Bug 148357 [Field Assist] - API - provide access for closing the proposal popup
I think that the field assist API needs more hooks to be customizable. For example : 1) There is no way to manually close/open the popup. Most of the times, this is the easier thing for a user to ask to implement his custom behaviour. 2) There is no way to intercept keystrokes/events directed to the field. 3) There is no way to control focus.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
} else {
					
					proposedBounds = rightProposedBounds;
				}
				getShell().setBounds(proposedBounds);
			}
			/*
			 * Set the text contents of the popup.
			 */
			void setContents(String newContents) {
				if (newContents == null) {
					newContents = EMPTY;
				}
				this.contents = newContents;
				if (text != null && !text.isDisposed()) {
					text.setText(contents);
				}
			}
			/*
			 * Return whether the popup has focus.
			 */
			boolean hasFocus() {
				if (text == null || text.isDisposed()) {
					return false;
				}
				return text.getShell().isFocusControl()
						|| text.isFocusControl();
			}
		}
		/*