use BufferLineWalker from BufferView

src/core/BufferView.cc

@@ -3,19 +3,17 @@
 BufferView::BufferView(std::shared_ptr<Buffer> buffer,
         std::shared_ptr<Buffer::Iterator> iterator,
         CharacterWidthDeterminer & character_width_determiner)
-    : m_buffer(buffer),
+    : m_iterator(iterator)
-      m_iterator(iterator),
-      m_character_width_determiner(character_width_determiner)
 {
-    m_width = 1;
     m_height = 1;
     m_scroll_offset = 0;
     m_cursor_screen_row = 0;
+    m_buffer_line_walker = std::make_shared<BufferLineWalker>(buffer, character_width_determiner);
 }
 
 void BufferView::resize(int width, int height)
 {
-    m_width = std::max(1, width);
+    m_buffer_line_walker->set_width(width);
     m_height = std::max(1, height);
 }
 

src/core/BufferView.h

@@ -4,6 +4,7 @@
 #include "Buffer.h"
 #include "CharacterWidthDeterminer.h"
 #include <functional>
+#include "BufferLineWalker.h"
 
 /**
  * Tracks a "view" of a buffer, which is a two-dimensional grid of characters
@@ -18,15 +19,19 @@ public:
     void resize(int width, int height);
     void set_scroll_offset(int scroll_offset);
     void iter_lines(std::function<bool(const Buffer::Iterator &)> callback);
+    void walk_line(
+            const Buffer::Iterator & start_of_line,
+            std::function<bool(int, int, int, int, const Buffer::Iterator &)> callback)
+    {
+        m_buffer_line_walker->walk_line(start_of_line, callback);
+    }
 
 protected:
-    std::shared_ptr<Buffer> m_buffer;
     std::shared_ptr<Buffer::Iterator> m_iterator;
-    CharacterWidthDeterminer & m_character_width_determiner;
-    int m_width;
     int m_height;
     int m_scroll_offset;
     int m_cursor_screen_row;
+    std::shared_ptr<BufferLineWalker> m_buffer_line_walker;
 
     int effective_scroll_offset()
     {