add support for multiline labels (applies #1138)

git-svn-id: http://svn.osgeo.org/qgis/trunk@8775 c8812cc2-4d05-0410-92ff-de0c093fc19c

python/core/qgslabel.sip

@@ -37,6 +37,7 @@ public:
   BorderWidth,
   BorderColor,
   BorderStyle,
+  MultilineEnabled,
   LabelFieldCount
 };
 

python/core/qgslabelattributes.sip

@@ -102,5 +102,7 @@ public:
     bool  borderStyleIsSet ( ) const;
     Qt::PenStyle   borderStyle ( ) const;
 
+    bool  multilineEnabled() const;
+    void  setMultilineEnabled( bool useMultiline );
 };
 

src/app/qgslabeldialog.cpp

@@ -239,6 +239,8 @@ void QgsLabelDialog::init ( )
   {
     spinBufferSize->setValue(1);
   }
+  //set the state of the multiline enabled checkbox
+  chkUseMultiline->setChecked(myLabelAttributes->multilineEnabled());   
   //set the state of the buffer enabled checkbox
   chkUseBuffer->setChecked(myLabelAttributes->bufferEnabled());   
   
@@ -360,6 +362,7 @@ void QgsLabelDialog::apply()
     if (radioBelow->isChecked())       myLabelAttributes->setAlignment(Qt::AlignTop   | Qt::AlignHCenter); 
     if (radioOver->isChecked())        myLabelAttributes->setAlignment(Qt::AlignCenter);
       
+    myLabelAttributes->setMultilineEnabled(chkUseMultiline->isChecked());
     myLabelAttributes->setBufferEnabled(chkUseBuffer->isChecked());
     myLabelAttributes->setBufferColor(mBufferColor); 
     myTypeInt = 0;

src/core/qgslabel.cpp

@@ -214,8 +214,26 @@ void QgsLabel::renderLabel( QPainter * painter, const QgsRect& viewExtent,
     /* Alignment */
     int alignment;
     QFontMetrics fm ( font );
-    int width = fm.width ( text );
-    int height = fm.height();
+    int width, height;
+
+    if( mLabelAttributes->multilineEnabled() )
+    {
+      QStringList texts = text.split("\n");
+      
+      width=0;
+      for(int i=0; i<texts.size(); i++) {
+        int w = fm.width(texts[i]);
+        if(w>width)
+          width=w;
+      }
+
+      height = fm.height()*texts.size();
+    }
+    else
+    { 
+      width = fm.width ( text );
+      height = fm.height();
+    }
     int dx = 0;
     int dy = 0;
 
@@ -319,7 +337,7 @@ void QgsLabel::renderLabel( QPainter * painter, const QgsRect& viewExtent,
     {
       renderLabel(painter, overridePoint, coordTransform, 
                   transform, text, font, pen, dx, dy,
-                  xoffset, yoffset, ang);
+                  xoffset, yoffset, ang, width, height, alignment);
     }
     else
     {
@@ -329,7 +347,7 @@ void QgsLabel::renderLabel( QPainter * painter, const QgsRect& viewExtent,
       {
         renderLabel(painter, points[i], coordTransform, 
                     transform, text, font, pen, dx, dy,
-                    xoffset, yoffset, ang);
+                    xoffset, yoffset, ang, width, height, alignment);
       }
     }
 }
@@ -340,7 +358,8 @@ void QgsLabel::renderLabel(QPainter* painter, QgsPoint point,
                            QString text, QFont font, QPen pen,
                            int dx, int dy, 
                            double xoffset, double yoffset, 
-                           double ang)
+                           double ang,
+                           int width, int height, int alignment)
 {
     // Convert point to projected units
     if (coordTransform)
@@ -372,6 +391,7 @@ void QgsLabel::renderLabel(QPainter* painter, QgsPoint point,
     painter->setFont ( font );
     painter->translate ( x, y );
     painter->rotate ( -ang );
+
     //
     // Draw a buffer behind the text if one is desired
     //
@@ -390,12 +410,18 @@ void QgsLabel::renderLabel(QPainter* painter, QgsPoint point,
       {
         for (int j = dy-myBufferSize; j <= dy+myBufferSize; j++)
         {
+          if( mLabelAttributes->multilineEnabled() )
+            painter->drawText( i , j-height, width, height, alignment, text);
+          else
             painter->drawText( i , j, text);
         }
       }
     }
 
     painter->setPen ( pen );
+    if( mLabelAttributes->multilineEnabled() )
+      painter->drawText ( dx, dy-height, width, height, alignment, text );
+    else
       painter->drawText ( dx, dy, text );
     painter->restore();
 }
@@ -882,6 +908,20 @@ void QgsLabel::readXML( const QDomNode& node )
         setLabelField ( BufferEnabled, _elementFieldIndex(el) );
     }
 
+    scratchNode = node.namedItem("multilineenabled");
+
+    if ( scratchNode.isNull() )
+    {
+        QgsDebugMsg("couldn't find QgsLabel ``multilineenabled'' attribute");
+    }
+    else
+    {
+        el = scratchNode.toElement();
+
+        mLabelAttributes->setMultilineEnabled ( (bool)el.attribute("on","0").toInt() );
+        setLabelField ( MultilineEnabled, _elementFieldIndex(el) );
+    }
+
 } // QgsLabel::readXML()
 
 
@@ -1158,6 +1198,26 @@ void QgsLabel::writeXML(std::ostream& xml)
     {
         xml << "\t\t\t<bufferenabled on=\"" << "\" field=\"" << "\" />\n";
     }
+
+    // multiline enabled
+    if (mLabelAttributes->multilineEnabled())
+    {
+      if (mLabelFieldIdx[MultilineEnabled] != -1)
+      {
+          xml << "\t\t\t<multilineenabled on=\"" << mLabelAttributes->multilineEnabled()
+              << "\" field=\"" << mLabelFieldIdx[MultilineEnabled] << "\" />\n";
+      }
+      else
+      {
+          xml << "\t\t\t<multilineenabled on=\"" << mLabelAttributes->multilineEnabled()
+              << "\" field=\"\" />\n";
+      }
+    }
+    else
+    {
+        xml << "\t\t\t<multilineenabled on=\"" << "\" field=\"" << "\" />\n";
+    }
+
     xml << "\t\t</labelattributes>\n";
 }
 

src/core/qgslabel.h

@@ -73,6 +73,7 @@ public:
 	BorderWidth,
 	BorderColor,
 	BorderStyle,
+	MultilineEnabled,
 	LabelFieldCount
     };
 
@@ -127,7 +128,8 @@ private:
                      QString text, QFont font, QPen pen,
                      int dx, int dy,
                      double xoffset, double yoffset,
-                     double ang);
+                     double ang,
+                     int width, int height, int alignment);
 
     /** Get label point for simple feature in map units */
     void labelPoint ( std::vector<QgsPoint>&, QgsFeature & feature );

src/core/qgslabelattributes.cpp

@@ -51,7 +51,8 @@ QgsLabelAttributes::QgsLabelAttributes( bool def )
       mBufferStyleIsSet( false ),
       mBorderColorIsSet( false ),
       mBorderWidthIsSet( false ),
-      mBorderStyleIsSet( false )
+      mBorderStyleIsSet( false ),
+      mMultilineEnabledFlag( false )
 {
 
     if ( def ) { // set defaults
@@ -388,9 +389,21 @@ Qt::PenStyle QgsLabelAttributes::borderStyle ( void ) const
     return mBorderPen.style();
 }
 
+  /* Multiline */
+bool QgsLabelAttributes::multilineEnabled() const
+{
+  return mMultilineEnabledFlag;
+}
+void QgsLabelAttributes::setMultilineEnabled(bool useMultilineFlag)
+{
+  mMultilineEnabledFlag=useMultilineFlag;
+}
+
+  /* units */
 QString QgsLabelAttributes::unitsName ( int units ) 
 {
-    if ( units == MapUnits ){ 
+  if ( units == MapUnits )
+  {
     return QString("mu");
   }
 
@@ -406,6 +419,7 @@ int QgsLabelAttributes::unitsCode ( const QString &name )
     return PointUnits;
 }
 
+ /* alignment */
 QString QgsLabelAttributes::alignmentName ( int alignment ) 
 {
   std::cout << "QString QgsLabelAttributes::alignmentName (" << alignment << ")" << std::endl;

src/core/qgslabelattributes.h

@@ -172,6 +172,9 @@ public:
     bool  borderStyleIsSet ( void ) const;
     Qt::PenStyle   borderStyle ( void ) const;
 
+    bool  multilineEnabled() const;
+    void  setMultilineEnabled( bool useMultiline );
+    
  protected:
     /* Text */
     QString mText;
@@ -224,6 +227,9 @@ public:
     bool mBorderColorIsSet;
     bool mBorderWidthIsSet;
     bool mBorderStyleIsSet;
+
+    /** Multiline enablement */
+    bool mMultilineEnabledFlag;
 };
 
 #endif

src/ui/qgslabeldialogbase.ui

@@ -449,6 +449,16 @@
         </widget>
        </item>
        <item row="5" column="0" >
+        <widget class="QCheckBox" name="chkUseMultiline" >
+         <property name="text" >
+          <string>Multiline labels?</string>
+         </property>
+         <property name="checked" >
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+       <item row="6" column="0" >
         <spacer>
          <property name="orientation" >
           <enum>Qt::Vertical</enum>