qtwebengine: enable video fullscreen

README.md

@@ -39,7 +39,9 @@ Like qutebrowser, keys mean different things depending on the mode:
 | `command` | `o`, `O`, `:`                | keys go to the command line        |
 | `hint`    | `f`                          | keys pick a link label             |
 
-`Escape` (or `Ctrl-[`) always returns to normal mode.
+`Escape` (or `Ctrl-[`) always returns to normal mode. In normal mode, it also
+leaves fullscreen when a page (e.g. a YouTube video) is fullscreen. The status bar
+is hidden while a page is fullscreen.
 
 > Note: unlike qutebrowser, att does not yet auto-switch to insert mode when you
 > click into a text field on a page — press `i` first. Doing it automatically

src/browserwindow.cpp

@@ -14,9 +14,11 @@
 #include <QMouseEvent>
 #include <QRegularExpression>
 #include <QVBoxLayout>
+#include <QWebEngineFullScreenRequest>
 #include <QWebEnginePage>
 #include <QWebEngineProfile>
 #include <QWebEngineScript>
+#include <QWebEngineSettings>
 #include <QWebEngineView>
 #include <QWidget>
 
@@ -92,6 +94,15 @@ void BrowserWindow::connectView()
             setMode(Mode::Normal);
     });
     connect(m_view, &QWebEngineView::loadProgress, m_status, &StatusBar::setProgress);
+
+    // Off by default in QtWebEngine: without it, element.requestFullscreen()
+    // (YouTube's fullscreen button, double-clicking a video) silently fails.
+    m_view->settings()->setAttribute(QWebEngineSettings::FullScreenSupportEnabled, true);
+    connect(m_view->page(), &QWebEnginePage::fullScreenRequested, this,
+            [this](QWebEngineFullScreenRequest request) {
+                request.accept();
+                setPageFullScreen(request.toggleOn());
+            });
     connect(m_view, &QWebEngineView::titleChanged, this, [this](const QString &title) {
         setWindowTitle(title.isEmpty() ? QStringLiteral("att")
                                        : QStringLiteral("%1 - att").arg(title));
@@ -123,23 +134,45 @@ void BrowserWindow::setMode(Mode mode)
     switch (mode) {
     case Mode::Normal:
         m_status->setMode(QString());
-        m_status->show();
         focusView();
         break;
     case Mode::Insert:
         m_status->setMode(QStringLiteral("insert"));
-        m_status->show();
         focusView();
         break;
     case Mode::Command:
-        m_status->hide();
         updateCompletion();
         break;
     case Mode::Hint:
         m_status->setMode(QStringLiteral("hint"));
-        m_status->show();
         break;
     }
+
+    updateStatusVisibility();
+}
+
+void BrowserWindow::setPageFullScreen(bool on)
+{
+    if (on == m_pageFullScreen)
+        return;
+    m_pageFullScreen = on;
+
+    if (on) {
+        m_windowStateBeforeFullScreen = windowState();
+        showFullScreen();
+    } else {
+        setWindowState(m_windowStateBeforeFullScreen);
+    }
+    updateStatusVisibility();
+}
+
+void BrowserWindow::updateStatusVisibility()
+{
+    // The command line replaces the status bar, and a fullscreen video gets the
+    // whole screen. Decided in one place so the bar is never shown just to be
+    // hidden again: toggling it while fullscreen knocks the window out of
+    // fullscreen.
+    m_status->setVisible(m_mode != Mode::Command && !m_pageFullScreen);
 }
 
 bool BrowserWindow::eventFilter(QObject *watched, QEvent *event)
@@ -154,6 +187,12 @@ bool BrowserWindow::eventFilter(QObject *watched, QEvent *event)
 
     if (key->key() == Qt::Key_Escape
         || (key->key() == Qt::Key_BracketLeft && key->modifiers() == Qt::ControlModifier)) {
+        // Escape is swallowed here, so the page would never see it to leave
+        // fullscreen itself. In insert/hint mode it still just returns to normal
+        // mode first, as everywhere else.
+        if (m_mode == Mode::Normal && m_pageFullScreen)
+            m_view->triggerPageAction(QWebEnginePage::ExitFullScreen);
+        else
             setMode(Mode::Normal);
         return true;
     }

src/browserwindow.h

@@ -55,6 +55,8 @@ private:
     void scrollPages(double factor);
     void scrollToEnd(bool bottom);
     void focusView();
+    void setPageFullScreen(bool on);
+    void updateStatusVisibility();
 
     AdBlocker *m_adBlocker;
     QWebEngineView *m_view;
@@ -65,4 +67,9 @@ private:
 
     Mode m_mode = Mode::Normal;
     QString m_pendingKeys;
+
+    // Set while the page (e.g. a video) is fullscreen; m_windowStateBeforeFullScreen
+    // is what to go back to afterwards, so a maximized window stays maximized.
+    bool m_pageFullScreen = false;
+    Qt::WindowStates m_windowStateBeforeFullScreen;
 };