TextEditor: Add vim status indicators to the statusbar

When using the VimEditingEngine in the TextEditor, vim's mode and the
previous key are shown in the editor's statusbar.

Userland/Applications/TextEditor/TextEditorWidget.cpp

@@ -39,11 +39,13 @@
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Button.h>
 #include <LibGUI/CppSyntaxHighlighter.h>
+#include <LibGUI/EditingEngine.h>
 #include <LibGUI/FilePicker.h>
 #include <LibGUI/FontPicker.h>
 #include <LibGUI/GMLSyntaxHighlighter.h>
 #include <LibGUI/INISyntaxHighlighter.h>
 #include <LibGUI/JSSyntaxHighlighter.h>
+#include <LibGUI/Label.h>
 #include <LibGUI/Menu.h>
 #include <LibGUI/MenuBar.h>
 #include <LibGUI/MessageBox.h>
@@ -57,6 +59,7 @@
 #include <LibGUI/ToolBarContainer.h>
 #include <LibGUI/VimEditingEngine.h>
 #include <LibGfx/Font.h>
+#include <LibGfx/FontDatabase.h>
 #include <LibMarkdown/Document.h>
 #include <LibWeb/OutOfProcessWebView.h>
 #include <string.h>
@@ -301,6 +304,21 @@ TextEditorWidget::TextEditorWidget()
 
     m_statusbar = *find_descendant_of_type_named<GUI::StatusBar>("statusbar");
 
+    m_statusbar->label(m_vim_mode_statusbar_index)->set_visible(m_editor->editing_engine()->type() == GUI::EditingEngineType::Vim);
+    m_statusbar->label(m_vim_mode_statusbar_index)->set_font(Gfx::FontDatabase::default_bold_font());
+
+    m_statusbar->label(m_vim_previous_keys_statusbar_index)->set_visible(m_editor->editing_engine()->type() == GUI::EditingEngineType::Vim);
+
+    m_editor->on_vim_statusbar_messages_changed = [this] {
+        m_statusbar->set_text(m_vim_mode_statusbar_index, m_editor->vim_mode_statusbar_message());
+        m_statusbar->set_text(m_vim_previous_keys_statusbar_index, m_editor->vim_previous_keys_statusbar_message());
+    };
+
+    m_editor->on_editing_engine_changed = [this]() {
+        m_statusbar->label(m_vim_mode_statusbar_index)->set_visible(m_editor->editing_engine()->type() == GUI::EditingEngineType::Vim);
+        m_statusbar->label(m_vim_previous_keys_statusbar_index)->set_visible(m_editor->editing_engine()->type() == GUI::EditingEngineType::Vim);
+    };
+
     m_editor->on_cursor_change = [this] { update_statusbar_cursor_position(); };
 
     m_new_action = GUI::Action::create("New", { Mod_Ctrl, Key_N }, Gfx::Bitmap::load_from_file("/res/icons/16x16/new.png"), [this](const GUI::Action&) {
@@ -666,5 +684,5 @@ void TextEditorWidget::update_statusbar_cursor_position()
 {
     StringBuilder builder;
     builder.appendff("Line: {}, Column: {}", m_editor->cursor().line() + 1, m_editor->cursor().column());
-    m_statusbar->set_text(builder.to_string());
+    m_statusbar->set_text(m_cursor_position_statusbar_index, builder.to_string());
 }

Userland/Applications/TextEditor/TextEditorWidget.h

@@ -91,6 +91,9 @@ private:
     RefPtr<GUI::Action> m_html_preview_action;
 
     RefPtr<GUI::StatusBar> m_statusbar;
+    const int m_cursor_position_statusbar_index = 0;
+    const int m_vim_mode_statusbar_index = 1;
+    const int m_vim_previous_keys_statusbar_index = 2;
 
     RefPtr<GUI::TextBox> m_find_textbox;
     RefPtr<GUI::TextBox> m_replace_textbox;

Userland/Applications/TextEditor/TextEditorWindow.gml

@@ -84,5 +84,6 @@
 
     @GUI::StatusBar {
         name: "statusbar"
+        label_count: 3
     }
 }

Userland/Libraries/LibGUI/EditingEngine.h

@@ -37,6 +37,11 @@ enum CursorWidth {
     WIDE
 };
 
+enum EditingEngineType {
+    Regular,
+    Vim
+};
+
 class EditingEngine {
     AK_MAKE_NONCOPYABLE(EditingEngine);
     AK_MAKE_NONMOVABLE(EditingEngine);
@@ -51,11 +56,15 @@ public:
 
     virtual bool on_key(const KeyEvent& event);
 
+    EditingEngineType type() const { return m_editing_engine_type; }
+
 protected:
     EditingEngine() { }
 
     WeakPtr<TextEditor> m_editor;
 
+    EditingEngineType m_editing_engine_type;
+
     void move_one_left(const KeyEvent& event);
     void move_one_right(const KeyEvent& event);
     void move_one_up(const KeyEvent& event);

Userland/Libraries/LibGUI/RegularEditingEngine.cpp

@@ -30,6 +30,11 @@
 
 namespace GUI {
 
+RegularEditingEngine::RegularEditingEngine()
+{
+    m_editing_engine_type = EditingEngineType::Regular;
+}
+
 CursorWidth RegularEditingEngine::cursor_width() const
 {
     return CursorWidth::NARROW;

Userland/Libraries/LibGUI/RegularEditingEngine.h

@@ -33,6 +33,8 @@ namespace GUI {
 class RegularEditingEngine final : public EditingEngine {
 
 public:
+    RegularEditingEngine();
+
     virtual CursorWidth cursor_width() const override;
 
     virtual bool on_key(const KeyEvent& event) override;

Userland/Libraries/LibGUI/TextEditor.cpp

@@ -40,6 +40,7 @@
 #include <LibGUI/ScrollBar.h>
 #include <LibGUI/SyntaxHighlighter.h>
 #include <LibGUI/TextEditor.h>
+#include <LibGUI/VimEditingEngine.h>
 #include <LibGUI/Window.h>
 #include <LibGfx/Bitmap.h>
 #include <LibGfx/Font.h>
@@ -1625,6 +1626,52 @@ void TextEditor::set_editing_engine(OwnPtr<EditingEngine> editing_engine)
     update_cursor();
     stop_timer();
     start_timer(500);
+
+    if (on_editing_engine_changed)
+        on_editing_engine_changed();
+
+    if (m_editing_engine->type() == EditingEngineType::Vim) {
+        VimEditingEngine* vim = dynamic_cast<VimEditingEngine*>(m_editing_engine.ptr());
+        vim->on_mode_change = [&](VimMode mode) {
+            switch (mode) {
+            case Normal:
+                m_vim_mode_statusbar_message = {};
+                break;
+            case Insert:
+                m_vim_mode_statusbar_message = "-- INSERT --";
+                break;
+            case Visual:
+                m_vim_mode_statusbar_message = "-- VISUAL --";
+                break;
+            default:
+                dbgln("Unhandled vim mode");
+                m_vim_mode_statusbar_message = {};
+            }
+            if (on_vim_statusbar_messages_changed)
+                on_vim_statusbar_messages_changed();
+        };
+
+        // FIXME: Update this method to take multiple previous keys when that is implemented
+        vim->on_previous_keys_change = [&](const VimEditingEngine::PreviousKey& event, bool has_previous_key) {
+            if (has_previous_key) {
+                StringBuilder sb = StringBuilder(1);
+                sb.append_code_point(event.code_point);
+                m_vim_previous_keys_statusbar_message = sb.to_string();
+            } else {
+                m_vim_previous_keys_statusbar_message = {};
+            }
+            if (on_vim_statusbar_messages_changed)
+                on_vim_statusbar_messages_changed();
+        };
+    } else {
+        m_vim_mode_statusbar_message = {};
+        m_vim_previous_keys_statusbar_message = {};
+        if (on_vim_statusbar_messages_changed)
+            on_vim_statusbar_messages_changed();
+        if (on_editing_engine_changed) {
+            on_editing_engine_changed();
+        }
+    }
 }
 
 int TextEditor::line_height() const

Userland/Libraries/LibGUI/TextEditor.h

@@ -150,6 +150,8 @@ public:
     Function<void()> on_down_pressed;
     Function<void()> on_pageup_pressed;
     Function<void()> on_pagedown_pressed;
+    Function<void()> on_vim_statusbar_messages_changed;
+    Function<void()> on_editing_engine_changed;
 
     Action& undo_action() { return *m_undo_action; }
     Action& redo_action() { return *m_redo_action; }
@@ -195,6 +197,9 @@ public:
 
     void delete_text_range(TextRange);
 
+    String vim_mode_statusbar_message() const { return m_vim_mode_statusbar_message; }
+    String vim_previous_keys_statusbar_message() const { return m_vim_previous_keys_statusbar_message; }
+
 protected:
     explicit TextEditor(Type = Type::MultiLine);
 
@@ -351,6 +356,9 @@ private:
     Gfx::IntPoint m_last_mousemove_position;
 
     RefPtr<Gfx::Bitmap> m_icon;
+
+    String m_vim_mode_statusbar_message {};
+    String m_vim_previous_keys_statusbar_message {};
 };
 
 }

Userland/Libraries/LibGUI/VimEditingEngine.cpp

@@ -30,6 +30,11 @@
 
 namespace GUI {
 
+VimEditingEngine::VimEditingEngine()
+{
+    m_editing_engine_type = EditingEngineType::Vim;
+}
+
 CursorWidth VimEditingEngine::cursor_width() const
 {
     return m_vim_mode == VimMode::Insert ? CursorWidth::NARROW : CursorWidth::WIDE;
@@ -101,19 +106,19 @@ bool VimEditingEngine::on_key_in_normal_mode(const KeyEvent& event)
             delete_to.set_column(delete_to.column() + 1);
             m_editor->delete_text_range(TextRange(m_editor->cursor(), delete_to).normalized());
         }
-        m_previous_key = {};
+        clear_previous_key();
     } else if (m_previous_key == KeyCode::Key_G) {
         if (event.key() == KeyCode::Key_G) {
             move_to_first_line();
         } else if (event.key() == KeyCode::Key_E) {
             move_to_end_of_previous_word();
         }
-        m_previous_key = {};
+        clear_previous_key();
     } else if (m_previous_key == KeyCode::Key_Y) {
         if (event.key() == KeyCode::Key_Y) {
             yank(Line);
         }
-        m_previous_key = {};
+        clear_previous_key();
     } else if (m_previous_key == KeyCode::Key_C) {
         if (event.key() == KeyCode::Key_C) {
             // Needed because the code to replace the deleted line is called after delete_line() so
@@ -169,7 +174,7 @@ bool VimEditingEngine::on_key_in_normal_mode(const KeyEvent& event)
             m_editor->delete_text_range(TextRange(adjusted_cursor, delete_to).normalized());
             switch_to_insert_mode();
         }
-        m_previous_key = {};
+        clear_previous_key();
     } else {
         // Handle first any key codes that are to be applied regardless of modifiers.
         switch (event.key()) {
@@ -240,7 +245,7 @@ bool VimEditingEngine::on_key_in_normal_mode(const KeyEvent& event)
                 move_to_beginning_of_previous_word();
                 break;
             case (KeyCode::Key_C):
-                m_previous_key = event.key();
+                set_previous_key(event);
                 break;
             case (KeyCode::Key_Backspace):
             case (KeyCode::Key_H):
@@ -248,13 +253,13 @@ bool VimEditingEngine::on_key_in_normal_mode(const KeyEvent& event)
                 move_one_left(event);
                 break;
             case (KeyCode::Key_D):
-                m_previous_key = event.key();
+                set_previous_key(event);
                 break;
             case (KeyCode::Key_E):
                 move_to_end_of_next_word();
                 break;
             case (KeyCode::Key_G):
-                m_previous_key = event.key();
+                set_previous_key(event);
                 break;
             case (KeyCode::Key_Down):
             case (KeyCode::Key_J):
@@ -293,7 +298,7 @@ bool VimEditingEngine::on_key_in_normal_mode(const KeyEvent& event)
                 switch_to_visual_mode();
                 break;
             case (KeyCode::Key_Y):
-                m_previous_key = event.key();
+                set_previous_key(event);
                 break;
             case (KeyCode::Key_P):
                 put(event);
@@ -316,7 +321,7 @@ bool VimEditingEngine::on_key_in_visual_mode(const KeyEvent& event)
             move_to_end_of_previous_word();
             update_selection_on_cursor_move();
         }
-        m_previous_key = {};
+        clear_previous_key();
     } else {
         // Handle first any key codes that are to be applied regardless of modifiers.
         switch (event.key()) {
@@ -391,7 +396,7 @@ bool VimEditingEngine::on_key_in_visual_mode(const KeyEvent& event)
                 update_selection_on_cursor_move();
                 break;
             case (KeyCode::Key_G):
-                m_previous_key = event.key();
+                set_previous_key(event);
                 break;
             case (KeyCode::Key_Down):
             case (KeyCode::Key_J):
@@ -448,26 +453,32 @@ void VimEditingEngine::switch_to_normal_mode()
 {
     m_vim_mode = VimMode::Normal;
     m_editor->reset_cursor_blink();
-    m_previous_key = {};
+    clear_previous_key();
     clear_visual_mode_data();
+    if (on_mode_change)
+        on_mode_change(m_vim_mode);
 };
 
 void VimEditingEngine::switch_to_insert_mode()
 {
     m_vim_mode = VimMode::Insert;
     m_editor->reset_cursor_blink();
-    m_previous_key = {};
+    clear_previous_key();
     clear_visual_mode_data();
+    if (on_mode_change)
+        on_mode_change(m_vim_mode);
 };
 
 void VimEditingEngine::switch_to_visual_mode()
 {
     m_vim_mode = VimMode::Visual;
     m_editor->reset_cursor_blink();
-    m_previous_key = {};
+    clear_previous_key();
     m_selection_start_position = m_editor->cursor();
     m_editor->selection()->set(m_editor->cursor(), { m_editor->cursor().line(), m_editor->cursor().column() + 1 });
     m_editor->did_update_selection();
+    if (on_mode_change)
+        on_mode_change(m_vim_mode);
 }
 
 void VimEditingEngine::update_selection_on_cursor_move()

Userland/Libraries/LibGUI/VimEditingEngine.h

@@ -30,20 +30,48 @@
 
 namespace GUI {
 
+enum VimMode {
+    Normal,
+    Insert,
+    Visual
+};
+
 class VimEditingEngine final : public EditingEngine {
 
 public:
+    VimEditingEngine();
+
     virtual CursorWidth cursor_width() const override;
 
     virtual bool on_key(const KeyEvent& event) override;
 
-private:
-    enum VimMode {
-        Normal,
-        Insert,
-        Visual
+    class PreviousKey {
+    public:
+        PreviousKey() = default;
+        PreviousKey(const KeyEvent& event)
+            : key(event.key())
+            , code_point(event.code_point())
+        {
+        }
+
+        bool operator==(const KeyCode& key) const
+        {
+            return this->key == key;
+        }
+
+        bool operator==(const u32& code_point) const
+        {
+            return this->code_point == code_point;
+        }
+
+        KeyCode key {};
+        u32 code_point {};
     };
 
+    Function<void(VimMode)> on_mode_change;
+    Function<void(const PreviousKey&, bool has_previous_key)> on_previous_keys_change;
+
+private:
     enum YankType {
         Line,
         Selection
@@ -61,7 +89,26 @@ private:
     void update_selection_on_cursor_move();
     void clear_visual_mode_data();
 
-    KeyCode m_previous_key {};
+    // FIXME Support multiple previous keys, this is a temporary measure.
+    PreviousKey m_previous_key {};
+    bool has_previous_key { false };
+
+    void set_previous_key(PreviousKey event)
+    {
+        m_previous_key = event;
+        has_previous_key = true;
+        if (on_previous_keys_change)
+            on_previous_keys_change(m_previous_key, has_previous_key);
+    }
+
+    void clear_previous_key()
+    {
+        m_previous_key = {};
+        has_previous_key = false;
+        if (on_previous_keys_change)
+            on_previous_keys_change(m_previous_key, has_previous_key);
+    }
+
     void switch_to_normal_mode();
     void switch_to_insert_mode();
     void switch_to_visual_mode();