Buffer is now responsible for window creation

src/buffer.cc

@@ -316,14 +316,12 @@ void Buffer::append_modification(Modification&& modification)
     m_current_undo_group.push_back(modification);
 }
 
-struct window_already_registered {};
-
-void Buffer::register_window(Window* window)
+Window* Buffer::get_or_create_window()
 {
-    if (std::find(m_windows.begin(), m_windows.end(), window) != m_windows.end())
-        throw window_already_registered();
+    if (m_windows.empty())
+        m_windows.push_front(std::unique_ptr<Window>(new Window(*this)));
 
-    m_windows.push_front(std::unique_ptr<Window>(window));
+    return m_windows.front().get();
 }
 
 void Buffer::delete_window(Window* window)

src/buffer.hh

@@ -100,7 +100,7 @@ public:
 
     const BufferString& content() const { return m_content; }
 
-    void register_window(Window* window);
+    Window* get_or_create_window();
     void delete_window(Window* window);
 
 private:

src/main.cc

@@ -4,6 +4,7 @@
 #include "file.hh"
 #include "regex_selector.hh"
 #include "command_manager.hh"
+#include "buffer_manager.hh"
 
 #include <unordered_map>
 #include <cassert>
@@ -160,17 +161,17 @@ void edit(const CommandParameters& params)
         throw wrong_argument_count();
 
     std::string filename = params[0];
+    Buffer* buffer = NULL;
     try
     {
-        Buffer* buffer = create_buffer_from_file(filename);
-        if (buffer)
-            current_window = new Window(*buffer);
+        buffer = create_buffer_from_file(filename);
     }
     catch (file_not_found& what)
     {
         print_status("new file " + filename);
-        current_window = new Window(*new Buffer(filename));
+        buffer = new Buffer(filename);
     }
+    current_window = buffer->get_or_create_window();
 }
 
 void write_buffer(const CommandParameters& params)
@@ -293,7 +294,7 @@ int main()
     try
     {
         auto buffer = new Buffer("<scratch>");
-        current_window = new Window(*buffer);
+        current_window = buffer->get_or_create_window();
 
         draw_window(*current_window);
         int count = 0;

src/window.cc

@@ -11,7 +11,6 @@ Window::Window(Buffer& buffer)
       m_cursor(0, 0),
       m_dimensions(0, 0)
 {
-    m_buffer.register_window(this);
 }
 
 void Window::erase()

src/window.hh

@@ -34,9 +34,6 @@ public:
     typedef BufferString String;
     typedef std::function<Selection (const BufferIterator&)> Selector;
 
-    Window(Buffer& buffer);
-    Window(const Window&) = delete;
-
     void erase();
     void insert(const String& string);
     void append(const String& string);
@@ -69,6 +66,11 @@ public:
     bool redo();
 
 private:
+    friend class Buffer;
+
+    Window(Buffer& buffer);
+    Window(const Window&) = delete;
+
     void scroll_to_keep_cursor_visible_ifn();
 
     Buffer&       m_buffer;