[composer] Move code for creating groups to QgsComposition

Previously this code was located in QgsComposerView. Moving it to
QgsComposition simplifies grouping items for plugins. Also start
a new unit test for QgsComposerItemGroup.

python/core/composer/qgscomposition.sip

@@ -407,6 +407,13 @@ class QgsComposition : QGraphicsScene
     void lockSelectedItems();
     /**Unlock all items*/
     void unlockAllItems();
+    
+    /**Creates a new group from a list of composer items and adds it to the composition.
+     * @param items items to include in group
+     * @returns QgsComposerItemGroup of grouped items, if grouping was possible
+     * @note added in QGIS 2.6
+    */
+    QgsComposerItemGroup* groupItems( QList<QgsComposerItem*> items );
 
     /**Sorts the zList. The only time where this function needs to be called is from QgsComposer
      * after reading all the items from xml file
@@ -521,7 +528,10 @@ class QgsComposition : QGraphicsScene
     QImage printPageAsRaster( int page );
 
     /**Render a page to a paint device
-        @note added in version 1.9*/
+     * @param p destination painter
+     * @param page page number, 0 based such that the first page is page 0
+     * @note added in version 1.9
+    */
     void renderPage( QPainter* p, int page );
 
     /** Compute world file parameters */

src/core/composer/qgscomposition.cpp

@@ -1791,6 +1791,26 @@ void QgsComposition::unlockAllItems()
   QgsProject::instance()->dirty( true );
 }
 
+QgsComposerItemGroup *QgsComposition::groupItems( QList<QgsComposerItem *> items )
+{
+  if ( items.size() < 2 )
+  {
+    //not enough items for a group
+    return 0;
+  }
+
+  QgsComposerItemGroup* itemGroup = new QgsComposerItemGroup( this );
+
+  QList<QgsComposerItem*>::iterator itemIter = items.begin();
+  for ( ; itemIter != items.end(); ++itemIter )
+  {
+    itemGroup->addItem( *itemIter );
+  }
+
+  addItem( itemGroup );
+  return itemGroup;
+}
+
 void QgsComposition::updateZValues( const bool addUndoCommands )
 {
   int counter = mItemsModel->zOrderListSize();

src/core/composer/qgscomposition.h

@@ -47,6 +47,7 @@ class QgsComposerMouseHandles;
 class QgsComposerHtml;
 class QgsComposerTableV2;
 class QgsComposerItem;
+class QgsComposerItemGroup;
 class QgsComposerLabel;
 class QgsComposerLegend;
 class QgsComposerMap;
@@ -470,6 +471,13 @@ class CORE_EXPORT QgsComposition : public QGraphicsScene
     /**Unlock all items*/
     void unlockAllItems();
 
+    /**Creates a new group from a list of composer items and adds it to the composition.
+     * @param items items to include in group
+     * @returns QgsComposerItemGroup of grouped items, if grouping was possible
+     * @note adde in QGIS 2.6
+    */
+    QgsComposerItemGroup* groupItems( QList<QgsComposerItem*> items );
+
     /**Sorts the zList. The only time where this function needs to be called is from QgsComposer
      * after reading all the items from xml file
      * @deprecated use refreshZList instead
@@ -583,7 +591,9 @@ class CORE_EXPORT QgsComposition : public QGraphicsScene
     QImage printPageAsRaster( int page );
 
     /**Render a page to a paint device
-        @note added in version 1.9*/
+     * @param p destination painter
+     * @param page page number, 0 based such that the first page is page 0
+     * @note added in version 1.9*/
     void renderPage( QPainter* p, int page );
 
     /** Compute world file parameters */

src/gui/qgscomposerview.cpp

@@ -1777,20 +1777,16 @@ void QgsComposerView::groupItems()
     return;
   }
 
+  //group selected items
   QList<QgsComposerItem*> selectionList = composition()->selectedComposerItems();
-  if ( selectionList.size() < 2 )
-  {
-    return; //not enough items for a group
-  }
-  QgsComposerItemGroup* itemGroup = new QgsComposerItemGroup( composition() );
+  QgsComposerItemGroup* itemGroup = composition()->groupItems( selectionList );
 
-  QList<QgsComposerItem*>::iterator itemIter = selectionList.begin();
-  for ( ; itemIter != selectionList.end(); ++itemIter )
+  if ( !itemGroup )
   {
-    itemGroup->addItem( *itemIter );
+    //group could not be created
+    return;
   }
 
-  composition()->addItem( itemGroup );
   itemGroup->setSelected( true );
   emit selectedItemChanged( itemGroup );
 }

tests/src/core/CMakeLists.txt

@@ -111,6 +111,7 @@ ADD_QGIS_TEST(composerutils testqgscomposerutils.cpp)
 ADD_QGIS_TEST(compositiontest testqgscomposition.cpp)
 ADD_QGIS_TEST(composermodel testqgscomposermodel.cpp)
 ADD_QGIS_TEST(composermultiframetest testqgscomposermultiframe.cpp)
+ADD_QGIS_TEST(composergrouptest testqgscomposergroup.cpp)
 ADD_QGIS_TEST(composerpapertest testqgscomposerpaper.cpp)
 ADD_QGIS_TEST(composermaptest testqgscomposermap.cpp)
 ADD_QGIS_TEST(composermapgridtest testqgscomposermapgrid.cpp)

tests/src/core/testqgscomposergroup.cpp

@@ -0,0 +1,116 @@
+/***************************************************************************
+                         testqgscomposergroup.cpp
+                         -----------------------
+    begin                : October 2014
+    copyright            : (C) 2014 by 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 "qgscomposeritemgroup.h"
+#include "qgscomposerlabel.h"
+#include "qgscomposition.h"
+#include "qgscompositionchecker.h"
+#include <QObject>
+#include <QtTest>
+
+class TestQgsComposerGroup: 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 createGroup(); //test grouping items
+    void ungroup(); //test ungrouping items
+    void deleteGroup(); //test deleting group works
+    void undoRedo(); //test that group/ungroup undo/redo commands don't crash
+
+  private:
+    QgsComposition* mComposition;
+    QgsMapSettings mMapSettings;
+    QgsComposerLabel* mItem1;
+    QgsComposerLabel* mItem2;
+    QString mReport;
+};
+
+void TestQgsComposerGroup::initTestCase()
+{
+  mComposition = new QgsComposition( mMapSettings );
+  mComposition->setPaperSize( 297, 210 ); //A4 landscape
+
+  //create some items
+  mItem1 = new QgsComposerLabel( mComposition );
+  mComposition->addItem( mItem1 );
+  mItem2 = new QgsComposerLabel( mComposition );
+  mComposition->addItem( mItem2 );
+
+  mReport = "<h1>Composer Grouped Item Tests</h1>\n";
+}
+
+void TestQgsComposerGroup::cleanupTestCase()
+{
+  delete mComposition;
+
+  QString myReportFile = QDir::tempPath() + QDir::separator() + "qgistest.html";
+  QFile myFile( myReportFile );
+  if ( myFile.open( QIODevice::WriteOnly | QIODevice::Append ) )
+  {
+    QTextStream myQTextStream( &myFile );
+    myQTextStream << mReport;
+    myFile.close();
+  }
+}
+
+void TestQgsComposerGroup::init()
+{
+
+}
+
+void TestQgsComposerGroup::cleanup()
+{
+
+}
+
+void TestQgsComposerGroup::createGroup()
+{
+  //group items
+  QList<QgsComposerItem*> items;
+  items << mItem1 << mItem2;
+  QgsComposerItemGroup* group = mComposition->groupItems( items );
+
+  //check result
+  QVERIFY( group );
+  QCOMPARE( group->items().size(), 2 );
+  QVERIFY( group->items().contains( mItem1 ) );
+  QVERIFY( group->items().contains( mItem2 ) );
+  QVERIFY( mItem1->isGroupMember() );
+  QVERIFY( mItem2->isGroupMember() );
+}
+
+void TestQgsComposerGroup::ungroup()
+{
+
+}
+
+void TestQgsComposerGroup::deleteGroup()
+{
+
+}
+
+void TestQgsComposerGroup::undoRedo()
+{
+
+}
+
+QTEST_MAIN( TestQgsComposerGroup )
+#include "moc_testqgscomposergroup.cxx"