Bug 81983 [preferences] Disabling and enabling folding on small file takes forever
3.1 M4 Using enable/disable folding on a small CU takes forever. This is caused by the recent change to apply the preference to all Java editors. In another (hidden) window (Debug) I had StyledText open which (understandably) took long to react on the preference change. Non-visible editor's should not react to this change until they become visible.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
}
		};
		fInformationPresenter= new InformationPresenter(informationControlCreator);
		fInformationPresenter.setSizeConstraints(60, 10, true, true);		
		fInformationPresenter.install(getSourceViewer());
		
		fEditorSelectionChangedListener= new EditorSelectionChangedListener();
		fEditorSelectionChangedListener.install(getSelectionProvider());
		
		if (fMarkOccurrenceAnnotations)
			installOccurrencesFinder();
		
		if (isSemanticHighlightingEnabled())
			installSemanticHighlighting();
		getEditorSite().getShell().addShellListener(fActivationListener);
	}
	
	protected void configureSourceViewerDecorationSupport(SourceViewerDecorationSupport support) {
		
		fBracketMatcher.setSourceVersion(getPreferenceStore().getString(JavaCore.COMPILER_SOURCE));
		support.setCharacterPairMatcher(fBracketMatcher);
		support.setMatchingCharacterPainterPreferenceKeys(MATCHING_BRACKETS, MATCHING_BRACKETS_COLOR);
		
		super.configureSourceViewerDecorationSupport(support);
	}
	
	/*
	 * @see org.eclipse.ui.texteditor.AbstractTextEditor#gotoMarker(org.eclipse.core.resources.IMarker)
	 */
	public void gotoMarker(IMarker marker) {