LibWebView+UI/Qt: Reuse an existing history tab when viewing history

Previously, the "View History" action always opened a new tab. We now
switch to an existing `about:history` tab when one exists in the active
window and fall back to opening a new tab otherwise.

Libraries/LibWebView/Application.cpp

@@ -1524,7 +1524,8 @@ void Application::initialize_actions()
 
     m_history_menu = Menu::create("History"sv);
     m_history_menu->add_action(Action::create("View History"sv, ActionID::ViewHistory, [this]() {
-        open_url_in_new_tab(URL::about_history(), Web::HTML::ActivateTab::Yes);
+        if (!activate_tab_with_url(URL::about_history()))
+            open_url_in_new_tab(URL::about_history(), Web::HTML::ActivateTab::Yes);
     }));
 
     m_inspect_menu = Menu::create("Inspect"sv);

Libraries/LibWebView/Application.h

@@ -110,6 +110,7 @@ public:
 
     virtual Optional<ViewImplementation&> active_web_view() const { return {}; }
     virtual Optional<ViewImplementation&> open_blank_new_tab(Web::HTML::ActivateTab) const { return {}; }
+    virtual bool activate_tab_with_url(URL::URL const&) const { return false; }
     void open_url_in_new_tab(URL::URL const&, Web::HTML::ActivateTab) const;
     void open_bookmark_in_new_tab(String const& bookmark_id, Web::HTML::ActivateTab) const;
 

UI/Qt/Application.cpp

@@ -177,6 +177,13 @@ Optional<WebView::ViewImplementation&> Application::open_blank_new_tab(Web::HTML
     return tab.view();
 }
 
+bool Application::activate_tab_with_url(URL::URL const& url) const
+{
+    if (!m_active_window)
+        return false;
+    return m_active_window->activate_tab_with_url(url);
+}
+
 void Application::open_url_in_new_window(URL::URL const& url)
 {
     this->new_window({ url });

UI/Qt/Application.h

@@ -46,6 +46,7 @@ private:
 
     virtual Optional<WebView::ViewImplementation&> active_web_view() const override;
     virtual Optional<WebView::ViewImplementation&> open_blank_new_tab(Web::HTML::ActivateTab) const override;
+    virtual bool activate_tab_with_url(URL::URL const&) const override;
     virtual void open_url_in_new_window(URL::URL const& url) override;
 
     virtual Optional<ByteString> ask_user_for_download_path(StringView file) const override;

UI/Qt/BrowserWindow.cpp

@@ -715,6 +715,18 @@ void BrowserWindow::activate_tab(int index)
     m_tabs_container->set_current_index(index);
 }
 
+bool BrowserWindow::activate_tab_with_url(URL::URL const& url)
+{
+    for (int index = 0; index < m_tabs_container->count(); ++index) {
+        auto* tab = m_tabs_container->tab(index);
+        if (tab && tab->view().url() == url) {
+            m_tabs_container->set_current_index(index);
+            return true;
+        }
+    }
+    return false;
+}
+
 void BrowserWindow::definitely_close_tab(int index)
 {
     auto* tab = m_tabs_container->tab(index);

UI/Qt/BrowserWindow.h

@@ -103,6 +103,7 @@ public:
 
     Tab& create_new_tab(Web::HTML::ActivateTab activate_tab);
     Tab* current_tab() const { return m_current_tab; }
+    bool activate_tab_with_url(URL::URL const&);
     FullscreenMode& fullscreen_mode();
 
     QMenu& hamburger_menu() const { return *m_hamburger_menu; }