Add key mapping support

11 files changed, 181 insertions, 5 deletions

diff --git a/src/buffer.cc b/src/buffer.cc
index 368d530e..249064bb 100644
--- a/src/buffer.cc
+++ b/src/buffer.cc
@@ -20,7 +20,8 @@ Buffer::Buffer(String name, Flags flags, std::vector<String> lines,
       m_timestamp(0),
       m_fs_timestamp(fs_timestamp),
       m_hooks(GlobalHooks::instance()),
-      m_options(GlobalOptions::instance())
+      m_options(GlobalOptions::instance()),
+      m_keymaps(GlobalKeymaps::instance())
 {
     BufferManager::instance().register_buffer(*this);
 
diff --git a/src/buffer.hh b/src/buffer.hh
index 4b67ce48..8727d217 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -1,9 +1,10 @@
 #ifndef buffer_hh_INCLUDED
 #define buffer_hh_INCLUDED
 
-#include "hook_manager.hh"
 #include "line_and_column.hh"
+#include "hook_manager.hh"
 #include "option_manager.hh"
+#include "keymap_manager.hh"
 #include "string.hh"
 #include "units.hh"
 
@@ -160,6 +161,8 @@ public:
     const OptionManager& options() const { return m_options; }
     HookManager&         hooks()         { return m_hooks; }
     const HookManager&   hooks()   const { return m_hooks; }
+    KeymapManager&       keymaps()       { return m_keymaps; }
+    const KeymapManager& keymaps() const { return m_keymaps; }
 
     std::unordered_set<BufferChangeListener*>& change_listeners() const { return m_change_listeners; }
 
@@ -212,6 +215,7 @@ private:
 
     OptionManager m_options;
     HookManager   m_hooks;
+    KeymapManager m_keymaps;
 
     friend constexpr Flags operator|(Flags lhs, Flags rhs)
     {
diff --git a/src/client.cc b/src/client.cc
index c81eab56..3b9827d6 100644
--- a/src/client.cc
+++ b/src/client.cc
@@ -33,6 +33,8 @@ public:
 
     virtual String description() const = 0;
 
+    virtual KeymapMode keymap_mode() const = 0;
+
     using Insertion = Client::Insertion;
     Insertion& last_insert() { return m_client.m_last_insert; }
 
@@ -91,6 +93,8 @@ public:
                (m_count != 0 ? " sel; param=" + to_string(m_count) : " sel");
     }
 
+    KeymapMode keymap_mode() const override { return KeymapMode::Normal; }
+
 private:
     int m_count = 0;
     Timer m_idle_timer;
@@ -270,6 +274,7 @@ public:
         return "menu";
     }
 
+    KeymapMode keymap_mode() const override { return KeymapMode::Menu; }
 
 private:
     MenuCallback m_callback;
@@ -472,6 +477,7 @@ public:
         return "prompt";
     }
 
+    KeymapMode keymap_mode() const override { return KeymapMode::Prompt; }
 
 private:
     void display() const
@@ -513,6 +519,8 @@ public:
         return "enter key";
     }
 
+    KeymapMode keymap_mode() const override { return KeymapMode::None; }
+
 private:
     KeyCallback m_callback;
 };
@@ -933,6 +941,9 @@ public:
     {
         return "insert";
     }
+
+    KeymapMode keymap_mode() const override { return KeymapMode::Insert; }
+
 private:
     enum class Mode { Default, Complete, InsertReg };
     Mode m_mode = Mode::Default;
@@ -1010,7 +1021,7 @@ void Client::on_next_key(KeyCallback callback)
     change_input_mode(new InputModes::NextKey(*this, callback));
 }
 
-bool is_valid(Key key)
+static bool is_valid(Key key)
 {
     return key != Key::Invalid and key.key <= 0x10FFFF;
 }
@@ -1031,7 +1042,15 @@ void Client::handle_key(Key key)
     {
         const bool was_recording = is_recording();
 
-        m_mode->on_key(key);
+        auto keymap_mode = m_mode->keymap_mode();
+        KeymapManager& keymaps = m_context.keymaps();
+        if (keymaps.is_mapped(key, keymap_mode))
+        {
+            for (auto& k : keymaps.get_mapping(key, keymap_mode))
+                m_mode->on_key(k);
+        }
+        else
+            m_mode->on_key(key);
 
         // do not record the key that made us enter or leave recording mode.
         if (was_recording and is_recording())
diff --git a/src/commands.cc b/src/commands.cc
index eeb33e1a..4b015c16 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -530,6 +530,42 @@ void declare_option(CommandParameters params, Context& context)
         opt->set_from_string(params[2]);
 }
 
+
+KeymapManager& get_keymap_manager(const String& scope, Context& context)
+{
+    if (prefix_match("global", scope))
+        return GlobalKeymaps::instance();
+    else if (prefix_match("buffer", scope))
+        return context.buffer().keymaps();
+    else if (prefix_match("window", scope))
+        return context.window().keymaps();
+    throw runtime_error("error: no such keymap container " + scope);
+}
+
+KeymapMode parse_keymap_mode(const String& str)
+{
+    if (prefix_match("normal", str)) return KeymapMode::Normal;
+    if (prefix_match("insert", str)) return KeymapMode::Insert;
+    if (prefix_match("menu", str))   return KeymapMode::Menu;
+    if (prefix_match("prompt", str)) return KeymapMode::Prompt;
+    throw runtime_error("unknown keymap mode '" + str + "'");
+}
+
+void map_key(CommandParameters params, Context& context)
+{
+    ParametersParser parser(params, {}, ParametersParser::Flags::None, 4, 4);
+
+    KeymapManager& keymaps = get_keymap_manager(params[0], context);
+    KeymapMode keymap_mode = parse_keymap_mode(params[1]);
+
+    KeyList key = parse_keys(params[2]);
+    if (key.size() != 1)
+        throw runtime_error("only a single key can be mapped");
+
+    KeyList mapping = parse_keys(params[3]);
+    keymaps.map_key(key[0], keymap_mode, std::move(mapping));
+}
+
 class DraftUI : public UserInterface
 {
 public:
@@ -857,5 +893,6 @@ void register_commands()
     cm.register_commands({"nc", "nameclient"}, set_client_name);
 
     cm.register_command("cd", change_working_directory, filename_completer);
+    cm.register_command("map", map_key);
 }
 }
diff --git a/src/context.cc b/src/context.cc
index 513bd6cb..49a64f7d 100644
--- a/src/context.cc
+++ b/src/context.cc
@@ -75,6 +75,15 @@ HookManager& Context::hooks() const
     return GlobalHooks::instance();
 }
 
+KeymapManager& Context::keymaps() const
+{
+    if (has_window())
+        return window().keymaps();
+    if (has_buffer())
+        return buffer().keymaps();
+    return GlobalKeymaps::instance();
+}
+
 void Context::print_status(DisplayLine status) const
 {
     if (has_client())
diff --git a/src/context.hh b/src/context.hh
index 07e4ffa1..d65e9d4e 100644
--- a/src/context.hh
+++ b/src/context.hh
@@ -12,6 +12,7 @@ class Buffer;
 class Client;
 class UserInterface;
 class DisplayLine;
+class KeymapManager;
 
 // A Context is used to access non singleton objects for various services
 // in commands.
@@ -48,6 +49,7 @@ struct Context
 
     OptionManager& options() const;
     HookManager& hooks() const;
+    KeymapManager& keymaps() const;
 
     void print_status(DisplayLine status) const;
 
diff --git a/src/keymap_manager.cc b/src/keymap_manager.cc
new file mode 100644
index 00000000..71f936fd
--- /dev/null
+++ b/src/keymap_manager.cc
@@ -0,0 +1,45 @@
+#include "keymap_manager.hh"
+
+namespace std
+{
+
+template<> struct hash<Kakoune::KeymapMode>
+{
+    size_t operator()(Kakoune::KeymapMode val) const
+    {
+        return hash<int>{}((int)val);
+    }
+};
+
+}
+
+namespace Kakoune
+{
+
+void KeymapManager::map_key(Key key, KeymapMode mode, std::vector<Key> mapping)
+{
+    m_mapping[{key, mode}] = mapping;
+}
+
+void KeymapManager::unmap_key(Key key, KeymapMode mode)
+{
+    m_mapping.erase({key, mode});
+}
+
+
+bool KeymapManager::is_mapped(Key key, KeymapMode mode) const
+{
+    return m_mapping.find({key, mode}) != m_mapping.end() or
+           (m_parent and m_parent->is_mapped(key, mode));
+}
+
+memoryview<Key> KeymapManager::get_mapping(Key key, KeymapMode mode) const
+{
+    auto it = m_mapping.find({key, mode});
+    if (it != m_mapping.end())
+        return { it->second };
+    kak_assert(m_parent);
+    return m_parent->get_mapping(key, mode);
+}
+
+}
diff --git a/src/keymap_manager.hh b/src/keymap_manager.hh
new file mode 100644
index 00000000..c9887a6b
--- /dev/null
+++ b/src/keymap_manager.hh
@@ -0,0 +1,52 @@
+#ifndef keymap_manager_hh_INCLUDED
+#define keymap_manager_hh_INCLUDED
+
+#include "idvaluemap.hh"
+#include "keys.hh"
+#include "utils.hh"
+
+#include <unordered_map>
+
+namespace Kakoune
+{
+
+enum class KeymapMode : int
+{
+    None,
+    Normal,
+    Insert,
+    Prompt,
+    Menu
+};
+
+class KeymapManager
+{
+public:
+    KeymapManager(KeymapManager& parent) : m_parent(&parent) {}
+
+    void map_key(Key key, KeymapMode mode, std::vector<Key> mapping);
+    void unmap_key(Key key, KeymapMode mode);
+
+    bool is_mapped(Key key, KeymapMode mode) const;
+    memoryview<Key> get_mapping(Key key, KeymapMode mode) const;
+private:
+    KeymapManager()
+        : m_parent(nullptr) {}
+    // the only one allowed to construct a root map manager
+    friend class GlobalKeymaps;
+
+    KeymapManager* m_parent;
+
+    using Keymap = std::unordered_map<std::pair<Key, KeymapMode>, std::vector<Key>>;
+    Keymap m_mapping;
+};
+
+class GlobalKeymaps : public KeymapManager,
+                      public Singleton<GlobalKeymaps>
+{
+};
+
+}
+
+#endif // keymap_manager_hh_INCLUDED
+
diff --git a/src/main.cc b/src/main.cc
index cd078d6c..40829135 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -14,6 +14,7 @@
 #include "hook_manager.hh"
 #include "ncurses.hh"
 #include "option_manager.hh"
+#include "keymap_manager.hh"
 #include "parameters_parser.hh"
 #include "register_manager.hh"
 #include "remote.hh"
@@ -264,6 +265,7 @@ int kakoune(memoryview<String> params)
     EventManager        event_manager;
     GlobalOptions       global_options;
     GlobalHooks         global_hooks;
+    GlobalKeymaps       global_keymaps;
     ShellManager        shell_manager;
     CommandManager      command_manager;
     BufferManager       buffer_manager;
diff --git a/src/window.cc b/src/window.cc
index c7ec5fff..2fdec0f8 100644
--- a/src/window.cc
+++ b/src/window.cc
@@ -19,7 +19,8 @@ void expand_unprintable(const Window& window, DisplayBuffer& display_buffer);
 Window::Window(Buffer& buffer)
     : Editor(buffer),
       m_hooks(buffer.hooks()),
-      m_options(buffer.options())
+      m_options(buffer.options()),
+      m_keymaps(buffer.keymaps())
 {
     Context hook_context{*this};
     m_hooks.run_hook("WinCreate", buffer.name(), hook_context);
diff --git a/src/window.hh b/src/window.hh
index 534d18b3..49bbe39e 100644
--- a/src/window.hh
+++ b/src/window.hh
@@ -8,6 +8,7 @@
 #include "highlighter.hh"
 #include "hook_manager.hh"
 #include "option_manager.hh"
+#include "keymap_manager.hh"
 
 namespace Kakoune
 {
@@ -46,6 +47,8 @@ public:
     const OptionManager& options() const { return m_options; }
     HookManager&         hooks()         { return m_hooks; }
     const HookManager&   hooks()   const { return m_hooks; }
+    KeymapManager&       keymaps()       { return m_keymaps; }
+    const KeymapManager& keymaps() const { return m_keymaps; }
 
     size_t timestamp() const { return m_timestamp; }
     void   forget_timestamp() { m_timestamp = -1; }
@@ -65,6 +68,7 @@ private:
 
     HookManager      m_hooks;
     OptionManager    m_options;
+    KeymapManager    m_keymaps;
 
     HighlighterGroup m_highlighters;
     HighlighterGroup m_builtin_highlighters;