/usr/include/BALL/VIEW/WIDGETS/ is in libballview1.4-dev 1.4.3~beta1-4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/BALL/VIEW/WIDGETS/HTMLView.h
/usr/include/BALL/VIEW/WIDGETS/SDWidget.h
/usr/include/BALL/VIEW/WIDGETS/canvasWidget.h
/usr/include/BALL/VIEW/WIDGETS/colorButton.h
/usr/include/BALL/VIEW/WIDGETS/colorTable.h
/usr/include/BALL/VIEW/WIDGETS/datasetControl.h
/usr/include/BALL/VIEW/WIDGETS/dockWidget.h
/usr/include/BALL/VIEW/WIDGETS/dockingController.h
/usr/include/BALL/VIEW/WIDGETS/editFunctions.h
/usr/include/BALL/VIEW/WIDGETS/fileObserver.h
/usr/include/BALL/VIEW/WIDGETS/genericControl.h
/usr/include/BALL/VIEW/WIDGETS/geometricControl.h
/usr/include/BALL/VIEW/WIDGETS/gridColorWidget.h
/usr/include/BALL/VIEW/WIDGETS/helpViewer.h
/usr/include/BALL/VIEW/WIDGETS/hotkeyTable.h
/usr/include/BALL/VIEW/WIDGETS/logView.h
/usr/include/BALL/VIEW/WIDGETS/molecularControl.h
/usr/include/BALL/VIEW/WIDGETS/molecularStructure.h
/usr/include/BALL/VIEW/WIDGETS/propertyEditor.h
/usr/include/BALL/VIEW/WIDGETS/pyWidget.h
/usr/include/BALL/VIEW/WIDGETS/regularData1DWidget.h
/usr/include/BALL/VIEW/WIDGETS/regularData2DWidget.h
/usr/include/BALL/VIEW/WIDGETS/scene.h
/usr/include/BALL/VIEW/WIDGETS/shortcutTableView.h
/usr/include/BALL/VIEW/WIDGETS/testFramework.h
/usr/include/BALL/VIEW/WIDGETS/textEditorWidget.h
/usr/include/BALL/VIEW/WIDGETS/widgets.doc