[LyX/master] #10571 improved handling of WM's signal when switching from or to full-screen window

[Stephan Witt]

commit 6dcd4ca4f168df0cd49295fdfff3d75f1f70ba95
Author: Stephan Witt <switt at lyx.org>
Date:   Tue Aug 4 15:23:53 2020 +0200

    #10571 improved handling of WM's signal when switching from or to full-screen window
---
 src/frontends/qt/GuiToolbar.cpp  |   16 ++++++++
 src/frontends/qt/GuiToolbar.h    |    4 ++
 src/frontends/qt/GuiView.cpp     |   75 +++++++++++++++++++++++---------------
 src/frontends/qt/GuiWorkArea.cpp |    9 ++---
 4 files changed, 68 insertions(+), 36 deletions(-)

diff --git a/src/frontends/qt/GuiToolbar.cpp b/src/frontends/qt/GuiToolbar.cpp
index 4b3ebf4..f58069b 100644
--- a/src/frontends/qt/GuiToolbar.cpp
+++ b/src/frontends/qt/GuiToolbar.cpp
@@ -84,6 +84,16 @@ void GuiToolbar::setVisible(bool visible)
 	// MainWindow::restoreState and which toolbars should be initialized
 	// by us (i.e., new toolbars)
 	restored_ = true;
+	// Record the actual visibility in toolbar state visibility_.
+	// This is useful to restore the visibility of toolbars when
+	// returning from full-screen. Therefore the recording is disabled
+	// while LyX is in full-screen state.
+	if (!owner_.isFullScreen()) {
+		if (visible)
+			visibility_ |= Toolbars::ON;
+		else
+			visibility_ &= ~Toolbars::ON;
+	}
 	QToolBar::setVisible(visible);
 }
 
@@ -595,6 +605,12 @@ void GuiToolbar::restoreSession()
 }
 
 
+bool GuiToolbar::isVisibiltyOn() const
+{
+	return visibility_ & Toolbars::ON;
+}
+
+
 void GuiToolbar::toggle()
 {
 	docstring state;
diff --git a/src/frontends/qt/GuiToolbar.h b/src/frontends/qt/GuiToolbar.h
index 24d11e3..eccd05a 100644
--- a/src/frontends/qt/GuiToolbar.h
+++ b/src/frontends/qt/GuiToolbar.h
@@ -145,6 +145,10 @@ public:
 	///
 	bool isRestored() const;
 
+	///
+	bool isVisibiltyOn() const;
+	int visibility() const { return visibility_; }
+
 	/// Refresh the contents of the bar.
 	void update(int context = 0);
 
diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index f939573..3160a1f 100644
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -117,7 +117,7 @@
 #include <QTimer>
 #include <QToolBar>
 #include <QUrl>
-
+#include <QWindowStateChangeEvent>
 
 
 // sync with GuiAlert.cpp
@@ -1401,6 +1401,49 @@ bool GuiView::event(QEvent * e)
 	//case QEvent::Drop:
 	//	break;
 
+	case QEvent::WindowStateChange: {
+		QWindowStateChangeEvent * ev = (QWindowStateChangeEvent*)e;
+		bool ofstate = (ev->oldState() & Qt::WindowFullScreen);
+		bool result = QMainWindow::event(e);
+		bool nfstate = (windowState() & Qt::WindowFullScreen);
+		if (!ofstate && nfstate) {
+			LYXERR(Debug::DEBUG, "GuiView: WindowStateChange(): full-screen " << nfstate);
+			// switch to full-screen state
+			if (lyxrc.full_screen_statusbar)
+				statusBar()->hide();
+			if (lyxrc.full_screen_menubar)
+				menuBar()->hide();
+			if (lyxrc.full_screen_toolbars) {
+				ToolbarMap::iterator end = d.toolbars_.end();
+				for (ToolbarMap::iterator it = d.toolbars_.begin(); it != end; ++it)
+					if (it->second->isVisibiltyOn() && it->second->isVisible())
+						it->second->hide();
+			}
+			for (int i = 0; i != d.splitter_->count(); ++i)
+				d.tabWorkArea(i)->setFullScreen(true);
+			setContentsMargins(-2, -2, -2, -2);
+			// bug 5274
+			hideDialogs("prefs", nullptr);
+		} else if (ofstate && !nfstate) {
+			LYXERR(Debug::DEBUG, "GuiView: WindowStateChange(): full-screen " << nfstate);
+			// switch back from full-screen state
+			if (lyxrc.full_screen_statusbar && !statusBar()->isVisible())
+				statusBar()->show();
+			if (lyxrc.full_screen_menubar && !menuBar()->isVisible())
+				menuBar()->show();
+			if (lyxrc.full_screen_toolbars) {
+				ToolbarMap::iterator end = d.toolbars_.end();
+				for (ToolbarMap::iterator it = d.toolbars_.begin(); it != end; ++it)
+					if (it->second->isVisibiltyOn() && !it->second->isVisible())
+						it->second->show();
+				//updateToolbars();
+			}
+			for (int i = 0; i != d.splitter_->count(); ++i)
+				d.tabWorkArea(i)->setFullScreen(false);
+			setContentsMargins(0, 0, 0, 0);
+		}
+		return result;
+		}
 	case QEvent::WindowActivate: {
 		GuiView * old_view = guiApp->currentView();
 		if (this == old_view) {
@@ -4641,35 +4684,7 @@ bool GuiView::lfunUiToggle(string const & ui_component)
 
 void GuiView::toggleFullScreen()
 {
-	if (isFullScreen()) {
-		for (int i = 0; i != d.splitter_->count(); ++i)
-			d.tabWorkArea(i)->setFullScreen(false);
-		setContentsMargins(0, 0, 0, 0);
-		setWindowState(windowState() ^ Qt::WindowFullScreen);
-		restoreLayout();
-		menuBar()->show();
-		statusBar()->show();
-	} else {
-		// bug 5274
-		hideDialogs("prefs", nullptr);
-		for (int i = 0; i != d.splitter_->count(); ++i)
-			d.tabWorkArea(i)->setFullScreen(true);
-		setContentsMargins(-2, -2, -2, -2);
-		saveLayout();
-		setWindowState(windowState() ^ Qt::WindowFullScreen);
-		if (lyxrc.full_screen_statusbar)
-			statusBar()->hide();
-		if (lyxrc.full_screen_menubar)
-			menuBar()->hide();
-		if (lyxrc.full_screen_toolbars) {
-			ToolbarMap::iterator end = d.toolbars_.end();
-			for (ToolbarMap::iterator it = d.toolbars_.begin(); it != end; ++it)
-				it->second->hide();
-		}
-	}
-
-	// give dialogs like the TOC a chance to adapt
-	updateDialogs();
+	setWindowState(windowState() ^ Qt::WindowFullScreen);
 }
 
 
diff --git a/src/frontends/qt/GuiWorkArea.cpp b/src/frontends/qt/GuiWorkArea.cpp
index 23d6efa..a2af82d 100644
--- a/src/frontends/qt/GuiWorkArea.cpp
+++ b/src/frontends/qt/GuiWorkArea.cpp
@@ -408,12 +408,9 @@ void GuiWorkArea::close()
 void GuiWorkArea::setFullScreen(bool full_screen)
 {
 	d->buffer_view_->setFullScreen(full_screen);
-	setFrameStyle(QFrame::NoFrame);
-	if (full_screen) {
-		setFrameStyle(QFrame::NoFrame);
-		if (lyxrc.full_screen_scrollbar)
-			setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-	} else
+	if (full_screen && lyxrc.full_screen_scrollbar)
+		setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+	else
 		setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
 }