Bug 5231 Add search for field read and write references
The UI should support the following new JDT Core feature: Search for field read and field write references. Two new constants have been added on IJavaSearchConstants to be used when creating a field reference search pattern: - READ_REFERENCES: the search results contain *only* read access to a field. - WRITE_REFERENCES: the search results contain *only* write access to a field. If REFERENCES is used, then search results contain both read and write accesss to a field.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchPage.java
if (data.javaElement != null && getPattern().equals(fInitialPattern))
			op= new JavaSearchOperation(workspace, data.javaElement, data.limitTo, scope, scopeDescription, collector);
		else {
			data.javaElement= null;
			op= new JavaSearchOperation(workspace, data.pattern, data.searchFor, data.limitTo, scope, scopeDescription, collector);
		}
		Shell shell= getControl().getShell();
		try {
			getContainer().getRunnableContext().run(true, true, op);
		} catch (InvocationTargetException ex) {
			ExceptionHandler.handle(ex, shell, SearchMessages.getString("Search.Error.search.title"), SearchMessages.getString("Search.Error.search.message")); 
			return false;
		} catch (InterruptedException ex) {
			return false;
		}
		return true;
	}
	
	private int getLimitTo() {
		for (int i= 0; i < fLimitTo.length; i++) {
			if (fLimitTo[i].getSelection())
				return i;
		}
		Assert.isTrue(false, SearchMessages.getString("SearchPage.shouldNeverHappen")); 
		return -1;
	}
	private String[] getPreviousSearchPatterns() {
		
		int patternCount= fgPreviousSearchPatterns.size();
		String [] patterns= new String[patternCount];