Bug 41491 Add constructors from fields issues
200300813 a. add visibility buttons like 'Add constructor from super class'
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/GenerateNewConstructorUsingFieldsAction.java
IScanner scanner= ToolFactory.createScanner(true, false, false, false);
						scanner.setSource(constructorFields[i].getSource().toCharArray());
						TokenScanner tokenScanner= new TokenScanner(scanner);
						tokenScanner.getTokenStartOffset(ITerminalSymbols.TokenNameEQUAL, 0);
					} catch (JavaModelException e) {
					} catch (CoreException e) {
						constructorFieldsList.add(constructorFields[i]);
					}			
				} else
					constructorFieldsList.add(constructorFields[i]);
			}
		}
		if (constructorFieldsList.isEmpty()) {
			MessageDialog.openInformation(getShell(), fDialogTitle, ActionMessages.getString("GenerateConstructorUsingFieldsAction.typeContainsNoFields.message")); 
			return;
		}
		JavaElementLabelProvider labelProvider= new JavaElementLabelProvider(JavaElementLabelProvider.SHOW_DEFAULT);
		GenerateConstructorUsingFieldsContentProvider contentProvider= new GenerateConstructorUsingFieldsContentProvider(constructorFieldsList);
		GenerateConstructorUsingFieldsSelectionDialog dialog= new GenerateConstructorUsingFieldsSelectionDialog(getShell(), labelProvider, contentProvider, fEditor, type);
		dialog.setCommentString(ActionMessages.getString("SourceActionDialog.createConstructorComment")); 
		dialog.setTitle(getDialogTitle());
		dialog.setInitialSelections(preselected);
		dialog.setContainerMode(true);
		dialog.setSize(60, 18);
		dialog.setInput(new Object());
		dialog.setMessage(ActionMessages.getString("GenerateConstructorUsingFieldsAction.dialog.label")); 
		dialog.setValidator(createValidator(constructorFieldsList.size(), dialog, type));
		if (dialog.getSuperConstructors().length == 0) {
			MessageDialog.openInformation(getShell(), getDialogTitle(), ActionMessages.getString("GenerateConstructorUsingFieldsAction.error.nothing_found"));