TextEditor: Don't launch a WebContent process until it's needed

The HTML and Markdown preview modes both use an OutOfProcessWebView to
render the preview pane, and we were instantiating this view from GML.
This caused us to always spawn a WebContent process alongside every
TextEditor instance.

Fix this by deferring the OOPWV construction until we actually need it.
This makes launching TextEditor on a text file quite a bit faster. :^)

Userland/Applications/TextEditor/MainWidget.cpp

@@ -67,23 +67,6 @@ MainWidget::MainWidget()
         window()->set_modified(modified);
     };
 
-    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();
-    };
-    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::GroupBox>("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");
@@ -347,6 +330,30 @@ MainWidget::~MainWidget()
 {
 }
 
+Web::OutOfProcessWebView& MainWidget::ensure_web_view()
+{
+    if (!m_page_view) {
+        auto& web_view_container = *find_descendant_of_type_named<GUI::Widget>("web_view_container");
+        m_page_view = web_view_container.add<Web::OutOfProcessWebView>();
+        m_page_view->on_link_hover = [this](auto& url) {
+            if (url.is_valid())
+                m_statusbar->set_text(url.to_string());
+            else
+                update_statusbar();
+        };
+        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);
+            }
+        };
+    }
+    return *m_page_view;
+}
+
 void MainWidget::initialize_menubar(GUI::Menubar& menubar)
 {
     auto& file_menu = menubar.add_menu("&File");
@@ -691,6 +698,15 @@ void MainWidget::drop_event(GUI::DropEvent& event)
     }
 }
 
+void MainWidget::set_web_view_visible(bool visible)
+{
+    if (!visible && !m_page_view)
+        return;
+    ensure_web_view();
+    auto& web_view_container = *find_descendant_of_type_named<GUI::Widget>("web_view_container");
+    web_view_container.set_visible(visible);
+}
+
 void MainWidget::set_preview_mode(PreviewMode mode)
 {
     if (m_preview_mode == mode)
@@ -699,15 +715,15 @@ void MainWidget::set_preview_mode(PreviewMode mode)
 
     if (m_preview_mode == PreviewMode::HTML) {
         m_html_preview_action->set_checked(true);
-        m_page_view->set_visible(true);
+        set_web_view_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);
+        set_web_view_visible(true);
         update_markdown_preview();
     } else {
         m_no_preview_action->set_checked(true);
-        m_page_view->set_visible(false);
+        set_web_view_visible(false);
     }
 }
 

Userland/Applications/TextEditor/MainWidget.h

@@ -48,6 +48,9 @@ private:
     void update_html_preview();
     void update_statusbar();
 
+    Web::OutOfProcessWebView& ensure_web_view();
+    void set_web_view_visible(bool);
+
     virtual void drop_event(GUI::DropEvent&) override;
 
     RefPtr<GUI::TextEditor> m_editor;

Userland/Applications/TextEditor/TextEditorWindow.gml

@@ -19,9 +19,12 @@
             name: "editor"
         }
 
-        @Web::OutOfProcessWebView {
-            name: "webview"
+        @GUI::Widget {
+            name: "web_view_container"
             visible: false
+
+            layout: @GUI::VerticalBoxLayout {
+            }
         }
     }