Allow importing and exporting to GIMP palette file (gpl) from color list

Author: nyalldawson

python/core/symbology-ng/qgssymbollayerv2utils.sip

@@ -217,6 +217,25 @@ class QgsSymbolLayerV2Utils
      */
     static QMimeData* colorListToMimeData( const QgsNamedColorList colorList, const bool allFormats = true );
 
+    /**
+     * Exports colors to a gpl GIMP palette file
+     * @param file destination file
+     * @param paletteName name of palette, which is stored in gpl file
+     * @param colors colors to export
+     * @returns true if export was successful
+     * @see importColorsFromGpl
+    */
+    static bool saveColorsToGpl( QFile &file, const QString paletteName, QgsNamedColorList colors );
+
+    /**
+     * Imports colors from a gpl GIMP palette file
+     * @param file source gpl file
+     * @param ok will be true if file was successfully read
+     * @returns list of imported colors
+     * @see saveColorsToGpl
+    */
+    static QgsNamedColorList importColorsFromGpl( QFile &file, bool &ok );
+    
     /**
      * Attempts to parse a string as a color using a variety of common formats, including hex
      * codes, rgb and rgba strings.

python/gui/qgscolorschemelist.sip

@@ -120,14 +120,26 @@ class QgsColorSchemeList: QTreeView
      */
     void setScheme( QgsColorScheme* scheme, const QString context = QString(), const QColor baseColor = QColor() );
 
-  public slots:
-
     /**Saves the current colors shown in the list back to a color scheme, if supported
      * by the color scheme.
      * @note this method is only effective if the color scheme is editable
      */
     bool saveColorsToScheme();
 
+    /**Import colors from a GPL palette file to the list
+     * @param file file to import
+     * @see exportColorsToGpl
+     */
+    bool importColorsFromGpl( QFile &file );
+
+    /**Export colors to a GPL palette file from the list
+     * @param file destination file
+     * @see importColorsFromGpl
+     */
+    bool exportColorsToGpl( QFile &file );
+    
+  public slots:
+
     /**Removes any selected colors from the list
      */
     void removeSelection();

src/app/qgsoptions.cpp

@@ -2089,3 +2089,61 @@ void QgsOptions::on_mButtonAddColor_clicked()
 
   mTreeCustomColors->addColor( newColor );
 }
+
+void QgsOptions::on_mButtonImportColors_clicked()
+{
+  QSettings s;
+  QString lastDir = s.value( "/UI/lastGplPaletteDir", "" ).toString();
+  QString filePath = QFileDialog::getOpenFileName( this, tr( "Select palette file" ), lastDir, "GPL (*.gpl);;All files (*.*)" );
+  activateWindow();
+  if ( filePath.isEmpty() )
+  {
+    return;
+  }
+
+  //check if file exists
+  QFileInfo fileInfo( filePath );
+  if ( !fileInfo.exists() || !fileInfo.isReadable() )
+  {
+    QMessageBox::critical( 0, tr( "Invalid file" ), tr( "Error, file does not exist or is not readable" ) );
+    return;
+  }
+
+  s.setValue( "/UI/lastGplPaletteDir", fileInfo.absolutePath() );
+  QFile file( filePath );
+  bool importOk = mTreeCustomColors->importColorsFromGpl( file );
+  if ( !importOk )
+  {
+    QMessageBox::critical( 0, tr( "Invalid file" ), tr( "Error, no colors found in palette file" ) );
+    return;
+  }
+}
+
+void QgsOptions::on_mButtonExportColors_clicked()
+{
+  QSettings s;
+  QString lastDir = s.value( "/UI/lastGplPaletteDir", "" ).toString();
+  QString fileName = QFileDialog::getSaveFileName( this, tr( "Palette file" ), lastDir, "GPL (*.gpl)" );
+  activateWindow();
+  if ( fileName.isEmpty() )
+  {
+    return;
+  }
+
+  // ensure filename contains extension
+  if ( !fileName.toLower().endsWith( ".gpl" ) )
+  {
+    fileName += ".gpl";
+  }
+
+  QFileInfo fileInfo( fileName );
+  s.setValue( "/UI/lastGplPaletteDir", fileInfo.absolutePath() );
+
+  QFile file( fileName );
+  bool exportOk = mTreeCustomColors->exportColorsToGpl( file );
+  if ( !exportOk )
+  {
+    QMessageBox::critical( 0, tr( "Error exporting" ), tr( "Error writing palette file" ) );
+    return;
+  }
+}

src/app/qgsoptions.h

@@ -242,6 +242,8 @@ class APP_EXPORT QgsOptions : public QgsOptionsDialogBase, private Ui::QgsOption
     void on_mAddDefaultTransformButton_clicked();
 
     void on_mButtonAddColor_clicked();
+    void on_mButtonImportColors_clicked();
+    void on_mButtonExportColors_clicked();
 
   private:
     QStringList i18nList();

src/app/qgsprojectproperties.cpp

@@ -1684,3 +1684,61 @@ void QgsProjectProperties::on_mButtonAddColor_clicked()
 
   mTreeProjectColors->addColor( newColor );
 }
+
+void QgsProjectProperties::on_mButtonImportColors_clicked()
+{
+  QSettings s;
+  QString lastDir = s.value( "/UI/lastGplPaletteDir", "" ).toString();
+  QString filePath = QFileDialog::getOpenFileName( this, tr( "Select palette file" ), lastDir, "GPL (*.gpl);;All files (*.*)" );
+  activateWindow();
+  if ( filePath.isEmpty() )
+  {
+    return;
+  }
+
+  //check if file exists
+  QFileInfo fileInfo( filePath );
+  if ( !fileInfo.exists() || !fileInfo.isReadable() )
+  {
+    QMessageBox::critical( 0, tr( "Invalid file" ), tr( "Error, file does not exist or is not readable" ) );
+    return;
+  }
+
+  s.setValue( "/UI/lastGplPaletteDir", fileInfo.absolutePath() );
+  QFile file( filePath );
+  bool importOk = mTreeProjectColors->importColorsFromGpl( file );
+  if ( !importOk )
+  {
+    QMessageBox::critical( 0, tr( "Invalid file" ), tr( "Error, no colors found in palette file" ) );
+    return;
+  }
+}
+
+void QgsProjectProperties::on_mButtonExportColors_clicked()
+{
+  QSettings s;
+  QString lastDir = s.value( "/UI/lastGplPaletteDir", "" ).toString();
+  QString fileName = QFileDialog::getSaveFileName( this, tr( "Palette file" ), lastDir, "GPL (*.gpl)" );
+  activateWindow();
+  if ( fileName.isEmpty() )
+  {
+    return;
+  }
+
+  // ensure filename contains extension
+  if ( !fileName.toLower().endsWith( ".gpl" ) )
+  {
+    fileName += ".gpl";
+  }
+
+  QFileInfo fileInfo( fileName );
+  s.setValue( "/UI/lastGplPaletteDir", fileInfo.absolutePath() );
+
+  QFile file( fileName );
+  bool exportOk = mTreeProjectColors->exportColorsToGpl( file );
+  if ( !exportOk )
+  {
+    QMessageBox::critical( 0, tr( "Error exporting" ), tr( "Error writing palette file" ) );
+    return;
+  }
+}

src/app/qgsprojectproperties.h

@@ -167,6 +167,8 @@ class APP_EXPORT QgsProjectProperties : public QgsOptionsDialogBase, private Ui:
     void projectionSelectorInitialized();
 
     void on_mButtonAddColor_clicked();
+    void on_mButtonImportColors_clicked();
+    void on_mButtonExportColors_clicked();
 
   signals:
     //! Signal used to inform listeners that the mouse display precision may have changed

src/core/qgscolorscheme.h

@@ -81,7 +81,6 @@ class CORE_EXPORT QgsColorScheme
      * @returns copy of color scheme
     */
     virtual QgsColorScheme* clone() const = 0;
-
 };
 
 /** \ingroup core

src/core/symbology-ng/qgssymbollayerv2utils.cpp

@@ -2953,6 +2953,101 @@ QMimeData* QgsSymbolLayerV2Utils::colorListToMimeData( const QgsNamedColorList c
   return mimeData;
 }
 
+bool QgsSymbolLayerV2Utils::saveColorsToGpl( QFile &file, const QString paletteName, QgsNamedColorList colors )
+{
+  if ( !file.open( QIODevice::ReadWrite ) )
+  {
+    return false;
+  }
+
+  QTextStream stream( &file );
+  stream << "GIMP Palette" << endl;
+  if ( paletteName.isEmpty() )
+  {
+    stream << "Name: QGIS Palette" << endl;
+  }
+  else
+  {
+    stream << "Name: " << paletteName << endl;
+  }
+  stream << "Columns: 4" << endl;
+  stream << "#" << endl;
+
+  for ( QgsNamedColorList::ConstIterator colorIt = colors.constBegin(); colorIt != colors.constEnd(); ++colorIt )
+  {
+    QColor color = ( *colorIt ).first;
+    if ( !color.isValid() )
+    {
+      continue;
+    }
+    stream << QString( "%1 %2 %3" ).arg( color.red(), 3 ).arg( color.green(), 3 ).arg( color.blue(), 3 );
+    stream << "\t" << (( *colorIt ).second.isEmpty() ? color.name() : ( *colorIt ).second ) << endl;
+  }
+  file.close();
+
+  return true;
+}
+
+QgsNamedColorList QgsSymbolLayerV2Utils::importColorsFromGpl( QFile &file, bool &ok )
+{
+  QgsNamedColorList importedColors;
+
+  if ( !file.open( QIODevice::ReadOnly ) )
+  {
+    ok = false;
+    return importedColors;
+  }
+
+  QTextStream in( &file );
+
+  QString line = in.readLine();
+  if ( !line.startsWith( "GIMP Palette" ) )
+  {
+    ok = false;
+    return importedColors;
+  }
+
+  //ignore lines until after "#"
+  while ( !in.atEnd() && !line.startsWith( "#" ) )
+  {
+    line = in.readLine();
+  }
+  if ( in.atEnd() )
+  {
+    ok = false;
+    return importedColors;
+  }
+
+  //ready to start reading colors
+  while ( !in.atEnd() )
+  {
+    line = in.readLine();
+    QStringList parts = line.simplified().split( " " );
+    if ( parts.length() < 3 )
+    {
+      continue;
+    }
+    int red = parts.at( 0 ).toInt();
+    int green = parts.at( 1 ).toInt();
+    int blue = parts.at( 2 ).toInt();
+    QColor color = QColor( red, green, blue );
+
+    //try to read color name
+    QString label;
+    parts = line.split( "\t" );
+    if ( parts.length() > 1 )
+    {
+      label = parts.at( parts.length() - 1 );
+    }
+
+    importedColors << qMakePair( color, label );
+  }
+
+  file.close();
+  ok = true;
+  return importedColors;
+}
+
 QColor QgsSymbolLayerV2Utils::parseColor( QString colorStr , bool strictEval )
 {
   bool hasAlpha;

src/core/symbology-ng/qgssymbollayerv2utils.h

@@ -255,6 +255,25 @@ class CORE_EXPORT QgsSymbolLayerV2Utils
      */
     static QMimeData* colorListToMimeData( const QgsNamedColorList colorList, const bool allFormats = true );
 
+    /**
+     * Exports colors to a gpl GIMP palette file
+     * @param file destination file
+     * @param paletteName name of palette, which is stored in gpl file
+     * @param colors colors to export
+     * @returns true if export was successful
+     * @see importColorsFromGpl
+    */
+    static bool saveColorsToGpl( QFile &file, const QString paletteName, QgsNamedColorList colors );
+
+    /**
+     * Imports colors from a gpl GIMP palette file
+     * @param file source gpl file
+     * @param ok will be true if file was successfully read
+     * @returns list of imported colors
+     * @see saveColorsToGpl
+    */
+    static QgsNamedColorList importColorsFromGpl( QFile &file, bool &ok );
+
     /**
      * Attempts to parse a string as a color using a variety of common formats, including hex
      * codes, rgb and rgba strings.

src/gui/qgscolorschemelist.cpp

@@ -131,6 +131,37 @@ void QgsColorSchemeList::copyColors()
   QApplication::clipboard()->setMimeData( mimeData );
 }
 
+bool QgsColorSchemeList::importColorsFromGpl( QFile &file )
+{
+  QgsNamedColorList importedColors;
+  bool ok = false;
+  importedColors = QgsSymbolLayerV2Utils::importColorsFromGpl( file, ok );
+  if ( !ok )
+  {
+    return false;
+  }
+
+  if ( importedColors.length() == 0 )
+  {
+    //no imported colors
+    return false;
+  }
+
+  //insert imported colors
+  QgsNamedColorList::const_iterator colorIt = importedColors.constBegin();
+  for ( ; colorIt != importedColors.constEnd(); ++colorIt )
+  {
+    mModel->addColor(( *colorIt ).first, ( *colorIt ).second );
+  }
+
+  return true;
+}
+
+bool QgsColorSchemeList::exportColorsToGpl( QFile &file )
+{
+  return QgsSymbolLayerV2Utils::saveColorsToGpl( file, QString(), mModel->colors() );
+}
+
 //
 // QgsColorSchemeModel
 //