Browser: Prevent opening multiple DOM Inspectors for the same Tab

Also simplify the logic by removing `Tab::view_dom_tree()`, and making
the Tab keep a pointer to the InspectorWidget instead of its Window,
since that's more often what we want to access.

Userland/Applications/Browser/Tab.cpp

@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
  * Copyright (c) 2021, Maciej Zygmanowski <sppmacd@pm.me>
+ * Copyright (c) 2021, Sam Atkins <atkinssj@gmail.com>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -79,20 +80,6 @@ void Tab::view_source(const URL& url, const String& source)
     window->show();
 }
 
-void Tab::view_dom_tree(const String& dom_tree)
-{
-    auto window = GUI::Window::construct(&this->window());
-    window->resize(300, 500);
-    window->set_title("DOM inspector");
-    window->set_icon(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/inspector-object.png"));
-    window->set_main_widget<InspectorWidget>();
-
-    auto* inspector_widget = static_cast<InspectorWidget*>(window->main_widget());
-    inspector_widget->set_dom_json(dom_tree);
-    window->show();
-    window->move_to_front();
-}
-
 Tab::Tab(BrowserWindow& window)
 {
     load_from_gml(tab_gml);
@@ -290,7 +277,8 @@ Tab::Tab(BrowserWindow& window)
     };
 
     hooks().on_get_dom_tree = [this](auto& dom_tree) {
-        view_dom_tree(dom_tree);
+        if (m_dom_inspector_widget)
+            m_dom_inspector_widget->set_dom_json(dom_tree);
     };
 
     hooks().on_js_console_output = [this](auto& method, auto& line) {
@@ -479,7 +467,22 @@ BrowserWindow& Tab::window()
 
 void Tab::show_inspector_window(Browser::Tab::InspectorTarget)
 {
+    if (!m_dom_inspector_widget) {
+        auto window = GUI::Window::construct(&this->window());
+        window->resize(300, 500);
+        window->set_title("DOM inspector");
+        window->set_icon(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/inspector-object.png"));
+        window->on_close = [&]() {
+            // FIXME: Clear inspected node for OOPWV
+        };
+        m_dom_inspector_widget = window->set_main_widget<InspectorWidget>();
+    }
+
     m_web_content_view->inspect_dom_tree();
+
+    auto* window = m_dom_inspector_widget->window();
+    window->show();
+    window->move_to_front();
 }
 
 }

Userland/Applications/Browser/Tab.h

@@ -22,6 +22,7 @@ class WebViewHooks;
 namespace Browser {
 
 class BrowserWindow;
+class InspectorWidget;
 
 class Tab final : public GUI::Widget {
     C_OBJECT(Tab);
@@ -82,7 +83,6 @@ private:
     void update_bookmark_button(const String& url);
     void start_download(const URL& url);
     void view_source(const URL& url, const String& source);
-    void view_dom_tree(const String&);
 
     History m_history;
 
@@ -90,6 +90,7 @@ private:
 
     RefPtr<GUI::UrlBox> m_location_box;
     RefPtr<GUI::Button> m_bookmark_button;
+    RefPtr<InspectorWidget> m_dom_inspector_widget;
     RefPtr<GUI::Window> m_console_window;
     RefPtr<GUI::Statusbar> m_statusbar;
     RefPtr<GUI::ToolbarContainer> m_toolbar_container;