CharacterMap: Add output box for copying arbitrary character sequences

This adds a TextBox along the bottom of the window. Double-clicking on a
character will append it to this box, which you can edit as any other
TextBox, or click the copy button to copy the output to the clipboard.

Userland/Applications/CharacterMap/CharacterMapWidget.cpp

@@ -14,6 +14,7 @@
 #include <LibGUI/Icon.h>
 #include <LibGUI/Label.h>
 #include <LibGUI/Menu.h>
+#include <LibGUI/TextBox.h>
 #include <LibGUI/Toolbar.h>
 #include <LibUnicode/CharacterTypes.h>
 
@@ -24,6 +25,8 @@ CharacterMapWidget::CharacterMapWidget()
     m_toolbar = find_descendant_of_type_named<GUI::Toolbar>("toolbar");
     m_font_name_label = find_descendant_of_type_named<GUI::Label>("font_name");
     m_glyph_map = find_descendant_of_type_named<GUI::GlyphMapWidget>("glyph_map");
+    m_output_box = find_descendant_of_type_named<GUI::TextBox>("output_box");
+    m_copy_output_button = find_descendant_of_type_named<GUI::Button>("copy_output_button");
     m_statusbar = find_descendant_of_type_named<GUI::Statusbar>("statusbar");
 
     m_choose_font_action = GUI::Action::create("Choose Font...", Gfx::Bitmap::try_load_from_file("/res/icons/16x16/app-font-editor.png").release_value_but_fixme_should_propagate_errors(), [&](auto&) {
@@ -54,6 +57,17 @@ CharacterMapWidget::CharacterMapWidget()
         update_statusbar();
     };
 
+    m_glyph_map->on_glyph_double_clicked = [&](int code_point) {
+        StringBuilder builder;
+        builder.append(m_output_box->text());
+        builder.append_code_point(code_point);
+        m_output_box->set_text(builder.string_view());
+    };
+
+    m_copy_output_button->on_click = [&](auto) {
+        GUI::Clipboard::the().set_plain_text(m_output_box->text());
+    };
+
     did_change_font();
     update_statusbar();
 }
@@ -77,6 +91,7 @@ void CharacterMapWidget::did_change_font()
 {
     m_glyph_map->set_font(font());
     m_font_name_label->set_text(font().qualified_name());
+    m_output_box->set_font(font());
 }
 
 void CharacterMapWidget::update_statusbar()

Userland/Applications/CharacterMap/CharacterMapWidget.h

@@ -27,6 +27,8 @@ private:
     RefPtr<GUI::Toolbar> m_toolbar;
     RefPtr<GUI::Label> m_font_name_label;
     RefPtr<GUI::GlyphMapWidget> m_glyph_map;
+    RefPtr<GUI::TextBox> m_output_box;
+    RefPtr<GUI::Button> m_copy_output_button;
     RefPtr<GUI::Statusbar> m_statusbar;
 
     RefPtr<GUI::Action> m_choose_font_action;

Userland/Applications/CharacterMap/CharacterMapWindow.gml

@@ -38,6 +38,25 @@
         name: "glyph_map"
     }
 
+    @GUI::Widget {
+        shrink_to_fit: true
+
+        layout: @GUI::HorizontalBoxLayout {
+            spacing: 4
+            margins: [0, 2, 0, 2]
+        }
+
+        @GUI::TextBox {
+            name: "output_box"
+        }
+
+        @GUI::Button {
+            name: "copy_output_button"
+            icon: "/res/icons/16x16/edit-copy.png"
+            fixed_width: 22
+        }
+    }
+
     @GUI::Statusbar {
         name: "statusbar"
     }