question: public void showTreeItemControlDecoration ( TreeViewer treeViewer , Object data , String message ) { if ( null == treeViewer ) { return ; } for ( TreeItemControlDecoration decoration : treeItemControlDecorations ) { if ( data == decoration . getData ( ) ) { decoration . show ( ) ; decoration . setDescriptionText ( message ) ; return ; } } for ( TreeItem treeItem : getAllTreeItems ( treeViewer ) ) { if ( treeItem . getData ( ) == data ) { TreeItemControlDecoration decoration = new TreeItemControlDecoration ( treeItem ) ; decoration . show ( ) ; decoration . setDescriptionText ( message ) ; treeItemControlDecorations . add ( decoration ) ; return ; } } }
target:  Shows the error decoration data.