From c05f9f31dda0e4cac5ac9a318aaf0eabed6734e8 Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Sun, 4 Aug 2013 19:34:08 +0200
Subject: [PATCH] add support for explicit insert mode completion using C-x
 prefix

---
 README.asciidoc      | 12 ++++++++++++
 src/input_handler.cc | 32 +++++++++++++++++++++-----------
 2 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/README.asciidoc b/README.asciidoc
index 6d0dfc14..3bccd879 100644
--- a/README.asciidoc
+++ b/README.asciidoc
@@ -380,6 +380,18 @@ Some options are built in kakoune, and can be used to control it's behaviour:
  * +insert_hide_sel+ _bool_: hide the selection (except the last
    element) in insert mode
 
+Insert mode completion
+----------------------
+
+Kakoune can propose completions while inserting text, the +completers+ option
+control automatic completion, which kicks in when a certain idle timeout is
+reached (100 milliseconds). Insert mode completion can be explicitely triggered
+using *control-x*, followed, by:
+
+ * *f* : filename completion
+ * *w* : buffer word completion
+ * *o* : option based completion
+
 Highlighters
 ------------
 
diff --git a/src/input_handler.cc b/src/input_handler.cc
index bf0cd368..a2ed3cae 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -689,7 +689,7 @@ public:
         return { begin.coord(), pos.coord(), std::move(res), buffer.timestamp() };
     }
 
-    BufferCompletion complete_opt(const Buffer& buffer, BufferCoord cursor_pos)
+    BufferCompletion complete_option(const Buffer& buffer, BufferCoord cursor_pos)
     {
         const StringList& opt = options()["completions"].get<StringList>();
         if (opt.empty())
@@ -748,7 +748,7 @@ private:
         if (not m_completions.is_valid())
         {
             auto& completers = options()["completers"].get<StringList>();
-            if (contains(completers, "option") and try_complete<&BufferCompleter::complete_opt>())
+            if (contains(completers, "option") and try_complete<&BufferCompleter::complete_option>())
                 return true;
             if (contains(completers, "word=buffer") and try_complete<&BufferCompleter::complete_word<false>>())
                 return true;
@@ -792,13 +792,25 @@ public:
             return reset_normal_mode().on_key(key);
 
         last_insert().second.push_back(key);
-        if (m_insert_reg)
+        if (m_mode == Mode::InsertReg)
         {
             if (key.modifiers == Key::Modifiers::None)
                 m_inserter.insert(RegisterManager::instance()[key.key].values(context()));
-            m_insert_reg = false;
+            m_mode = Mode::Default;
             return;
         }
+        if (m_mode == Mode::Complete)
+        {
+            if (key.key == 'f')
+                m_completer.try_complete<&BufferCompleter::complete_filename>();
+            if (key.key == 'w')
+                m_completer.try_complete<&BufferCompleter::complete_word<true>>();
+            if (key.key == 'o')
+                m_completer.try_complete<&BufferCompleter::complete_option>();
+            m_mode = Mode::Default;
+            return;
+        }
+
         bool update_completions = true;
         bool moved = false;
         if (key == Key::Escape or key == Key{ Key::Modifiers::Control, 'c' })
@@ -835,7 +847,7 @@ public:
             context().hooks().run_hook("InsertKey", key_to_str(key), context());
         }
         else if (key == Key{ Key::Modifiers::Control, 'r' })
-            m_insert_reg = true;
+            m_mode = Mode::InsertReg;
         else if ( key == Key{ Key::Modifiers::Control, 'm' })
             m_inserter.insert(String() + '\n');
         else if ( key == Key{ Key::Modifiers::Control, 'i' })
@@ -850,11 +862,8 @@ public:
             m_completer.select(-1);
             update_completions = false;
         }
-        else if ( key == Key{ Key::Modifiers::Control, 'f' })
-        {
-            m_completer.try_complete<&BufferCompleter::complete_filename>();
-            update_completions = false;
-        }
+        else if ( key == Key{ Key::Modifiers::Control, 'x' })
+            m_mode = Mode::Complete;
 
         if (update_completions)
             m_idle_timer.set_next_date(Clock::now() + idle_timeout);
@@ -862,7 +871,8 @@ public:
             context().hooks().run_hook("InsertMove", key_to_str(key), context());
     }
 private:
-    bool m_insert_reg = false;
+    enum class Mode { Default, Complete, InsertReg };
+    Mode m_mode = Mode::Default;
     IncrementalInserter m_inserter;
     BufferCompleter     m_completer;
     Timer               m_idle_timer;