LibGUI: Support cycling through focusable widgets with Tab and Shift-Tab.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/ad731cc08f2

Applications/FontEditor/GlyphEditorWidget.h

@@ -21,7 +21,6 @@ private:
     virtual void paint_event(GPaintEvent&) override;
     virtual void mousedown_event(GMouseEvent&) override;
     virtual void mousemove_event(GMouseEvent&) override;
-    virtual bool accepts_focus() const override { return true; }
 
     void draw_at_mouse(const GMouseEvent&);
 

Applications/FontEditor/GlyphMapWidget.h

@@ -27,7 +27,6 @@ public:
 private:
     virtual void paint_event(GPaintEvent&) override;
     virtual void mousedown_event(GMouseEvent&) override;
-    virtual bool accepts_focus() const override { return true; }
 
     Rect get_outer_rect(byte glyph) const;
 

LibGUI/GButton.cpp

@@ -60,9 +60,15 @@ void GButton::paint_event(GPaintEvent& event)
         content_rect.move_by(m_icon->width() + 4, 0);
         content_rect.set_width(content_rect.width() - m_icon->width() - 4);
     }
-    if (is_enabled())
+    if (is_enabled()) {
         painter.draw_text(content_rect, m_caption, font, text_alignment(), foreground_color(), TextElision::Right);
-    else {
+        if (is_focused()) {
+            Rect focus_rect = { 0, 0, font.width(m_caption), font.glyph_height() };
+            focus_rect.inflate(6, 4);
+            focus_rect.center_within(content_rect);
+            painter.draw_rect(focus_rect, Color(140, 140, 140));
+        }
+    } else {
         painter.draw_text(content_rect.translated(1, 1), m_caption, font, text_alignment(), Color::White, TextElision::Right);
         painter.draw_text(content_rect, m_caption, font, text_alignment(), Color::from_rgb(0x808080), TextElision::Right);
     }

LibGUI/GButton.h

@@ -40,6 +40,7 @@ public:
     void set_action(GAction&);
 
     virtual const char* class_name() const override { return "GButton"; }
+    virtual bool accepts_focus() const override { return true; }
 
 protected:
     virtual void paint_event(GPaintEvent&) override;

LibGUI/GCheckBox.cpp

@@ -60,7 +60,9 @@ void GCheckBox::paint_event(GPaintEvent& event)
 
     auto text_rect = rect();
     text_rect.set_left(s_box_width + 4);
+    text_rect.set_width(font().width(m_caption));
     text_rect.set_top(height() / 2 - font().glyph_height() / 2);
+    text_rect.set_height(font().glyph_height());
 
     if (fill_with_background_color())
         painter.fill_rect(rect(), background_color());
@@ -78,8 +80,14 @@ void GCheckBox::paint_event(GPaintEvent& event)
     if (m_checked)
         painter.draw_bitmap(box_rect.shrunken(4, 4).location(), *s_checked_bitmap, foreground_color());
 
-    if (!caption().is_empty())
+    if (!caption().is_empty()) {
         painter.draw_text(text_rect, caption(), TextAlignment::TopLeft, foreground_color());
+        if (is_focused()) {
+            Rect focus_rect = text_rect;
+            focus_rect.inflate(6, 4);
+            painter.draw_rect(focus_rect, Color(140, 140, 140));
+        }
+    }
 }
 
 void GCheckBox::mousemove_event(GMouseEvent& event)

LibGUI/GTextEditor.cpp

@@ -315,6 +315,9 @@ void GTextEditor::toggle_selection_if_needed_for_event(const GKeyEvent& event)
 
 void GTextEditor::keydown_event(GKeyEvent& event)
 {
+    if (is_single_line() && event.key() == KeyCode::Key_Tab)
+        return GWidget::keydown_event(event);
+
     if (event.key() == KeyCode::Key_Escape) {
         if (on_escape_pressed)
             on_escape_pressed();
@@ -505,8 +508,6 @@ void GTextEditor::keydown_event(GKeyEvent& event)
 
     if (!is_readonly() && !event.ctrl() && !event.alt() && !event.text().is_empty())
         insert_at_cursor_or_replace_selection(event.text());
-
-    return GWidget::keydown_event(event);
 }
 
 void GTextEditor::delete_current_line()

LibGUI/GWidget.cpp

@@ -243,8 +243,14 @@ void GWidget::hide_event(GHideEvent&)
 {
 }
 
-void GWidget::keydown_event(GKeyEvent&)
+void GWidget::keydown_event(GKeyEvent& event)
 {
+    if (!event.alt() && !event.ctrl() && !event.logo() && event.key() == KeyCode::Key_Tab) {
+        if (event.shift())
+            focus_previous_widget();
+        else
+            focus_next_widget();
+    }
 }
 
 void GWidget::keyup_event(GKeyEvent&)
@@ -543,3 +549,29 @@ void GWidget::set_updates_enabled(bool enabled)
     if (enabled)
         update();
 }
+
+void GWidget::focus_previous_widget()
+{
+    auto focusable_widgets = window()->focusable_widgets();
+    for (int i = focusable_widgets.size() - 1; i >= 0; --i) {
+        if (focusable_widgets[i] != this)
+            continue;
+        if (i > 0)
+            focusable_widgets[i - 1]->set_focus(true);
+        else
+            focusable_widgets.last()->set_focus(true);
+    }
+}
+
+void GWidget::focus_next_widget()
+{
+    auto focusable_widgets = window()->focusable_widgets();
+    for (int i = 0; i < focusable_widgets.size(); ++i) {
+        if (focusable_widgets[i] != this)
+            continue;
+        if (i < focusable_widgets.size() - 1)
+            focusable_widgets[i + 1]->set_focus(true);
+        else
+            focusable_widgets.first()->set_focus(true);
+    }
+}

LibGUI/GWidget.h

@@ -194,6 +194,8 @@ private:
     void handle_enter_event(CEvent&);
     void handle_leave_event(CEvent&);
     void do_layout();
+    void focus_previous_widget();
+    void focus_next_widget();
 
     CElapsedTimer& click_clock(GMouseButton);
 

LibGUI/GWindow.cpp

@@ -513,3 +513,27 @@ void GWindow::start_wm_resize()
     message.wm.window_id = m_window_id;
     GEventLoop::post_message_to_server(message);
 }
+
+Vector<GWidget*> GWindow::focusable_widgets() const
+{
+    if (!m_main_widget)
+        return { };
+
+    Vector<GWidget*> collected_widgets;
+
+    Function<void(GWidget&)> collect_focusable_widgets = [&] (GWidget& widget) {
+        if (widget.accepts_focus())
+            collected_widgets.append(&widget);
+        for (auto& child : widget.children()) {
+            if (!child->is_widget())
+                continue;
+            auto& child_widget = *static_cast<GWidget*>(child);
+            if (!child_widget.is_visible())
+                continue;
+            collect_focusable_widgets(child_widget);
+        }
+    };
+
+    collect_focusable_widgets(*m_main_widget);
+    return collected_widgets;
+}

LibGUI/GWindow.h

@@ -113,6 +113,8 @@ public:
     String icon_path() const { return m_icon_path; }
     void set_icon_path(const String&);
 
+    Vector<GWidget*> focusable_widgets() const;
+
     virtual const char* class_name() const override { return "GWindow"; }
 
 protected: