LibGUI+HackStudio: Make gutter a first class element

Gutter -- a space left of the text, before the ruler -- is not a part of
the ruler, nor should it be treated as such. This commit implements
gutter handling in LibGUI::TextEditor as part of mild cleaning up of the
gutter handling (breakpoint icons) in HackStudio's Editor.

This commit also enables separate theming of the gutter.

2 files changed, 63 insertions, 11 deletions

diff --git a/Userland/Libraries/LibGUI/TextEditor.cpp b/Userland/Libraries/LibGUI/TextEditor.cpp
index cd475d994c..5801d9185a 100644
--- a/Userland/Libraries/LibGUI/TextEditor.cpp
+++ b/Userland/Libraries/LibGUI/TextEditor.cpp
@@ -127,7 +127,7 @@ void TextEditor::update_content_size()
         content_width = max(frame_inner_rect().width(), content_width);
 
     set_content_size({ content_width, content_height });
-    set_size_occupied_by_fixed_elements({ ruler_width(), 0 });
+    set_size_occupied_by_fixed_elements({ ruler_width() + gutter_width(), 0 });
 }
 
 TextPosition TextEditor::text_position_at_content_position(const Gfx::IntPoint& content_position) const
@@ -195,7 +195,7 @@ TextPosition TextEditor::text_position_at(const Gfx::IntPoint& widget_position)
 {
     auto content_position = widget_position;
     content_position.translate_by(horizontal_scrollbar().value(), vertical_scrollbar().value());
-    content_position.translate_by(-(m_horizontal_content_padding + ruler_width()), 0);
+    content_position.translate_by(-(m_horizontal_content_padding + ruler_width() + gutter_width()), 0);
     content_position.translate_by(-frame_thickness(), -frame_thickness());
     return text_position_at_content_position(content_position);
 }
@@ -339,10 +339,17 @@ int TextEditor::ruler_width() const
     if (!m_ruler_visible)
         return 0;
     int line_count_digits = static_cast<int>(log10(line_count())) + 1;
-    constexpr size_t padding = 20;
+    constexpr size_t padding = 5;
     return line_count() < 10 ? (line_count_digits + 1) * font().glyph_width('x') + padding : line_count_digits * font().glyph_width('x') + padding;
 }
 
+int TextEditor::gutter_width() const
+{
+    if (!m_gutter_visible)
+        return 0;
+    return line_height(); // square gutter
+}
+
 Gfx::IntRect TextEditor::ruler_content_rect(size_t line_index) const
 {
     if (!m_ruler_visible)
@@ -355,9 +362,26 @@ Gfx::IntRect TextEditor::ruler_content_rect(size_t line_index) const
     };
 }
 
+Gfx::IntRect TextEditor::gutter_content_rect(size_t line_index) const
+{
+    if (!m_gutter_visible)
+        return {};
+    return {
+        0 - ruler_width() - gutter_width() + horizontal_scrollbar().value(),
+        line_content_rect(line_index).y(),
+        gutter_width(),
+        line_content_rect(line_index).height()
+    };
+}
+
 Gfx::IntRect TextEditor::ruler_rect_in_inner_coordinates() const
 {
-    return { 0, 0, ruler_width(), height() - height_occupied_by_horizontal_scrollbar() };
+    return { gutter_width(), 0, ruler_width(), height() - height_occupied_by_horizontal_scrollbar() };
+}
+
+Gfx::IntRect TextEditor::gutter_rect_in_inner_coordinates() const
+{
+    return { 0, 0, gutter_width(), height() - height_occupied_by_horizontal_scrollbar() };
 }
 
 Gfx::IntRect TextEditor::visible_text_rect_in_inner_coordinates() const
@@ -398,16 +422,22 @@ void TextEditor::paint_event(PaintEvent& event)
 
     painter.translate(frame_thickness(), frame_thickness());
 
-    auto ruler_rect = ruler_rect_in_inner_coordinates();
+    if (m_gutter_visible) {
+        auto gutter_rect = gutter_rect_in_inner_coordinates();
+        painter.fill_rect(gutter_rect, palette().gutter());
+        if (!m_ruler_visible)
+            painter.draw_line(gutter_rect.top_right(), gutter_rect.bottom_right(), palette().gutter_border());
+    }
 
     if (m_ruler_visible) {
+        auto ruler_rect = ruler_rect_in_inner_coordinates();
         painter.fill_rect(ruler_rect, palette().ruler());
         painter.draw_line(ruler_rect.top_right(), ruler_rect.bottom_right(), palette().ruler_border());
     }
 
     painter.translate(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
-    if (m_ruler_visible)
-        painter.translate(ruler_width(), 0);
+    painter.translate(gutter_width(), 0);
+    painter.translate(ruler_width(), 0);
 
     size_t first_visible_line = text_position_at(event.rect().top_left()).line();
     size_t last_visible_line = text_position_at(event.rect().bottom_right()).line();
@@ -428,14 +458,19 @@ void TextEditor::paint_event(PaintEvent& event)
         }
     }
 
+    auto text_left = 0;
+    if (m_ruler_visible)
+        text_left = ruler_rect_in_inner_coordinates().right() + 1;
+    else if (m_gutter_visible)
+        text_left = gutter_rect_in_inner_coordinates().right() + 1;
+    text_left += frame_thickness();
+
     Gfx::IntRect text_clip_rect {
-        (m_ruler_visible ? (ruler_rect_in_inner_coordinates().right() + frame_thickness() + 1) : frame_thickness()),
+        0,
         frame_thickness(),
-        width() - width_occupied_by_vertical_scrollbar() - ruler_width(),
+        width() - width_occupied_by_vertical_scrollbar() - text_left,
         height() - height_occupied_by_horizontal_scrollbar()
     };
-    if (m_ruler_visible)
-        text_clip_rect.translate_by(-ruler_width(), 0);
     text_clip_rect.translate_by(horizontal_scrollbar().value(), vertical_scrollbar().value());
     painter.add_clip_rect(text_clip_rect);
 
@@ -1860,6 +1895,15 @@ void TextEditor::set_ruler_visible(bool visible)
     update();
 }
 
+void TextEditor::set_gutter_visible(bool visible)
+{
+    if (m_gutter_visible == visible)
+        return;
+    m_gutter_visible = visible;
+    recompute_all_visual_lines();
+    update();
+}
+
 void TextEditor::undo()
 {
     clear_selection();
diff --git a/Userland/Libraries/LibGUI/TextEditor.h b/Userland/Libraries/LibGUI/TextEditor.h
index 72f6a46b5a..591bff461f 100644
--- a/Userland/Libraries/LibGUI/TextEditor.h
+++ b/Userland/Libraries/LibGUI/TextEditor.h
@@ -90,6 +90,9 @@ public:
     bool is_ruler_visible() const { return m_ruler_visible; }
     void set_ruler_visible(bool);
 
+    bool is_gutter_visible() const { return m_gutter_visible; }
+    void set_gutter_visible(bool);
+
     void set_icon(const Gfx::Bitmap*);
     const Gfx::Bitmap* icon() const { return m_icon; }
 
@@ -209,11 +212,14 @@ protected:
     virtual void theme_change_event(ThemeChangeEvent&) override;
     virtual void cursor_did_change() { }
     Gfx::IntRect ruler_content_rect(size_t line) const;
+    Gfx::IntRect gutter_content_rect(size_t line) const;
 
     TextPosition text_position_at(const Gfx::IntPoint&) const;
     bool ruler_visible() const { return m_ruler_visible; }
+    bool gutter_visible() const { return m_gutter_visible; }
     Gfx::IntRect content_rect_for_position(const TextPosition&) const;
     int ruler_width() const;
+    int gutter_width() const;
 
 private:
     friend class TextDocumentLine;
@@ -272,6 +278,7 @@ private:
     void delete_selection();
     int content_x_for_position(const TextPosition&) const;
     Gfx::IntRect ruler_rect_in_inner_coordinates() const;
+    Gfx::IntRect gutter_rect_in_inner_coordinates() const;
     Gfx::IntRect visible_text_rect_in_inner_coordinates() const;
     void recompute_all_visual_lines();
     void ensure_cursor_is_valid();
@@ -302,6 +309,7 @@ private:
     bool m_cursor_state { true };
     bool m_in_drag_select { false };
     bool m_ruler_visible { false };
+    bool m_gutter_visible { false };
     bool m_has_pending_change_notification { false };
     bool m_automatic_indentation_enabled { false };
     WrappingMode m_wrapping_mode { WrappingMode::NoWrap };