[labeling] Fix setting a wrap character conflicts with newlines

in label text (fix #12750)

python/core/qgspallabeling.sip

@@ -764,6 +764,14 @@ class QgsPalLabeling : QgsLabelingEngineInterface
      */
     static bool geometryRequiresPreparation( const QgsGeometry *geometry, const QgsRenderContext &context, const QgsCoordinateTransform *ct, QgsGeometry *clipGeometry = 0 );
 
+    /** Splits a text string to a list of seperate lines, using a specified wrap character.
+     * The text string will be split on either newline characters or the wrap character.
+     * @param text text string to split
+     * @param wrapCharacter additional character to wrap on
+     * @returns list of text split to lines
+     * @note added in QGIS 2.9
+     */
+    static QStringList splitToLines( const QString& text, const QString& wrapCharacter );
 
   protected:
     // update temporary QgsPalLayerSettings with any data defined text style values

src/core/qgspallabeling.cpp

@@ -1405,12 +1405,12 @@ void QgsPalLayerSettings::calculateLabelSize( const QFontMetricsF* fm, QString t
     }
     else
     {
-      text.prepend( dirSym + wrapchr ); // SymbolAbove or SymbolBelow
+      text.prepend( dirSym + QString( "\n" ) ); // SymbolAbove or SymbolBelow
     }
   }
 
   double w = 0.0, h = 0.0;
-  QStringList multiLineSplit = text.split( wrapchr );
+  QStringList multiLineSplit = QgsPalLabeling::splitToLines( text, wrapchr );
   int lines = multiLineSplit.size();
 
   double labelHeight = fm->ascent() + fm->descent(); // ignore +1 for baseline
@@ -3393,6 +3393,25 @@ bool QgsPalLabeling::geometryRequiresPreparation( const QgsGeometry* geometry, c
   return false;
 }
 
+QStringList QgsPalLabeling::splitToLines( const QString &text, const QString &wrapCharacter )
+{
+  QStringList multiLineSplit;
+  if ( !wrapCharacter.isEmpty() && wrapCharacter != QString( "\n" ) )
+  {
+    //wrap on both the wrapchr and new line characters
+    foreach ( QString line, text.split( wrapCharacter ) )
+    {
+      multiLineSplit.append( line.split( QString( "\n" ) ) );
+    }
+  }
+  else
+  {
+    multiLineSplit = text.split( "\n" );
+  }
+
+  return multiLineSplit;
+}
+
 QgsGeometry* QgsPalLabeling::prepareGeometry( const QgsGeometry* geometry, const QgsRenderContext& context, const QgsCoordinateTransform* ct, double minSize, QgsGeometry* clipGeometry )
 {
   if ( !geometry )
@@ -4436,8 +4455,6 @@ void QgsPalLabeling::drawLabel( pal::LabelPosition* label, QgsRenderContext& con
     QString txt = ( label->getPartId() == -1 ? text : QString( text[label->getPartId()] ) );
     QFontMetricsF* labelfm = (( QgsPalGeometry* )label->getFeaturePart()->getUserGeometry() )->getLabelFontMetrics();
 
-    QString wrapchr = !tmpLyr.wrapChar.isEmpty() ? tmpLyr.wrapChar : QString( "\n" );
-
     //add the direction symbol if needed
     if ( !txt.isEmpty() && tmpLyr.placement == QgsPalLayerSettings::Line &&
          tmpLyr.addDirectionSymbol )
@@ -4468,12 +4485,12 @@ void QgsPalLabeling::drawLabel( pal::LabelPosition* label, QgsRenderContext& con
       if ( tmpLyr.placeDirectionSymbol == QgsPalLayerSettings::SymbolAbove )
       {
         prependSymb = true;
-        symb = symb + wrapchr;
+        symb = symb + QString( "\n" );
       }
       else if ( tmpLyr.placeDirectionSymbol == QgsPalLayerSettings::SymbolBelow )
       {
         prependSymb = false;
-        symb = wrapchr + symb;
+        symb = QString( "\n" ) + symb;
       }
 
       if ( prependSymb )
@@ -4487,8 +4504,7 @@ void QgsPalLabeling::drawLabel( pal::LabelPosition* label, QgsRenderContext& con
     }
 
     //QgsDebugMsgLevel( "drawLabel " + txt, 4 );
-
-    QStringList multiLineList = txt.split( wrapchr );
+    QStringList multiLineList = QgsPalLabeling::splitToLines( text, tmpLyr.wrapChar );
     int lines = multiLineList.size();
 
     double labelWidest = 0.0;

src/core/qgspallabeling.h

@@ -527,6 +527,7 @@ class CORE_EXPORT QgsPalLayerSettings
     bool showingShadowRects; // whether to show debug rectangles for drop shadows
 
   private:
+
     void readDataDefinedPropertyMap( QgsVectorLayer* layer,
                                      QMap < QgsPalLayerSettings::DataDefinedProperties,
                                      QgsDataDefined* > & propertyMap );
@@ -833,6 +834,15 @@ class CORE_EXPORT QgsPalLabeling : public QgsLabelingEngineInterface
      */
     static bool geometryRequiresPreparation( const QgsGeometry *geometry, const QgsRenderContext &context, const QgsCoordinateTransform *ct, QgsGeometry *clipGeometry = 0 );
 
+    /** Splits a text string to a list of seperate lines, using a specified wrap character.
+     * The text string will be split on either newline characters or the wrap character.
+     * @param text text string to split
+     * @param wrapCharacter additional character to wrap on
+     * @returns list of text split to lines
+     * @note added in QGIS 2.9
+     */
+    static QStringList splitToLines( const QString& text, const QString& wrapCharacter );
+
   protected:
     // update temporary QgsPalLayerSettings with any data defined text style values
     void dataDefinedTextStyle( QgsPalLayerSettings& tmpLyr,

tests/src/core/CMakeLists.txt

@@ -157,4 +157,6 @@ ADD_QGIS_TEST(painteffecttest testqgspainteffect.cpp)
 ADD_QGIS_TEST(painteffectregistrytest testqgspainteffectregistry.cpp)
 ADD_QGIS_TEST(statisticalsummarytest testqgsstatisticalsummary.cpp)
 ADD_QGIS_TEST(histogramtest testqgshistogram.cpp)
+ADD_QGIS_TEST(pallabelingtest testqgspallabeling.cpp)
+
 

tests/src/core/testqgspallabeling.cpp

@@ -0,0 +1,67 @@
+/***************************************************************************
+     testqgspallabeling.cpp
+     ----------------------
+    Date                 : May 2015
+    Copyright            : (C) 2015 Nyall Dawson
+    Email                : nyall dot dawson at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include <QtTest/QtTest>
+#include <QObject>
+#include <QString>
+#include <QStringList>
+#include <QSharedPointer>
+
+#include "qgspallabeling.h"
+
+class TestQgsPalLabeling: public QObject
+{
+    Q_OBJECT
+
+  private slots:
+    void initTestCase();// will be called before the first testfunction is executed.
+    void cleanupTestCase();// will be called after the last testfunction was executed.
+    void init();// will be called before each testfunction is executed.
+    void cleanup();// will be called after every testfunction.
+    void wrapChar();//test wrapping text lines
+
+  private:
+};
+
+void TestQgsPalLabeling::initTestCase()
+{
+}
+
+void TestQgsPalLabeling::cleanupTestCase()
+{
+
+}
+
+void TestQgsPalLabeling::init()
+{
+
+}
+
+void TestQgsPalLabeling::cleanup()
+{
+
+}
+
+void TestQgsPalLabeling::wrapChar()
+{
+  QCOMPARE( QgsPalLabeling::splitToLines( "nolines", QString() ) , QStringList() << "nolines" );
+  QCOMPARE( QgsPalLabeling::splitToLines( "new line\nonly", QString() ), QStringList() << "new line" << "only" );
+  QCOMPARE( QgsPalLabeling::splitToLines( "new line\nonly", QString( "\n" ) ), QStringList() << "new line" << "only" );
+  QCOMPARE( QgsPalLabeling::splitToLines( "mixed new line\nand char", QString( " " ) ), QStringList() << "mixed" << "new" << "line" << "and" << "char" );
+  QCOMPARE( QgsPalLabeling::splitToLines( "no matching chars", QString( "#" ) ), QStringList() << "no matching chars" );
+  QCOMPARE( QgsPalLabeling::splitToLines( "no\nmatching\nchars", QString( "#" ) ), QStringList() << "no" << "matching" << "chars" );
+}
+
+QTEST_MAIN( TestQgsPalLabeling )
+#include "testqgspallabeling.moc"