[composer] When opening pre 2.3 projects keep picture item placement at middle (fix #10458)

Author: nyalldawson

src/core/qgsprojectfiletransform.cpp

@@ -52,7 +52,11 @@ QgsProjectFileTransform::transform QgsProjectFileTransform::transformers[] =
   {PFV( 1, 5, 0 ), PFV( 1, 6, 0 ), &QgsProjectFileTransform::transformNull},
   {PFV( 1, 6, 0 ), PFV( 1, 7, 0 ), &QgsProjectFileTransform::transformNull},
   {PFV( 1, 7, 0 ), PFV( 1, 8, 0 ), &QgsProjectFileTransform::transformNull},
-  {PFV( 1, 8, 0 ), PFV( 1, 9, 0 ), &QgsProjectFileTransform::transform1800to1900}
+  {PFV( 1, 8, 0 ), PFV( 1, 9, 0 ), &QgsProjectFileTransform::transform1800to1900},
+  {PFV( 1, 9, 0 ), PFV( 2, 0, 0 ), &QgsProjectFileTransform::transformNull},
+  {PFV( 2, 0, 0 ), PFV( 2, 1, 0 ), &QgsProjectFileTransform::transformNull},
+  {PFV( 2, 1, 0 ), PFV( 2, 2, 0 ), &QgsProjectFileTransform::transformNull},
+  {PFV( 2, 2, 0 ), PFV( 2, 3, 0 ), &QgsProjectFileTransform::transform2200to2300},
 };
 
 bool QgsProjectFileTransform::updateRevision( QgsProjectVersion newVersion )
@@ -594,6 +598,17 @@ void QgsProjectFileTransform::transform1800to1900()
   QgsDebugMsg( mDom.toString() );
 }
 
+void QgsProjectFileTransform::transform2200to2300()
+{
+  //composer: set placement for all picture items to middle, to mimic <=2.2 behaviour
+  QDomNodeList composerPictureList = mDom.elementsByTagName( "ComposerPicture" );
+  for ( int i = 0; i < composerPictureList.size(); ++i )
+  {
+    QDomElement picture = composerPictureList.at( i ).toElement();
+    picture.setAttribute( "anchorPoint", QString::number( 4 ) );
+  }
+}
+
 void QgsProjectFileTransform::convertRasterProperties( QDomDocument& doc, QDomNode& parentNode,
     QDomElement& rasterPropertiesElem, QgsRasterLayer* rlayer )
 {

src/core/qgsprojectfiletransform.h

@@ -85,6 +85,7 @@ class CORE_EXPORT QgsProjectFileTransform
     void transform1100to1200();
     void transform1400to1500();
     void transform1800to1900();
+    void transform2200to2300();
 
     //helper functions
     static int rasterBandNumber( const QDomElement &rasterPropertiesElem, const QString &bandName, QgsRasterLayer *rlayer );