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.

10 files changed, 171 insertions, 20 deletions

diff --git a/Userland/Applications/TextEditor/TextEditorWidget.cpp b/Userland/Applications/TextEditor/TextEditorWidget.cpp
index 9d31b106f8..1bd7ac19aa 100644
--- a/Userland/Applications/TextEditor/TextEditorWidget.cpp
+++ b/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());
 }
diff --git a/Userland/Applications/TextEditor/TextEditorWidget.h b/Userland/Applications/TextEditor/TextEditorWidget.h
index 763087b9e4..28c4a9c3fd 100644
--- a/Userland/Applications/TextEditor/TextEditorWidget.h
+++ b/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;
diff --git a/Userland/Applications/TextEditor/TextEditorWindow.gml b/Userland/Applications/TextEditor/TextEditorWindow.gml
index 433d01abff..b13865f697 100644
--- a/Userland/Applications/TextEditor/TextEditorWindow.gml
+++ b/Userland/Applications/TextEditor/TextEditorWindow.gml
@@ -84,5 +84,6 @@
 
     @GUI::StatusBar {
         name: "statusbar"
+        label_count: 3
     }
 }
diff --git a/Userland/Libraries/LibGUI/EditingEngine.h b/Userland/Libraries/LibGUI/EditingEngine.h
index a9eb525acf..3da65d2f09 100644
--- a/Userland/Libraries/LibGUI/EditingEngine.h
+++ b/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);
diff --git a/Userland/Libraries/LibGUI/RegularEditingEngine.cpp b/Userland/Libraries/LibGUI/RegularEditingEngine.cpp
index ffcbe941cd..653d6da7bb 100644
--- a/Userland/Libraries/LibGUI/RegularEditingEngine.cpp
+++ b/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;
diff --git a/Userland/Libraries/LibGUI/RegularEditingEngine.h b/Userland/Libraries/LibGUI/RegularEditingEngine.h
index 87e51b08d8..c91250333d 100644
--- a/Userland/Libraries/LibGUI/RegularEditingEngine.h
+++ b/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;
diff --git a/Userland/Libraries/LibGUI/TextEditor.cpp b/Userland/Libraries/LibGUI/TextEditor.cpp
index 55be2949e6..20615bcdce 100644
--- a/Userland/Libraries/LibGUI/TextEditor.cpp
+++ b/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
diff --git a/Userland/Libraries/LibGUI/TextEditor.h b/Userland/Libraries/LibGUI/TextEditor.h
index 956e3cfcce..0bc742b80e 100644
--- a/Userland/Libraries/LibGUI/TextEditor.h
+++ b/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 {};
 };
 
 }
diff --git a/Userland/Libraries/LibGUI/VimEditingEngine.cpp b/Userland/Libraries/LibGUI/VimEditingEngine.cpp
index 60a6a2b21b..213e267d35 100644
--- a/Userland/Libraries/LibGUI/VimEditingEngine.cpp
+++ b/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()
diff --git a/Userland/Libraries/LibGUI/VimEditingEngine.h b/Userland/Libraries/LibGUI/VimEditingEngine.h
index 007472d0f9..7af4e60677 100644
--- a/Userland/Libraries/LibGUI/VimEditingEngine.h
+++ b/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();