Applications: Move to Userland/Applications/

Userland/Applications/TextEditor/CMakeLists.txt

@@ -0,0 +1,10 @@
+compile_gml(TextEditorWindow.gml TextEditorWindowGML.h text_editor_window_gml)
+
+set(SOURCES
+    main.cpp
+    TextEditorWidget.cpp
+    TextEditorWindowGML.h
+)
+
+serenity_app(TextEditor ICON app-text-editor)
+target_link_libraries(TextEditor LibWeb LibMarkdown LibGUI LibShell LibRegex LibDesktop)

Userland/Applications/TextEditor/TextEditorWidget.cpp

@@ -0,0 +1,667 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "TextEditorWidget.h"
+#include <AK/JsonObject.h>
+#include <AK/JsonValue.h>
+#include <AK/Optional.h>
+#include <AK/StringBuilder.h>
+#include <AK/URL.h>
+#include <Applications/TextEditor/TextEditorWindowGML.h>
+#include <LibCore/File.h>
+#include <LibCore/MimeData.h>
+#include <LibDesktop/Launcher.h>
+#include <LibGUI/Action.h>
+#include <LibGUI/ActionGroup.h>
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/CppSyntaxHighlighter.h>
+#include <LibGUI/FilePicker.h>
+#include <LibGUI/FontPicker.h>
+#include <LibGUI/GMLSyntaxHighlighter.h>
+#include <LibGUI/INISyntaxHighlighter.h>
+#include <LibGUI/JSSyntaxHighlighter.h>
+#include <LibGUI/Menu.h>
+#include <LibGUI/MenuBar.h>
+#include <LibGUI/MessageBox.h>
+#include <LibGUI/RegularEditingEngine.h>
+#include <LibGUI/ShellSyntaxHighlighter.h>
+#include <LibGUI/Splitter.h>
+#include <LibGUI/StatusBar.h>
+#include <LibGUI/TextBox.h>
+#include <LibGUI/TextEditor.h>
+#include <LibGUI/ToolBar.h>
+#include <LibGUI/ToolBarContainer.h>
+#include <LibGUI/VimEditingEngine.h>
+#include <LibGfx/Font.h>
+#include <LibMarkdown/Document.h>
+#include <LibWeb/OutOfProcessWebView.h>
+#include <string.h>
+
+TextEditorWidget::TextEditorWidget()
+{
+    load_from_gml(text_editor_window_gml);
+
+    auto& toolbar = *find_descendant_of_type_named<GUI::ToolBar>("toolbar");
+
+    m_editor = *find_descendant_of_type_named<GUI::TextEditor>("editor");
+    m_editor->set_ruler_visible(true);
+    m_editor->set_automatic_indentation_enabled(true);
+    m_editor->set_line_wrapping_enabled(true);
+    m_editor->set_editing_engine(make<GUI::RegularEditingEngine>());
+
+    m_editor->on_change = [this] {
+        update_preview();
+
+        // Do not mark as dirty on the first change (When document is first opened.)
+        if (m_document_opening) {
+            m_document_opening = false;
+            return;
+        }
+
+        bool was_dirty = m_document_dirty;
+        m_document_dirty = true;
+        if (!was_dirty)
+            update_title();
+    };
+
+    m_page_view = *find_descendant_of_type_named<Web::OutOfProcessWebView>("webview");
+    m_page_view->on_link_hover = [this](auto& url) {
+        if (url.is_valid())
+            m_statusbar->set_text(url.to_string());
+        else
+            update_statusbar_cursor_position();
+    };
+    m_page_view->on_link_click = [&](auto& url, auto&, unsigned) {
+        if (!Desktop::Launcher::open(url)) {
+            GUI::MessageBox::show(
+                window(),
+                String::formatted("The link to '{}' could not be opened.", url),
+                "Failed to open link",
+                GUI::MessageBox::Type::Error);
+        }
+    };
+
+    m_find_replace_widget = *find_descendant_of_type_named<GUI::Widget>("find_replace_widget");
+
+    m_find_widget = *find_descendant_of_type_named<GUI::Widget>("find_widget");
+
+    m_replace_widget = *find_descendant_of_type_named<GUI::Widget>("replace_widget");
+
+    m_find_textbox = m_find_widget->add<GUI::TextBox>();
+    m_replace_textbox = m_replace_widget->add<GUI::TextBox>();
+
+    m_find_next_action = GUI::Action::create("Find next", { Mod_Ctrl, Key_G }, Gfx::Bitmap::load_from_file("/res/icons/16x16/find-next.png"), [&](auto&) {
+        auto needle = m_find_textbox->text();
+        if (needle.is_empty()) {
+            dbgln("find_next(\"\")");
+            return;
+        }
+
+        if (m_find_use_regex)
+            m_editor->document().update_regex_matches(needle);
+
+        auto found_range = m_editor->document().find_next(needle, m_editor->normalized_selection().end(), GUI::TextDocument::SearchShouldWrap::Yes, m_find_use_regex);
+        dbgln("find_next('{}') returned {}", needle, found_range);
+        if (found_range.is_valid()) {
+            m_editor->set_selection(found_range);
+        } else {
+            GUI::MessageBox::show(window(),
+                String::formatted("Not found: \"{}\"", needle),
+                "Not found",
+                GUI::MessageBox::Type::Information);
+        }
+    });
+
+    m_find_regex_action = GUI::Action::create("Find regex", { Mod_Ctrl | Mod_Shift, Key_R }, [&](auto&) {
+        m_find_regex_button->set_checked(!m_find_regex_button->is_checked());
+        m_find_use_regex = m_find_regex_button->is_checked();
+    });
+
+    m_find_previous_action = GUI::Action::create("Find previous", { Mod_Ctrl | Mod_Shift, Key_G }, [&](auto&) {
+        auto needle = m_find_textbox->text();
+        if (needle.is_empty()) {
+            dbgln("find_prev(\"\")");
+            return;
+        }
+
+        auto selection_start = m_editor->normalized_selection().start();
+        if (!selection_start.is_valid())
+            selection_start = m_editor->normalized_selection().end();
+
+        if (m_find_use_regex)
+            m_editor->document().update_regex_matches(needle);
+
+        auto found_range = m_editor->document().find_previous(needle, selection_start, GUI::TextDocument::SearchShouldWrap::Yes, m_find_use_regex);
+
+        dbgln("find_prev(\"{}\") returned {}", needle, found_range);
+        if (found_range.is_valid()) {
+            m_editor->set_selection(found_range);
+        } else {
+            GUI::MessageBox::show(window(),
+                String::formatted("Not found: \"{}\"", needle),
+                "Not found",
+                GUI::MessageBox::Type::Information);
+        }
+    });
+
+    m_replace_next_action = GUI::Action::create("Replace next", { Mod_Ctrl, Key_F1 }, [&](auto&) {
+        auto needle = m_find_textbox->text();
+        auto substitute = m_replace_textbox->text();
+
+        if (needle.is_empty())
+            return;
+
+        auto selection_start = m_editor->normalized_selection().start();
+        if (!selection_start.is_valid())
+            selection_start = m_editor->normalized_selection().start();
+
+        if (m_find_use_regex)
+            m_editor->document().update_regex_matches(needle);
+
+        auto found_range = m_editor->document().find_next(needle, selection_start, GUI::TextDocument::SearchShouldWrap::Yes, m_find_use_regex);
+
+        if (found_range.is_valid()) {
+            m_editor->set_selection(found_range);
+            m_editor->insert_at_cursor_or_replace_selection(substitute);
+        } else {
+            GUI::MessageBox::show(window(),
+                String::formatted("Not found: \"{}\"", needle),
+                "Not found",
+                GUI::MessageBox::Type::Information);
+        }
+    });
+
+    m_replace_previous_action = GUI::Action::create("Replace previous", { Mod_Ctrl | Mod_Shift, Key_F1 }, [&](auto&) {
+        auto needle = m_find_textbox->text();
+        auto substitute = m_replace_textbox->text();
+        if (needle.is_empty())
+            return;
+
+        auto selection_start = m_editor->normalized_selection().start();
+        if (!selection_start.is_valid())
+            selection_start = m_editor->normalized_selection().start();
+
+        if (m_find_use_regex)
+            m_editor->document().update_regex_matches(needle);
+
+        auto found_range = m_editor->document().find_previous(needle, selection_start);
+
+        if (found_range.is_valid()) {
+            m_editor->set_selection(found_range);
+            m_editor->insert_at_cursor_or_replace_selection(substitute);
+        } else {
+            GUI::MessageBox::show(window(),
+                String::formatted("Not found: \"{}\"", needle),
+                "Not found",
+                GUI::MessageBox::Type::Information);
+        }
+    });
+
+    m_replace_all_action = GUI::Action::create("Replace all", { Mod_Ctrl, Key_F2 }, [&](auto&) {
+        auto needle = m_find_textbox->text();
+        auto substitute = m_replace_textbox->text();
+        if (needle.is_empty())
+            return;
+        if (m_find_use_regex)
+            m_editor->document().update_regex_matches(needle);
+
+        auto found_range = m_editor->document().find_next(needle, {}, GUI::TextDocument::SearchShouldWrap::Yes, m_find_use_regex);
+        while (found_range.is_valid()) {
+            m_editor->set_selection(found_range);
+            m_editor->insert_at_cursor_or_replace_selection(substitute);
+            found_range = m_editor->document().find_next(needle, {}, GUI::TextDocument::SearchShouldWrap::Yes, m_find_use_regex);
+        }
+    });
+
+    m_find_previous_button = *find_descendant_of_type_named<GUI::Button>("find_previous_button");
+    m_find_previous_button->set_action(*m_find_previous_action);
+
+    m_find_next_button = *find_descendant_of_type_named<GUI::Button>("find_next_button");
+    m_find_next_button->set_action(*m_find_next_action);
+
+    m_find_textbox->on_return_pressed = [this] {
+        m_find_next_button->click();
+    };
+
+    m_find_regex_button = m_find_widget->add<GUI::Button>(".*");
+    m_find_regex_button->set_fixed_width(20);
+    m_find_regex_button->set_action(*m_find_regex_action);
+
+    m_find_textbox->on_escape_pressed = [this] {
+        m_find_replace_widget->set_visible(false);
+        m_editor->set_focus(true);
+    };
+
+    m_replace_previous_button = *find_descendant_of_type_named<GUI::Button>("replace_previous_button");
+    m_replace_previous_button->set_action(*m_replace_previous_action);
+
+    m_replace_next_button = *find_descendant_of_type_named<GUI::Button>("replace_next_button");
+    m_replace_next_button->set_action(*m_replace_next_action);
+
+    m_replace_all_button = *find_descendant_of_type_named<GUI::Button>("replace_all_button");
+    m_replace_all_button->set_action(*m_replace_all_action);
+
+    m_replace_textbox->on_return_pressed = [this] {
+        m_replace_next_button->click();
+    };
+
+    m_replace_textbox->on_escape_pressed = [this] {
+        m_find_replace_widget->set_visible(false);
+        m_editor->set_focus(true);
+    };
+
+    m_vim_emulation_setting_action = GUI::Action::create_checkable("Vim emulation", { Mod_Ctrl | Mod_Shift | Mod_Alt, Key_V }, [&](auto& action) {
+        if (action.is_checked())
+            m_editor->set_editing_engine(make<GUI::VimEditingEngine>());
+        else
+            m_editor->set_editing_engine(make<GUI::RegularEditingEngine>());
+    });
+    m_vim_emulation_setting_action->set_checked(false);
+
+    m_find_replace_action = GUI::Action::create("Find/Replace...", { Mod_Ctrl, Key_F }, Gfx::Bitmap::load_from_file("/res/icons/16x16/find.png"), [this](auto&) {
+        m_find_replace_widget->set_visible(true);
+        m_find_widget->set_visible(true);
+        m_replace_widget->set_visible(true);
+        m_find_textbox->set_focus(true);
+
+        if (m_editor->has_selection()) {
+            auto selected_text = m_editor->document().text_in_range(m_editor->normalized_selection());
+            m_find_textbox->set_text(selected_text);
+        }
+        m_find_textbox->select_all();
+    });
+
+    m_editor->add_custom_context_menu_action(*m_find_replace_action);
+    m_editor->add_custom_context_menu_action(*m_find_next_action);
+    m_editor->add_custom_context_menu_action(*m_find_previous_action);
+
+    m_statusbar = *find_descendant_of_type_named<GUI::StatusBar>("statusbar");
+
+    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&) {
+        if (m_document_dirty) {
+            auto save_document_first_result = GUI::MessageBox::show(window(), "Save changes to current document first?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
+            if (save_document_first_result == GUI::Dialog::ExecResult::ExecYes)
+                m_save_action->activate();
+            if (save_document_first_result == GUI::Dialog::ExecResult::ExecCancel)
+                return;
+        }
+
+        m_document_dirty = false;
+        m_editor->set_text(StringView());
+        set_path(LexicalPath());
+        update_title();
+    });
+
+    m_open_action = GUI::CommonActions::make_open_action([this](auto&) {
+        Optional<String> open_path = GUI::FilePicker::get_open_filepath(window());
+
+        if (!open_path.has_value())
+            return;
+
+        if (m_document_dirty) {
+            auto save_document_first_result = GUI::MessageBox::show(window(), "Save changes to current document first?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
+            if (save_document_first_result == GUI::Dialog::ExecResult::ExecYes)
+                m_save_action->activate();
+            if (save_document_first_result == GUI::Dialog::ExecResult::ExecCancel)
+                return;
+        }
+
+        open_sesame(open_path.value());
+    });
+
+    m_save_as_action = GUI::CommonActions::make_save_as_action([&](auto&) {
+        Optional<String> save_path = GUI::FilePicker::get_save_filepath(window(), m_name.is_null() ? "Untitled" : m_name, m_extension.is_null() ? "txt" : m_extension);
+        if (!save_path.has_value())
+            return;
+
+        if (!m_editor->write_to_file(save_path.value())) {
+            GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
+            return;
+        }
+
+        m_document_dirty = false;
+        set_path(LexicalPath(save_path.value()));
+        dbgln("Wrote document to {}", save_path.value());
+    });
+
+    m_save_action = GUI::CommonActions::make_save_action([&](auto&) {
+        if (!m_path.is_empty()) {
+            if (!m_editor->write_to_file(m_path)) {
+                GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
+            } else {
+                m_document_dirty = false;
+                update_title();
+            }
+            return;
+        }
+
+        m_save_as_action->activate();
+    });
+
+    m_line_wrapping_setting_action = GUI::Action::create_checkable("Line wrapping", [&](auto& action) {
+        m_editor->set_line_wrapping_enabled(action.is_checked());
+    });
+    m_line_wrapping_setting_action->set_checked(m_editor->is_line_wrapping_enabled());
+
+    auto menubar = GUI::MenuBar::construct();
+    auto& app_menu = menubar->add_menu("Text Editor");
+    app_menu.add_action(*m_new_action);
+    app_menu.add_action(*m_open_action);
+    app_menu.add_action(*m_save_action);
+    app_menu.add_action(*m_save_as_action);
+    app_menu.add_separator();
+    app_menu.add_action(GUI::CommonActions::make_quit_action([this](auto&) {
+        if (!request_close())
+            return;
+        GUI::Application::the()->quit();
+    }));
+
+    auto& edit_menu = menubar->add_menu("Edit");
+    edit_menu.add_action(m_editor->undo_action());
+    edit_menu.add_action(m_editor->redo_action());
+    edit_menu.add_separator();
+    edit_menu.add_action(m_editor->cut_action());
+    edit_menu.add_action(m_editor->copy_action());
+    edit_menu.add_action(m_editor->paste_action());
+    edit_menu.add_action(m_editor->delete_action());
+    edit_menu.add_separator();
+    edit_menu.add_action(*m_vim_emulation_setting_action);
+    edit_menu.add_separator();
+    edit_menu.add_action(*m_find_replace_action);
+    edit_menu.add_action(*m_find_next_action);
+    edit_menu.add_action(*m_find_regex_action);
+    edit_menu.add_action(*m_find_previous_action);
+    edit_menu.add_action(*m_replace_next_action);
+    edit_menu.add_action(*m_replace_previous_action);
+    edit_menu.add_action(*m_replace_all_action);
+
+    m_no_preview_action = GUI::Action::create_checkable(
+        "No preview", [this](auto&) {
+            set_preview_mode(PreviewMode::None);
+        });
+
+    m_markdown_preview_action = GUI::Action::create_checkable(
+        "Markdown preview", [this](auto&) {
+            set_preview_mode(PreviewMode::Markdown);
+        },
+        this);
+
+    m_html_preview_action = GUI::Action::create_checkable(
+        "HTML preview", [this](auto&) {
+            set_preview_mode(PreviewMode::HTML);
+        },
+        this);
+
+    m_preview_actions.add_action(*m_no_preview_action);
+    m_preview_actions.add_action(*m_markdown_preview_action);
+    m_preview_actions.add_action(*m_html_preview_action);
+    m_preview_actions.set_exclusive(true);
+
+    auto& view_menu = menubar->add_menu("View");
+    view_menu.add_action(GUI::Action::create("Editor font...", Gfx::Bitmap::load_from_file("/res/icons/16x16/app-font-editor.png"),
+        [&](auto&) {
+            auto picker = GUI::FontPicker::construct(window(), &m_editor->font(), true);
+            if (picker->exec() == GUI::Dialog::ExecOK) {
+                dbgln("setting font {}", picker->font()->qualified_name());
+                m_editor->set_font(picker->font());
+            }
+        }));
+
+    view_menu.add_separator();
+    view_menu.add_action(*m_line_wrapping_setting_action);
+    view_menu.add_separator();
+    view_menu.add_action(*m_no_preview_action);
+    view_menu.add_action(*m_markdown_preview_action);
+    view_menu.add_action(*m_html_preview_action);
+    view_menu.add_separator();
+
+    syntax_actions.set_exclusive(true);
+
+    auto& syntax_menu = view_menu.add_submenu("Syntax");
+    m_plain_text_highlight = GUI::Action::create_checkable("Plain text", [&](auto&) {
+        m_editor->set_syntax_highlighter({});
+        m_editor->update();
+    });
+    m_plain_text_highlight->set_checked(true);
+    syntax_actions.add_action(*m_plain_text_highlight);
+    syntax_menu.add_action(*m_plain_text_highlight);
+
+    m_cpp_highlight = GUI::Action::create_checkable("C++", [&](auto&) {
+        m_editor->set_syntax_highlighter(make<GUI::CppSyntaxHighlighter>());
+        m_editor->update();
+    });
+    syntax_actions.add_action(*m_cpp_highlight);
+    syntax_menu.add_action(*m_cpp_highlight);
+
+    m_js_highlight = GUI::Action::create_checkable("JavaScript", [&](auto&) {
+        m_editor->set_syntax_highlighter(make<GUI::JSSyntaxHighlighter>());
+        m_editor->update();
+    });
+    syntax_actions.add_action(*m_js_highlight);
+    syntax_menu.add_action(*m_js_highlight);
+
+    m_gml_highlight = GUI::Action::create_checkable("GML", [&](auto&) {
+        m_editor->set_syntax_highlighter(make<GUI::GMLSyntaxHighlighter>());
+        m_editor->update();
+    });
+    syntax_actions.add_action(*m_gml_highlight);
+    syntax_menu.add_action(*m_gml_highlight);
+
+    m_ini_highlight = GUI::Action::create_checkable("INI File", [&](auto&) {
+        m_editor->set_syntax_highlighter(make<GUI::IniSyntaxHighlighter>());
+        m_editor->update();
+    });
+    syntax_actions.add_action(*m_ini_highlight);
+    syntax_menu.add_action(*m_ini_highlight);
+
+    m_shell_highlight = GUI::Action::create_checkable("Shell File", [&](auto&) {
+        m_editor->set_syntax_highlighter(make<GUI::ShellSyntaxHighlighter>());
+        m_editor->update();
+    });
+    syntax_actions.add_action(*m_shell_highlight);
+    syntax_menu.add_action(*m_shell_highlight);
+
+    auto& help_menu = menubar->add_menu("Help");
+    help_menu.add_action(GUI::CommonActions::make_about_action("Text Editor", GUI::Icon::default_icon("app-text-editor"), window()));
+
+    GUI::Application::the()->set_menubar(move(menubar));
+
+    toolbar.add_action(*m_new_action);
+    toolbar.add_action(*m_open_action);
+    toolbar.add_action(*m_save_action);
+
+    toolbar.add_separator();
+
+    toolbar.add_action(m_editor->cut_action());
+    toolbar.add_action(m_editor->copy_action());
+    toolbar.add_action(m_editor->paste_action());
+    toolbar.add_action(m_editor->delete_action());
+
+    toolbar.add_separator();
+
+    toolbar.add_action(m_editor->undo_action());
+    toolbar.add_action(m_editor->redo_action());
+}
+
+TextEditorWidget::~TextEditorWidget()
+{
+}
+
+void TextEditorWidget::set_path(const LexicalPath& lexical_path)
+{
+    m_path = lexical_path.string();
+    m_name = lexical_path.title();
+    m_extension = lexical_path.extension();
+
+    if (m_extension == "c" || m_extension == "cc" || m_extension == "cxx" || m_extension == "cpp" || m_extension == "h") {
+        m_cpp_highlight->activate();
+    } else if (m_extension == "js" || m_extension == "json") {
+        m_js_highlight->activate();
+    } else if (m_extension == "gml") {
+        m_gml_highlight->activate();
+    } else if (m_extension == "ini") {
+        m_ini_highlight->activate();
+    } else {
+        m_plain_text_highlight->activate();
+    }
+
+    if (m_auto_detect_preview_mode) {
+        if (m_extension == "md")
+            set_preview_mode(PreviewMode::Markdown);
+        else if (m_extension == "html")
+            set_preview_mode(PreviewMode::HTML);
+        else
+            set_preview_mode(PreviewMode::None);
+    }
+
+    update_title();
+}
+
+void TextEditorWidget::update_title()
+{
+    StringBuilder builder;
+    if (m_path.is_empty())
+        builder.append("Untitled");
+    else
+        builder.append(m_path);
+    if (m_document_dirty)
+        builder.append(" (*)");
+    builder.append(" - Text Editor");
+    window()->set_title(builder.to_string());
+}
+
+void TextEditorWidget::open_sesame(const String& path)
+{
+    auto file = Core::File::construct(path);
+    if (!file->open(Core::IODevice::ReadOnly) && file->error() != ENOENT) {
+        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: {}", path, strerror(errno)), "Error", GUI::MessageBox::Type::Error);
+        return;
+    }
+
+    m_editor->set_text(file->read_all());
+    m_document_dirty = false;
+    m_document_opening = true;
+
+    set_path(LexicalPath(path));
+
+    m_editor->set_focus(true);
+}
+
+bool TextEditorWidget::request_close()
+{
+    if (!m_document_dirty)
+        return true;
+    auto result = GUI::MessageBox::show(window(), "The document has been modified. Would you like to save?", "Unsaved changes", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
+
+    if (result == GUI::MessageBox::ExecYes) {
+        m_save_action->activate();
+        return true;
+    }
+
+    if (result == GUI::MessageBox::ExecNo)
+        return true;
+
+    return false;
+}
+
+void TextEditorWidget::drop_event(GUI::DropEvent& event)
+{
+    event.accept();
+    window()->move_to_front();
+
+    if (event.mime_data().has_urls()) {
+        auto urls = event.mime_data().urls();
+        if (urls.is_empty())
+            return;
+        if (urls.size() > 1) {
+            GUI::MessageBox::show(window(), "TextEditor can only open one file at a time!", "One at a time please!", GUI::MessageBox::Type::Error);
+            return;
+        }
+        open_sesame(urls.first().path());
+    }
+}
+
+void TextEditorWidget::set_preview_mode(PreviewMode mode)
+{
+    if (m_preview_mode == mode)
+        return;
+    m_preview_mode = mode;
+
+    if (m_preview_mode == PreviewMode::HTML) {
+        m_html_preview_action->set_checked(true);
+        m_page_view->set_visible(true);
+        update_html_preview();
+    } else if (m_preview_mode == PreviewMode::Markdown) {
+        m_markdown_preview_action->set_checked(true);
+        m_page_view->set_visible(true);
+        update_markdown_preview();
+    } else {
+        m_no_preview_action->set_checked(true);
+        m_page_view->set_visible(false);
+    }
+}
+
+void TextEditorWidget::update_preview()
+{
+    switch (m_preview_mode) {
+    case PreviewMode::Markdown:
+        update_markdown_preview();
+        break;
+    case PreviewMode::HTML:
+        update_html_preview();
+        break;
+    default:
+        break;
+    }
+}
+
+void TextEditorWidget::update_markdown_preview()
+{
+    auto document = Markdown::Document::parse(m_editor->text());
+    if (document) {
+        auto html = document->render_to_html();
+        auto current_scroll_pos = m_page_view->visible_content_rect();
+        m_page_view->load_html(html, URL::create_with_file_protocol(m_path));
+        m_page_view->scroll_into_view(current_scroll_pos, true, true);
+    }
+}
+
+void TextEditorWidget::update_html_preview()
+{
+    auto current_scroll_pos = m_page_view->visible_content_rect();
+    m_page_view->load_html(m_editor->text(), URL::create_with_file_protocol(m_path));
+    m_page_view->scroll_into_view(current_scroll_pos, true, true);
+}
+
+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());
+}

Userland/Applications/TextEditor/TextEditorWidget.h

@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Function.h>
+#include <AK/LexicalPath.h>
+#include <LibGUI/ActionGroup.h>
+#include <LibGUI/Application.h>
+#include <LibGUI/Icon.h>
+#include <LibGUI/TextEditor.h>
+#include <LibGUI/Widget.h>
+#include <LibGUI/Window.h>
+#include <LibWeb/Forward.h>
+
+class TextEditorWidget final : public GUI::Widget {
+    C_OBJECT(TextEditorWidget)
+public:
+    virtual ~TextEditorWidget() override;
+    void open_sesame(const String& path);
+    bool request_close();
+
+    GUI::TextEditor& editor() { return *m_editor; }
+
+    enum class PreviewMode {
+        None,
+        Markdown,
+        HTML,
+    };
+
+    void set_preview_mode(PreviewMode);
+    void set_auto_detect_preview_mode(bool value) { m_auto_detect_preview_mode = value; }
+
+    void update_title();
+
+private:
+    TextEditorWidget();
+    void set_path(const LexicalPath& file);
+    void update_preview();
+    void update_markdown_preview();
+    void update_html_preview();
+    void update_statusbar_cursor_position();
+
+    virtual void drop_event(GUI::DropEvent&) override;
+
+    RefPtr<GUI::TextEditor> m_editor;
+    String m_path;
+    String m_name;
+    String m_extension;
+    RefPtr<GUI::Action> m_new_action;
+    RefPtr<GUI::Action> m_open_action;
+    RefPtr<GUI::Action> m_save_action;
+    RefPtr<GUI::Action> m_save_as_action;
+    RefPtr<GUI::Action> m_find_replace_action;
+    RefPtr<GUI::Action> m_line_wrapping_setting_action;
+    RefPtr<GUI::Action> m_vim_emulation_setting_action;
+
+    RefPtr<GUI::Action> m_find_next_action;
+    RefPtr<GUI::Action> m_find_regex_action;
+    RefPtr<GUI::Action> m_find_previous_action;
+    RefPtr<GUI::Action> m_replace_next_action;
+    RefPtr<GUI::Action> m_replace_previous_action;
+    RefPtr<GUI::Action> m_replace_all_action;
+
+    GUI::ActionGroup m_preview_actions;
+    RefPtr<GUI::Action> m_no_preview_action;
+    RefPtr<GUI::Action> m_markdown_preview_action;
+    RefPtr<GUI::Action> m_html_preview_action;
+
+    RefPtr<GUI::StatusBar> m_statusbar;
+
+    RefPtr<GUI::TextBox> m_find_textbox;
+    RefPtr<GUI::TextBox> m_replace_textbox;
+    RefPtr<GUI::Button> m_find_previous_button;
+    RefPtr<GUI::Button> m_find_next_button;
+    RefPtr<GUI::Button> m_find_regex_button;
+    RefPtr<GUI::Button> m_replace_previous_button;
+    RefPtr<GUI::Button> m_replace_next_button;
+    RefPtr<GUI::Button> m_replace_all_button;
+    RefPtr<GUI::Widget> m_find_replace_widget;
+    RefPtr<GUI::Widget> m_find_widget;
+    RefPtr<GUI::Widget> m_replace_widget;
+
+    GUI::ActionGroup syntax_actions;
+    RefPtr<GUI::Action> m_plain_text_highlight;
+    RefPtr<GUI::Action> m_cpp_highlight;
+    RefPtr<GUI::Action> m_js_highlight;
+    RefPtr<GUI::Action> m_gml_highlight;
+    RefPtr<GUI::Action> m_ini_highlight;
+    RefPtr<GUI::Action> m_shell_highlight;
+
+    RefPtr<Web::OutOfProcessWebView> m_page_view;
+
+    bool m_document_dirty { false };
+    bool m_document_opening { false };
+    bool m_auto_detect_preview_mode { false };
+    bool m_find_use_regex { false };
+
+    PreviewMode m_preview_mode { PreviewMode::None };
+};

Userland/Applications/TextEditor/TextEditorWindow.gml

@@ -0,0 +1,88 @@
+@GUI::Widget {
+    name: "main"
+    fill_with_background_color: true
+
+    layout: @GUI::VerticalBoxLayout {
+        spacing: 2
+    }
+
+    @GUI::ToolBarContainer {
+        @GUI::ToolBar {
+            name: "toolbar"
+        }
+    }
+
+    @GUI::HorizontalSplitter {
+        @GUI::TextEditor {
+            name: "editor"
+        }
+
+        @Web::OutOfProcessWebView {
+            name: "webview"
+            visible: false
+        }
+    }
+
+    @GUI::Widget {
+        name: "find_replace_widget"
+        visible: false
+        fill_with_background_color: true
+        fixed_height: 48
+
+        layout: @GUI::VerticalBoxLayout {
+            margins: [2, 2, 2, 4]
+        }
+
+        @GUI::Widget {
+            name: "find_widget"
+            fill_with_background_color: true
+            fixed_height: 22
+
+            layout: @GUI::HorizontalBoxLayout {
+            }
+
+            @GUI::Button {
+                name: "find_previous_button"
+                text: "Find previous"
+                fixed_width: 150
+            }
+
+            @GUI::Button {
+                name: "find_next_button"
+                text: "Find next"
+                fixed_width: 150
+            }
+        }
+
+        @GUI::Widget {
+            name: "replace_widget"
+            fill_with_background_color: true
+            fixed_height: 22
+
+            layout: @GUI::HorizontalBoxLayout {
+            }
+
+            @GUI::Button {
+                name: "replace_previous_button"
+                text: "Replace previous"
+                fixed_width: 100
+            }
+
+            @GUI::Button {
+                name: "replace_next_button"
+                text: "Replace next"
+                fixed_width: 100
+            }
+
+            @GUI::Button {
+                name: "replace_all_button"
+                text: "Replace all"
+                fixed_width: 100
+            }
+        }
+    }
+
+    @GUI::StatusBar {
+        name: "statusbar"
+    }
+}

Userland/Applications/TextEditor/main.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "TextEditorWidget.h"
+#include <LibCore/ArgsParser.h>
+#include <LibGfx/Bitmap.h>
+#include <stdio.h>
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio thread rpath accept cpath wpath shared_buffer unix fattr", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    auto app = GUI::Application::construct(argc, argv);
+
+    if (pledge("stdio thread rpath accept cpath wpath shared_buffer unix", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    const char* preview_mode = "auto";
+    const char* file_to_edit = nullptr;
+    Core::ArgsParser parser;
+    parser.add_option(preview_mode, "Preview mode, one of 'none', 'html', 'markdown', 'auto'", "preview-mode", '\0', "mode");
+    parser.add_positional_argument(file_to_edit, "File to edit", "file", Core::ArgsParser::Required::No);
+
+    parser.parse(argc, argv);
+
+    StringView preview_mode_view = preview_mode;
+
+    auto app_icon = GUI::Icon::default_icon("app-text-editor");
+
+    auto window = GUI::Window::construct();
+    window->resize(640, 400);
+
+    auto& text_widget = window->set_main_widget<TextEditorWidget>();
+
+    text_widget.editor().set_focus(true);
+
+    window->on_close_request = [&]() -> GUI::Window::CloseRequestDecision {
+        if (text_widget.request_close())
+            return GUI::Window::CloseRequestDecision::Close;
+        return GUI::Window::CloseRequestDecision::StayOpen;
+    };
+
+    if (preview_mode_view == "auto") {
+        text_widget.set_auto_detect_preview_mode(true);
+    } else if (preview_mode_view == "markdown") {
+        text_widget.set_preview_mode(TextEditorWidget::PreviewMode::Markdown);
+    } else if (preview_mode_view == "html") {
+        text_widget.set_preview_mode(TextEditorWidget::PreviewMode::HTML);
+    } else if (preview_mode_view == "none") {
+        text_widget.set_preview_mode(TextEditorWidget::PreviewMode::None);
+    } else {
+        warnln("Invalid mode '{}'", preview_mode);
+        return 1;
+    }
+
+    if (file_to_edit)
+        text_widget.open_sesame(file_to_edit);
+    else
+        text_widget.update_title();
+
+    window->show();
+    window->set_icon(app_icon.bitmap_for_size(16));
+
+    return app->exec();
+}