Undo-redo stack used for background objects.

src/board/UBBoardController.cpp

@@ -855,6 +855,10 @@ void UBBoardController::downloadURL(const QUrl& url, const QPointF& pPos, const
 
 void UBBoardController::downloadFinished(bool pSuccess, QUrl sourceUrl, QString pContentTypeHeader, QByteArray pData, QPointF pPos, QSize pSize, bool isBackground)
 {
+    QGraphicsItem *oldBackgroundObject = NULL;
+    if (isBackground) 
+        oldBackgroundObject = mActiveScene->backgroundObject();
+
     QString mimeType = pContentTypeHeader;
 
     // In some cases "image/jpeg;charset=" is returned by the drag-n-drop. That is
@@ -1193,6 +1197,15 @@ void UBBoardController::downloadFinished(bool pSuccess, QUrl sourceUrl, QString
         UBApplication::showMessage(tr("Unknown content type %1").arg(pContentTypeHeader));
         qWarning() << "ignoring mime type" << pContentTypeHeader ;
     }
+
+    if (isBackground && oldBackgroundObject != mActiveScene->backgroundObject())
+    {
+        if (mActiveScene->isURStackIsEnabled()) { //should be deleted after scene own undo stack implemented
+            UBGraphicsItemUndoCommand* uc = new UBGraphicsItemUndoCommand(mActiveScene, oldBackgroundObject, mActiveScene->backgroundObject());
+            UBApplication::undoStack->push(uc);
+        }
+
+    }
 }
 
 

src/domain/UBGraphicsItemUndoCommand.cpp

@@ -91,8 +91,15 @@ void UBGraphicsItemUndoCommand::undo()
     while (itRemoved.hasNext())
     {
         QGraphicsItem* item = itRemoved.next();
-        mScene->addItem(item);
-        UBApplication::boardController->freezeW3CWidget(item, false);
+        if (item)
+        {
+            if (UBItemLayerType::FixedBackground == item->data(UBGraphicsItemData::ItemLayerType))
+                mScene->setAsBackgroundObject(item);
+            else
+                mScene->addItem(item);
+
+            UBApplication::boardController->freezeW3CWidget(item, false);
+        }
     }
 
     // force refresh, QT is a bit lazy and take a lot of time (nb item ^2 ?) to trigger repaint
@@ -123,8 +130,15 @@ void UBGraphicsItemUndoCommand::redo()
         while (itAdded.hasNext())
         {
             QGraphicsItem* item = itAdded.next();
-            mScene->addItem(item);
-            UBApplication::boardController->freezeW3CWidget(item, false);
+            if (item)
+            {
+                if (UBItemLayerType::FixedBackground == item->data(UBGraphicsItemData::ItemLayerType))
+                    mScene->setAsBackgroundObject(item);
+                else
+                    mScene->addItem(item);
+
+                UBApplication::boardController->freezeW3CWidget(item, false);
+            }
         }
 
         // force refresh, QT is a bit lazy and take a lot of time (nb item ^2) to trigger repaint

src/domain/UBGraphicsScene.cpp

@@ -1292,6 +1292,11 @@ void UBGraphicsScene::clearBackground()
 {
     if(mBackgroundObject){
         removeItem(mBackgroundObject);
+
+        if (enableUndoRedoStack) { //should be deleted after scene own undo stack implemented
+            UBGraphicsItemUndoCommand* uc = new UBGraphicsItemUndoCommand(this, mBackgroundObject, NULL);
+            UBApplication::undoStack->push(uc);
+        }
         mBackgroundObject = 0;
     }
     update(sceneRect());

src/domain/UBGraphicsScene.h

@@ -102,6 +102,7 @@ class UBGraphicsScene: public UBCoreGraphicsScene, public UBItem
 
     //        tmp stub for divide addings scene objects from undo mechanism implementation
     void setURStackEnable(bool set = true) {enableUndoRedoStack = set;}
+    bool isURStackIsEnabled(){ return enableUndoRedoStack;}
 
     UBGraphicsScene(UBDocumentProxy *parent);
         virtual ~UBGraphicsScene();