DisplayBuffer: add a split method to split an atom

3 files changed, 40 insertions, 38 deletions

diff --git a/src/display_buffer.cc b/src/display_buffer.cc
index ea5342bc..03cc5b18 100644
--- a/src/display_buffer.cc
+++ b/src/display_buffer.cc
@@ -1,5 +1,7 @@
 #include "display_buffer.hh"
 
+#include "assert.h"
+
 namespace Kakoune
 {
 
@@ -7,4 +9,17 @@ DisplayBuffer::DisplayBuffer()
 {
 }
 
+DisplayBuffer::iterator DisplayBuffer::split(iterator atom, size_t pos_in_atom)
+{
+    assert(atom < end());
+    assert(pos_in_atom < atom->content.length());
+    DisplayAtom new_atom(atom->begin, atom->begin + pos_in_atom,
+                         atom->content.substr(0, pos_in_atom),
+                         atom->fg_color, atom->bg_color, atom->attribute);
+
+    atom->begin = atom->begin + pos_in_atom;
+    atom->content = atom->content.substr(pos_in_atom);
+    return insert(atom, std::move(new_atom));
+}
+
 }
diff --git a/src/display_buffer.hh b/src/display_buffer.hh
index d1a1eebb..e422e38a 100644
--- a/src/display_buffer.hh
+++ b/src/display_buffer.hh
@@ -43,13 +43,16 @@ struct DisplayAtom
     Attribute      attribute;
 
     DisplayAtom(BufferIterator begin, BufferIterator end,
-                const std::string& content)
+                const std::string& content,
+                Color fg_color = Color::Default,
+                Color bg_color = Color::Default,
+                Attribute attribute = Attributes::Normal)
         : content(content),
           begin(begin),
           end(end),
-          fg_color(Color::Default),
-          bg_color(Color::Default),
-          attribute(Attributes::Normal)
+          fg_color(fg_color),
+          bg_color(bg_color),
+          attribute(attribute)
     {}
 };
 
@@ -65,6 +68,7 @@ public:
     void clear() { m_atoms.clear(); }
     void append(const DisplayAtom& atom) { m_atoms.push_back(atom); }
     iterator insert(iterator where, const DisplayAtom& atom) { return m_atoms.insert(where, atom); }
+    iterator split(iterator atom, size_t pos_in_atom);
 
     iterator begin() { return m_atoms.begin(); }
     iterator end()   { return m_atoms.end(); }
diff --git a/src/window.cc b/src/window.cc
index 58a85f48..e94394c9 100644
--- a/src/window.cc
+++ b/src/window.cc
@@ -61,45 +61,34 @@ public:
             if (atom.begin >= sel.begin() and atom.begin < sel.end() and atom.end > sel.end())
             {
                 size_t length = sel.end() - atom.begin;
-                DisplayAtom selected(atom.begin, sel.end(),
-                                     atom.content.substr(0, length));
-                selected.attribute = Attributes::Underline;
-                atom.content = atom.content.substr(length);
-                atom.begin = sel.end();
-                atom_it = display_buffer.insert(atom_it, selected) + 1;
+                atom_it = display_buffer.split(atom_it, length);
+                atom_it->attribute |= Attributes::Underline;
+                ++atom_it;
                 ++sel_it;
             }
             // [---###---]
             else if (atom.begin < sel.begin() and atom.end > sel.end())
             {
                 size_t prefix_length = sel.begin() - atom.begin;
-                DisplayAtom prefix(atom.begin, sel.begin(),
-                                   atom.content.substr(0, prefix_length));
+                atom_it = display_buffer.split(atom_it, prefix_length);
                 size_t sel_length = sel.end() - sel.begin();
-                DisplayAtom selected(sel.begin(), sel.end(),
-                                     atom.content.substr(prefix_length, sel_length));
-                selected.attribute = Attributes::Underline;
-                atom.content = atom.content.substr(prefix_length + sel_length);
-                atom_it = display_buffer.insert(atom_it, selected);
-                atom_it = display_buffer.insert(atom_it, prefix);
-                atom_it += 2;
+                atom_it = display_buffer.split(atom_it + 1, sel_length);
+                atom_it->attribute |= Attributes::Underline;
+                ++atom_it;
                 ++sel_it;
             }
             // [------###]
             else if (atom.begin < sel.begin() and atom.end > sel.begin())
             {
-                size_t length = sel.end() - atom.begin;
-                DisplayAtom prefix(atom.begin, sel.end(),
-                                   atom.content.substr(0, length));
-                atom.content = atom.content.substr(length);
-                atom.begin = sel.end();
-                atom.attribute = Attributes::Underline;
-                atom_it = display_buffer.insert(atom_it, prefix) + 2;
+                size_t length = sel.begin() - atom.begin;
+                atom_it = display_buffer.split(atom_it, length) + 1;
+                atom_it->attribute |= Attributes::Underline;
+                ++atom_it;
             }
             // [#########]
             else if (atom.begin >= sel.begin() and atom.end <= sel.end())
             {
-                atom.attribute = Attributes::Underline;
+                atom_it->attribute |= Attributes::Underline;
                 ++atom_it;
             }
             // [---------]
@@ -122,19 +111,13 @@ static void blink_void(DisplayBuffer& display_buffer)
     for (auto atom_it = display_buffer.begin();
          atom_it != display_buffer.end();)
     {
-        DisplayAtom& atom = *atom_it;
-        size_t pos = atom.content.find("void");
+        size_t pos = atom_it->content.find("void");
         if (pos != std::string::npos)
         {
-            DisplayAtom prefix(atom.begin, atom.begin + pos,
-                               atom.content.substr(0, pos));
-            prefix.attribute = atom.attribute;
-            DisplayAtom match(prefix.end, prefix.end + 4, "void");
-            match.attribute = atom.attribute | Attributes::Blink;
-            atom.begin = prefix.end + 4;
-            atom.content = atom.content.substr(pos + 4);
-            atom_it = display_buffer.insert(atom_it, match);
-            atom_it = display_buffer.insert(atom_it, prefix) + 2;
+            atom_it = display_buffer.split(atom_it, pos) + 1;
+            atom_it = display_buffer.split(atom_it, 4);
+            atom_it->attribute |= Attributes::Blink;
+            ++atom_it;
         }
         else
             ++atom_it;