X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2Fsupport%2FFileMonitor.cpp;h=a3b17ad012f3f9a86e6505790ee16a400532b446;hb=41a8994da902031a743373c1c57d028b7c900797;hp=f1fefb8d18afb918cdc3dd676f0813b5b7a6a91e;hpb=db58111360d68f76c5797069a7b80967447d1379;p=lyx.git

diff --git a/src/support/FileMonitor.cpp b/src/support/FileMonitor.cpp
index f1fefb8d18..a3b17ad012 100644
--- a/src/support/FileMonitor.cpp
+++ b/src/support/FileMonitor.cpp
@@ -118,31 +118,37 @@ FileMonitorGuard::~FileMonitorGuard()
 }
 
 
-void FileMonitorGuard::refresh()
+void FileMonitorGuard::refresh(bool const emit)
 {
 	if (filename_.empty())
 		return;
 	QString const qfilename = toqstr(filename_);
-	if(!qwatcher_->files().contains(qfilename)) {
-		bool exists = QFile(qfilename).exists();
+	if (!qwatcher_->files().contains(qfilename)) {
+		bool const existed = exists_;
+		exists_ = QFile(qfilename).exists();
 #if (QT_VERSION >= 0x050000)
-		if (!exists || !qwatcher_->addPath(qfilename))
+		if (exists_ && !qwatcher_->addPath(qfilename))
 #else
 		auto add_path = [&]() {
 			qwatcher_->addPath(qfilename);
 			return qwatcher_->files().contains(qfilename);
 		};
-		if (!exists || !add_path())
+		if (exists_ && !add_path())
 #endif
 		{
-			if (exists)
-				LYXERR(Debug::FILES,
-				       "Could not add path to QFileSystemWatcher: "
-				       << filename_);
-			QTimer::singleShot(2000, this, SLOT(refresh()));
-		} else if (exists && !exists_)
-			Q_EMIT fileChanged();
-		setExists(exists);
+			LYXERR(Debug::FILES,
+			       "Could not add path to QFileSystemWatcher: " << filename_);
+			QTimer::singleShot(5000, this, SLOT(refresh()));
+		} else {
+			if (!exists_)
+				// The standard way to overwrite a file is to delete it and
+				// create a new file with the same name. Therefore if the file
+				// has just been deleted, it is smart to check not too long
+				// after whether it has been recreated.
+			    QTimer::singleShot(existed ? 100 : 2000, this, SLOT(refresh()));
+			if (existed != exists_ && emit)
+				Q_EMIT fileChanged(exists_);
+		}
 	}
 }
 
@@ -150,11 +156,12 @@ void FileMonitorGuard::refresh()
 void FileMonitorGuard::notifyChange(QString const & path)
 {
 	if (path == toqstr(filename_)) {
-		Q_EMIT fileChanged();
 		// If the file has been modified by delete-move, we are notified of the
 		// deletion but we no longer track the file. See
 		// <https://bugreports.qt.io/browse/QTBUG-46483> (not a bug).
-		refresh();
+		// Therefore we must refresh.
+		refresh(false);
+		Q_EMIT fileChanged(exists_);
 	}
 }
 
@@ -162,17 +169,22 @@ void FileMonitorGuard::notifyChange(QString const & path)
 FileMonitor::FileMonitor(std::shared_ptr<FileMonitorGuard> monitor)
 	: monitor_(monitor)
 {
-	QObject::connect(monitor_.get(), SIGNAL(fileChanged()),
-	                 this, SLOT(changed()));
+	connectToFileMonitorGuard();
 	refresh();
 }
 
 
-void FileMonitor::reconnectToFileMonitorGuard()
+void FileMonitor::connectToFileMonitorGuard()
 {
-	monitor_->setExists(true);
-	QObject::connect(monitor_.get(), SIGNAL(fileChanged()),
-	                 this, SLOT(changed()));
+	// Connections need to be asynchronous because the receiver can own this
+	// object and therefore is allowed to delete it.
+	// Qt signal:
+	QObject::connect(monitor_.get(), SIGNAL(fileChanged(bool)),
+	                 this, SIGNAL(fileChanged(bool)),
+	                 Qt::QueuedConnection);
+	// Boost signal:
+	QObject::connect(this, SIGNAL(fileChanged(bool)),
+	                 this, SLOT(changed(bool)));
 }
 
 
@@ -182,54 +194,10 @@ signals2::connection FileMonitor::connect(slot const & slot)
 }
 
 
-void FileMonitor::disconnect()
-{
-	fileChanged_.disconnect_all_slots();
-	QObject::disconnect(this, SIGNAL(fileChanged()));
-}
-
-
-void FileMonitor::changed()
+void FileMonitor::changed(bool const exists)
 {
 	// emit boost signal
-	fileChanged_();
-	Q_EMIT fileChanged();
-}
-
-
-FileMonitorBlocker FileMonitor::block(int delay)
-{
-	FileMonitorBlocker blocker = blocker_.lock();
-	if (!blocker)
-		blocker_ = blocker = make_shared<FileMonitorBlockerGuard>(this);
-	blocker->setDelay(delay);
-	return blocker;
-}
-
-
-FileMonitorBlockerGuard::FileMonitorBlockerGuard(FileMonitor * monitor)
-	: monitor_(monitor), delay_(0)
-{
-	QObject::disconnect(monitor->monitor_.get(), SIGNAL(fileChanged()),
-	                    monitor, SLOT(changed()));
-}
-
-
-void FileMonitorBlockerGuard::setDelay(int delay)
-{
-	delay_ = max(delay_, delay);
-}
-
-
-FileMonitorBlockerGuard::~FileMonitorBlockerGuard()
-{
-	if (!monitor_)
-		return;
-	// Even if delay_ is 0, the QTimer is necessary. Indeed, the notifications
-	// from QFileSystemWatcher that we meant to ignore are not going to be
-	// treated immediately, so we must yield to give us the opportunity to
-	// ignore them.
-	QTimer::singleShot(delay_, monitor_, SLOT(reconnectToFileMonitorGuard()));
+	fileChanged_(exists);
 }
 
 
@@ -238,8 +206,9 @@ ActiveFileMonitor::ActiveFileMonitor(std::shared_ptr<FileMonitorGuard> monitor,
 	: FileMonitor(monitor), filename_(filename), interval_(interval),
 	  timestamp_(0), checksum_(0), cooldown_(true)
 {
-	QObject::connect(this, SIGNAL(fileChanged()), this, SLOT(setCooldown()));
+	QObject::connect(this, SIGNAL(fileChanged(bool)), this, SLOT(setCooldown()));
 	QTimer::singleShot(interval_, this, SLOT(clearCooldown()));
+	filename_.refresh();
 	if (!filename_.exists())
 		return;
 	timestamp_ = filename_.lastModified();
@@ -254,7 +223,9 @@ void ActiveFileMonitor::checkModified()
 
 	cooldown_ = true;
 	bool changed = false;
-	if (!filename_.exists()) {
+	filename_.refresh();
+	bool exists = filename_.exists();
+	if (!exists) {
 		changed = timestamp_ || checksum_;
 		timestamp_ = 0;
 		checksum_ = 0;
@@ -272,7 +243,7 @@ void ActiveFileMonitor::checkModified()
 		}
 	}
 	if (changed)
-		FileMonitor::changed();
+		Q_EMIT FileMonitor::fileChanged(exists);
 	QTimer::singleShot(interval_, this, SLOT(clearCooldown()));
 }