Handle out-of-memory situations by offering to save the project.

Author: Tulon

BackgroundExecutor.cpp

@@ -1,6 +1,6 @@
 /*
     Scan Tailor - Interactive post-processing tool for scanned pages.
-    Copyright (C) 2007-2008  Joseph Artsimovich <joseph_a@mail.ru>
+	Copyright (C)  Joseph Artsimovich <joseph.artsimovich@gmail.com>
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -17,10 +17,12 @@
 */
 
 #include "BackgroundExecutor.h"
+#include "OutOfMemoryHandler.h"
 #include <QCoreApplication>
 #include <QObject>
 #include <QThread>
 #include <QEvent>
+#include <new>
 #include <assert.h>
 
 template<typename T>
@@ -103,17 +105,21 @@ BackgroundExecutor::Dispatcher::Dispatcher(Impl& owner)
 void
 BackgroundExecutor::Dispatcher::customEvent(QEvent* event)
 {
-	TaskEvent* evt = dynamic_cast<TaskEvent*>(event);
-	assert(evt);
-	
-	TaskPtr const& task = evt->payload();
-	assert(task);
-	
-	TaskResultPtr const result((*task)());
-	if (result) {
-		QCoreApplication::postEvent(
-			&m_rOwner, new ResultEvent(result)
-		);
+	try {
+		TaskEvent* evt = dynamic_cast<TaskEvent*>(event);
+		assert(evt);
+
+		TaskPtr const& task = evt->payload();
+		assert(task);
+
+		TaskResultPtr const result((*task)());
+		if (result) {
+			QCoreApplication::postEvent(
+				&m_rOwner, new ResultEvent(result)
+			);
+		}
+	} catch (std::bad_alloc const&) {
+		OutOfMemoryHandler::instance().handleOutOfMemorySituation();
 	}
 }
 

CMakeLists.txt

@@ -441,6 +441,7 @@ SET(
 	SkinnedButton.cpp SkinnedButton.h
 	BubbleAnimation.cpp BubbleAnimation.h
 	ProcessingIndicationWidget.cpp ProcessingIndicationWidget.h
+	NonOwningWidget.cpp NonOwningWidget.h
 	Dpi.cpp Dpi.h Dpm.cpp Dpm.h
 	SmartFilenameOrdering.cpp SmartFilenameOrdering.h
 	ImageInfo.cpp ImageInfo.h
@@ -452,6 +453,8 @@ SET(
 	FixDpiSinglePageDialog.cpp FixDpiSinglePageDialog.h
 	ProjectCreationContext.cpp ProjectCreationContext.h
 	ProjectOpeningContext.cpp ProjectOpeningContext.h
+	OutOfMemoryHandler.cpp OutOfMemoryHandler.h
+	OutOfMemoryDialog.cpp OutOfMemoryDialog.h
 	MainWindow.cpp MainWindow.h
 	ConsoleBatch.cpp ConsoleBatch.h
 	CommandLine.cpp CommandLine.h

MainWindow.cpp

@@ -57,6 +57,8 @@
 #include "OrthogonalRotation.h"
 #include "FixDpiSinglePageDialog.h"
 #include "SettingsDialog.h"
+#include "OutOfMemoryHandler.h"
+#include "OutOfMemoryDialog.h"
 #include "filters/fix_orientation/Filter.h"
 #include "filters/fix_orientation/Task.h"
 #include "filters/fix_orientation/CacheDrivenTask.h"
@@ -128,6 +130,7 @@ MainWindow::MainWindow()
 	m_ptrStages(new StageSequence(m_ptrPages, PageSelectionAccessor(this))),
 	m_ptrWorkerThread(new WorkerThread),
 	m_ptrInteractiveQueue(new ProcessingTaskQueue(ProcessingTaskQueue::RANDOM_ORDER)),
+	m_ptrOutOfMemoryDialog(new OutOfMemoryDialog),
 	m_curFilter(0),
 	m_ignoreSelectionChanges(0),
 	m_ignorePageOrderingChanges(0),
@@ -166,14 +169,21 @@ MainWindow::MainWindow()
 	addAction(actionPrevPage);
 	addAction(actionPrevPageQ);
 	addAction(actionNextPageW);
-	
+
+	// Should be enough to save a project.
+	OutOfMemoryHandler::instance().allocateEmergencyMemory(3*1024*1024);
+
 	connect(actionFirstPage, SIGNAL(triggered(bool)), SLOT(goFirstPage()));
 	connect(actionLastPage, SIGNAL(triggered(bool)), SLOT(goLastPage()));
 	connect(actionPrevPage, SIGNAL(triggered(bool)), SLOT(goPrevPage()));
 	connect(actionNextPage, SIGNAL(triggered(bool)), SLOT(goNextPage()));
 	connect(actionPrevPageQ, SIGNAL(triggered(bool)), this, SLOT(goPrevPage()));
 	connect(actionNextPageW, SIGNAL(triggered(bool)), this, SLOT(goNextPage()));
 	connect(actionAbout, SIGNAL(triggered(bool)), this, SLOT(showAboutDialog()));
+	connect(
+		&OutOfMemoryHandler::instance(),
+		SIGNAL(outOfMemory()), SLOT(handleOutOfMemorySituation())
+	);
 
 	connect(
 		filterList->selectionModel(),
@@ -1201,6 +1211,8 @@ MainWindow::saveProjectTriggered()
 void
 MainWindow::saveProjectAsTriggered()
 {
+	// XXX: this function is duplicated in OutOfMemoryDialog.
+
 	QString project_dir;
 	if (!m_projectFile.isEmpty()) {
 		project_dir = QFileInfo(m_projectFile).absolutePath();
@@ -1371,6 +1383,24 @@ MainWindow::showAboutDialog()
 	dialog->show();
 }
 
+/**
+ * This function is called asynchronously, always from the main thread.
+ */
+void
+MainWindow::handleOutOfMemorySituation()
+{
+	deleteLater();
+
+	m_ptrOutOfMemoryDialog->setParams(
+		m_projectFile, m_ptrStages, m_ptrPages, m_selectedPage, m_outFileNameGen
+	);
+
+	closeProjectWithoutSaving();
+
+	m_ptrOutOfMemoryDialog->setAttribute(Qt::WA_DeleteOnClose);
+	m_ptrOutOfMemoryDialog.release()->show();
+}
+
 /**
  * Note: the removed widgets are not deleted.
  */

MainWindow.h

@@ -63,6 +63,7 @@ class ProjectOpeningContext;
 class CompositeCacheDrivenTask;
 class TabbedDebugImages;
 class ProcessingTaskQueue;
+class OutOfMemoryDialog;
 class QLineF;
 class QRectF;
 class QLayout;
@@ -155,6 +156,8 @@ private slots:
 	void openSettingsDialog();
 
 	void showAboutDialog();
+
+	void handleOutOfMemorySituation();
 private:
 	enum SavePromptResult { SAVE, DONT_SAVE, CANCEL };
 
@@ -272,6 +275,7 @@ private slots:
 	SelectedPage m_selectedPage;
 	QObjectCleanupHandler m_optionsWidgetCleanup;
 	QObjectCleanupHandler m_imageWidgetCleanup;
+	std::auto_ptr<OutOfMemoryDialog> m_ptrOutOfMemoryDialog;
 	int m_curFilter;
 	int m_ignoreSelectionChanges;
 	int m_ignorePageOrderingChanges;

NonOwningWidget.cpp

@@ -0,0 +1,34 @@
+/*
+    Scan Tailor - Interactive post-processing tool for scanned pages.
+    Copyright (C)  Joseph Artsimovich <joseph.artsimovich@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "NonOwningWidget.h"
+#include <boost/foreach.hpp>
+
+NonOwningWidget::NonOwningWidget(QWidget* parent)
+:	QWidget(parent)
+{
+}
+
+NonOwningWidget::~NonOwningWidget()
+{
+	BOOST_FOREACH(QObject* child, children()) {
+		if (QWidget* widget = dynamic_cast<QWidget*>(child)) {
+			widget->setParent(0);
+		}
+	}
+}

NonOwningWidget.h

@@ -0,0 +1,36 @@
+/*
+    Scan Tailor - Interactive post-processing tool for scanned pages.
+    Copyright (C)  Joseph Artsimovich <joseph.artsimovich@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef NON_OWNING_WIDGET_H_
+#define NON_OWNING_WIDGET_H_
+
+#include <QWidget>
+
+/**
+ * \brief Your normal QWidget, except it doesn't delete its children with itself,
+ *        rather it calls setParent(0) on them.
+ */
+class NonOwningWidget : public QWidget
+{
+public:
+	NonOwningWidget(QWidget* parent = 0);
+
+	virtual ~NonOwningWidget();
+};
+
+#endif

OutOfMemoryDialog.cpp

@@ -0,0 +1,132 @@
+/*
+    Scan Tailor - Interactive post-processing tool for scanned pages.
+	Copyright (C)  Joseph Artsimovich <joseph.artsimovich@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "OutOfMemoryDialog.h"
+#include "OutOfMemoryDialog.h.moc"
+#include "ProjectWriter.h"
+#include "RecentProjects.h"
+#include <QFileDialog>
+#include <QMessageBox>
+#include <QFileInfo>
+#include <QSettings>
+#include <QVariant>
+
+OutOfMemoryDialog::OutOfMemoryDialog(QWidget* parent)
+:	QDialog(parent)
+{
+	ui.setupUi(this);
+
+	ui.topLevelStack->setCurrentWidget(ui.mainPage);
+
+	connect(ui.saveProjectBtn, SIGNAL(clicked()), SLOT(saveProject()));
+	connect(ui.saveProjectAsBtn, SIGNAL(clicked()), SLOT(saveProjectAs()));
+	connect(ui.dontSaveBtn, SIGNAL(clicked()), SLOT(reject()));
+}
+
+void
+OutOfMemoryDialog::setParams(
+	QString const& project_file,
+	IntrusivePtr<StageSequence> const& stages,
+	IntrusivePtr<ProjectPages> const& pages,
+	SelectedPage const& selected_page,
+	OutputFileNameGenerator const& out_file_name_gen)
+{
+	m_projectFile = project_file;
+	m_ptrStages = stages;
+	m_ptrPages = pages;
+	m_selectedPage = selected_page;
+	m_outFileNameGen = out_file_name_gen;
+
+	ui.saveProjectBtn->setVisible(!project_file.isEmpty());
+}
+
+void
+OutOfMemoryDialog::saveProject()
+{
+	if (m_projectFile.isEmpty()) {
+		saveProjectAs();
+	} else if (saveProjectWithFeedback(m_projectFile)) {
+		showSaveSuccessScreen();
+	}
+}
+
+void
+OutOfMemoryDialog::saveProjectAs()
+{
+	// XXX: this function is duplicated MainWindow
+
+	QString project_dir;
+	if (!m_projectFile.isEmpty()) {
+		project_dir = QFileInfo(m_projectFile).absolutePath();
+	} else {
+		QSettings settings;
+		project_dir = settings.value("project/lastDir").toString();
+	}
+
+	QString project_file(
+		QFileDialog::getSaveFileName(
+			this, QString(), project_dir,
+			tr("Scan Tailor Projects")+" (*.ScanTailor)"
+		)
+	);
+	if (project_file.isEmpty()) {
+		return;
+	}
+
+	if (!project_file.endsWith(".ScanTailor", Qt::CaseInsensitive)) {
+		project_file += ".ScanTailor";
+	}
+
+	if (saveProjectWithFeedback(project_file)) {
+		m_projectFile = project_file;
+		showSaveSuccessScreen();
+
+		QSettings settings;
+		settings.setValue(
+			"project/lastDir",
+			QFileInfo(m_projectFile).absolutePath()
+		);
+
+		RecentProjects rp;
+		rp.read();
+		rp.setMostRecent(m_projectFile);
+		rp.write();
+	}
+}
+
+bool
+OutOfMemoryDialog::saveProjectWithFeedback(QString const& project_file)
+{
+	ProjectWriter writer(m_ptrPages, m_selectedPage, m_outFileNameGen);
+
+	if (!writer.write(project_file, m_ptrStages->filters())) {
+		QMessageBox::warning(
+			this, tr("Error"),
+			tr("Error saving the project file!")
+		);
+		return false;
+	}
+
+	return true;
+}
+
+void
+OutOfMemoryDialog::showSaveSuccessScreen()
+{
+	ui.topLevelStack->setCurrentWidget(ui.saveSuccessPage);
+}