Bug 250604 [FieldAssist] API - ContentProposalAdapter needs isShowing() method
Please implement a method ContentProposalAdapter.isShwoing(). The method should return a boolean whether the content assistant proposal popup is open or not.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
e.doit = false;
					Object p = getSelectedProposal();
					if (p != null) {
						acceptCurrentProposal();
					} else {
						close();
					}
					break;
				case SWT.TAB:
					e.doit = false;
					getShell().setFocus();
					return;
				case SWT.BS:
					
					if (filterStyle != FILTER_NONE) {
						
						if (filterText.length() == 0) {
							return;
						}
						
						filterText = filterText.substring(0, filterText
								.length() - 1);
						asyncRecomputeProposals(filterText);
						return;
					}
					
					
					
					
					int pos = getControlContentAdapter().getCursorPosition(