Window lifetime is now handled by it's buffer.

A window cannot outlive it's buffer, so it makes sense to keep only a
reference on it hand have the buffer manage the window lifetime.

src/buffer.cc

@@ -1,8 +1,10 @@
 #include "buffer.hh"
 
 #include "buffer_manager.hh"
+#include "window.hh"
 
 #include <cassert>
+#include <algorithm>
 
 namespace Kakoune
 {
@@ -314,4 +316,22 @@ void Buffer::append_modification(Modification&& modification)
     m_current_undo_group.push_back(modification);
 }
 
+struct window_already_registered {};
+
+void Buffer::register_window(Window* window)
+{
+    if (std::find(m_windows.begin(), m_windows.end(), window) != m_windows.end())
+        throw window_already_registered();
+
+    m_windows.push_front(std::unique_ptr<Window>(window));
+}
+
+void Buffer::delete_window(Window* window)
+{
+    assert(&window->buffer() == this);
+    auto window_it = std::find(m_windows.begin(), m_windows.end(), window);
+    assert(window_it != m_windows.end());
+    m_windows.erase(window_it);
+}
+
 }

src/buffer.hh

@@ -3,6 +3,8 @@
 
 #include <string>
 #include <vector>
+#include <list>
+#include <memory>
 
 #include "utils.hh"
 
@@ -10,6 +12,8 @@ namespace Kakoune
 {
 
 class Buffer;
+class Window;
+
 typedef int      BufferPos;
 typedef int      BufferSize;
 typedef char     BufferChar;
@@ -96,6 +100,9 @@ public:
 
     const BufferString& content() const { return m_content; }
 
+    void register_window(Window* window);
+    void delete_window(Window* window);
+
 private:
     BufferChar at(BufferPos position) const;
 
@@ -140,6 +147,8 @@ private:
     void revert_modification(const Modification& modification);
 
     void append_modification(Modification&& modification);
+
+    std::list<std::unique_ptr<Window>> m_windows;
 };
 
 }

src/main.cc

@@ -152,7 +152,7 @@ void do_insert(Window& window)
     print_status("");
 }
 
-std::shared_ptr<Window> current_window;
+Window* current_window;
 
 void edit(const CommandParameters& params)
 {
@@ -162,14 +162,14 @@ void edit(const CommandParameters& params)
     std::string filename = params[0];
     try
     {
-        std::shared_ptr<Buffer> buffer(create_buffer_from_file(filename));
+        Buffer* buffer = create_buffer_from_file(filename);
         if (buffer)
-            current_window = std::make_shared<Window>(buffer);
+            current_window = new Window(*buffer);
     }
     catch (file_not_found& what)
     {
         print_status("new file " + filename);
-        current_window = std::make_shared<Window>(std::make_shared<Buffer>(filename));
+        current_window = new Window(*new Buffer(filename));
     }
 }
 
@@ -178,7 +178,7 @@ void write_buffer(const CommandParameters& params)
     if (params.size() > 1)
         throw wrong_argument_count();
 
-    Buffer& buffer = *current_window->buffer();
+    Buffer& buffer = current_window->buffer();
     std::string filename = params.empty() ? buffer.name() : params[0];
 
     write_buffer_to_file(buffer, filename);
@@ -292,8 +292,8 @@ int main()
 
     try
     {
-        auto buffer = std::make_shared<Buffer>("<scratch>");
+        auto buffer = new Buffer("<scratch>");
-        current_window = std::make_shared<Window>(buffer);
+        current_window = new Window(*buffer);
 
         draw_window(*current_window);
         int count = 0;

src/window.cc

@@ -5,29 +5,30 @@
 namespace Kakoune
 {
 
-Window::Window(const std::shared_ptr<Buffer> buffer)
+Window::Window(Buffer& buffer)
     : m_buffer(buffer),
       m_position(0, 0),
       m_cursor(0, 0),
       m_dimensions(0, 0)
 {
+    m_buffer.register_window(this);
 }
 
 void Window::erase()
 {
-    m_buffer->begin_undo_group();
+    m_buffer.begin_undo_group();
     if (m_selections.empty())
     {
         BufferIterator cursor = iterator_at(m_cursor);
-        m_buffer->erase(cursor, cursor+1);
+        m_buffer.erase(cursor, cursor+1);
     }
 
     for (auto sel = m_selections.begin(); sel != m_selections.end(); ++sel)
     {
-        m_buffer->erase(sel->begin, sel->end);
+        m_buffer.erase(sel->begin, sel->end);
         sel->end = sel->begin;
     }
-    m_buffer->end_undo_group();
+    m_buffer.end_undo_group();
 }
 
 static WindowCoord measure_string(const Window::String& string)
@@ -48,25 +49,25 @@ static WindowCoord measure_string(const Window::String& string)
 
 void Window::insert(const String& string)
 {
-    m_buffer->begin_undo_group();
+    m_buffer.begin_undo_group();
     if (m_selections.empty())
     {
-        m_buffer->insert(iterator_at(m_cursor), string);
+        m_buffer.insert(iterator_at(m_cursor), string);
         move_cursor(measure_string(string));
     }
 
     for (auto sel = m_selections.begin(); sel != m_selections.end(); ++sel)
     {
-        m_buffer->insert(sel->begin, string);
+        m_buffer.insert(sel->begin, string);
         sel->begin += string.length();
         sel->end += string.length();
     }
-    m_buffer->end_undo_group();
+    m_buffer.end_undo_group();
 }
 
 void Window::append(const String& string)
 {
-    m_buffer->begin_undo_group();
+    m_buffer.begin_undo_group();
     if (m_selections.empty())
     {
         move_cursor(WindowCoord(0 , 1));
@@ -75,19 +76,19 @@ void Window::append(const String& string)
 
     for (auto sel = m_selections.begin(); sel != m_selections.end(); ++sel)
     {
-        m_buffer->insert(sel->end, string);
+        m_buffer.insert(sel->end, string);
     }
-    m_buffer->end_undo_group();
+    m_buffer.end_undo_group();
 }
 
 bool Window::undo()
 {
-    return m_buffer->undo();
+    return m_buffer.undo();
 }
 
 bool Window::redo()
 {
-    return m_buffer->redo();
+    return m_buffer.redo();
 }
 
 BufferCoord Window::window_to_buffer(const WindowCoord& window_pos) const
@@ -104,12 +105,12 @@ WindowCoord Window::buffer_to_window(const BufferCoord& buffer_pos) const
 
 BufferIterator Window::iterator_at(const WindowCoord& window_pos) const
 {
-    return m_buffer->iterator_at(window_to_buffer(window_pos));
+    return m_buffer.iterator_at(window_to_buffer(window_pos));
 }
 
 WindowCoord Window::line_and_column_at(const BufferIterator& iterator) const
 {
-    return buffer_to_window(m_buffer->line_and_column_at(iterator));
+    return buffer_to_window(m_buffer.line_and_column_at(iterator));
 }
 
 void Window::empty_selections()
@@ -141,7 +142,7 @@ void Window::move_cursor(const WindowCoord& offset)
         window_to_buffer(WindowCoord(m_cursor.line + offset.line,
                                      m_cursor.column + offset.column));
 
-    m_cursor = buffer_to_window(m_buffer->clamp(target_position));
+    m_cursor = buffer_to_window(m_buffer.clamp(target_position));
 
     scroll_to_keep_cursor_visible_ifn();
 }
@@ -154,29 +155,29 @@ void Window::update_display_buffer()
     std::sort(sorted_selections.begin(), sorted_selections.end(),
               [](const Selection& lhs, const Selection& rhs) { return lhs.begin < rhs.begin; });
 
-    BufferIterator current_position = m_buffer->iterator_at(m_position);
+    BufferIterator current_position = m_buffer.iterator_at(m_position);
 
     for (Selection& sel : sorted_selections)
     {
         if (current_position != sel.begin)
         {
             DisplayAtom atom;
-            atom.content = m_buffer->string(current_position, sel.begin);
+            atom.content = m_buffer.string(current_position, sel.begin);
             m_display_buffer.append(atom);
         }
         if (sel.begin != sel.end)
         {
             DisplayAtom atom;
-            atom.content = m_buffer->string(sel.begin, sel.end);
+            atom.content = m_buffer.string(sel.begin, sel.end);
             atom.attribute = UNDERLINE;
             m_display_buffer.append(atom);
         }
         current_position = sel.end;
     }
-    if (current_position != m_buffer->end())
+    if (current_position != m_buffer.end())
     {
         DisplayAtom atom;
-        atom.content = m_buffer->string(current_position, m_buffer->end());
+        atom.content = m_buffer.string(current_position, m_buffer.end());
         m_display_buffer.append(atom);
     }
 }

src/window.hh

@@ -1,7 +1,6 @@
 #ifndef window_hh_INCLUDED
 #define window_hh_INCLUDED
 
-#include <memory>
 #include <functional>
 
 #include "utils.hh"
@@ -35,7 +34,7 @@ public:
     typedef BufferString String;
     typedef std::function<Selection (const BufferIterator&)> Selector;
 
-    Window(const std::shared_ptr<Buffer> buffer);
+    Window(Buffer& buffer);
     Window(const Window&) = delete;
 
     void erase();
@@ -45,7 +44,7 @@ public:
     const BufferCoord& position() const { return m_position; }
     const WindowCoord& cursor_position() const { return m_cursor; }
 
-    const std::shared_ptr<Buffer>& buffer() const { return m_buffer; }
+    Buffer& buffer() const { return m_buffer; }
 
     BufferCoord window_to_buffer(const WindowCoord& window_pos) const;
     WindowCoord buffer_to_window(const BufferCoord& buffer_pos) const;
@@ -72,7 +71,7 @@ public:
 private:
     void scroll_to_keep_cursor_visible_ifn();
 
-    std::shared_ptr<Buffer> m_buffer;
+    Buffer&       m_buffer;
     BufferCoord   m_position;
     WindowCoord   m_cursor;
     WindowCoord   m_dimensions;