Bug 26979 Outline pop-up: flicker when filtering
1) open the outline pop-up (ctrl-O) 2) type in a letter ->observe that you can watch how the tree items are removed and then added again. Use of setRedraw(false/true) during filtering should avoid this flickering
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/text/JavaSourceViewerConfiguration.java
int tabWidth= preferences.getInt(JavaCore.FORMATTER_TAB_SIZE);
		boolean useSpaces= getPreferenceStore().getBoolean(SPACES_FOR_TABS);
		
		for (int i= 0; i <= tabWidth; i++) {
		    StringBuffer prefix= new StringBuffer();
			if (useSpaces) {
			    for (int j= 0; j + i < tabWidth; j++)
			    	prefix.append(' ');
		    	
				if (i != 0)
		    		prefix.append('\t');				
			} else {    
			    for (int j= 0; j < i; j++)
			    	prefix.append(' ');
		    	
				if (i != tabWidth)
		    		prefix.append('\t');
			}
			
			vector.add(prefix.toString());
		}
		vector.add(""); 
		
		return (String[]) vector.toArray(new String[vector.size()]);
	}
	/*
	 * @see SourceViewerConfiguration#getTabWidth(ISourceViewer)
	 */
	public int getTabWidth(ISourceViewer sourceViewer) {
		return getPreferenceStore().getInt(PREFERENCE_TAB_WIDTH);