Detach Buffer preview and update preview in a new thread. Only for Qt4.4 users. This new feature can be disabled by setting EXPORT_in_THREAD to 0 in GuiView.cpp.

Two things are missing (but are fixable):
- the lack of feedback of the background latex compilation
- the error list is not shown in case of compilation error.

* Buffer:
- create a "cloned buffer" type.
- Transfer LFUN_MASTER_BUFFER_UPDATE, LFUN_MASTER_BUFFER_VIEW, LFUN_BUFFER_UPDATE and LFUN_BUFFER_VIEW to GuiView. This is good itself as these LFUN are GUI oriented.

* GuiView: detach the above LFUNs to a new thread as was already done for autosave. 


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@32584 a592a061-630c-0410-9148-cb99ea01b6c8

src/Buffer.cpp

@@ -147,7 +147,7 @@ class BufferSet : public std::set<Buffer const *> {};
 class Buffer::Impl
 {
 public:
-	Impl(Buffer & parent, FileName const & file, bool readonly);
+	Impl(Buffer & parent, FileName const & file, bool readonly, Buffer const * cloned_buffer);
 
 	~Impl()
 	{
@@ -258,9 +258,13 @@ public:
 			LYXERR0("Warning: a buffer should not have two parents!");
 		parent_buffer = pb;
 	}
-private:
+
 	/// So we can force access via the accessors.
 	mutable Buffer const * parent_buffer;
+
+	/// If non zero, this buffer is a clone of existing buffer \p cloned_buffer_
+	/// This one is useful for preview detached in a thread.
+	Buffer const * cloned_buffer_;
 };
 
 
@@ -283,22 +287,31 @@ static FileName createBufferTmpDir()
 }
 
 
-Buffer::Impl::Impl(Buffer & parent, FileName const & file, bool readonly_)
+Buffer::Impl::Impl(Buffer & parent, FileName const & file, bool readonly_,
+	Buffer const * cloned_buffer)
 	: lyx_clean(true), bak_clean(true), unnamed(false),
 	  read_only(readonly_), filename(file), file_fully_loaded(false),
 	  toc_backend(&parent), macro_lock(false), timestamp_(0),
 	  checksum_(0), wa_(0), undo_(parent), bibinfoCacheValid_(false),
-	  parent_buffer(0)
+	  parent_buffer(0), cloned_buffer_(cloned_buffer)
 {
-	temppath = createBufferTmpDir();
+	if (!cloned_buffer_) {
-	lyxvc.setBuffer(&parent);
+		temppath = createBufferTmpDir();
-	if (use_gui)
+		lyxvc.setBuffer(&parent);
-		wa_ = new frontend::WorkAreaManager;
+		if (use_gui)
+			wa_ = new frontend::WorkAreaManager;
+		return;
+	}
+	temppath = cloned_buffer_->d->temppath;
+	file_fully_loaded = true;
+	params = cloned_buffer_->d->params;
+	inset = static_cast<InsetText *>(cloned_buffer_->d->inset->clone());
+	inset->setBuffer(parent);
 }
 
 
-Buffer::Buffer(string const & file, bool readonly)
+Buffer::Buffer(string const & file, bool readonly, Buffer const * cloned_buffer)
-	: d(new Impl(*this, FileName(file), readonly)), gui_(0)
+	: d(new Impl(*this, FileName(file), readonly, cloned_buffer)), gui_(0)
 {
 	LYXERR(Debug::INFO, "Buffer::Buffer()");
 
@@ -343,7 +356,7 @@ Buffer::~Buffer()
 	d->children_positions.clear();
 	d->position_to_children.clear();
 
-	if (!d->temppath.destroyDirectory()) {
+	if (!d->cloned_buffer_ && !d->temppath.destroyDirectory()) {
 		Alert::warning(_("Could not remove temporary directory"),
 			bformat(_("Could not remove the temporary directory %1$s"),
 			from_utf8(d->temppath.absFilename())));
@@ -358,12 +371,7 @@ Buffer::~Buffer()
 
 Buffer * Buffer::clone() const
 {
-	Buffer * clone = new Buffer(fileName().absFilename(), false);
+	return new Buffer(fileName().absFilename(), false, this);
-	clone->d->file_fully_loaded = true;
-	clone->d->params = d->params;
-	clone->d->inset = static_cast<InsetText *>(d->inset->clone());
-	clone->d->inset->setBuffer(*clone);
-	return clone;
 }
 
 
@@ -1652,6 +1660,21 @@ void Buffer::markDepClean(string const & name)
 }
 
 
+bool Buffer::isExportableFormat(string const & format) const
+{
+		typedef vector<Format const *> Formats;
+		Formats formats;
+		formats = exportableFormats(true);
+		Formats::const_iterator fit = formats.begin();
+		Formats::const_iterator end = formats.end();
+		for (; fit != end ; ++fit) {
+			if ((*fit)->name() == format)
+				return true;
+		}
+		return false;
+}
+
+
 bool Buffer::getStatus(FuncRequest const & cmd, FuncStatus & flag)
 {
 	if (isInternal()) {
@@ -1687,27 +1710,6 @@ bool Buffer::getStatus(FuncRequest const & cmd, FuncStatus & flag)
 			break;
 		}
 
-		case LFUN_MASTER_BUFFER_UPDATE:
-		case LFUN_MASTER_BUFFER_VIEW: 
-			enable = parent() != 0;
-			break;
-		case LFUN_BUFFER_UPDATE:
-		case LFUN_BUFFER_VIEW: {
-			string format = to_utf8(cmd.argument());
-			if (cmd.argument().empty())
-				format = getDefaultOutputFormat();
-			typedef vector<Format const *> Formats;
-			Formats formats;
-			formats = exportableFormats(true);
-			Formats::const_iterator fit = formats.begin();
-			Formats::const_iterator end = formats.end();
-			enable = false;
-			for (; fit != end ; ++fit) {
-				if ((*fit)->name() == format)
-					enable = true;
-			}
-			break;
-		}
 		case LFUN_BUFFER_CHKTEX:
 			enable = isLatex() && !lyxrc.chktex_command.empty();
 			break;
@@ -1773,10 +1775,6 @@ void Buffer::dispatch(FuncRequest const & func, DispatchResult & dr)
 		break;
 
 	case LFUN_BUFFER_EXPORT: {
-		if (argument == "custom") {
-			lyx::dispatch(FuncRequest(LFUN_DIALOG_SHOW, "sendto"));
-			break;
-		}
 		bool success = doExport(argument, false);
 		dr.setError(success);
 		if (!success)
@@ -1785,38 +1783,6 @@ void Buffer::dispatch(FuncRequest const & func, DispatchResult & dr)
 		break;
 	}
 
-	case LFUN_BUFFER_UPDATE: {
-		string format = argument;
-		if (argument.empty())
-			format = getDefaultOutputFormat();
-		doExport(format, true);
-		break;
-	}
-
-	case LFUN_BUFFER_VIEW: {
-		string format = argument;
-		if (argument.empty())
-			format = getDefaultOutputFormat();
-		preview(format);
-		break;
-	}
-
-	case LFUN_MASTER_BUFFER_UPDATE: {
-		string format = argument;
-		if (argument.empty())
-			format = masterBuffer()->getDefaultOutputFormat();
-		masterBuffer()->doExport(format, true);
-		break;
-	}
-
-	case LFUN_MASTER_BUFFER_VIEW: {
-		string format = argument;
-		if (argument.empty())
-			format = masterBuffer()->getDefaultOutputFormat();
-		masterBuffer()->preview(format);
-		break;
-	}
-
 	case LFUN_BUILD_PROGRAM:
 		doExport("program", true);
 		break;
@@ -3132,14 +3098,18 @@ bool Buffer::doExport(string const & format, bool put_in_tempdir,
 				path = p;
 			}
 		}
-		if (!path.empty())
+		if (path.empty()) {
-			runparams.flavor = theConverters().getFlavor(path);
+			if (!put_in_tempdir) {
-		else {
+				// Only show this alert if this is an export to a non-temporary
-			Alert::error(_("Couldn't export file"),
+				// file (not for previewing).
-				bformat(_("No information for exporting the format %1$s."),
+				Alert::error(_("Couldn't export file"), bformat(
-				   formats.prettyName(format)));
+					_("No information for exporting the format %1$s."),
+					formats.prettyName(format)));
+			}
 			return false;
 		}
+		runparams.flavor = theConverters().getFlavor(path);
+
 	} else {
 		backend_format = format;
 		// FIXME: Don't hardcode format names here, but use a flag

src/Buffer.h

@@ -125,7 +125,8 @@ public:
 	};
 
 	/// Constructor
-	explicit Buffer(std::string const & file, bool b = false);
+	explicit Buffer(std::string const & file, bool readonly = false,
+		Buffer const * cloned_buffer = 0);
 
 	/// Destructor
 	~Buffer();
@@ -512,6 +513,8 @@ public:
 	bool isExportable(std::string const & format) const;
 	///
 	std::vector<Format const *> exportableFormats(bool only_viewable) const;
+	///
+	bool isExportableFormat(std::string const & format) const;
 
 	///
 	typedef std::vector<std::pair<InsetRef *, ParIterator> > References;

src/frontends/qt4/GuiView.cpp

@@ -102,6 +102,8 @@
 #include <QUrl>
 #include <QScrollBar>
 
+#define EXPORT_in_THREAD 1
+
 // QtConcurrent was introduced in Qt 4.4
 #if (QT_VERSION >= 0x040400)
 #include <QFuture>
@@ -300,7 +302,8 @@ public:
 
 #if (QT_VERSION >= 0x040400)
 	///
-	QFutureWatcher<bool> autosave_watcher_;
+	QFutureWatcher<docstring> autosave_watcher_;
+	QFutureWatcher<docstring> preview_watcher_;
 #endif
 };
 
@@ -365,7 +368,9 @@ GuiView::GuiView(int id)
 
 #if (QT_VERSION >= 0x040400)
 	connect(&d.autosave_watcher_, SIGNAL(finished()), this,
-		SLOT(autoSaveFinished()));
+		SLOT(threadFinished()));
+	connect(&d.preview_watcher_, SIGNAL(finished()), this,
+		SLOT(threadFinished()));
 #endif
 }
 
@@ -376,12 +381,12 @@ GuiView::~GuiView()
 }
 
 
-void GuiView::autoSaveFinished()
+void GuiView::threadFinished()
 {
 #if (QT_VERSION >= 0x040400)
-	docstring const msg = d.autosave_watcher_.result()
+	QFutureWatcher<docstring> const * watcher =
-		? _("Automatic save done.") : _("Automatic save failed!");
+		static_cast<QFutureWatcher<docstring> const *>(sender());
-	message(msg);
+	message(watcher->result());
 #endif
 }
 
@@ -1222,7 +1227,7 @@ BufferView const * GuiView::currentBufferView() const
 }
 
 
-static bool saveAndDestroyBuffer(Buffer * buffer, FileName const & fname)
+static docstring saveAndDestroyBuffer(Buffer * buffer, FileName const & fname)
 {
 	bool failed = true;
 	FileName const tmp_ret = FileName::tempName("lyxauto");
@@ -1235,7 +1240,9 @@ static bool saveAndDestroyBuffer(Buffer * buffer, FileName const & fname)
 		failed = buffer->writeFile(fname);
 	}
 	delete buffer;
-	return !failed;
+	return failed
+		? _("Automatic save failed!")
+		: _("Automatic save done.");
 }
 
 
@@ -1249,7 +1256,7 @@ void GuiView::autoSave()
 		return;
 
 #if (QT_VERSION >= 0x040400)
-	QFuture<bool> f = QtConcurrent::run(saveAndDestroyBuffer, buffer->clone(),
+	QFuture<docstring> f = QtConcurrent::run(saveAndDestroyBuffer, buffer->clone(),
 		buffer->getAutosaveFilename());
 	d.autosave_watcher_.setFuture(f);
 #else
@@ -1296,6 +1303,24 @@ bool GuiView::getStatus(FuncRequest const & cmd, FuncStatus & flag)
 	case LFUN_BUFFER_IMPORT:
 		break;
 
+	case LFUN_MASTER_BUFFER_UPDATE:
+	case LFUN_MASTER_BUFFER_VIEW: 
+		enable = doc_buffer && doc_buffer->parent() != 0;
+		break;
+
+	case LFUN_BUFFER_UPDATE:
+	case LFUN_BUFFER_VIEW: {
+		if (!doc_buffer) {
+			enable = false;
+			break;
+		}
+		string format = to_utf8(cmd.argument());
+		if (cmd.argument().empty())
+			format = doc_buffer->getDefaultOutputFormat();
+		enable = doc_buffer->isExportableFormat(format);
+		break;
+	}
+
 	case LFUN_BUFFER_RELOAD:
 		enable = doc_buffer && !doc_buffer->isUnnamed()
 			&& doc_buffer->fileName().exists()
@@ -2585,6 +2610,26 @@ bool GuiView::goToFileRow(string const & argument)
 }
 
 
+static docstring exportAndDestroy(Buffer * buffer, docstring const & format)
+{
+	bool const success = buffer->doExport(to_utf8(format), true);
+	delete buffer;
+	return success
+		? bformat(_("Successful export to format: %1$s."), format)
+		: bformat(_("Error exporting to format: %1$s."), format);
+}
+
+
+static docstring previewAndDestroy(Buffer * buffer, docstring const & format)
+{
+	bool const success = buffer->preview(to_utf8(format));
+	delete buffer;
+	return success
+		? bformat(_("Successful preview of format: %1$s."), format)
+		: bformat(_("Error previewing format: %1$s."), format);
+}
+
+
 bool GuiView::dispatch(FuncRequest const & cmd)
 {
 	BufferView * bv = currentBufferView();
@@ -2603,6 +2648,8 @@ bool GuiView::dispatch(FuncRequest const & cmd)
 		return true;
 	}
 
+	string const argument = to_utf8(cmd.argument());
+
 	switch(cmd.action) {
 		case LFUN_BUFFER_CHILD_OPEN:
 			openChildDocument(to_utf8(cmd.argument()));
@@ -2612,6 +2659,80 @@ bool GuiView::dispatch(FuncRequest const & cmd)
 			importDocument(to_utf8(cmd.argument()));
 			break;
 
+		case LFUN_BUFFER_EXPORT: {
+			if (!doc_buffer)
+				break;
+			if (cmd.argument() == "custom") {
+				lyx::dispatch(FuncRequest(LFUN_DIALOG_SHOW, "sendto"));
+				break;
+			}
+			if (doc_buffer->doExport(argument, false)) {
+				message(bformat(_("Error exporting to format: %1$s."),
+					cmd.argument()));
+			}
+			break;
+		}
+
+		case LFUN_BUFFER_UPDATE: {
+			if (!doc_buffer)
+				break;
+			string format = argument;
+			if (argument.empty())
+				format = doc_buffer->getDefaultOutputFormat();
+#if EXPORT_in_THREAD && (QT_VERSION >= 0x040400)
+			QFuture<docstring> f = QtConcurrent::run(exportAndDestroy,
+				doc_buffer->clone(), cmd.argument());
+			d.preview_watcher_.setFuture(f);
+#else
+			doc_buffer->doExport(format, true);
+#endif
+			break;
+		}
+		case LFUN_BUFFER_VIEW: {
+			if (!doc_buffer)
+				break;
+			string format = argument;
+			if (argument.empty())
+				format = doc_buffer->getDefaultOutputFormat();
+#if EXPORT_in_THREAD && (QT_VERSION >= 0x040400)
+			QFuture<docstring> f = QtConcurrent::run(previewAndDestroy,
+				doc_buffer->clone(), cmd.argument());
+			d.preview_watcher_.setFuture(f);
+#else
+			doc_buffer->preview(format);
+#endif
+			break;
+		}
+		case LFUN_MASTER_BUFFER_UPDATE: {
+			if (!doc_buffer)
+				break;
+			string format = argument;
+			Buffer const * master = doc_buffer->masterBuffer();
+			if (argument.empty())
+				format = master->getDefaultOutputFormat();
+#if EXPORT_in_THREAD && (QT_VERSION >= 0x040400)
+			QFuture<docstring> f = QtConcurrent::run(exportAndDestroy,
+				master->clone(), cmd.argument());
+			d.preview_watcher_.setFuture(f);
+#else
+			master->doExport(format, true);
+#endif
+			break;
+		}
+		case LFUN_MASTER_BUFFER_VIEW: {
+			string format = argument;
+			Buffer const * master = doc_buffer->masterBuffer();
+			if (argument.empty())
+				format = master->getDefaultOutputFormat();
+#if EXPORT_in_THREAD && (QT_VERSION >= 0x040400)
+			QFuture<docstring> f = QtConcurrent::run(previewAndDestroy,
+				master->clone(), cmd.argument());
+			d.preview_watcher_.setFuture(f);
+#else
+			master->preview(format);
+#endif
+			break;
+		}
 		case LFUN_BUFFER_SWITCH:
 			if (FileName::isAbsolute(to_utf8(cmd.argument()))) {
 				Buffer * buffer = 

src/frontends/qt4/GuiView.h

@@ -180,8 +180,8 @@ private Q_SLOTS:
 	void normalSizedIcons();
 	void bigSizedIcons();
 
-	/// For completion of Buffer autosave thread.
+	/// For completion of autosave or exporrt threads.
-	void autoSaveFinished();
+	void threadFinished();
 
 private:
 	/// Open given child document in current buffer directory.