ladybird/Userland/Applications/FontEditor/MainWidget.cpp

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2022, the SerenityOS developers.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "MainWidget.h"
#include "GlyphEditorWidget.h"
#include "NewFontDialog.h"
#include <AK/Array.h>
#include <AK/StringBuilder.h>
#include <AK/StringUtils.h>
#include <Applications/FontEditor/FontEditorWindowGML.h>
#include <Applications/FontEditor/FontPreviewWindowGML.h>
#include <LibConfig/Client.h>
#include <LibDesktop/Launcher.h>
#include <LibGUI/Action.h>
#include <LibGUI/Application.h>
#include <LibGUI/Button.h>
#include <LibGUI/CheckBox.h>
#include <LibGUI/Clipboard.h>
#include <LibGUI/ComboBox.h>
#include <LibGUI/FilePicker.h>
#include <LibGUI/GlyphMapWidget.h>
#include <LibGUI/GroupBox.h>
#include <LibGUI/InputBox.h>
#include <LibGUI/ItemListModel.h>
#include <LibGUI/Label.h>
#include <LibGUI/ListView.h>
#include <LibGUI/Menu.h>
#include <LibGUI/Menubar.h>
#include <LibGUI/MessageBox.h>
#include <LibGUI/SpinBox.h>
#include <LibGUI/Statusbar.h>
#include <LibGUI/TextBox.h>
#include <LibGUI/ToolbarContainer.h>
#include <LibGUI/Window.h>
#include <LibGfx/Font/BitmapFont.h>
#include <LibGfx/Font/Emoji.h>
#include <LibGfx/Font/FontStyleMapping.h>
#include <LibGfx/TextDirection.h>
#include <LibUnicode/CharacterTypes.h>

namespace FontEditor {

static constexpr Array pangrams = {
    "quick fox jumps nightly above wizard"sv,
    "five quacking zephyrs jolt my wax bed"sv,
    "pack my box with five dozen liquor jugs"sv,
    "quick brown fox jumps over the lazy dog"sv,
    "waxy and quivering jocks fumble the pizza"sv,
    "~#:[@_1%]*{$2.3}/4^(5'6\"sv)-&|7+8!=<9,0\\>?;"sv,
    "byxfjärmat föl gick på duvshowen"sv,
    "         "sv,
    "float Fox.quick(h){ is_brown && it_jumps_over(doges.lazy) }"sv,
    "<fox color=\"brown\" speed=\"quick\" jumps=\"over\">lazy dog</fox>"sv
};

ErrorOr<RefPtr<GUI::Window>> MainWidget::create_preview_window()
{
    auto window = TRY(GUI::Window::try_create(this));
    window->set_window_mode(GUI::WindowMode::RenderAbove);
    window->set_title("Preview");
    window->resize(400, 150);
    window->center_within(*this->window());

    auto main_widget = TRY(window->try_set_main_widget<GUI::Widget>());
    main_widget->load_from_gml(font_preview_window_gml);

    m_preview_label = find_descendant_of_type_named<GUI::Label>("preview_label");
    m_preview_label->set_font(edited_font());

    m_preview_textbox = find_descendant_of_type_named<GUI::TextBox>("preview_textbox");
    m_preview_textbox->on_change = [&] {
        auto preview = String::formatted("{}\n{}", m_preview_textbox->text(), Unicode::to_unicode_uppercase_full(m_preview_textbox->text()));
        m_preview_label->set_text(preview);
    };
    m_preview_textbox->set_text(pangrams[0]);

    auto& reload_button = *find_descendant_of_type_named<GUI::Button>("reload_button");
    reload_button.on_click = [&](auto) {
        static size_t i = 1;
        if (i >= pangrams.size())
            i = 0;
        m_preview_textbox->set_text(pangrams[i]);
        i++;
    };

    return window;
}

ErrorOr<void> MainWidget::create_actions()
{
    m_new_action = GUI::Action::create("&New Font...", { Mod_Ctrl, Key_N }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/filetype-font.png"sv)), [&](auto&) {
        if (!request_close())
            return;
        auto new_font_wizard = NewFontDialog::construct(window());
        if (new_font_wizard->exec() != GUI::Dialog::ExecResult::OK)
            return;
        new_font_wizard->hide();
        auto maybe_font = new_font_wizard->create_font();
        if (maybe_font.is_error())
            return show_error("Failed to create new font"sv, maybe_font.error());
        if (auto result = initialize({}, move(maybe_font.value())); result.is_error())
            show_error("Failed to initialize font"sv, result.error());
    });
    m_new_action->set_status_tip("Create a new font");

    m_open_action = GUI::CommonActions::make_open_action([&](auto&) {
        if (!request_close())
            return;
        Optional<String> open_path = GUI::FilePicker::get_open_filepath(window(), {}, "/res/fonts/"sv);
        if (!open_path.has_value())
            return;
        if (auto result = open_file(open_path.value()); result.is_error())
            show_error("Failed to open font"sv, result.error());
    });

    m_save_action = GUI::CommonActions::make_save_action([&](auto&) {
        if (m_path.is_empty())
            return m_save_as_action->activate();
        if (auto result = save_file(m_path); result.is_error())
            show_error("Failed to save font"sv, result.error());
    });

    m_save_as_action = GUI::CommonActions::make_save_as_action([&](auto&) {
        LexicalPath lexical_path(m_path.is_empty() ? "Untitled.font" : m_path);
        Optional<String> save_path = GUI::FilePicker::get_save_filepath(window(), lexical_path.title(), lexical_path.extension());
        if (!save_path.has_value())
            return;
        if (auto result = save_file(save_path.value()); result.is_error())
            show_error("Failed to save font"sv, result.error());
    });

    m_cut_action = GUI::CommonActions::make_cut_action([&](auto&) {
        if (auto result = cut_selected_glyphs(); result.is_error())
            show_error("Failed to cut selection"sv, result.error());
    });

    m_copy_action = GUI::CommonActions::make_copy_action([&](auto&) {
        if (auto result = copy_selected_glyphs(); result.is_error())
            show_error("Failed to copy selection"sv, result.error());
    });

    m_paste_action = GUI::CommonActions::make_paste_action([&](auto&) {
        paste_glyphs();
    });
    m_paste_action->set_enabled(GUI::Clipboard::the().fetch_mime_type() == "glyph/x-fonteditor");

    GUI::Clipboard::the().on_change = [&](String const& data_type) {
        m_paste_action->set_enabled(data_type == "glyph/x-fonteditor");
    };

    m_delete_action = GUI::CommonActions::make_delete_action([this](auto&) {
        delete_selected_glyphs();
    });

    m_undo_action = GUI::CommonActions::make_undo_action([&](auto&) {
        undo();
    });
    m_undo_action->set_enabled(false);

    m_redo_action = GUI::CommonActions::make_redo_action([&](auto&) {
        redo();
    });
    m_redo_action->set_enabled(false);

    m_select_all_action = GUI::CommonActions::make_select_all_action([this](auto&) {
        m_glyph_map_widget->set_selection(m_range.first, m_range.last - m_range.first + 1);
        m_glyph_map_widget->update();
        auto selection = m_glyph_map_widget->selection().normalized();
        m_undo_selection->set_start(selection.start());
        m_undo_selection->set_size(selection.size());
    });

    m_open_preview_action = GUI::Action::create("&Preview Font", { Mod_Ctrl, Key_P }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/find.png"sv)), [&](auto&) {
        if (!m_font_preview_window) {
            if (auto maybe_window = create_preview_window(); maybe_window.is_error())
                show_error("Failed to create preview window"sv, maybe_window.error());
            else
                m_font_preview_window = maybe_window.release_value();
        }
        if (m_font_preview_window)
            m_font_preview_window->show();
    });
    m_open_preview_action->set_status_tip("Preview the current font");

    bool show_metadata = Config::read_bool("FontEditor"sv, "Layout"sv, "ShowMetadata"sv, true);
    set_show_font_metadata(show_metadata);
    m_show_metadata_action = GUI::Action::create_checkable("Font &Metadata", { Mod_Ctrl, Key_M }, [&](auto& action) {
        set_show_font_metadata(action.is_checked());
        Config::write_bool("FontEditor"sv, "Layout"sv, "ShowMetadata"sv, action.is_checked());
    });
    m_show_metadata_action->set_checked(show_metadata);
    m_show_metadata_action->set_status_tip("Show or hide metadata about the current font");

    bool show_unicode_blocks = Config::read_bool("FontEditor"sv, "Layout"sv, "ShowUnicodeBlocks"sv, true);
    set_show_unicode_blocks(show_unicode_blocks);
    m_show_unicode_blocks_action = GUI::Action::create_checkable("&Unicode Blocks", { Mod_Ctrl, Key_U }, [&](auto& action) {
        set_show_unicode_blocks(action.is_checked());
        Config::write_bool("FontEditor"sv, "Layout"sv, "ShowUnicodeBlocks"sv, action.is_checked());
    });
    m_show_unicode_blocks_action->set_checked(show_unicode_blocks);
    m_show_unicode_blocks_action->set_status_tip("Show or hide the Unicode block list");

    bool highlight_modifications = Config::read_bool("FontEditor"sv, "Display"sv, "HighlightModifications"sv, true);
    set_highlight_modifications(highlight_modifications);
    m_highlight_modifications_action = GUI::Action::create_checkable("&Highlight Modifications", { Mod_Ctrl, Key_H }, [&](auto& action) {
        set_highlight_modifications(action.is_checked());
        Config::write_bool("FontEditor"sv, "Display"sv, "HighlightModifications"sv, action.is_checked());
    });
    m_highlight_modifications_action->set_checked(highlight_modifications);
    m_highlight_modifications_action->set_status_tip("Show or hide highlights on modified glyphs. (Green = New, Blue = Modified, Red = Deleted)");

    m_go_to_glyph_action = GUI::Action::create("&Go to Glyph...", { Mod_Ctrl, Key_G }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/go-to.png"sv)), [&](auto&) {
        String input;
        if (GUI::InputBox::show(window(), input, "Hexadecimal:"sv, "Go to glyph"sv) == GUI::InputBox::ExecResult::OK && !input.is_empty()) {
            auto maybe_code_point = AK::StringUtils::convert_to_uint_from_hex(input);
            if (!maybe_code_point.has_value())
                return;
            auto code_point = maybe_code_point.value();
            code_point = clamp(code_point, m_range.first, m_range.last);
            m_glyph_map_widget->set_focus(true);
            m_glyph_map_widget->set_active_glyph(code_point);
            m_glyph_map_widget->scroll_to_glyph(code_point);
        }
    });
    m_go_to_glyph_action->set_status_tip("Go to the specified code point");

    m_previous_glyph_action = GUI::Action::create("Pre&vious Glyph", { Mod_Alt, Key_Left }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/go-back.png"sv)), [&](auto&) {
        m_glyph_map_widget->select_previous_existing_glyph();
    });
    m_previous_glyph_action->set_status_tip("Seek the previous visible glyph");

    m_next_glyph_action = GUI::Action::create("&Next Glyph", { Mod_Alt, Key_Right }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/go-forward.png"sv)), [&](auto&) {
        m_glyph_map_widget->select_next_existing_glyph();
    });
    m_next_glyph_action->set_status_tip("Seek the next visible glyph");

    i32 scale = Config::read_i32("FontEditor"sv, "GlyphEditor"sv, "Scale"sv, 10);
    set_scale(scale);
    m_scale_five_action = GUI::Action::create_checkable("500%", { Mod_Ctrl, Key_1 }, [this](auto&) {
        set_scale_and_save(5);
    });
    m_scale_five_action->set_checked(scale == 5);
    m_scale_five_action->set_status_tip("Scale the editor in proportion to the current font");
    m_scale_ten_action = GUI::Action::create_checkable("1000%", { Mod_Ctrl, Key_2 }, [this](auto&) {
        set_scale_and_save(10);
    });
    m_scale_ten_action->set_checked(scale == 10);
    m_scale_ten_action->set_status_tip("Scale the editor in proportion to the current font");
    m_scale_fifteen_action = GUI::Action::create_checkable("1500%", { Mod_Ctrl, Key_3 }, [this](auto&) {
        set_scale_and_save(15);
    });
    m_scale_fifteen_action->set_checked(scale == 15);
    m_scale_fifteen_action->set_status_tip("Scale the editor in proportion to the current font");

    m_glyph_editor_scale_actions.add_action(*m_scale_five_action);
    m_glyph_editor_scale_actions.add_action(*m_scale_ten_action);
    m_glyph_editor_scale_actions.add_action(*m_scale_fifteen_action);
    m_glyph_editor_scale_actions.set_exclusive(true);

    m_paint_glyph_action = GUI::Action::create_checkable("Paint Glyph", { Mod_Ctrl, KeyCode::Key_J }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/pixelpaint/pen.png"sv)), [&](auto&) {
        m_glyph_editor_widget->set_mode(GlyphEditorWidget::Paint);
    });
    m_paint_glyph_action->set_checked(true);

    m_move_glyph_action = GUI::Action::create_checkable("Move Glyph", { Mod_Ctrl, KeyCode::Key_K }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/selection-move.png"sv)), [&](auto&) {
        m_glyph_editor_widget->set_mode(GlyphEditorWidget::Move);
    });

    m_glyph_tool_actions.add_action(*m_paint_glyph_action);
    m_glyph_tool_actions.add_action(*m_move_glyph_action);
    m_glyph_tool_actions.set_exclusive(true);

    m_rotate_counterclockwise_action = GUI::CommonActions::make_rotate_counterclockwise_action([&](auto&) {
        m_glyph_editor_widget->rotate_90(GlyphEditorWidget::Counterclockwise);
    });

    m_rotate_clockwise_action = GUI::CommonActions::make_rotate_clockwise_action([&](auto&) {
        m_glyph_editor_widget->rotate_90(GlyphEditorWidget::Clockwise);
    });

    m_flip_horizontal_action = GUI::Action::create("Flip Horizontally", { Mod_Ctrl | Mod_Shift, Key_Q }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/edit-flip-horizontal.png"sv)), [&](auto&) {
        m_glyph_editor_widget->flip_horizontally();
    });

    m_flip_vertical_action = GUI::Action::create("Flip Vertically", { Mod_Ctrl | Mod_Shift, Key_W }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/edit-flip-vertical.png"sv)), [&](auto&) {
        m_glyph_editor_widget->flip_vertically();
    });

    m_copy_text_action = GUI::Action::create("Copy as Te&xt", { Mod_Ctrl, Key_T }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/edit-copy.png"sv)), [&](auto&) {
        StringBuilder builder;
        auto selection = m_glyph_map_widget->selection().normalized();
        for (auto code_point = selection.start(); code_point < selection.start() + selection.size(); ++code_point) {
            if (!m_glyph_map_widget->font().contains_glyph(code_point))
                continue;
            builder.append_code_point(code_point);
        }
        GUI::Clipboard::the().set_plain_text(builder.to_string());
    });
    m_copy_text_action->set_status_tip("Copy to clipboard as text");

    return {};
}

ErrorOr<void> MainWidget::create_toolbars()
{
    auto& toolbar = *find_descendant_of_type_named<GUI::Toolbar>("toolbar");
    (void)TRY(toolbar.try_add_action(*m_new_action));
    (void)TRY(toolbar.try_add_action(*m_open_action));
    (void)TRY(toolbar.try_add_action(*m_save_action));
    TRY(toolbar.try_add_separator());
    (void)TRY(toolbar.try_add_action(*m_cut_action));
    (void)TRY(toolbar.try_add_action(*m_copy_action));
    (void)TRY(toolbar.try_add_action(*m_paste_action));
    (void)TRY(toolbar.try_add_action(*m_delete_action));
    TRY(toolbar.try_add_separator());
    (void)TRY(toolbar.try_add_action(*m_undo_action));
    (void)TRY(toolbar.try_add_action(*m_redo_action));
    TRY(toolbar.try_add_separator());
    (void)TRY(toolbar.try_add_action(*m_open_preview_action));
    TRY(toolbar.try_add_separator());
    (void)TRY(toolbar.try_add_action(*m_previous_glyph_action));
    (void)TRY(toolbar.try_add_action(*m_next_glyph_action));
    (void)TRY(toolbar.try_add_action(*m_go_to_glyph_action));

    auto& glyph_transform_toolbar = *find_descendant_of_type_named<GUI::Toolbar>("glyph_transform_toolbar");
    (void)TRY(glyph_transform_toolbar.try_add_action(*m_flip_horizontal_action));
    (void)TRY(glyph_transform_toolbar.try_add_action(*m_flip_vertical_action));
    (void)TRY(glyph_transform_toolbar.try_add_action(*m_rotate_counterclockwise_action));
    (void)TRY(glyph_transform_toolbar.try_add_action(*m_rotate_clockwise_action));

    auto& glyph_mode_toolbar = *find_descendant_of_type_named<GUI::Toolbar>("glyph_mode_toolbar");
    (void)TRY(glyph_mode_toolbar.try_add_action(*m_paint_glyph_action));
    (void)TRY(glyph_mode_toolbar.try_add_action(*m_move_glyph_action));

    return {};
}

ErrorOr<void> MainWidget::create_models()
{
    for (auto& it : Gfx::font_slope_names)
        TRY(m_font_slope_list.try_append(it.name));
    m_slope_combobox->set_model(GUI::ItemListModel<String>::create(m_font_slope_list));

    for (auto& it : Gfx::font_weight_names)
        TRY(m_font_weight_list.try_append(it.name));
    m_weight_combobox->set_model(GUI::ItemListModel<String>::create(m_font_weight_list));

    auto unicode_blocks = Unicode::block_display_names();
    TRY(m_unicode_block_list.try_append("Show All"));
    for (auto& block : unicode_blocks)
        TRY(m_unicode_block_list.try_append(block.display_name));

    m_unicode_block_model = GUI::ItemListModel<String>::create(m_unicode_block_list);
    m_filter_model = TRY(GUI::FilteringProxyModel::create(*m_unicode_block_model));
    m_filter_model->set_filter_term(""sv);

    m_unicode_block_listview = find_descendant_of_type_named<GUI::ListView>("unicode_block_listview");
    m_unicode_block_listview->on_selection_change = [this, unicode_blocks] {
        auto index = m_unicode_block_listview->selection().first();
        auto mapped_index = m_filter_model->map(index);
        if (mapped_index.row() > 0)
            m_range = unicode_blocks[mapped_index.row() - 1].code_point_range;
        else
            m_range = { 0x0000, 0x10FFFF };
        m_glyph_map_widget->set_active_range(m_range);
    };
    m_unicode_block_listview->set_model(m_filter_model);
    m_unicode_block_listview->set_activates_on_selection(true);
    m_unicode_block_listview->horizontal_scrollbar().set_visible(false);
    m_unicode_block_listview->set_cursor(m_unicode_block_model->index(0, 0), GUI::AbstractView::SelectionUpdate::Set);

    return {};
}

ErrorOr<void> MainWidget::create_undo_stack()
{
    m_undo_stack = TRY(try_make<GUI::UndoStack>());
    m_undo_stack->on_state_change = [this] {
        m_undo_action->set_enabled(m_undo_stack->can_undo());
        m_redo_action->set_enabled(m_undo_stack->can_redo());
        if (m_undo_stack->is_current_modified())
            did_modify_font();
    };

    return {};
}

MainWidget::MainWidget()
{
    load_from_gml(font_editor_window_gml);

    m_font_metadata_groupbox = find_descendant_of_type_named<GUI::GroupBox>("font_metadata_groupbox");
    m_unicode_block_container = find_descendant_of_type_named<GUI::Widget>("unicode_block_container");

    m_glyph_map_widget = find_descendant_of_type_named<GUI::GlyphMapWidget>("glyph_map_widget");
    m_glyph_editor_widget = find_descendant_of_type_named<GlyphEditorWidget>("glyph_editor_widget");
    m_glyph_editor_widget->on_glyph_altered = [this](int glyph) {
        m_glyph_map_widget->update_glyph(glyph);
        update_preview();
        did_modify_font();
    };

    m_glyph_editor_widget->on_undo_event = [this] {
        reset_selection_and_push_undo();
    };

    m_glyph_editor_width_spinbox = find_descendant_of_type_named<GUI::SpinBox>("glyph_editor_width_spinbox");
    m_glyph_editor_present_checkbox = find_descendant_of_type_named<GUI::CheckBox>("glyph_editor_present_checkbox");
    m_glyph_map_widget->on_active_glyph_changed = [this](int glyph) {
        if (m_undo_selection) {
            auto selection = m_glyph_map_widget->selection().normalized();
            m_undo_selection->set_start(selection.start());
            m_undo_selection->set_size(selection.size());
            m_undo_selection->set_active_glyph(glyph);
        }
        m_glyph_editor_widget->set_glyph(glyph);
        auto glyph_width = m_edited_font->raw_glyph_width(glyph);
        if (m_edited_font->is_fixed_width())
            m_glyph_editor_present_checkbox->set_checked(glyph_width > 0, GUI::AllowCallback::No);
        else
            m_glyph_editor_width_spinbox->set_value(glyph_width, GUI::AllowCallback::No);
        update_statusbar();
    };

    m_glyph_map_widget->on_context_menu_request = [this](auto& event) {
        m_context_menu->popup(event.screen_position());
    };

    m_name_textbox = find_descendant_of_type_named<GUI::TextBox>("name_textbox");
    m_name_textbox->on_change = [&] {
        m_edited_font->set_name(m_name_textbox->text());
        did_modify_font();
    };

    m_family_textbox = find_descendant_of_type_named<GUI::TextBox>("family_textbox");
    m_family_textbox->on_change = [&] {
        m_edited_font->set_family(m_family_textbox->text());
        did_modify_font();
    };

    m_fixed_width_checkbox = find_descendant_of_type_named<GUI::CheckBox>("fixed_width_checkbox");
    m_fixed_width_checkbox->on_checked = [this](bool checked) {
        m_edited_font->set_fixed_width(checked);
        auto glyph_width = m_edited_font->raw_glyph_width(m_glyph_map_widget->active_glyph());
        m_glyph_editor_width_spinbox->set_visible(!checked);
        m_glyph_editor_width_spinbox->set_value(glyph_width, GUI::AllowCallback::No);
        m_glyph_editor_present_checkbox->set_visible(checked);
        m_glyph_editor_present_checkbox->set_checked(glyph_width > 0, GUI::AllowCallback::No);
        m_glyph_editor_widget->update();
        update_preview();
        did_modify_font();
    };

    m_glyph_editor_width_spinbox->on_change = [this](int value) {
        reset_selection_and_push_undo();
        m_edited_font->set_glyph_width(m_glyph_map_widget->active_glyph(), value);
        m_glyph_editor_widget->update();
        m_glyph_map_widget->update_glyph(m_glyph_map_widget->active_glyph());
        update_preview();
        update_statusbar();
        did_modify_font();
    };

    m_glyph_editor_present_checkbox->on_checked = [this](bool checked) {
        reset_selection_and_push_undo();
        m_edited_font->set_glyph_width(m_glyph_map_widget->active_glyph(), checked ? m_edited_font->glyph_fixed_width() : 0);
        m_glyph_editor_widget->update();
        m_glyph_map_widget->update_glyph(m_glyph_map_widget->active_glyph());
        update_preview();
        update_statusbar();
        did_modify_font();
    };

    m_weight_combobox = find_descendant_of_type_named<GUI::ComboBox>("weight_combobox");
    m_weight_combobox->on_change = [this](auto&, auto&) {
        m_edited_font->set_weight(Gfx::name_to_weight(m_weight_combobox->text()));
        did_modify_font();
    };

    m_slope_combobox = find_descendant_of_type_named<GUI::ComboBox>("slope_combobox");
    m_slope_combobox->on_change = [this](auto&, auto&) {
        m_edited_font->set_slope(Gfx::name_to_slope(m_slope_combobox->text()));
        did_modify_font();
    };

    m_presentation_spinbox = find_descendant_of_type_named<GUI::SpinBox>("presentation_spinbox");
    m_presentation_spinbox->on_change = [this](int value) {
        m_edited_font->set_presentation_size(value);
        update_preview();
        did_modify_font();
    };

    m_spacing_spinbox = find_descendant_of_type_named<GUI::SpinBox>("spacing_spinbox");
    m_spacing_spinbox->on_change = [this](int value) {
        m_edited_font->set_glyph_spacing(value);
        update_preview();
        did_modify_font();
    };

    m_baseline_spinbox = find_descendant_of_type_named<GUI::SpinBox>("baseline_spinbox");
    m_baseline_spinbox->on_change = [this](int value) {
        m_edited_font->set_baseline(value);
        m_glyph_editor_widget->update();
        update_preview();
        did_modify_font();
    };

    m_mean_line_spinbox = find_descendant_of_type_named<GUI::SpinBox>("mean_line_spinbox");
    m_mean_line_spinbox->on_change = [this](int value) {
        m_edited_font->set_mean_line(value);
        m_glyph_editor_widget->update();
        update_preview();
        did_modify_font();
    };

    m_search_textbox = find_descendant_of_type_named<GUI::TextBox>("search_textbox");
    m_search_textbox->on_return_pressed = [this] {
        if (!m_unicode_block_listview->selection().is_empty())
            m_unicode_block_listview->activate_selected();
    };

    m_search_textbox->on_down_pressed = [this] {
        m_unicode_block_listview->move_cursor(GUI::AbstractView::CursorMovement::Down, GUI::AbstractView::SelectionUpdate::Set);
    };

    m_search_textbox->on_up_pressed = [this] {
        m_unicode_block_listview->move_cursor(GUI::AbstractView::CursorMovement::Up, GUI::AbstractView::SelectionUpdate::Set);
    };

    m_search_textbox->on_change = [this] {
        m_filter_model->set_filter_term(m_search_textbox->text());
        if (m_filter_model->row_count() != 0)
            m_unicode_block_listview->set_cursor(m_filter_model->index(0, 0), GUI::AbstractView::SelectionUpdate::Set);
    };

    m_statusbar = find_descendant_of_type_named<GUI::Statusbar>("statusbar");
    GUI::Application::the()->on_action_enter = [this](GUI::Action& action) {
        auto text = action.status_tip();
        if (text.is_empty())
            text = Gfx::parse_ampersand_string(action.text());
        m_statusbar->set_override_text(move(text));
    };

    GUI::Application::the()->on_action_leave = [this](GUI::Action&) {
        m_statusbar->set_override_text({});
    };
}

ErrorOr<void> MainWidget::initialize(String const& path, RefPtr<Gfx::BitmapFont>&& edited_font)
{
    if (m_edited_font == edited_font)
        return {};

    auto selection = m_glyph_map_widget->selection().normalized();
    m_undo_selection = TRY(try_make_ref_counted<UndoSelection>(selection.start(), selection.size(), m_glyph_map_widget->active_glyph(), *edited_font, *m_glyph_map_widget));
    m_undo_stack->clear();

    m_path = path;
    m_edited_font = edited_font;

    if (m_preview_label)
        m_preview_label->set_font(*m_edited_font);

    m_glyph_map_widget->set_font(*m_edited_font);
    m_glyph_editor_widget->set_font(*m_edited_font);
    m_glyph_editor_widget->set_fixed_size(m_glyph_editor_widget->preferred_width(), m_glyph_editor_widget->preferred_height());

    m_glyph_editor_width_spinbox->set_visible(!m_edited_font->is_fixed_width());
    m_glyph_editor_width_spinbox->set_max(m_edited_font->max_glyph_width(), GUI::AllowCallback::No);
    m_glyph_editor_width_spinbox->set_value(m_edited_font->raw_glyph_width(m_glyph_map_widget->active_glyph()), GUI::AllowCallback::No);

    m_glyph_editor_present_checkbox->set_visible(m_edited_font->is_fixed_width());
    m_glyph_editor_present_checkbox->set_checked(m_edited_font->contains_raw_glyph(m_glyph_map_widget->active_glyph()), GUI::AllowCallback::No);
    m_fixed_width_checkbox->set_checked(m_edited_font->is_fixed_width(), GUI::AllowCallback::No);

    m_name_textbox->set_text(m_edited_font->name(), GUI::AllowCallback::No);
    m_family_textbox->set_text(m_edited_font->family(), GUI::AllowCallback::No);

    m_presentation_spinbox->set_value(m_edited_font->presentation_size(), GUI::AllowCallback::No);
    m_spacing_spinbox->set_value(m_edited_font->glyph_spacing(), GUI::AllowCallback::No);

    m_mean_line_spinbox->set_range(0, max(m_edited_font->glyph_height() - 2, 0), GUI::AllowCallback::No);
    m_baseline_spinbox->set_range(0, max(m_edited_font->glyph_height() - 2, 0), GUI::AllowCallback::No);
    m_mean_line_spinbox->set_value(m_edited_font->mean_line(), GUI::AllowCallback::No);
    m_baseline_spinbox->set_value(m_edited_font->baseline(), GUI::AllowCallback::No);

    int i = 0;
    for (auto& it : Gfx::font_weight_names) {
        if (it.style == m_edited_font->weight()) {
            m_weight_combobox->set_selected_index(i, GUI::AllowCallback::No);
            break;
        }
        i++;
    }
    i = 0;
    for (auto& it : Gfx::font_slope_names) {
        if (it.style == m_edited_font->slope()) {
            m_slope_combobox->set_selected_index(i, GUI::AllowCallback::No);
            break;
        }
        i++;
    }

    update_statusbar();

    deferred_invoke([this] {
        auto glyph = m_glyph_map_widget->active_glyph();
        m_glyph_map_widget->set_focus(true);
        m_glyph_map_widget->scroll_to_glyph(glyph);
        m_glyph_editor_widget->set_glyph(glyph);

        VERIFY(window());
        window()->set_modified(false);
        update_title();
    });

    return {};
}

ErrorOr<void> MainWidget::initialize_menubar(GUI::Window& window)
{
    auto file_menu = TRY(window.try_add_menu("&File"));
    TRY(file_menu->try_add_action(*m_new_action));
    TRY(file_menu->try_add_action(*m_open_action));
    TRY(file_menu->try_add_action(*m_save_action));
    TRY(file_menu->try_add_action(*m_save_as_action));
    TRY(file_menu->try_add_separator());
    TRY(file_menu->try_add_action(GUI::CommonActions::make_quit_action([this](auto&) {
        if (!request_close())
            return;
        GUI::Application::the()->quit();
    })));

    auto edit_menu = TRY(window.try_add_menu("&Edit"));
    TRY(edit_menu->try_add_action(*m_undo_action));
    TRY(edit_menu->try_add_action(*m_redo_action));
    TRY(edit_menu->try_add_separator());
    TRY(edit_menu->try_add_action(*m_cut_action));
    TRY(edit_menu->try_add_action(*m_copy_action));
    TRY(edit_menu->try_add_action(*m_paste_action));
    TRY(edit_menu->try_add_action(*m_delete_action));
    TRY(edit_menu->try_add_separator());
    TRY(edit_menu->try_add_action(*m_select_all_action));
    TRY(edit_menu->try_add_separator());
    TRY(edit_menu->try_add_action(*m_copy_text_action));

    m_context_menu = edit_menu;

    auto go_menu = TRY(window.try_add_menu("&Go"));
    TRY(go_menu->try_add_action(*m_previous_glyph_action));
    TRY(go_menu->try_add_action(*m_next_glyph_action));
    TRY(go_menu->try_add_action(*m_go_to_glyph_action));

    auto view_menu = TRY(window.try_add_menu("&View"));
    TRY(view_menu->try_add_action(*m_open_preview_action));
    TRY(view_menu->try_add_separator());
    TRY(view_menu->try_add_action(*m_show_metadata_action));
    TRY(view_menu->try_add_action(*m_show_unicode_blocks_action));
    TRY(view_menu->try_add_separator());
    TRY(view_menu->try_add_action(*m_highlight_modifications_action));
    TRY(view_menu->try_add_separator());
    auto scale_menu = TRY(view_menu->try_add_submenu("&Scale"));
    TRY(scale_menu->try_add_action(*m_scale_five_action));
    TRY(scale_menu->try_add_action(*m_scale_ten_action));
    TRY(scale_menu->try_add_action(*m_scale_fifteen_action));

    auto help_menu = TRY(window.try_add_menu("&Help"));
    TRY(help_menu->try_add_action(GUI::CommonActions::make_help_action([](auto&) {
        Desktop::Launcher::open(URL::create_with_file_protocol("/usr/share/man/man1/FontEditor.md"), "/bin/Help");
    })));
    TRY(help_menu->try_add_action(GUI::CommonActions::make_about_action("Font Editor", TRY(GUI::Icon::try_create_default_icon("app-font-editor"sv)), &window)));

    return {};
}

ErrorOr<void> MainWidget::save_file(String const& path)
{
    auto masked_font = TRY(m_edited_font->masked_character_set());
    TRY(masked_font->write_to_file(path));
    m_path = path;
    m_undo_stack->set_current_unmodified();
    window()->set_modified(false);
    update_title();
    return {};
}

void MainWidget::set_show_font_metadata(bool show)
{
    if (m_font_metadata == show)
        return;
    m_font_metadata = show;
    m_font_metadata_groupbox->set_visible(m_font_metadata);
}

void MainWidget::set_show_unicode_blocks(bool show)
{
    if (m_unicode_blocks == show)
        return;
    m_unicode_blocks = show;
    m_unicode_block_container->set_visible(m_unicode_blocks);
}

void MainWidget::set_highlight_modifications(bool highlight_modifications)
{
    m_glyph_map_widget->set_highlight_modifications(highlight_modifications);
}

ErrorOr<void> MainWidget::open_file(String const& path)
{
    auto unmasked_font = TRY(TRY(Gfx::BitmapFont::try_load_from_file(path))->unmasked_character_set());
    TRY(initialize(path, move(unmasked_font)));
    return {};
}

void MainWidget::push_undo()
{
    auto maybe_state = m_undo_selection->save_state();
    if (maybe_state.is_error())
        return show_error("Failed to save undo state"sv, maybe_state.error());
    auto maybe_command = try_make<SelectionUndoCommand>(*m_undo_selection, move(maybe_state.value()));
    if (maybe_command.is_error())
        return show_error("Failed to make undo command"sv, maybe_command.error());
    if (auto maybe_push = m_undo_stack->try_push(move(maybe_command.value())); maybe_push.is_error())
        show_error("Failed to push undo stack"sv, maybe_push.error());
}

void MainWidget::reset_selection_and_push_undo()
{
    auto selection = m_glyph_map_widget->selection().normalized();
    if (selection.size() != 1) {
        auto start = m_glyph_map_widget->active_glyph();
        m_undo_selection->set_start(start);
        m_undo_selection->set_size(1);
        m_glyph_map_widget->set_selection(start, 1);
        m_glyph_map_widget->update();
    }
    push_undo();
}

void MainWidget::undo()
{
    if (!m_undo_stack->can_undo())
        return;
    m_undo_stack->undo();

    auto glyph = m_undo_selection->restored_active_glyph();
    auto glyph_width = edited_font().raw_glyph_width(glyph);
    if (glyph < m_range.first || glyph > m_range.last)
        m_search_textbox->set_text(""sv);

    deferred_invoke([this, glyph] {
        auto start = m_undo_selection->restored_start();
        auto size = m_undo_selection->restored_size();
        m_glyph_map_widget->set_selection(start, size, glyph);
        m_glyph_map_widget->scroll_to_glyph(glyph);
        m_glyph_map_widget->set_focus(true);
    });

    if (m_edited_font->is_fixed_width()) {
        m_glyph_editor_present_checkbox->set_checked(glyph_width > 0, GUI::AllowCallback::No);
    } else {
        m_glyph_editor_width_spinbox->set_value(glyph_width, GUI::AllowCallback::No);
    }
    m_glyph_editor_widget->update();
    m_glyph_map_widget->update();
    update_preview();
    update_statusbar();
}

void MainWidget::redo()
{
    if (!m_undo_stack->can_redo())
        return;
    m_undo_stack->redo();

    auto glyph = m_undo_selection->restored_active_glyph();
    auto glyph_width = edited_font().raw_glyph_width(glyph);
    if (glyph < m_range.first || glyph > m_range.last)
        m_search_textbox->set_text(""sv);

    deferred_invoke([this, glyph] {
        auto start = m_undo_selection->restored_start();
        auto size = m_undo_selection->restored_size();
        m_glyph_map_widget->set_selection(start, size, glyph);
        m_glyph_map_widget->scroll_to_glyph(glyph);
        m_glyph_map_widget->set_focus(true);
    });

    if (m_edited_font->is_fixed_width()) {
        m_glyph_editor_present_checkbox->set_checked(glyph_width > 0, GUI::AllowCallback::No);
    } else {
        m_glyph_editor_width_spinbox->set_value(glyph_width, GUI::AllowCallback::No);
    }
    m_glyph_editor_widget->update();
    m_glyph_map_widget->update();
    update_preview();
    update_statusbar();
}

bool MainWidget::request_close()
{
    if (!window()->is_modified())
        return true;
    auto result = GUI::MessageBox::ask_about_unsaved_changes(window(), m_path, m_undo_stack->last_unmodified_timestamp());
    if (result == GUI::MessageBox::ExecResult::Yes) {
        m_save_action->activate();
        if (!window()->is_modified())
            return true;
    }
    if (result == GUI::MessageBox::ExecResult::No)
        return true;
    return false;
}

void MainWidget::update_title()
{
    StringBuilder title;
    if (m_path.is_empty())
        title.append("Untitled"sv);
    else
        title.append(m_path);
    title.append("[*] - Font Editor"sv);
    window()->set_title(title.to_string());
}

void MainWidget::did_modify_font()
{
    if (!window() || window()->is_modified())
        return;
    window()->set_modified(true);
    update_title();
}

void MainWidget::update_statusbar()
{
    auto glyph = m_glyph_map_widget->active_glyph();
    StringBuilder builder;
    builder.appendff("U+{:04X} (", glyph);

    if (auto abbreviation = Unicode::code_point_abbreviation(glyph); abbreviation.has_value()) {
        builder.append(*abbreviation);
    } else if (Gfx::get_char_bidi_class(glyph) == Gfx::BidirectionalClass::STRONG_RTL) {
        // FIXME: This is a necessary hack, as RTL text will mess up the painting of the statusbar text.
        // For now, replace RTL glyphs with U+FFFD, the replacement character.
        builder.append_code_point(0xFFFD);
    } else {
        builder.append_code_point(glyph);
    }

    builder.append(')');

    auto glyph_name = Unicode::code_point_display_name(glyph);
    if (glyph_name.has_value()) {
        builder.appendff(" {}", glyph_name.value());
    }

    if (m_edited_font->contains_raw_glyph(glyph))
        builder.appendff(" [{}x{}]", m_edited_font->raw_glyph_width(glyph), m_edited_font->glyph_height());
    else if (Gfx::Emoji::emoji_for_code_point(glyph))
        builder.appendff(" [emoji]");
    m_statusbar->set_text(builder.to_string());
}

void MainWidget::update_preview()
{
    if (m_font_preview_window)
        m_font_preview_window->update();
}

void MainWidget::drop_event(GUI::DropEvent& event)
{
    event.accept();

    if (event.mime_data().has_urls()) {
        auto urls = event.mime_data().urls();
        if (urls.is_empty())
            return;

        window()->move_to_front();
        if (!request_close())
            return;

        if (auto result = open_file(urls.first().path()); result.is_error())
            show_error("Failed to load font"sv, result.error());
    }
}

void MainWidget::set_scale(i32 scale)
{
    m_glyph_editor_widget->set_scale(scale);
}

void MainWidget::set_scale_and_save(i32 scale)
{
    set_scale(scale);
    Config::write_i32("FontEditor"sv, "GlyphEditor"sv, "Scale"sv, scale);
    m_glyph_editor_widget->set_fixed_size(m_glyph_editor_widget->preferred_width(), m_glyph_editor_widget->preferred_height());
}

ErrorOr<void> MainWidget::copy_selected_glyphs()
{
    size_t bytes_per_glyph = Gfx::GlyphBitmap::bytes_per_row() * edited_font().glyph_height();
    auto selection = m_glyph_map_widget->selection().normalized();
    auto* rows = m_edited_font->rows() + selection.start() * bytes_per_glyph;
    auto* widths = m_edited_font->widths() + selection.start();

    ByteBuffer buffer;
    TRY(buffer.try_append(rows, bytes_per_glyph * selection.size()));
    TRY(buffer.try_append(widths, selection.size()));

    HashMap<String, String> metadata;
    metadata.set("start", String::number(selection.start()));
    metadata.set("count", String::number(selection.size()));
    metadata.set("width", String::number(edited_font().max_glyph_width()));
    metadata.set("height", String::number(edited_font().glyph_height()));
    GUI::Clipboard::the().set_data(buffer.bytes(), "glyph/x-fonteditor", metadata);

    return {};
}

ErrorOr<void> MainWidget::cut_selected_glyphs()
{
    TRY(copy_selected_glyphs());
    delete_selected_glyphs();
    return {};
}

void MainWidget::paste_glyphs()
{
    auto [data, mime_type, metadata] = GUI::Clipboard::the().fetch_data_and_type();
    if (!mime_type.starts_with("glyph/"sv))
        return;

    auto glyph_count = metadata.get("count").value().to_uint().value_or(0);
    if (!glyph_count)
        return;

    auto height = metadata.get("height").value().to_uint().value_or(0);
    if (!height)
        return;

    auto selection = m_glyph_map_widget->selection().normalized();
    auto range_bound_glyph_count = min(glyph_count, 1 + m_range.last - selection.start());
    m_undo_selection->set_size(range_bound_glyph_count);
    push_undo();

    size_t bytes_per_glyph = Gfx::GlyphBitmap::bytes_per_row() * edited_font().glyph_height();
    size_t bytes_per_copied_glyph = Gfx::GlyphBitmap::bytes_per_row() * height;
    size_t copyable_bytes_per_glyph = min(bytes_per_glyph, bytes_per_copied_glyph);
    auto* rows = m_edited_font->rows() + selection.start() * bytes_per_glyph;
    auto* widths = m_edited_font->widths() + selection.start();

    for (size_t i = 0; i < range_bound_glyph_count; ++i) {
        auto copyable_width = edited_font().is_fixed_width()
            ? data[bytes_per_copied_glyph * glyph_count + i] ? edited_font().glyph_fixed_width() : 0
            : min(edited_font().max_glyph_width(), data[bytes_per_copied_glyph * glyph_count + i]);
        memcpy(&rows[i * bytes_per_glyph], &data[i * bytes_per_copied_glyph], copyable_bytes_per_glyph);
        memset(&widths[i], copyable_width, sizeof(u8));
        m_glyph_map_widget->set_glyph_modified(selection.start() + i, true);
    }

    m_glyph_map_widget->set_selection(selection.start() + range_bound_glyph_count - 1, -range_bound_glyph_count + 1);

    if (m_edited_font->is_fixed_width())
        m_glyph_editor_present_checkbox->set_checked(m_edited_font->contains_raw_glyph(m_glyph_map_widget->active_glyph()), GUI::AllowCallback::No);
    else
        m_glyph_editor_width_spinbox->set_value(m_edited_font->raw_glyph_width(m_glyph_map_widget->active_glyph()), GUI::AllowCallback::No);

    m_glyph_editor_widget->update();
    m_glyph_map_widget->update();
    update_statusbar();
}

void MainWidget::delete_selected_glyphs()
{
    push_undo();

    auto selection = m_glyph_map_widget->selection().normalized();
    size_t bytes_per_glyph = Gfx::GlyphBitmap::bytes_per_row() * m_edited_font->glyph_height();
    auto* rows = m_edited_font->rows() + selection.start() * bytes_per_glyph;
    auto* widths = m_edited_font->widths() + selection.start();
    memset(rows, 0, bytes_per_glyph * selection.size());
    memset(widths, 0, selection.size());

    if (m_edited_font->is_fixed_width())
        m_glyph_editor_present_checkbox->set_checked(false, GUI::AllowCallback::No);
    else
        m_glyph_editor_width_spinbox->set_value(0, GUI::AllowCallback::No);

    m_glyph_editor_widget->update();
    m_glyph_map_widget->update();
    update_statusbar();
}

void MainWidget::show_error(StringView preface, Error error)
{
    auto formatted_error = String::formatted("{}: {}", preface, error);
    GUI::MessageBox::show_error(window(), formatted_error);
    warnln(formatted_error);
}

}