Files rewriting with backup

Author: vorlov-playrix

src/cegui/CEGUIProject.cpp

@@ -1,9 +1,11 @@
 #include "src/cegui/CEGUIProject.h"
 #include "src/cegui/CEGUIProjectItem.h"
+#include "src/Application.h"
 #include "qfile.h"
 #include "qdir.h"
 #include "qdom.h"
 #include "qtextstream.h"
+#include <qmessagebox.h>
 
 const QString CEGUIProject::EditorEmbeddedCEGUIVersion("1.0");
 const QStringList CEGUIProject::CEGUIVersions = { "0.6", "0.7", "0.8", "1.0" };
@@ -128,18 +130,43 @@ bool CEGUIProject::save(const QString& newFilePath)
     xmlRoot.appendChild(xmlItems);
     doc.appendChild(xmlRoot);
 
-    // Save to file
+    // If the file already exists, rename it to avoid data losing due to save error
+    const bool tmpUsed = QFileInfo(filePath).exists();
+    if (tmpUsed)
+    {
+        QFile prevFile(filePath);
+        if (!prevFile.rename(filePath + ".bak"))
+        {
+            QMessageBox::critical(qobject_cast<Application*>(qApp)->getMainWindow(),
+                                  "Error saving project!",
+                                  "CEED encountered an error trying to save the project file " + filePath);
+            return false;
+        }
+    }
 
+    // Save to file
     QFile file(filePath);
-    if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
+    if (file.open(QIODevice::WriteOnly | QIODevice::Text))
     {
-        qDebug(QString("CEGUIProject::save() > can't open the file for writing: %1").arg(filePath).toLocal8Bit().data());
-        return false;
+        QTextStream stream(&file);
+        doc.save(stream, 4);
+        file.close();
+        if (tmpUsed) QFile(filePath + ".bak").remove();
+        return true;
     }
 
-    QTextStream stream(&file);
-    doc.save(stream, 4);
-    return true;
+    // Something went wrong, show error and restore backup
+    QMessageBox::critical(qobject_cast<Application*>(qApp)->getMainWindow(),
+                          "Error saving project!",
+                          "CEED encountered an error trying to save the project file " + filePath);
+
+    if (tmpUsed)
+    {
+        QFile(filePath).remove();
+        QFile(filePath + ".bak").rename(filePath);
+    }
+
+    return false;
 }
 
 void CEGUIProject::unload()

src/editors/EditorBase.cpp

@@ -274,39 +274,67 @@ bool EditorBase::saveAs(const QString& targetPath)
     // watching it, so re-enabling monitor is necessary.
     enableFileMonitoring(false);
 
-    QFile file(actualPath);
-    if (!file.open(QIODevice::WriteOnly))
+    // If the file already exists, rename it to avoid data losing due to save error
+    const bool tmpUsed = QFileInfo(actualPath).exists();
+    if (tmpUsed)
     {
-        QMessageBox::critical(qobject_cast<Application*>(qApp)->getMainWindow(),
-                              "Error saving file!",
-                              "CEED encountered an error trying to save the file " + actualPath);
-        enableFileMonitoring(true);
-        return false;
+        QFile prevFile(actualPath);
+        if (!prevFile.rename(actualPath + ".bak"))
+        {
+            QMessageBox::critical(qobject_cast<Application*>(qApp)->getMainWindow(),
+                                  "Error saving file!",
+                                  "CEED encountered an error trying to save the file " + actualPath);
+            return false;
+        }
     }
 
-    // Do it before obtaining raw data since it may contain relative pathes.
-    // For example imageset XML contains a relative path to underlying image.
-    _filePath = actualPath;
+    QFile file(actualPath);
+    if (file.open(QIODevice::WriteOnly))
+    {
+        // Do it before obtaining raw data since it may contain relative pathes.
+        // For example imageset XML contains a relative path to underlying image.
+        _filePath = actualPath;
 
-    QByteArray rawData;
-    getRawData(rawData);
-/*
-    if self.compatibilityManager is not None:
-        outputData = self.compatibilityManager.transform(self.compatibilityManager.EditorNativeType, self.desiredSavingDataType, self.nativeData)
-*/
-    file.write(rawData);
-    file.close();
+        QByteArray rawData;
+        getRawData(rawData);
+        /*
+            if self.compatibilityManager is not None:
+                outputData = self.compatibilityManager.transform(self.compatibilityManager.EditorNativeType, self.desiredSavingDataType, self.nativeData)
+        */
 
-    enableFileMonitoring(true);
-    markAsUnchanged();
+        const auto written = file.write(rawData);
+        file.close();
+
+        if (written == rawData.size())
+        {
+            if (tmpUsed) QFile(actualPath + ".bak").remove();
+            enableFileMonitoring(true);
+
+            markAsUnchanged();
+
+            if (prevFilePath != _filePath)
+            {
+                _labelText = QFileInfo(_filePath).fileName();
+                emit filePathChanged(prevFilePath, _filePath);
+            }
 
-    if (prevFilePath != _filePath)
+            return true;
+        }
+    }
+
+    // Something went wrong, show error and restore backup
+    QMessageBox::critical(qobject_cast<Application*>(qApp)->getMainWindow(),
+                          "Error saving file!",
+                          "CEED encountered an error trying to save the file " + actualPath);
+
+    if (tmpUsed)
     {
-        _labelText = QFileInfo(_filePath).fileName();
-        emit filePathChanged(prevFilePath, _filePath);
+        QFile(actualPath).remove();
+        QFile(actualPath + ".bak").rename(actualPath);
     }
+    enableFileMonitoring(true);
 
-    return true;
+    return false;
 }
 
 // Either reload file from disk or confirm desynchronization

src/ui/MainWindow.cpp

@@ -660,7 +660,7 @@ void MainWindow::on_tabs_currentChanged(int index)
     const bool hasEditor = (currentEditor != nullptr);
     fsBrowser->activeFileDirectoryButton()->setEnabled(hasEditor);
     ui->actionRevert->setEnabled(hasEditor);
-    ui->actionSave->setEnabled(hasEditor);
+    ui->actionSave->setEnabled(hasEditor && currentEditor->hasChanges());
     ui->actionSaveAs->setEnabled(hasEditor);
     ui->actionCloseTab->setEnabled(hasEditor);
     ui->actionCloseOtherTabs->setEnabled(hasEditor);
@@ -680,7 +680,6 @@ void MainWindow::on_tabs_currentChanged(int index)
         {
             undoViewer->setUndoStack(undoStack);
 
-            ui->actionSave->setEnabled(undoStack->isClean());
             ui->actionUndo->setEnabled(undoStack->canUndo());
             ui->actionRedo->setEnabled(undoStack->canRedo());
             ui->actionUndo->setText("Undo " + undoStack->undoText());