Bug 120168 [Field Assist] - should be able to specify character activation subset when auto-activating
ControlContentAdapter (initial release) When there is no triggering keystroke set on a ControlContentAdapter, auto-activation is assumed, and alpha-numerics trigger the auto-activation. It is useful to be able to specify a subset of characters that trigger auto-activation. This is done, for example, by the find/replace dialog RexExProcessor, so that only those characters involving regular expressions will auto-activate the content assist.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
* @return the String contents of the control. Never <code>null</code>.
	 */
	public String getControlContent() {
		if (isValid())
			return controlContentAdapter.getControlContents(control);
		return ""; 
	}
	/*
	 * Set the text content of the control to the specified text.
	 */
	private void setControlContent(String text) {
		if (isValid())
			controlContentAdapter.setControlContents(control, text);
	}
	/*
	 * Insert the specified text into the control content.
	 */
	private void insertControlContent(String text) {
		if (isValid())
			controlContentAdapter.insertControlContents(control, text);
	}
	/*
	 * Check that the control and content adapter are valid.
	 */
	private boolean isValid() {
		return control != null && !control.isDisposed()
				&& controlContentAdapter != null;
	}
}