItem* item) {
   if (selected->GetState() != MenuState::kSplit) {
     buffer = selected;
   }
-  selected = highlighted;
+  selected = item;
 }

src/menu.h

@@ -85,6 +85,13 @@ class Menu {
    */
   MenuState GetState();
   
+  /*
+   * Set the menu state.
+   *
+   * @param state menu state
+   */
+  void SetState(MenuState state);
+
   /*
    * Returns the previously selected menu item.
    *
@@ -102,6 +109,13 @@ class Menu {
    * Select the currently highlighted menu item.
    */
   void Select();
+
+  /*
+   * Select the given menu item.
+   *
+   * @param item menu item to select
+   */
+  void Select(MenuItem* item);
 };
 
 #endif // DROPLETS_MENU_H_