[needs-docs] Use QgsTextRender to power up copyright decoration styling (#6684)

- we gain all of the styling capabilities of our text renderer engine (i.e. what powers
the rendering of labels)
- HTML support is gone for now, with virtually all of styling possibilities
covered by the above text renderer

Author: nirvn

python/core/qgstextrenderer.sip.in

@@ -1495,6 +1495,13 @@ and background shapes.
 %End
   public:
 
+    enum DrawMode
+    {
+      Rect,
+      Point,
+      Label,
+    };
+
     enum TextPart
     {
       Text,
@@ -1594,6 +1601,29 @@ with the text or background parts)
 :param drawAsOutlines: set to false to render text as text. This allows outputs to
 formats like SVG to maintain text as text objects, but at the cost of degraded
 rendering and may result in side effects like misaligned text buffers.
+%End
+
+    static double textWidth( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines,
+                             QFontMetricsF *fontMetrics = 0 );
+%Docstring
+Returns the width of a text based on a given format.
+
+:param context: render context
+:param format: text format
+:param textLines: list of lines of text to calculate width from
+:param fontMetrics: font metrics
+%End
+
+    static double textHeight( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, DrawMode mode,
+                              QFontMetricsF *fontMetrics = 0 );
+%Docstring
+Returns the height of a text based on a given format.
+
+:param context: render context
+:param format: text format
+:param textLines: list of lines of text to calculate width from
+:param mode: draw mode
+:param fontMetrics: font metrics
 %End
 
 };

src/app/qgsdecorationcopyright.cpp

@@ -31,12 +31,13 @@ email                : tim@linfiniti.com
 #include "qgslogger.h"
 #include "qgsmapcanvas.h"
 #include "qgsproject.h"
+#include "qgsreadwritecontext.h"
 #include "qgssymbollayerutils.h"
 
 #include <QPainter>
 #include <QMenu>
 #include <QDate>
-#include <QTextDocument>
+#include <QDomDocument>
 #include <QMatrix>
 #include <QFile>
 
@@ -59,25 +60,43 @@ void QgsDecorationCopyright::projectRead()
 {
   QgsDecorationItem::projectRead();
 
-  // there is no font setting in the UI, so just use the Qt/QGIS default font (what mQFont gets when created)
-  //  mQFont.setFamily( QgsProject::instance()->readEntry( "CopyrightLabel", "/FontName", "Sans Serif" ) );
-  //  mQFont.setPointSize( QgsProject::instance()->readNumEntry( "CopyrightLabel", "/FontSize", 9 ) );
-
   mLabelText = QgsProject::instance()->readEntry( mNameConfig, QStringLiteral( "/Label" ), QString() );
   mMarginHorizontal = QgsProject::instance()->readNumEntry( mNameConfig, QStringLiteral( "/MarginH" ), 0 );
   mMarginVertical = QgsProject::instance()->readNumEntry( mNameConfig, QStringLiteral( "/MarginV" ), 0 );
-  mColor = QgsSymbolLayerUtils::decodeColor( QgsProject::instance()->readEntry( mNameConfig, QStringLiteral( "/Color" ), QStringLiteral( "#000000" ) ) );
+
+  QDomDocument doc;
+  QDomElement elem;
+  QString textXml = QgsProject::instance()->readEntry( mNameConfig, QStringLiteral( "/Font" ) );
+  if ( !textXml.isEmpty() )
+  {
+    doc.setContent( textXml );
+    elem = doc.documentElement();
+    QgsReadWriteContext rwContext;
+    rwContext.setPathResolver( QgsProject::instance()->pathResolver() );
+    mTextFormat.readXml( elem, rwContext );
+  }
+
+  // Migratation for pre QGIS 3.2 settings
+  QColor oldColor = QgsSymbolLayerUtils::decodeColor( QgsProject::instance()->readEntry( mNameConfig, QStringLiteral( "/Color" ) ) );
+  if ( oldColor.isValid() )
+  {
+    mTextFormat.setColor( oldColor );
+  }
 }
 
 void QgsDecorationCopyright::saveToProject()
 {
   QgsDecorationItem::saveToProject();
-  QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/FontName" ), mQFont.family() );
-  QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/FontSize" ), mQFont.pointSize() );
   QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/Label" ), mLabelText );
-  QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/Color" ), QgsSymbolLayerUtils::encodeColor( mColor ) );
   QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/MarginH" ), mMarginHorizontal );
   QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/MarginV" ), mMarginVertical );
+
+  QDomDocument textDoc;
+  QgsReadWriteContext rwContext;
+  rwContext.setPathResolver( QgsProject::instance()->pathResolver() );
+  QDomElement textElem = mTextFormat.writeXml( textDoc, rwContext );
+  textDoc.appendChild( textElem );
+  QgsProject::instance()->writeEntry( mNameConfig, QStringLiteral( "/Font" ), textDoc.toString() );
 }
 
 // Slot called when the buffer menu item is activated
@@ -91,77 +110,82 @@ void QgsDecorationCopyright::run()
 void QgsDecorationCopyright::render( const QgsMapSettings &mapSettings, QgsRenderContext &context )
 {
   Q_UNUSED( mapSettings );
-  //Large IF statement to enable/disable copyright label
-  if ( enabled() )
-  {
-    QString displayString = QgsExpression::replaceExpressionText( mLabelText, &context.expressionContext() );
+  if ( !enabled() )
+    return;
 
-    // need width/height of paint device
-    int myHeight = context.painter()->device()->height();
-    int myWidth = context.painter()->device()->width();
+  context.painter()->save();
+  context.painter()->setRenderHint( QPainter::Antialiasing, true );
 
-    QTextDocument text;
-    text.setDefaultFont( mQFont );
-    // To set the text color in a QTextDocument we use a CSS style
+  QString displayString = QgsExpression::replaceExpressionText( mLabelText, &context.expressionContext() );
+  QStringList displayStringList = displayString.split( "\n" );
 
-    QString style = "<style type=\"text/css\"> p {color: " +
-                    QStringLiteral( "rgba( %1, %2, %3, %4 )" ).arg( mColor.red() ).arg( mColor.green() ).arg( mColor.blue() ).arg( QString::number( mColor.alphaF(), 'f', 2 ) ) + "}</style>";
-    text.setHtml( style + "<p>" + displayString + "</p>" );
-    QSizeF size = text.size();
+  QFontMetricsF fm( mTextFormat.scaledFont( context ) );
+  double textWidth = QgsTextRenderer::textWidth( context, mTextFormat, displayStringList, &fm );
+  double textHeight = QgsTextRenderer::textHeight( context, mTextFormat, displayStringList, QgsTextRenderer::Point, &fm );
 
-    float myXOffset( 0 ), myYOffset( 0 );
+  int deviceHeight = context.painter()->device()->height();
+  int deviceWidth = context.painter()->device()->width();
 
-    // Set  margin according to selected units
-    switch ( mMarginUnit )
+  float xOffset( 0 ), yOffset( 0 );
+
+  // Set  margin according to selected units
+  switch ( mMarginUnit )
+  {
+    case QgsUnitTypes::RenderMillimeters:
+    {
+      int pixelsInchX = context.painter()->device()->logicalDpiX();
+      int pixelsInchY = context.painter()->device()->logicalDpiY();
+      xOffset = pixelsInchX * INCHES_TO_MM * mMarginHorizontal;
+      yOffset = pixelsInchY * INCHES_TO_MM * mMarginVertical;
+      break;
+    }
+    case QgsUnitTypes::RenderPixels:
     {
-      case QgsUnitTypes::RenderMillimeters:
-      {
-        int myPixelsInchX = context.painter()->device()->logicalDpiX();
-        int myPixelsInchY = context.painter()->device()->logicalDpiY();
-        myXOffset = myPixelsInchX * INCHES_TO_MM * mMarginHorizontal;
-        myYOffset = myPixelsInchY * INCHES_TO_MM * mMarginVertical;
-        break;
-      }
-
-      case QgsUnitTypes::RenderPixels:
-        myXOffset = mMarginHorizontal;
-        myYOffset = mMarginVertical;
-        break;
-
-      case QgsUnitTypes::RenderPercentage:
-        myXOffset = ( ( myWidth - size.width() ) / 100. ) * mMarginHorizontal;
-        myYOffset = ( ( myHeight - size.height() ) / 100. ) * mMarginVertical;
-        break;
-
-      default:  // Use default of top left
-        break;
+      xOffset = mMarginHorizontal;
+      yOffset = mMarginVertical;
+      break;
     }
-    //Determine placement of label from form combo box
-    switch ( mPlacement )
+    case QgsUnitTypes::RenderPercentage:
     {
-      case BottomLeft: // Bottom Left. myXOffset is set above
-        myYOffset = myHeight - myYOffset - size.height();
-        break;
-      case TopLeft: // Top left. Already setup above
-        break;
-      case TopRight: // Top Right. myYOffset is set above
-        myXOffset = myWidth - myXOffset - size.width();
-        break;
-      case BottomRight: // Bottom Right
-        //Define bottom right hand corner start point
-        myYOffset = myHeight - myYOffset - size.height();
-        myXOffset = myWidth - myXOffset - size.width();
-        break;
-      default:
-        QgsDebugMsg( QString( "Unknown placement index of %1" ).arg( static_cast<int>( mPlacement ) ) );
+      xOffset = ( ( deviceWidth - textWidth ) / 100. ) * mMarginHorizontal;
+      yOffset = ( ( deviceHeight - textHeight ) / 100. ) * mMarginVertical;
+      break;
     }
+    case QgsUnitTypes::RenderMapUnits:
+    case QgsUnitTypes::RenderPoints:
+    case QgsUnitTypes::RenderInches:
+    case QgsUnitTypes::RenderUnknownUnit:
+    case QgsUnitTypes::RenderMetersInMapUnits:
+      break;
+  }
 
-    //Paint label to canvas
-    QMatrix worldMatrix = context.painter()->worldMatrix();
-    context.painter()->translate( myXOffset, myYOffset );
-    text.drawContents( context.painter() );
-    // Put things back how they were
-    context.painter()->setWorldMatrix( worldMatrix );
+  // Determine placement of label from form combo box
+  QgsTextRenderer::HAlignment horizontalAlignment = QgsTextRenderer::AlignLeft;
+  switch ( mPlacement )
+  {
+    case BottomLeft: // Bottom Left, xOffset is set above
+      yOffset = deviceHeight - yOffset;
+      break;
+    case TopLeft: // Top left, xOffset is set above
+      yOffset = yOffset + textHeight;
+      break;
+    case TopRight: // Top Right
+      yOffset = yOffset + textHeight;
+      xOffset = deviceWidth - xOffset;
+      horizontalAlignment = QgsTextRenderer::AlignRight;
+      break;
+    case BottomRight: // Bottom Right
+      yOffset = deviceHeight - yOffset;
+      xOffset = deviceWidth - xOffset;
+      horizontalAlignment = QgsTextRenderer::AlignRight;
+      break;
+    default:
+      QgsDebugMsg( QString( "Unknown placement index of %1" ).arg( static_cast<int>( mPlacement ) ) );
   }
+
+  //Paint label to canvas
+  QgsTextRenderer::drawText( QPointF( xOffset, yOffset ), 0.0, horizontalAlignment, displayStringList, context, mTextFormat );
+
+  context.painter()->restore();
 }
 

src/app/qgsdecorationcopyright.h

@@ -20,6 +20,7 @@
 #define QGSCOPYRIGHTLABELPLUGIN
 
 #include "qgsdecorationitem.h"
+#include "qgstextrenderer.h"
 
 #include <QColor>
 #include <QFont>
@@ -49,19 +50,32 @@ class APP_EXPORT QgsDecorationCopyright : public QgsDecorationItem
     //! render the copyright label
     void render( const QgsMapSettings &mapSettings, QgsRenderContext &context ) override;
 
+    /**
+     * Returns the text format for extent labels.
+     * \see setTextFormat()
+     * \see labelExtents()
+     * \since QGIS 3.2
+     */
+    QgsTextFormat textFormat() const { return mTextFormat; }
+
+    /**
+     * Sets the text \a format for extent labels.
+     * \see textFormat()
+     * \see setLabelExtents()
+     * \since QGIS 3.2
+     */
+    void setTextFormat( const QgsTextFormat &format ) { mTextFormat = format; }
+
   private:
-    //! This is the font that will be used for the copyright label
-    QFont mQFont;
     //! This is the string that will be used for the copyright label
     QString mLabelText;
 
-    //! This is the color for the copyright label
-    QColor mColor;
-
     //! enable or disable use of position percentage for placement
     int mMarginHorizontal = 0;
     int mMarginVertical = 0;
 
+    QgsTextFormat mTextFormat;
+
     friend class QgsDecorationCopyrightDialog;
 };
 

src/app/qgsdecorationcopyrightdialog.cpp

@@ -36,7 +36,6 @@ QgsDecorationCopyrightDialog::QgsDecorationCopyrightDialog( QgsDecorationCopyrig
   connect( buttonBox, &QDialogButtonBox::accepted, this, &QgsDecorationCopyrightDialog::buttonBox_accepted );
   connect( buttonBox, &QDialogButtonBox::rejected, this, &QgsDecorationCopyrightDialog::buttonBox_rejected );
   connect( mInsertExpressionButton, &QPushButton::clicked, this, &QgsDecorationCopyrightDialog::mInsertExpressionButton_clicked );
-  connect( pbnColorChooser, &QgsColorButton::colorChanged, this, &QgsDecorationCopyrightDialog::pbnColorChooser_colorChanged );
   connect( buttonBox, &QDialogButtonBox::helpRequested, this, &QgsDecorationCopyrightDialog::showHelp );
 
   QgsSettings settings;
@@ -48,6 +47,7 @@ QgsDecorationCopyrightDialog::QgsDecorationCopyrightDialog( QgsDecorationCopyrig
   grpEnable->setChecked( mDeco.enabled() );
 
   // label text
+  txtCopyrightText->setAcceptRichText( false );
   if ( !mDeco.enabled() && mDeco.mLabelText.isEmpty() )
   {
     QDate now = QDate::currentDate();
@@ -70,16 +70,10 @@ QgsDecorationCopyrightDialog::QgsDecorationCopyrightDialog( QgsDecorationCopyrig
   wgtUnitSelection->setUnits( QgsUnitTypes::RenderUnitList() << QgsUnitTypes::RenderMillimeters << QgsUnitTypes::RenderPercentage << QgsUnitTypes::RenderPixels );
   wgtUnitSelection->setUnit( mDeco.mMarginUnit );
 
-  // color
-  pbnColorChooser->setAllowOpacity( true );
-  pbnColorChooser->setColor( mDeco.mColor );
-  pbnColorChooser->setContext( QStringLiteral( "gui" ) );
-  pbnColorChooser->setColorDialogTitle( tr( "Select Text color" ) );
-
-  QTextCursor cursor = txtCopyrightText->textCursor();
-  txtCopyrightText->selectAll();
-  txtCopyrightText->setTextColor( mDeco.mColor );
-  txtCopyrightText->setTextCursor( cursor );
+  // font settings
+  mButtonFontStyle->setDialogTitle( tr( "Copyright Label Text Format" ) );
+  mButtonFontStyle->setMapCanvas( QgisApp::instance()->mapCanvas() );
+  mButtonFontStyle->setTextFormat( mDeco.textFormat() );
 }
 
 QgsDecorationCopyrightDialog::~QgsDecorationCopyrightDialog()
@@ -120,19 +114,10 @@ void QgsDecorationCopyrightDialog::mInsertExpressionButton_clicked()
   }
 }
 
-void QgsDecorationCopyrightDialog::pbnColorChooser_colorChanged( const QColor &c )
-{
-  QTextCursor cursor = txtCopyrightText->textCursor();
-  txtCopyrightText->selectAll();
-  txtCopyrightText->setTextColor( c );
-  txtCopyrightText->setTextCursor( cursor );
-}
-
 void QgsDecorationCopyrightDialog::apply()
 {
-  mDeco.mQFont = txtCopyrightText->currentFont();
+  mDeco.setTextFormat( mButtonFontStyle->textFormat() );
   mDeco.mLabelText = txtCopyrightText->toPlainText();
-  mDeco.mColor = pbnColorChooser->color();
   mDeco.setPlacement( static_cast< QgsDecorationItem::Placement>( cboPlacement->currentData().toInt() ) );
   mDeco.mMarginUnit = wgtUnitSelection->unit();
   mDeco.mMarginHorizontal = spnHorizontal->value();

src/app/qgsdecorationcopyrightdialog.h

@@ -33,7 +33,6 @@ class APP_EXPORT QgsDecorationCopyrightDialog : public QDialog, private Ui::QgsD
     void buttonBox_rejected();
     void mInsertExpressionButton_clicked();
     void showHelp();
-    void pbnColorChooser_colorChanged( const QColor &c );
     void apply();
 
   protected: