Bug 31214 [Show in] Fails for Package Explorer in non-Java project
- create a simple project P - create a simple file called "x.java" in P - open it with the Default Text Editor - in the editor activate "Show in" and select Package Explorer as target -> nothing happens even if P and "x.java" are visible in the Package Explorer
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
void toggleLayout() {
		
		fIsCurrentLayoutFlat= !fIsCurrentLayoutFlat;
		saveLayoutState(null);
		
		fContentProvider.setIsFlatLayout(isFlatLayout());
		fLabelProvider.setIsFlatLayout(isFlatLayout());
		
		fViewer.getControl().setRedraw(false);
		fViewer.refresh();
		fViewer.getControl().setRedraw(true);
	}
	
	/**
	 * This method should only be called inside this class
	 * and from test cases.
	 */
	public PackageExplorerContentProvider createContentProvider() {
		IPreferenceStore store= PreferenceConstants.getPreferenceStore();
		boolean showCUChildren= store.getBoolean(PreferenceConstants.SHOW_CU_CHILDREN);
		boolean reconcile= PreferenceConstants.UPDATE_WHILE_EDITING.equals(store.getString(PreferenceConstants.UPDATE_JAVA_VIEWS));
		return new PackageExplorerContentProvider(showCUChildren, reconcile);
	}
	
	private PackageExplorerLabelProvider createLabelProvider() {
		return new PackageExplorerLabelProvider(AppearanceAwareLabelProvider.DEFAULT_TEXTFLAGS | JavaElementLabels.P_COMPRESSED,
				AppearanceAwareLabelProvider.DEFAULT_IMAGEFLAGS | JavaElementImageProvider.SMALL_ICONS,
				fContentProvider);			
	}