Buffer: add support for modification listeners

src/buffer.cc

@@ -5,8 +5,6 @@
 #include "assert.hh"
 #include "utils.hh"
 
-#include <algorithm>
-
 namespace Kakoune
 {
 
@@ -35,13 +33,11 @@ void Buffer::erase(const BufferIterator& begin, const BufferIterator& end)
 {
     append_modification(BufferModification(BufferModification::Erase,
                                            begin, string(begin, end)));
-    do_erase(begin, end);
 }
 
 void Buffer::insert(const BufferIterator& position, const BufferString& string)
 {
     append_modification(BufferModification(BufferModification::Insert, position, string));
-    do_insert(position, string);
 }
 
 void Buffer::do_erase(const BufferIterator& begin, const BufferIterator& end)
@@ -182,7 +178,7 @@ bool Buffer::undo()
     --m_history_cursor;
 
     for (const BufferModification& modification : reversed(*m_history_cursor))
-        replay_modification(modification.inverse());
+        apply_modification(modification.inverse());
 }
 
 bool Buffer::redo()
@@ -191,12 +187,12 @@ bool Buffer::redo()
         return false;
 
     for (const BufferModification& modification : *m_history_cursor)
-        replay_modification(modification);
+        apply_modification(modification);
 
     ++m_history_cursor;
 }
 
-void Buffer::replay_modification(const BufferModification& modification)
+void Buffer::apply_modification(const BufferModification& modification)
 {
     switch (modification.type)
     {
@@ -214,10 +210,13 @@ void Buffer::replay_modification(const BufferModification& modification)
     default:
         assert(false);
     }
+    for (auto listener : m_modification_listeners)
+        listener->on_modification(modification);
 }
 
 void Buffer::append_modification(BufferModification&& modification)
 {
+    apply_modification(modification);
     m_current_undo_group.push_back(std::move(modification));
 }
 
@@ -248,4 +247,21 @@ void Buffer::notify_saved()
     m_last_save_undo_group = m_history_cursor;
 }
 
+void Buffer::register_modification_listener(BufferModificationListener* listener)
+{
+    assert(listener);
+    assert(not contains(m_modification_listeners, listener));
+    m_modification_listeners.push_back(listener);
+}
+
+void Buffer::unregister_modification_listener(BufferModificationListener* listener)
+{
+    assert(listener);
+    auto it = std::find(m_modification_listeners.begin(),
+                        m_modification_listeners.end(),
+                        listener);
+    assert(it != m_modification_listeners.end());
+    m_modification_listeners.erase(it);
+}
+
 }

src/buffer.hh

@@ -87,6 +87,12 @@ struct BufferModification
     BufferModification inverse() const;
 };
 
+class BufferModificationListener
+{
+public:
+    virtual void on_modification(const BufferModification& modification) = 0;
+};
+
 class Buffer
 {
 public:
@@ -135,6 +141,9 @@ public:
     Type type() const { return m_type; }
     void notify_saved();
 
+    void register_modification_listener(BufferModificationListener* listener);
+    void unregister_modification_listener(BufferModificationListener* listener);
+
 private:
     BufferChar at(BufferPos position) const;
 
@@ -163,7 +172,7 @@ private:
     std::vector<UndoGroup>::iterator m_history_cursor;
     UndoGroup                        m_current_undo_group;
 
-    void replay_modification(const BufferModification& modification);
+    void apply_modification(const BufferModification& modification);
     void revert_modification(const BufferModification& modification);
 
     void append_modification(BufferModification&& modification);