I added a new QDockWidget as all the other ones I already have. However this time the Widget is not resized within the QDockWidget, as if it had not layout.

It is created with this code:
Qt Code: 
  1. dockAppMessages = new QDockWidget(this);
  2. 	dockAppMessages->setAllowedAreas(Qt::BottomDockWidgetArea | Qt::RightDockWidgetArea | Qt::LeftDockWidgetArea);
  3. 	widgetDockErrorMessageImpl = new widgetDockErrorMessage(dockAppMessages);
  4.     dockAppMessages->setWidget(widgetDockPhaseShapesImpl);	
  5. 	dockAppMessages->setWindowTitle("Application Messages");
  6.     addDockWidget(Qt::BottomDockWidgetArea , dockAppMessages);    
  7. 	menuView->addAction(dockAppMessages->toggleViewAction());
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widgetDockErrorMessage, the widget displayed within QDockWidget has a Layout, set to Expanding.

The ui file is the following
Qt Code: 
  1. void setupUi(QWidget *widgetDockErrorMessage)
  2.     {
  3.     if (widgetDockErrorMessage->objectName().isEmpty())
  4.         widgetDockErrorMessage->setObjectName(QString::fromUtf8("widgetDockErrorMessage"));
  5.     widgetDockErrorMessage->resize(499, 153);
  6.     QSizePolicy sizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  7.     sizePolicy.setHorizontalStretch(0);
  8.     sizePolicy.setVerticalStretch(0);
  9.     sizePolicy.setHeightForWidth(widgetDockErrorMessage->sizePolicy().hasHeightForWidth());
  10.     widgetDockErrorMessage->setSizePolicy(sizePolicy);
  11.     gridLayout = new QGridLayout(widgetDockErrorMessage);
  12.     gridLayout->setObjectName(QString::fromUtf8("gridLayout"));
  13.     ErrorList = new WidgetListStringStack(widgetDockErrorMessage);
  14.     ErrorList->setObjectName(QString::fromUtf8("ErrorList"));
  15.     sizePolicy.setHeightForWidth(ErrorList->sizePolicy().hasHeightForWidth());
  16.     ErrorList->setSizePolicy(sizePolicy);
  17.  
  18.     gridLayout->addWidget(ErrorList, 0, 0, 1, 1);
  19.  
  20.     horizontalLayout = new QHBoxLayout();
  21.     horizontalLayout->setObjectName(QString::fromUtf8("horizontalLayout"));
  22.     horizontalSpacer = new QSpacerItem(40, 20, QSizePolicy::Expanding, QSizePolicy::Minimum);
  23.  
  24.     horizontalLayout->addItem(horizontalSpacer);
  25.  
  26.     pushButtonClearList = new QPushButton(widgetDockErrorMessage);
  27.     pushButtonClearList->setObjectName(QString::fromUtf8("pushButtonClearList"));
  28.  
  29.     horizontalLayout->addWidget(pushButtonClearList);
  30.  
  31.  
  32.     gridLayout->addLayout(horizontalLayout, 1, 0, 1, 1);
  33.  
  34.  
  35.     retranslateUi(widgetDockErrorMessage);
  36.  
  37.     QMetaObject::connectSlotsByName(widgetDockErrorMessage);
  38.     } // setupUi
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Any ideas?

Matthias