How should build in QT after changing code?

[webphone]

I would like to make the central widget to be larger and want to put the right hand side table of content dockwidget to left.

MainWindow.cpp

m_TableOfContents = new TableOfContents( this );
m_TableOfContents->setObjectName( TABLE_OF_CONTENTS_NAME );    //addDockWidget( Qt::RightDockWidgetArea, m_TableOfContents );
addDockWidget( Qt::LeftDockWidgetArea, m_TableOfContents );

After build it, it shows error:
:-1: error: ERROR: file copy failed from "/Developer/Applications/Qt/plugins/accessible/libqtaccessiblewidgets.dylib"
:-1: error: ERROR: file copy failed from "/Developer/Applications/Qt/plugins/bearer/libqgenericbearer.dylib"
.....30 errors.

Then, I deleted the target build and re-run cmake then build, it is ok and no build error.

However, the right hand side table of content dockwidget does not place in the left hand side under Book Browser.

The layout I want is
http://doc.trolltech.com/4.7/mainwin...ckwidgets.html
(just put the "Letter" central widget to right hand side)

My questions:
1. How should I edit the code
addDockWidget( Qt::LeftDockWidgetArea, m_TableOfContents );

2. How should I rebuild the project after changing code in QT?

For a first time build, it takes 20 mins to build all projects. I do not want to build all, just rebuild the changed project.