FIXED/REWORKED issue https://github.com/jkriege2/JKQtPlotter/issues/111 : Can't write to PDF files with JKQTPlotter::saveImage() when passing a filename ending in ".pdf" (thanks to https://github.com/fpalazzolo for reporting)

IMPROVED/REWORKED: The functions JKQTBasePlotter::saveImage(), JKQTBasePlotter::saveAsPixelImage(), JKQTBasePlotter::saveAsPDF(), JKQTBasePlotter::saveSVG(), ... gained a bool return value to indicate whether sacing was successful.
IMPROVED/REWORKED: More <code>save...()</code> functions will appear in the API of JKQTPlotter, so you don't have to go via JKQTPlotter::getPlotter(). These are merely forwarding the call to the internel JKQTBasePlotter instance.

doc/dox/whatsnew.dox

@@ -47,6 +47,7 @@ Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
     <li>FIXED issue <a href="https://github.com/jkriege2/JKQtPlotter/pull/99">#99: Height of one-column key/legend was too large</a> (thanks to <a href="https://github.com/allenbarnett5">user:allenbarnett5/a> for reporting)</li>
     <li>FIXED/IMPROVED issue <a href="https://github.com/jkriege2/JKQtPlotter/issues/100">#100: Add option to disable resize delay feature by setting the delay to zero</a> (thanks to <a href="https://github.com/fpalazzolo">user:fpalazzolo</a> for reporting)</li>
     <li>FIXED/NEW: placement of plot-title (was not centerd in its box, but glued to the bottom) by adding a plotstyle parameter JKQTBasePlotterStyle::plotLabelOffset</li>
+    <li>FIXED/REWORKED issue <a href="https://github.com/jkriege2/JKQtPlotter/issues/111">#111: Can't write to PDF files with JKQTPlotter::saveImage() when passing a filename ending in ".pdf"</a> (thanks to <a href="https://github.com/fpalazzolo">user:fpalazzolo/a> for reporting):<br/>While fixing this issue, the functions JKQTBasePlotter::saveImage() etc. gained a bool return value to indicate whether sacing was successful.</li>
     <li>REORGANIZED: separated line-graphs from jkqtpscatter.h/.cpp into jkqtplines.h/.cpp</li>
     <li>IMPROVED: QT6-compatibility by removing deprecated warnings</li>
     <li>IMPROVED: added missing override declarations</li>
@@ -57,6 +58,8 @@ Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
     <li>IMPROVED/REWORKED: zomm/pan by mouse-wheel: now there are modes that support zoomin AND panning by trakpad and mouse-wheel simultaneously! This can only be implemented using heuristics, due to the way that Qt handles track-pad events, but the current solution should at least improve the behaviour seen before. Mainly <code>jkqtpmwaZoomByWheelAndTrackpadPan</code> was introduced into <code>JKQTPMouseWheelActions</code> und is set as default mode: Here JKQTPlotter tries to distinguish the QWheelEvent s sent by an actual mouse wheel and a trackpad.</li>
     <li>IMPROVED/REWORKED: better example graphs in \link JKQTPlotterStyling.</li>
     <li>IMPROVED/REWORKED: legend/key positioning as combination of 3 values, e.g. \c JKQTPKeyOutsideTop|JKQTPKeyTop|JKQTPKeyRight or \c JKQTPKeyInside|JKQTPKeyTopJKQTPKeyRight</li>
+    <li>IMPROVED/REWORKED: The functions JKQTBasePlotter::saveImage(), JKQTBasePlotter::saveAsPixelImage(), JKQTBasePlotter::saveAsPDF(), JKQTBasePlotter::saveSVG(), ... gained a bool return value to indicate whether sacing was successful.</li>
+    <li>IMPROVED/REWORKED: More <code>save...()</code> functions will appear in the API of JKQTPlotter, so you don't have to go via JKQTPlotter::getPlotter(). These are merely forwarding the call to the internel JKQTBasePlotter instance.</li>
     <li>IMPROVED: documentation of styles: automatized doc image generation.</li>
     <li>NEW: JKQTPFilledCurveXGraph and JKQTPFilledCurveYGraph can now plot wiggle plots with different fill styles above and below the baseline (feature request <a href="https://github.com/jkriege2/JKQtPlotter/issues/68">#68 Wiggle Plots</a> from <a href="https://github.com/xichaoqiang">user:xichaoqiang</a>   </li>
     <li>NEW/BREAKING CHANGE: data tooltip can now also be shown when "just" moving the mouse (so far this was only possible when dragging the mouse with a button pressed). This also removes JKQtPlotter::getActMouseLeftAsToolTip() and adds JKQtPlotter::getActMouseMoveToolTip() instead! Also the default toolbars and context menus changed!</li>

lib/jkqtplotter/jkqtpbaseplotter.cpp

@@ -3501,7 +3501,7 @@ void JKQTBasePlotter::saveAsGerExcelCSV(const QString& filename) {
 }
 
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-void JKQTBasePlotter::saveAsPDF(const QString& filename, bool displayPreview) {
+bool JKQTBasePlotter::saveAsPDF(const QString& filename, bool displayPreview) {
     loadUserSettings();
     QString fn=filename;
     if (fn.isEmpty()) {
@@ -3513,7 +3513,7 @@ void JKQTBasePlotter::saveAsPDF(const QString& filename, bool displayPreview) {
 
     if (!fn.isEmpty()) {
         emit beforeExporting();; auto __finalpaint=JKQTPFinally([&]() { emit afterExporting();});
-        QPrinter* printer=new QPrinter;
+        std::shared_ptr<QPrinter> printer=std::make_shared<QPrinter>();
         bool doLandscape=widgetWidth>widgetHeight;
         if (gridPrinting) {
             gridPrintingCalc();
@@ -3529,91 +3529,133 @@ void JKQTBasePlotter::saveAsPDF(const QString& filename, bool displayPreview) {
         printer->setOutputFileName(fn);
         printer->setPageMargins(QMarginsF(0,0,0,0),QPageLayout::Millimeter);
         printer->setColorMode(QPrinter::Color);
-        printpreviewNew(printer, true, -1.0, -1.0, displayPreview);
+        return printpreviewNew(printer.get(), true, -1.0, -1.0, displayPreview);
-        delete printer;
     }
     saveUserSettings();
+    return false;
 }
 #endif
 
-void JKQTBasePlotter::saveImage(const QString& filename, bool displayPreview) {
+bool JKQTBasePlotter::saveImage(const QString& filename, bool displayPreview) {
     loadUserSettings();
     QString fn=filename;
-    QStringList filt;
+    QStringList filterstrings;
+    QList<QStringList> filterextensions;
+
+    const auto findExporterByExtension=[&filterextensions](const QString& ext) {
+        const QString extl=ext.toLower();
+        for (int i=0; i<filterextensions.size(); i++) {
+            if (filterextensions[i].contains(extl)) return i;
+        }
+        return -1;
+    };
+
+    // add default exporters
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-    filt<<tr("Portable Document Format PDF [Qt] (*.pdf)");
+    filterstrings<<tr("Portable Document Format PDF [Qt] (*.pdf)");    filterextensions<<(QStringList()<<"pdf");
-    filt<<tr("Scalable Vector Graphics [Qt] (*.svg)");
+    const int idxDefaultPDF=filterstrings.size()-1;
+    filterstrings<<tr("Scalable Vector Graphics [Qt] (*.svg)");    filterextensions<<(QStringList()<<"svg");
+    const int idxDefaultSVG=filterstrings.size()-1;
 #endif
-    filt<<tr("PNG Image [Qt] (*.png)");
+    filterstrings<<tr("PNG Image [Qt] (*.png)");    filterextensions<<(QStringList()<<"png");
-    filt<<tr("BMP Image [Qt] (*.bmp)");
+    filterstrings<<tr("BMP Image [Qt] (*.bmp)");    filterextensions<<(QStringList()<<"bmp");
-    filt<<tr("TIFF Image [Qt] (*.tif *.tiff)");
+    filterstrings<<tr("TIFF Image [Qt] (*.tif *.tiff)");    filterextensions<<(QStringList()<<"tif"<<"tiff");
-    filt<<tr("JPEG Image [Qt] (*.jpg *.jpeg)");
+    filterstrings<<tr("JPEG Image [Qt] (*.jpg *.jpeg)");    filterextensions<<(QStringList()<<"jpg"<<"jpeg");
-    const int filtStartSize=filt.size();
+    //  add JKQTPPaintDeviceAdapter exporters
+    const int filtersIndexFirstExporterPLugin=filterstrings.size();
     {
         JKQTPSynchronized<QList<JKQTPPaintDeviceAdapter*>>::Locker lock(jkqtpPaintDeviceAdapters);
         for (int i=0; i<jkqtpPaintDeviceAdapters.get().size(); i++) {
-            filt<<jkqtpPaintDeviceAdapters.get()[i]->getFilter();
+            filterstrings<<jkqtpPaintDeviceAdapters.get()[i]->getFilter();
+            filterextensions<<QStringList();
+            for (const auto& ext: jkqtpPaintDeviceAdapters.get()[i]->getFileExtension()) filterextensions.last()<<ext.toLower();
         }
     }
-    int qtwritersidx=filt.size();
+    const bool isWithSpecialDeviceAdapter=(filterstrings.size()>filtersIndexFirstExporterPLugin);
-    QList<QByteArray> writerformats=QImageWriter::supportedImageFormats();
+    // add remaining QImageWriter exporters
+    const int filtersIndexFirstQtWriter=filterstrings.size();
+    const QList<QByteArray> writerformats=QImageWriter::supportedImageFormats();
     for (int i=0; i<writerformats.size(); i++) {
-        filt<<QString("%1 Image (*.%2)").arg(QString(writerformats[i]).toUpper()).arg(QString(writerformats[i].toLower()));
+        const QString ext=writerformats[i].toLower();
+        const int extIdx=findExporterByExtension(ext);
+        const QString name=writerformats[i].toUpper();
+        // only add QtWriters that are not yt contained in the default filters options
+        if (extIdx<0 || extIdx>=filtersIndexFirstExporterPLugin) {
+            filterstrings<<QString("%1 Image (*.%2)").arg(name).arg(ext);
+            filterextensions<<(QStringList()<<ext);
+        }
     }
-    QString selFormat="";
+
+    QString selFormat;
     if (fn.isEmpty()) {
         selFormat=currentFileFormat;
         fn = QFileDialog::getSaveFileName(nullptr, tr("Save Plot"),
                                     currentSaveDirectory,
-                                          filt.join(";;"), &selFormat);
+                                          filterstrings.join(";;"), &selFormat);
         if (!fn.isEmpty()) {
             currentSaveDirectory=QFileInfo(fn).absolutePath();
             currentFileFormat=selFormat;
         }
+    } else {
+        const QString fnExt=QFileInfo(filename).suffix().toLower();
+        const int filtidx=findExporterByExtension(fnExt);
+        if (filtidx>=0) selFormat=filterstrings[filtidx];
+
     }
 
     //qDebug()<<"fn="<<fn<<"  selFormat="<<selFormat;
 
     saveUserSettings();
     if (!fn.isEmpty()) {
-        int filtID=filt.indexOf(selFormat);
+        const QString fnExt=QFileInfo(filename).suffix().toLower();
-        JKQTPSynchronized<QList<JKQTPPaintDeviceAdapter*>>::Locker lock(jkqtpPaintDeviceAdapters);
 
-        bool isWithSpecialDeviceAdapter=filtID>=filtStartSize && filtID<filtStartSize+jkqtpPaintDeviceAdapters.get().size();
+        const int filtID=[&](){
-        int adapterID=filtID-filtStartSize;
+            // 1. look for the selected format
-        QString e=QFileInfo(filename).suffix().toLower();
+            int idx=filterstrings.indexOf(selFormat);
-        if (!isWithSpecialDeviceAdapter) {
+            // 2. if not found try to match up the file extension
-            for (int i=0; i<jkqtpPaintDeviceAdapters.get().size(); i++) {
+            if (idx<0) idx=findExporterByExtension(fnExt);
-                if (jkqtpPaintDeviceAdapters.get()[i]->getFileExtension().contains(e)) {
+            return idx;
-                    adapterID=i;
+        }();
-                    isWithSpecialDeviceAdapter=true;
+        JKQTPSynchronized<QList<JKQTPPaintDeviceAdapter*>>::Locker lock(jkqtpPaintDeviceAdapters);
-                    break;
+        // now we determine whether we selected a jkqtpPaintDeviceAdapters, if not adapterID will be <0
-                }
+        const int adapterID=[&](){
-            }
+            int idx=filtID-filtersIndexFirstExporterPLugin;
+            if (idx<0) idx=-1;
+            if (idx>=jkqtpPaintDeviceAdapters.get().size()) idx=-1;
+            return idx;
+        }();
+
+
+        if (filtID<0) {
+            qWarning()<<"You tried to save an image to to '"<<fn<<"', but JKQTPlottter did not recognize the file format!";
+            return false;
         }
-        //qDebug()<<"filtID="<<filtID<<"   isWithSpecialDeviceAdapter="<<isWithSpecialDeviceAdapter<<"   adapterID="<<adapterID;
+
+
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-        if (filtID==0) {
+        // SVG and PDF need to be treated separately!
-            saveAsPDF(fn, displayPreview);
+        if (filtID==idxDefaultPDF) {
-            return;
+            return saveAsPDF(fn, displayPreview);
         }
-        if (filtID==1) {
+        if (filtID==idxDefaultSVG) {
-            saveAsSVG(fn, displayPreview);
+            return saveAsSVG(fn, displayPreview);
-            return;
         }
 #endif
-        if (isWithSpecialDeviceAdapter && adapterID>=0 && adapterID<jkqtpPaintDeviceAdapters.get().size()) {
+
+        // we need to use a jkqtpPaintDeviceAdapters
+        if (adapterID>=0) {
             QString tempFM="";
             if (QFile::exists(fn)) {
+                // if the file fn already exists, we make a temporary copy, so it is not destroyed by the export process!
 #ifdef QFWIDLIB_LIBRARY
-                QFTemporaryFile* tf=new QFTemporaryFile();
+                QSharedPointer<QFTemporaryFile> tf=QSharedPointer<QTemporaryFile>(new QFTemporaryFile());
 #else
-                QTemporaryFile* tf=new QTemporaryFile();
+                QSharedPointer<QTemporaryFile> tf=QSharedPointer<QTemporaryFile>(new QTemporaryFile());
 #endif
                 tf->open();
                 tempFM=tf->fileName();
                 tf->close();
-                delete tf;
+                tf.reset();
                 QFile::copy(fn, tempFM);
             }
 
@@ -3621,35 +3663,33 @@ void JKQTBasePlotter::saveImage(const QString& filename, bool displayPreview) {
             emit beforeExporting();; auto __finalpaint=JKQTPFinally([&]() { emit afterExporting();});
 
             gridPrintingCalc();
-            QPaintDevice* paintDevice=jkqtpPaintDeviceAdapters.get()[adapterID]->createPaintdevice(fn, jkqtp_roundTo<int>(gridPrintingSize.width()), jkqtp_roundTo<int>(gridPrintingSize.height()));
+            QSharedPointer<QPaintDevice> paintDevice=QSharedPointer<QPaintDevice>(jkqtpPaintDeviceAdapters.get()[adapterID]->createPaintdevice(fn, jkqtp_roundTo<int>(gridPrintingSize.width()), jkqtp_roundTo<int>(gridPrintingSize.height())));
 
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-            if (!printpreviewNew(paintDevice, jkqtpPaintDeviceAdapters.get()[adapterID]->getSetAbsolutePaperSize(), jkqtpPaintDeviceAdapters.get()[adapterID]->getPrintSizeXInMM(), jkqtpPaintDeviceAdapters.get()[adapterID]->getPrintSizeYInMM(), displayPreview)) {
+            if (!printpreviewNew(paintDevice.get(), jkqtpPaintDeviceAdapters.get()[adapterID]->getSetAbsolutePaperSize(), jkqtpPaintDeviceAdapters.get()[adapterID]->getPrintSizeXInMM(), jkqtpPaintDeviceAdapters.get()[adapterID]->getPrintSizeYInMM(), displayPreview)) {
-                delete paintDevice;
-
-
                 if (QFile::exists(tempFM)) {
                     QFile::copy(tempFM, fn);
                     QFile::remove(tempFM);
                 }
-            } else {
+                return false;
-#else
+            } else
-            {
 #endif
-                delete paintDevice;
+            {
-                paintDevice=jkqtpPaintDeviceAdapters.get()[adapterID]->createPaintdeviceMM(fn,printSizeX_Millimeter,printSizeY_Millimeter);
+                paintDevice.reset(jkqtpPaintDeviceAdapters.get()[adapterID]->createPaintdeviceMM(fn,printSizeX_Millimeter,printSizeY_Millimeter));
-                printpreviewPaintRequestedNewPaintDevice(paintDevice);
+                printpreviewPaintRequestedNewPaintDevice(paintDevice.get());
-                delete paintDevice;
+                return true;
             }
 
         } else {
-            saveAsPixelImage(fn, displayPreview, writerformats.value(filtID-qtwritersidx, QByteArray()));
+            // here we can let Qt figure out the correct exporter
+            return saveAsPixelImage(fn, displayPreview, writerformats.value(filtID-filtersIndexFirstQtWriter, QByteArray()));
         }
     }
+    return false;
 }
 
 
-void JKQTBasePlotter::saveAsPixelImage(const QString& filename, bool displayPreview, const QByteArray& outputFormat, const QSize &outputSizeIncrease) {
+bool JKQTBasePlotter::saveAsPixelImage(const QString& filename, bool displayPreview, const QByteArray& outputFormat, const QSize &outputSizeIncrease) {
     loadUserSettings();
     QString fn=filename;
     QStringList filt;
@@ -3668,15 +3708,17 @@ void JKQTBasePlotter::saveAsPixelImage(const QString& filename, bool displayPrev
 
     saveUserSettings();
     if (!fn.isEmpty()) {
-        int filtID=filt.indexOf(selFormat);
+        const int filtID=filt.indexOf(selFormat);
         //QString ext=tolower(extract_file_ext(fn.toStdString()));
-        QString form="NONE";
+        const QString form=[&]()->QString{
-        if (filtID>=0 && filtID<writerformats.size()) {
+            if (filtID>=0 && filtID<writerformats.size()) {
-            form=writerformats[filtID];
+                return writerformats[filtID];
-        }
+            }
-        if (outputFormat.size()>0) {
+            if (outputFormat.size()>0) {
-            form =outputFormat;
+                return outputFormat;
-        }
+            }
+            return "NONE";
+        }();
 
 
         emit beforeExporting();; auto __finalpaint=JKQTPFinally([&]() { emit afterExporting();});
@@ -3692,26 +3734,29 @@ void JKQTBasePlotter::saveAsPixelImage(const QString& filename, bool displayPrev
 
             QImage png(QSizeF(double(printSizeX_Millimeter)+outputSizeIncrease.width(), double(printSizeY_Millimeter)+outputSizeIncrease.height()).toSize(), QImage::Format_ARGB32);
             png.fill(Qt::transparent);
-            JKQTPEnhancedPainter painter;
+            {
-            painter.begin(&png);
+                JKQTPEnhancedPainter painter;
-            painter.setRenderHint(JKQTPEnhancedPainter::Antialiasing);
+                painter.begin(&png);
-            painter.setRenderHint(JKQTPEnhancedPainter::TextAntialiasing);
+                painter.setRenderHint(JKQTPEnhancedPainter::Antialiasing);
-            painter.setRenderHint(JKQTPEnhancedPainter::SmoothPixmapTransform);
+                painter.setRenderHint(JKQTPEnhancedPainter::TextAntialiasing);
-#if (QT_VERSION<QT_VERSION_CHECK(6, 0, 0))
+                painter.setRenderHint(JKQTPEnhancedPainter::SmoothPixmapTransform);
-            painter.setRenderHint(JKQTPEnhancedPainter::NonCosmeticDefaultPen, true);
+    #if (QT_VERSION<QT_VERSION_CHECK(6, 0, 0))
-            painter.setRenderHint(JKQTPEnhancedPainter::HighQualityAntialiasing);
+                painter.setRenderHint(JKQTPEnhancedPainter::NonCosmeticDefaultPen, true);
-#endif
+                painter.setRenderHint(JKQTPEnhancedPainter::HighQualityAntialiasing);
+    #endif
 
-            /*calcPlotScaling(painter);
+                /*calcPlotScaling(painter);
-            gridPaint(painter, png.rect().size());*/\
+                gridPaint(painter, png.rect().size());*/\
-            //qDebug()<<QSize(printSizeX_Millimeter, printSizeY_Millimeter);
+                //qDebug()<<QSize(printSizeX_Millimeter, printSizeY_Millimeter);
-            exportpreviewPaintRequested(painter, QSize(jkqtp_roundTo<int>(printSizeX_Millimeter), jkqtp_roundTo<int>(printSizeY_Millimeter)));
+                exportpreviewPaintRequested(painter, QSize(jkqtp_roundTo<int>(printSizeX_Millimeter), jkqtp_roundTo<int>(printSizeY_Millimeter)));
-            painter.end();
+                painter.end();
-            if (form=="NONE") png.save(fn);
+            }
-            else png.save(fn, form.toLatin1().data());
+            if (form=="NONE") return png.save(fn);
+            else return png.save(fn, form.toLatin1().data());
         }
 
     }
+    return false;
 }
 
 QImage JKQTBasePlotter::grabPixelImage(QSize size, bool showPreview)
@@ -3843,7 +3888,8 @@ void JKQTBasePlotter::copyPixelImage(bool showPreview) {
 }
 
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-void JKQTBasePlotter::saveAsSVG(const QString& filename, bool displayPreview) {
+bool JKQTBasePlotter::saveAsSVG(const QString& filename, bool displayPreview) {
+    bool printed=false;
     loadUserSettings();
     QString fn=filename;
     if (fn.isEmpty()) {
@@ -3870,23 +3916,23 @@ void JKQTBasePlotter::saveAsSVG(const QString& filename, bool displayPreview) {
 
         emit beforeExporting();; auto __finalpaint=JKQTPFinally([&]() { emit afterExporting();});
         gridPrintingCalc();
-        QSvgGenerator* svg=new QSvgGenerator;
+        std::shared_ptr<QSvgGenerator> svg=std::make_shared<QSvgGenerator>();
         svg->setResolution(96);
         QSize size=QSizeF(gridPrintingSize.width()*25.4/svg->resolution(), gridPrintingSize.height()*25.4/svg->resolution()).toSize();
         svg->setSize(size);
         svg->setFileName(fn);
-
+        printed=printpreviewNew(svg.get(), true, -1.0, -1.0, displayPreview);
-        if (!printpreviewNew(svg, true, -1.0, -1.0, displayPreview)) {
+        if (!printed) {
             if (QFile::exists(tempFM)) {
                 QFile::copy(tempFM, fn);
                 QFile::remove(tempFM);
             }
         }
 
-        delete svg;
 
     }
     saveUserSettings();
+    return printed;
 }
 #endif
 

lib/jkqtplotter/jkqtpbaseplotter.h

@@ -72,7 +72,9 @@ JKQTPLOTTER_LIB_EXPORT void initJKQTBasePlotterResources();
 class JKQTPLOTTER_LIB_EXPORT JKQTPSaveDataAdapter {
     public:
         virtual ~JKQTPSaveDataAdapter() ;
+        /** \brief Filter-String for a Qt File-Dialog, e.g. <code>"CSV Files (*.csv)"</code> */
         virtual QString getFilter() const=0;
+        /** \brief actually save the table \a data into file \a filename . The parameter \a columnNames provides a name for each column */
         virtual void saveJKQTPData(const QString& filename, const QList<QVector<double> >& data, const QStringList& columnNames) const=0;
 };
 
@@ -82,9 +84,13 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPSaveDataAdapter {
 class JKQTPLOTTER_LIB_EXPORT JKQTPPaintDeviceAdapter {
     public:
         virtual ~JKQTPPaintDeviceAdapter()  {}
+        /** \brief Filter-String for a Qt File-Dialog, e.g. <code>"JPEG Files (*.jpg)"</code> */
         virtual QString getFilter() const=0;
+        /** \brief Human readable name for the format */
         virtual QString getFormatName() const=0;
+        /** \brief a plugin-ID, i.e. a unique name for this format plugin, e.g. \c MyPluginExport_JPEG */
         virtual QString getFormatID() const=0;
+        /** \brief returns a list (in lower-case) of the file extensions supported by this plugin, e.g. \c {"jpg","jpeg"} */
         virtual QStringList getFileExtension() const=0;
         virtual bool getSetAbsolutePaperSize() const=0;
         virtual double getPrintSizeXInMM() const =0;
@@ -1731,8 +1737,9 @@ class JKQTPLOTTER_LIB_EXPORT JKQTBasePlotter: public QObject {
          *  \param displayPreview if \c true a dialog is shown that allows to modify the generated output (zoo, scaling, ...)
          *  \param outputFormmat specify the file format for the generated file
          *  \param  outputSizeIncrease if given, the size of the generated pixel image is increased by this number of pixels in addition to the required space
+         *  \return returns \c true on success
          */
-        void saveAsPixelImage(const QString& filename=QString(""), bool displayPreview=true, const QByteArray &outputFormat=QByteArray(), const QSize& outputSizeIncrease=QSize(0,0));
+        bool saveAsPixelImage(const QString& filename=QString(""), bool displayPreview=true, const QByteArray &outputFormat=QByteArray(), const QSize& outputSizeIncrease=QSize(0,0));
 
         /** \brief save the current plot as a pixel image into a QImage with the given size */
         QImage grabPixelImage(QSize size=QSize(), bool showPreview=false);
@@ -1741,21 +1748,34 @@ class JKQTPLOTTER_LIB_EXPORT JKQTBasePlotter: public QObject {
 
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
         /** \brief save the current plot as a SVG file, with the current widget aspect ratio, if filename is empty a file selection dialog is displayed
+         *
+         *   \param filename the filename to save to, if empty a file save dialog is displayed
+         *   \param displayPreview if \C true, a save/print-preview dialog is displayed that allows to make some modifications to the generated image, otherwise the image is saved with default settings.
+         *   \return Returns \c true if the file was save successfully
          *
          *  \note Exporting to SVG requires QPrinter-support, if it is not available on your platform, this function will not be available either!
          */
-        void saveAsSVG(const QString& filename=QString(""), bool displayPreview=true);
+        bool saveAsSVG(const QString& filename=QString(""), bool displayPreview=true);
 
         /** \brief save the current plot as a PDF file, with the current widget aspect ratio, if filename is empty a file selection dialog is displayed
+         *
+         *   \param filename the filename to save to, if empty a file save dialog is displayed
+         *   \param displayPreview if \C true, a save/print-preview dialog is displayed that allows to make some modifications to the generated image, otherwise the image is saved with default settings.
+         *   \return Returns \c true if the file was save successfully
          *
          *  \note Exporting to PDF requires QPrinter-support, if it is not available on your platform, this function will not be available either!
          */
-        void saveAsPDF(const QString& filename=QString(""), bool displayPreview=true);
+        bool saveAsPDF(const QString& filename=QString(""), bool displayPreview=true);
 #endif
 
         /** \brief save the current plot as an image file, with the current widget aspect ratio, if filename is empty a file selection dialog is displayed.
-        *          The image format is extracted from the file extension (jpeg, tiff, png, pdf, ...) */
+        *          The image format is extracted from the file extension (jpeg, tiff, png, pdf, ...)
-        void saveImage(const QString& filename=QString(""), bool displayPreview=true);
+        *
+        *   \param filename the filename to save to, if empty a file save dialog is displayed
+        *   \param displayPreview if \C true, a save/print-preview dialog is displayed that allows to make some modifications to the generated image, otherwise the image is saved with default settings.
+        *   \return Returns \c true if the file was save successfully
+        */
+        bool saveImage(const QString& filename=QString(""), bool displayPreview=true);
 
         /** \brief save the data used for the current plot. The file format is extracted from the file extension (csv, ...)
          *

lib/jkqtplotter/jkqtplotter.h

@@ -408,19 +408,13 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPlotter: public QWidget {
         const JKQTBasePlotter* getConstplotter() const { return const_cast<const JKQTBasePlotter*>(plotter); }
 
 
-        /** \brief returns the JKQTPBaseKey object representing the main plot key/legend
+        /** \copydoc JKQTBasePlotter::getMainKey()  */
-         *
-         *  \see JKQTBasePlotter::getMainKey()
-         */
         inline JKQTPBaseKey* getMainKey()
         {
             return plotter->getMainKey();
         }
 
-        /** \brief returns the JKQTPBaseKey object representing the main plot key/legend
+        /** \copydoc JKQTBasePlotter::getMainKey()  */
-         *
-         *  \see JKQTBasePlotter::getMainKey()
-         */
         inline const JKQTPBaseKey* getMainKey() const
         {
             return plotter->getMainKey();
@@ -613,18 +607,13 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPlotter: public QWidget {
 
 
 
-        /** \brief returns a pointer to the datastore used by this object */
+        /** \copydoc JKQTBasePlotter::getDatastore()  */
         inline JKQTPDatastore* getDatastore() { return plotter->getDatastore(); }
 
-        /** \brief returns a pointer to the datastore used by this object */
+        /** \copydoc JKQTBasePlotter::getDatastore()  */
         inline const JKQTPDatastore* getDatastore() const { return plotter->getDatastore(); }
 
-        /** \brief tells the plotter object to use the given external datastore.
+        /** \copydoc JKQTBasePlotter::useExternalDatastore()  */
-         *
-         * If the current datastore is internally managed, this method will free that object and use the supplied datastore
-         * with external management. If the current datastore is already external, this method will simply replace it by the
-         * new one.
-         */
         inline void useExternalDatastore(JKQTPDatastore* newStore) { plotter->useExternalDatastore(newStore); }
 
         /** \copydoc JKQTBasePlotter::useAsInternalDatastore() */
@@ -930,7 +919,7 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPlotter: public QWidget {
     public Q_SLOTS:
         /** \brief set the current plot magnification */
         void setMagnification(double m);
-        /** \brief sets x/ymin and x/ymax to the supplied values and replots the graph (zoom operation!) */
+        /** \copydoc JKQTBasePlotter::zoom() */
         inline void zoom(double nxmin, double nxmax, double nymin, double nymax) {
             plotter->zoom(nxmin, nxmax, nymin, nymax);
         }
@@ -991,61 +980,70 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPlotter: public QWidget {
             plotter->setShowZeroAxes(showXY);
         }
 
-        /** \brief save the current plot as an image file, with the current widget aspect ratio, if filename is empty a file selection dialog is displayed.
+        /** \copydoc JKQTBasePlotter::saveImage() */
-        *          The image format is extracted from the file extension (jpeg, tiff, png, pdf, ...) */
+        inline bool saveImage(const QString& filename=QString(""), bool displayPreview=true) {
-        inline void saveImage(const QString& filename=QString(""), bool displayPreview=true) {
+            return plotter->saveImage(filename, displayPreview);
-            plotter->saveImage(filename, displayPreview);
         }
 
-        /** \brief save the data used for the current plot. The file format is extracted from the file extension (csv, ...)
+        /** \copydoc JKQTBasePlotter::saveAsPixelImage() */
-         *
+        inline bool saveAsPixelImage(const QString& filename=QString(""), bool displayPreview=true, const QByteArray &outputFormat=QByteArray(), const QSize& outputSizeIncrease=QSize(0,0)) {
-         * The parameter \a format specifies the export format. if it is empty the format will be choosen according to the file extension, or
+            return plotter->saveAsPixelImage(filename, displayPreview, outputFormat, outputSizeIncrease);
-         * if \a filename is also empty the format will be choosen according to what is selected in the file selection dialog.
+        }
-         *
+
-         * If \a format is \c "slk" the output will be in SYLK format, if \a format is \c "csv" or \a "dat" the output will be comma separated values
+#ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-         * and if \a format is \c "txt" the output will be tab separated values.
+        /** \copydoc JKQTBasePlotter::saveAsSVG() */
-         */
+        inline bool saveAsSVG(const QString& filename=QString(""), bool displayPreview=true) { return plotter->saveAsSVG(filename, displayPreview); }
+        /** \copydoc JKQTBasePlotter::saveAsPDF() */
+        inline bool saveAsPDF(const QString& filename=QString(""), bool displayPreview=true) { return plotter->saveAsPDF(filename, displayPreview); }
+#endif
+
+        /** \copydoc JKQTBasePlotter::saveAsCSV() */
+        inline void saveAsCSV(const QString& filename=QString("")) { plotter->saveAsCSV(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsSemicolonSV() */
+        inline void saveAsSemicolonSV(const QString& filename=QString("")) { plotter->saveAsSemicolonSV(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsTabSV() */
+        inline void saveAsTabSV(const QString& filename=QString("")) { plotter->saveAsTabSV(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsDIF() */
+        inline void saveAsDIF(const QString& filename=QString("")) { plotter->saveAsDIF(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsSYLK() */
+        inline void saveAsSYLK(const QString& filename=QString("")) { plotter->saveAsSYLK(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsMatlab() */
+        inline void saveAsMatlab(const QString& filename=QString("")) { plotter->saveAsMatlab(filename); }
+        /** \copydoc JKQTBasePlotter::saveAsGerExcelCSV() */
+        inline void saveAsGerExcelCSV(const QString& filename=QString("")) { plotter->saveAsGerExcelCSV(filename); }
+
+
+        /** \copydoc JKQTBasePlotter::saveData() */
         inline void saveData(const QString& filename=QString(""), const QString& format=QString("")) {
             plotter->saveData(filename, format);
         }
 
 #ifndef JKQTPLOTTER_COMPILE_WITHOUT_PRINTSUPPORT
-        /** \brief print the current plot, if printer is \c nullptr a printer selection dialog is displayed */
+        /** \copydoc JKQTBasePlotter::print() */
         inline void print(QPrinter* printer=nullptr) {
             plotter->print(printer);
         }
 #endif
 
-        /** \brief copy displayed data to cpliboard */
+        /** \copydoc JKQTBasePlotter::copyData() */
         inline void copyData() {
             plotter->copyData();
         }
 
-        /** \brief copy displayed data to cpliboard in Matlab syntax */
+        /** \copydoc JKQTBasePlotter::copyDataMatlab() */
         inline void copyDataMatlab() {
             plotter->copyDataMatlab();
         }
 
 
-        /** \brief this method zooms the graph so that all plotted datapoints are visible.
+        /** \copydoc JKQTBasePlotter::zoomToFit() */
-         *
-         * \param zoomX if set \c true (default) zooms the x axis
-         * \param zoomY if set \c true (default) zooms the y axis
-         * \param includeX0 if this is \c true zoomToFit() will ensure that \f$ x=0 \f$ is visible in the plot (only for non-logx plots, default: false)
-         * \param includeY0 if this is \c true zoomToFit() will ensure that \f$ y=0 \f$ is visible in the plot (only for non-logy plots, default: false)
-         * \param scaleX the plot will have a width of \f$ \mbox{Xscale}\cdot\Delta x \f$ where \f$ \Delta x \f$ is the actual x-axis data range
-         *               For logx plots we actually use this on the logarithmized data! (default: 1.05)
-         * \param scaleY the plot will have a height of \f$ \mbox{Yscale}\cdot\Delta < \f$ where \f$ \Delta < \f$ is the actual <-axis data range
-         *               For log< plots we actually use this on the logarithmized data! (default: 1.05)
-         *
-         */
         inline void zoomToFit(bool zoomX=true, bool zoomY=true, bool includeX0=false, bool includeY0=false, double scaleX=1.05, double scaleY=1.05) {
             plotter->zoomToFit(zoomX, zoomY, includeX0, includeY0, scaleX, scaleY);
         }
 
-        /** \brief zooms into the graph (the same as turning the mouse wheel) by the given factor */
+        /** \copydoc JKQTBasePlotter::zoomIn() */
         inline void zoomIn(double factor=2.0) { plotter->zoomIn(factor); }
-        /** \brief zooms out of the graph (the same as turning the mouse wheel) by the given factor */
+        /** \copydoc JKQTBasePlotter::zoomOut() */
         inline void zoomOut(double factor=2.0) { plotter->zoomOut(factor); }
 
         /** \brief update the plot and the overlays */
@@ -1151,95 +1149,22 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPlotter: public QWidget {
         /** \brief open the standard context menu with the special context menu integrated at the mouse position \a x and \a y \see \ref JKQTPLOTTER_CONTEXTMENU , \ref JKQTPLOTTER_SPECIALCONTEXTMENU, \ref JKQTPLOTTER_USERMOUSEINTERACTION */
         void openStandardAndSpecialContextMenu(int x, int y);
 
-        /** \brief sets absolutely limiting x-range of the plot
+        /** \copydoc JKQTBasePlotter::setAbsoluteX()  */
-         *
-         *  \param xminn absolute minimum of x-axis
-         *  \param xmaxx absolute maximum of x-axis
-         *
-         * \note if the aspect ratio of this does not fit into the widget, it is possible that you don't see the complete contents!
-         *
-         * \see setAbsoluteXY(), setAbsoluteY(), JKQTBasePlotter::setAbsoluteX()
-         */
         inline void setAbsoluteX(double xminn, double xmaxx) { plotter->setAbsoluteX(xminn, xmaxx); }
 
-        /** \brief sets absolute minimum and maximum y-value to plot
+        /** \copydoc JKQTBasePlotter::setAbsoluteY()  */
-         *
-         *  \param yminn absolute minimum of y-axis
-         *  \param ymaxx absolute maximum of y-axis
-         *
-         * \note if the aspect ratio of this does not fit into the widget, it is possible that you don't see the complete contents!
-         *
-         * \see setAbsoluteXY(), setAbsoluteX(), JKQTBasePlotter::setAbsoluteY()
-         */
         inline void setAbsoluteY(double yminn, double ymaxx) { plotter->setAbsoluteY(yminn, ymaxx); }
 
-        /** \brief sets absolutely limiting x- and y-range of the plot
+        /** \copydoc JKQTBasePlotter::setAbsoluteXY()  */
-         *
-         * The user (or programmer) cannot zoom to a viewport that is larger than the range given to this function.
-         *
-         *  \param xminn absolute minimum of x-axis
-         *  \param xmaxx absolute maximum of x-axis
-         *  \param yminn absolute minimum of y-axis
-         *  \param ymaxx absolute maximum of y-axis
-         *
-         * \note if the aspect ratio of this does not fit into the widget, it is possible that you don't see the complete contents!
-         *
-         * \see setAbsoluteX(), setAbsoluteY(), zoomToFit(), JKQTBasePlotter::setAbsoluteXY()
-         */
         inline void setAbsoluteXY(double xminn, double xmaxx, double yminn, double ymaxx) { plotter->setAbsoluteXY(xminn, xmaxx, yminn, ymaxx); }
 
-        /** \brief sets the x-range of the plot (minimum and maximum x-value on the x-axis)
+        /** \copydoc JKQTBasePlotter::setX()  */
-         *
-         *  \param xminn absolute minimum of x-axis
-         *  \param xmaxx absolute maximum of x-axis
-         *
-         * \note You cannot expand the x-range outside the absolute x-range set e.g. by setAbsoluteX()!
-         *       Also the range will be limited to possible values (e.g. to positive values if you use
-         *       logarithmic axes).
-         *
-         * Uppon setting, this function emits the signal zoomChangedLocally(), if emitting signals
-         * is activated at the moment (e.g. using JKQTBasePlotter::setEmittingSignalsEnabled() ).
-         *
-         * \see setY(), setXY(), zoomToFit(), setAbsoluteXY(), JKQTBasePlotter::setY()
-         */
         inline void setX(double xminn, double xmaxx) { plotter->setX(xminn, xmaxx); }
 
-        /** \brief sets the y-range of the plot (minimum and maximum y-value on the y-axis)
+        /** \copydoc JKQTBasePlotter::setY()  */
-         *
-         *  \param yminn absolute minimum of y-axis
-         *  \param ymaxx absolute maximum of y-axis
-         *
-         * \note You cannot expand the y-range outside the absolute y-range set e.g. by setAbsoluteY()!
-         *       Also the range will be limited to possible values (e.g. to positive values if you use
-         *       logarithmic axes).
-         *
-         * Uppon setting, this function emits the signal zoomChangedLocally(), if emitting signals
-         * is activated at the moment (e.g. using JKQTBasePlotter::setEmittingSignalsEnabled() ).
-         *
-         * \see setX(), setXY(), zoomToFit(), setAbsoluteXY(), JKQTBasePlotter::setX()
-         */
         inline void setY(double yminn, double ymaxx) { plotter->setY(yminn, ymaxx); }
 
-        /** \brief sets the x- and y-range of the plot (minimum and maximum values on the x-/y-axis)
+        /** \copydoc JKQTBasePlotter::setXY()  */
-         *
-         *  \param xminn absolute minimum of x-axis
-         *  \param xmaxx absolute maximum of x-axis
-         *  \param yminn absolute minimum of y-axis
-         *  \param ymaxx absolute maximum of y-axis
-         *  \param affectsSecondaryAxes if \c true, the secondary axes are affectedtoo, by using a relative zooming scheme,
-         *                              i.e. if a major axis range shrinks by 50%, also the secondary ranges shrink by 50%
-         *                              [default: \c false]
-         *
-         *
-         * \note You cannot expand the ranges outside the absolute ranges set e.g. by setAbsoluteXY()!
-         *       Also the range will be limited to possible values (e.g. to positive values if you use
-         *       logarithmic axes).
-         *
-         * Uppon setting, this function emits the signal zoomChangedLocally(), if emitting signals
-         * is activated at the moment (e.g. using JKQTBasePlotter::setEmittingSignalsEnabled() ).
-         *
-         * \see setX(), setX(), zoomToFit(), setAbsoluteXY(), JKQTBasePlotter::setXY()
-         */
          inline void setXY(double xminn, double xmaxx, double yminn, double ymaxx, bool affectsSecondaryAxes=false) { plotter->setXY(xminn, xmaxx, yminn, ymaxx, affectsSecondaryAxes); }
     Q_SIGNALS:
         /** \brief emitted whenever the mouse moves