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
+ PopupDialog.POPUP_HORIZONTALSPACING, parentBounds.y
						+ PopupDialog.POPUP_VERTICALSPACING,
						parentBounds.width, parentBounds.height);
				rightProposedBounds = getConstrainedShellBounds(rightProposedBounds);
				
				if (rightProposedBounds.intersects(parentBounds)) {
					Rectangle leftProposedBounds = new Rectangle(parentBounds.x
							- parentBounds.width - POPUP_HORIZONTALSPACING - 1,
							parentBounds.y, parentBounds.width,
							parentBounds.height);
					leftProposedBounds = getConstrainedShellBounds(leftProposedBounds);
					
					
					if (leftProposedBounds.intersects(parentBounds)) {
						if (rightProposedBounds.x - parentBounds.x >= parentBounds.x
								- leftProposedBounds.x) {
							rightProposedBounds.x = parentBounds.x
									+ parentBounds.width
									+ PopupDialog.POPUP_HORIZONTALSPACING;
							proposedBounds = rightProposedBounds;
						} else {
							leftProposedBounds.width = parentBounds.x
									- POPUP_HORIZONTALSPACING
									- leftProposedBounds.x;
							proposedBounds = leftProposedBounds;
						}
					} else {
						
						proposedBounds = leftProposedBounds;
					}