Add user notification when defined labeling font is not found on system, then substituted

- [API] add signal to QgsVectorLayer that is emitted when its labeling font is not found
- Message bar notification on first rendering of layer offers link to open layer's labeling dialog
- Add 'font not found' notification to labeling dialog
- Labeling dialog defaults to 'Text style' section when font is not found, to show notice
- Substituted font is not saved with project, unless user applies changes.
- Change labeling gui font selector dialog to font family combobox (since only family is being chosen)

Author: dakcarto

python/core/qgspallabeling.sip

@@ -222,7 +222,9 @@ class QgsPalLayerSettings
     QgsExpression* getLabelExpression();
 
     QFont textFont;
+    //QString textFontFamily;
     QString textNamedStyle;
+    //bool textFontFound;
     bool fontSizeInMapUnits; //true if font size is in map units (otherwise in points)
     QColor textColor;
     int textTransp;

python/core/qgsvectorlayer.sip

@@ -1047,6 +1047,11 @@ class QgsVectorLayer : QgsMapLayer
     void committedAttributeValuesChanges( const QString& layerId, const QgsChangedAttributesMap& changedAttributesValues );
     void committedGeometriesChanges( const QString& layerId, const QgsGeometryMap& changedGeometries );
 
+    /** Emitted when the font family defined for labeling layer is not found on system
+     * @note added in 1.9
+     */
+    void labelingFontNotFound( QgsVectorLayer* layer, const QString& fontfamily );
+
   protected:
     /** Set the extent */
     void setExtent( const QgsRectangle &rect );

src/app/qgisapp.cpp

@@ -4279,6 +4279,63 @@ void QgisApp::modifyAnnotation()
   mMapCanvas->setMapTool( mMapTools.mAnnotation );
 }
 
+void QgisApp::labelingFontNotFound( QgsVectorLayer* vlayer, const QString& fontfamily )
+{
+  // TODO: update when pref for how to resolve missing family (use matching algorithm or just default font) is implemented
+  QString substitute = tr( "Default system font substituted." );
+
+  QWidget* fontMsg = QgsMessageBar::createMessage(
+                       tr( "Labeling" ),
+                       tr( "Font for layer <b><u>%1</u></b> was not found (<i>%2</i>). %3" ).arg( vlayer->name() ).arg( fontfamily ).arg( substitute ),
+                       QgsApplication::getThemeIcon( "/mIconWarn.png" ),
+                       messageBar() );
+
+  QToolButton* btnOpenPrefs = new QToolButton( fontMsg );
+  btnOpenPrefs->setStyleSheet( "QToolButton{ background-color: rgba(255, 255, 255, 0); color: black; text-decoration: underline; }" );
+  btnOpenPrefs->setCursor( Qt::PointingHandCursor );
+  btnOpenPrefs->setSizePolicy( QSizePolicy::Maximum, QSizePolicy::Preferred );
+  btnOpenPrefs->setToolButtonStyle( Qt::ToolButtonTextOnly );
+
+  // store pointer to vlayer in data of QAction
+  QAction* act = new QAction( fontMsg );
+  act->setData( QVariant( QMetaType::QObjectStar, &vlayer ) );
+  act->setText( tr( "Open labeling dialog" ) );
+  btnOpenPrefs->addAction( act );
+  btnOpenPrefs->setDefaultAction( act );
+  btnOpenPrefs->setToolTip( "" );
+
+  connect( btnOpenPrefs, SIGNAL( triggered( QAction* ) ), this, SLOT( labelingDialogFontNotFound( QAction* ) ) );
+  fontMsg->layout()->addWidget( btnOpenPrefs );
+
+  // no timeout set, since notice needs attention and is only shown first time layer is labeled
+  messageBar()->pushWidget( fontMsg, QgsMessageBar::WARNING );
+}
+
+void QgisApp::labelingDialogFontNotFound( QAction* act )
+{
+  if ( !act )
+  {
+    return;
+  }
+
+  // get base pointer to layer
+  QObject* obj = qvariant_cast<QObject*>( act->data() );
+
+  // remove calling messagebar widget
+  messageBar()->popWidget();
+
+  if ( !obj )
+  {
+    return;
+  }
+
+  QgsMapLayer* layer = qobject_cast<QgsMapLayer*>( obj );
+  if ( layer && setActiveLayer( layer ) )
+  {
+    labeling();
+  }
+}
+
 void QgisApp::labeling()
 {
   QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer*>( activeLayer() );
@@ -7658,6 +7715,9 @@ void QgisApp::layersWereAdded( QList<QgsMapLayer *> theLayers )
     QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
     if ( vlayer )
     {
+      // notify user about any font family substitution, but only when rendering labels (i.e. not when opening settings dialog)
+      connect( vlayer, SIGNAL( labelingFontNotFound( QgsVectorLayer*, QString ) ), this, SLOT( labelingFontNotFound( QgsVectorLayer*, QString ) ) );
+
       QgsVectorDataProvider* vProvider = vlayer->dataProvider();
       if ( vProvider && vProvider->capabilities() & QgsVectorDataProvider::EditingCapabilities )
       {

src/app/qgisapp.h

@@ -1020,6 +1020,16 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
     void addSvgAnnotation();
     void modifyAnnotation();
 
+    /** Alerts user when labeling font for layer has not been found on system
+     * @note added in 1.9
+     */
+    void labelingFontNotFound( QgsVectorLayer* vlayer, const QString& fontfamily );
+
+    /** Opens the labeling dialog for a layer when called from labelingFontNotFound alert
+     * @note added in 1.9
+     */
+    void labelingDialogFontNotFound( QAction* act );
+
     //! shows label settings dialog (for labeling-ng)
     void labeling();
 

src/app/qgslabelinggui.cpp

@@ -73,7 +73,6 @@ QgsLabelingGui::QgsLabelingGui( QgsPalLabeling* lbl, QgsVectorLayer* layer, QgsM
 
   // preview and basic option connections
   connect( btnTextColor, SIGNAL( colorChanged( const QColor& ) ), this, SLOT( changeTextColor( const QColor& ) ) );
-  connect( btnChangeFont, SIGNAL( clicked() ), this, SLOT( changeTextFont() ) );
   connect( mFontTranspSpinBox, SIGNAL( valueChanged( int ) ), this, SLOT( updatePreview() ) );
   connect( mBufferDrawChkBx, SIGNAL( toggled( bool ) ), this, SLOT( updatePreview() ) );
   connect( btnBufferColor, SIGNAL( colorChanged( const QColor& ) ), this, SLOT( changeBufferColor( const QColor& ) ) );
@@ -366,6 +365,22 @@ void QgsLabelingGui::init()
   QgsFontUtils::updateFontViaStyle( mRefFont, lyr.textNamedStyle );
   updateFont( mRefFont );
 
+  // show 'font not found' if substitution has occurred (should come after updateFont())
+  if ( !lyr.mTextFontFound )
+  {
+    mFontMissingLabel->setVisible( true );
+    QString missingTxt = tr( "%1 not found. Default substituted." );
+    QString txtPrepend = tr( "Chosen font" );
+    if ( !lyr.mTextFontFamily.isEmpty() )
+    {
+      txtPrepend = QString( "'%1'" ).arg( lyr.mTextFontFamily );
+    }
+    mFontMissingLabel->setText( missingTxt.arg( txtPrepend ) );
+
+    // ensure user is sent to 'Text style' section to see notice
+    mLabelingOptionsListWidget->setCurrentRow( 0 );
+  }
+
   // shape background
   mShapeDrawChkBx->setChecked( lyr.shapeDraw );
   mShapeTypeCmbBx->blockSignals( true );
@@ -474,6 +489,7 @@ void QgsLabelingGui::collapseSample( bool collapse )
 void QgsLabelingGui::apply()
 {
   writeSettingsToLayer();
+  mFontMissingLabel->setVisible( false );
   QgisApp::instance()->markDirty();
   // trigger refresh
   if ( mMapCanvas )
@@ -1019,41 +1035,6 @@ void QgsLabelingGui::changeTextColor( const QColor &color )
   updatePreview();
 }
 
-void QgsLabelingGui::changeTextFont()
-{
-  // store properties of QFont that might be stripped by font dialog
-  QFont::Capitalization captials = mRefFont.capitalization();
-  double wordspacing = mRefFont.wordSpacing();
-  double letterspacing = mRefFont.letterSpacing();
-
-  bool ok;
-#if defined(Q_WS_MAC) && QT_VERSION >= 0x040500 && defined(QT_MAC_USE_COCOA)
-  // Native Mac dialog works only for Qt Carbon
-  QFont font = QFontDialog::getFont( &ok, mRefFont, 0, QString(), QFontDialog::DontUseNativeDialog );
-#else
-  QFont font = QFontDialog::getFont( &ok, mRefFont );
-#endif
-  if ( ok )
-  {
-    if ( mFontSizeUnitComboBox->currentIndex() == 1 )
-    {
-      // don't override map units size with selected size from font dialog
-      font.setPointSizeF( mFontSizeSpinBox->value() );
-    }
-    else
-    {
-      mFontSizeSpinBox->setValue( font.pointSizeF() );
-    }
-
-    // reassign possibly stripped QFont properties
-    font.setCapitalization( captials );
-    font.setWordSpacing( wordspacing );
-    font.setLetterSpacing( QFont::AbsoluteSpacing, letterspacing );
-
-    updateFont( font );
-  }
-}
-
 void QgsLabelingGui::updateFont( QFont font )
 {
   // update background reference font
@@ -1063,31 +1044,13 @@ void QgsLabelingGui::updateFont( QFont font )
   }
 
   // test if font is actually available
-  QString missingtxt = QString( "" );
-  bool missing = false;
-  if ( QApplication::font().toString() != mRefFont.toString() )
-  {
-    QFont testfont = mFontDB.font( mRefFont.family(), mFontDB.styleString( mRefFont ), 12 );
-    if ( QApplication::font().toString() == testfont.toString() )
-    {
-      missing = true;
-    }
-  }
-  if ( missing )
-  {
-    missingtxt = tr( " (not found!)" );
-    lblFontName->setStyleSheet( "color: #990000;" );
-  }
-  else
-  {
-    lblFontName->setStyleSheet( "color: #000000;" );
-  }
+  mFontMissingLabel->setVisible( QgsFontUtils::fontMatchOnSystem( mRefFont ) );
 
-  lblFontName->setText( QString( "%1%2" ).arg( mRefFont.family() ).arg( missingtxt ) );
   mDirectSymbLeftLineEdit->setFont( mRefFont );
   mDirectSymbRightLineEdit->setFont( mRefFont );
 
   blockFontChangeSignals( true );
+  mFontFamilyCmbBx->setCurrentFont( mRefFont );
   populateFontStyleComboBox();
   int idx = mFontCapitalsComboBox->findData( QVariant(( unsigned int ) mRefFont.capitalization() ) );
   mFontCapitalsComboBox->setCurrentIndex( idx == -1 ? 0 : idx );
@@ -1097,13 +1060,13 @@ void QgsLabelingGui::updateFont( QFont font )
 
   // update font name with font face
 //  font.setPixelSize( 24 );
-//  lblFontName->setFont( QFont( font ) );
 
   updatePreview();
 }
 
 void QgsLabelingGui::blockFontChangeSignals( bool blk )
 {
+  mFontFamilyCmbBx->blockSignals( blk );
   mFontStyleComboBox->blockSignals( blk );
   mFontCapitalsComboBox->blockSignals( blk );
   mFontUnderlineBtn->blockSignals( blk );
@@ -1333,7 +1296,15 @@ void QgsLabelingGui::populateFontStyleComboBox()
   {
     mFontStyleComboBox->addItem( style );
   }
-  mFontStyleComboBox->setCurrentIndex( mFontStyleComboBox->findText( mFontDB.styleString( mRefFont ) ) );
+
+  int curIndx = 0;
+  int stylIndx = mFontStyleComboBox->findText( mFontDB.styleString( mRefFont ) );
+  if ( stylIndx > -1 )
+  {
+    curIndx = stylIndx;
+  }
+
+  mFontStyleComboBox->setCurrentIndex( curIndx );
 }
 
 void QgsLabelingGui::on_mPreviewSizeSlider_valueChanged( int i )
@@ -1355,6 +1326,12 @@ void QgsLabelingGui::on_mFontCapitalsComboBox_currentIndexChanged( int index )
   updateFont( mRefFont );
 }
 
+void QgsLabelingGui::on_mFontFamilyCmbBx_currentFontChanged( const QFont& f )
+{
+  mRefFont.setFamily( f.family() );
+  updateFont( mRefFont );
+}
+
 void QgsLabelingGui::on_mFontStyleComboBox_currentIndexChanged( const QString & text )
 {
   QgsFontUtils::updateFontViaStyle( mRefFont, text );

src/app/qgslabelinggui.h

@@ -44,7 +44,6 @@ class QgsLabelingGui : public QWidget, private Ui::QgsLabelingGuiBase
     void collapseSample( bool collapse );
     void apply();
     void changeTextColor( const QColor &color );
-    void changeTextFont();
     void showEngineConfigDialog();
     void showExpressionDialog();
     void changeBufferColor( const QColor &color );
@@ -58,6 +57,7 @@ class QgsLabelingGui : public QWidget, private Ui::QgsLabelingGuiBase
     void on_mPreviewSizeSlider_valueChanged( int i );
     void on_mFontSizeSpinBox_valueChanged( double d );
     void on_mFontCapitalsComboBox_currentIndexChanged( int index );
+    void on_mFontFamilyCmbBx_currentFontChanged( const QFont& f );
     void on_mFontStyleComboBox_currentIndexChanged( const QString & text );
     void on_mFontUnderlineBtn_toggled( bool ckd );
     void on_mFontStrikethroughBtn_toggled( bool ckd );

src/core/qgspallabeling.cpp

@@ -212,12 +212,15 @@ QgsPalLayerSettings::QgsPalLayerSettings()
 
   // text style
   textFont = QApplication::font();
-  fontSizeInMapUnits = false;
   textNamedStyle = QString( "" );
+  fontSizeInMapUnits = false;
   textColor = Qt::black;
   textTransp = 0;
   blendMode = QPainter::CompositionMode_SourceOver;
   previewBkgrdColor = Qt::white;
+  // font processing info
+  mTextFontFound = true;
+  mTextFontFamily = QApplication::font().family();
 
   // text formatting
   wrapChar = "";
@@ -432,12 +435,15 @@ QgsPalLayerSettings::QgsPalLayerSettings( const QgsPalLayerSettings& s )
   fieldName = s.fieldName;
   isExpression = s.isExpression;
   textFont = s.textFont;
-  fontSizeInMapUnits = s.fontSizeInMapUnits;
   textNamedStyle = s.textNamedStyle;
+  fontSizeInMapUnits = s.fontSizeInMapUnits;
   textColor = s.textColor;
   textTransp = s.textTransp;
   blendMode = s.blendMode;
   previewBkgrdColor = s.previewBkgrdColor;
+  // font processing info
+  mTextFontFound = s.mTextFontFound;
+  mTextFontFamily = s.mTextFontFamily;
 
   // text formatting
   wrapChar = s.wrapChar;
@@ -796,7 +802,21 @@ void QgsPalLayerSettings::readFromLayer( QgsVectorLayer* layer )
   // text style
   fieldName = layer->customProperty( "labeling/fieldName" ).toString();
   isExpression = layer->customProperty( "labeling/isExpression" ).toBool();
-  QString fontFamily = layer->customProperty( "labeling/fontFamily", QVariant( QApplication::font().family() ) ).toString();
+  QFont appFont = QApplication::font();
+  mTextFontFamily = layer->customProperty( "labeling/fontFamily", QVariant( appFont.family() ) ).toString();
+  QString fontFamily = mTextFontFamily;
+  if ( mTextFontFamily != appFont.family() && !QgsFontUtils::fontFamilyMatchOnSystem( mTextFontFamily ) )
+  {
+    // trigger to notify user about font family substitution (signal emitted in QgsVectorLayer::prepareLabelingAndDiagrams)
+    mTextFontFound = false;
+
+    // TODO: update when pref for how to resolve missing family (use matching algorithm or just default font) is implemented
+    // currently only defaults to matching algorithm for resolving [foundry], if a font of similar family is found (default for QFont)
+
+    // for now, do not use matching algorithm for substitution if family not found, substitute default instead
+    fontFamily = appFont.family();
+  }
+
   double fontSize = layer->customProperty( "labeling/fontSize" ).toDouble();
   fontSizeInMapUnits = layer->customProperty( "labeling/fontSizeInMapUnits" ).toBool();
   int fontWeight = layer->customProperty( "labeling/fontWeight" ).toInt();

src/core/qgspallabeling.h

@@ -492,6 +492,7 @@ class CORE_EXPORT QgsPalLayerSettings
     QMap<QgsPalLayerSettings::DataDefinedProperties, QPair<QString, int> > dataDefinedNames() const { return mDataDefinedNames; }
 
     // temporary stuff: set when layer gets prepared or labeled
+    // NOTE: not in Python binding
     pal::Layer* palLayer;
     QgsFeature* mCurFeat;
     const QgsFields* mCurFields;
@@ -505,6 +506,9 @@ class CORE_EXPORT QgsPalLayerSettings
     int mFeatsSendingToPal; // total features tested for sending into PAL (relative to maxNumLabels)
     int mFeatsRegPal; // number of features registered in PAL, when using limitNumLabels
 
+    QString mTextFontFamily;
+    bool mTextFontFound;
+
     bool showingShadowRects; // whether to show debug rectangles for drop shadows
 
   private:

src/core/qgsvectorlayer.cpp

@@ -122,6 +122,7 @@ QgsVectorLayer::QgsVectorLayer( QString vectorLayerPath,
     , mRendererV2( NULL )
     , mLabel( 0 )
     , mLabelOn( false )
+    , mLabelFontNotFoundNotified( false )
     , mFeatureBlendMode( QPainter::CompositionMode_SourceOver ) // Default to normal feature blending
     , mLayerTransparency( 0 )
     , mVertexMarkerOnlyForSelection( false )
@@ -3477,8 +3478,9 @@ void QgsVectorLayer::prepareLabelingAndDiagrams( QgsRenderContext& rendererConte
 
   if ( labeling )
   {
-    // see if feature count limit is set for labeling
     QgsPalLayerSettings& palyr = rendererContext.labelingEngine()->layer( this->id() );
+
+    // see if feature count limit is set for labeling
     if ( palyr.limitNumLabels && palyr.maxNumLabels > 0 )
     {
       QgsFeatureIterator fit = getFeatures( QgsFeatureRequest()
@@ -3494,6 +3496,13 @@ void QgsVectorLayer::prepareLabelingAndDiagrams( QgsRenderContext& rendererConte
       }
       palyr.mFeaturesToLabel = nFeatsToLabel;
     }
+
+    // notify user about any font substitution
+    if ( !palyr.mTextFontFound && !mLabelFontNotFoundNotified )
+    {
+      emit labelingFontNotFound( this, palyr.mTextFontFamily );
+      mLabelFontNotFoundNotified = true;
+    }
   }
 
   //register diagram layers