Spreadsheet - Install listeners on context menu actions

[astarno-dev]

Describe your motivation

Currently it is possible to install listeners on several things, like values changing in cells or selection changing. However, a major missing option is to install listeners on any of the actions performed within the context menu. In particular: adding and removing rows/columns. There is also nothing mentioned about this in the documentation: https://vaadin.com/docs/latest/components/spreadsheet

Our current use-case is blocked because of this issue. We want users to be able to see a live overview of the modifications made to the sheet compared to an original one. Ideally, this is done by installing appropriate listeners and only doing the necessary comparisons when something changed. Currently, we cannot detect any changes in rows/columns being added/deleted, which is a huge gap in our modification detection.

I'm sure there is a multitude of other use-cases where this functionality would be useful.

Describe the solution you'd like

I would like to be able to install listeners in which I can catch actions such as users adding or removing rows/columns. Other context menu actions seems less essential, but would be nice to be able to install listeners on as well.

As a bonus, context menu actions are currently not mentioned in the documentation at all. Having some sentences about them and potential work-arounds until this functionality is implemented would be good.

Describe alternatives you've considered

We are currently experimenting with ActionHandlers. Unsure about the possibilities/outcome yet, but there would in our opinion still be a need for a more straight forward approach.

Additional context

No response

[astarno-dev]

Current workaround:

1. Define an interface for an ActionCallback function

@FunctionalInterface
public interface ActionCallback {
    void execute(Action action, Object sender, Object target);
}

2. Extend the SpreadsheetDefaultActionHandler with your own ListeningSpreadsheetDefaultActionHandler

public class ListeningSpreadsheetDefaultActionHandler extends SpreadsheetDefaultActionHandler {

    private final List<ActionCallback> callbacks = new ArrayList<>();

    @Override
    public Action[] getActions(Object target, Object sender) {
        return super.getActions(target, sender);
    }

    @Override
    public void handleAction(Action action, Object sender, Object target) {
        super.handleAction(action, sender, target);

        for (ActionCallback callback : callbacks) {
            callback.execute(action, sender, target);
        }
    }

    public void addActionListener(ActionCallback fun) {
        callbacks.add(fun);
    }    
}

3. Remove the SpreadsheetDefaultActionHandler from your spreadsheet and install your newly created ListeningSpreadsheetDefaultActionHandler instead

spreadsheet.removeDefaultActionHandler();
ListeningSpreadsheetDefaultActionHandler actionHandler = new ListeningSpreadsheetDefaultActionHandler();
actionHandler.addActionListener((action, sender, target) ->
        if (action instanceof DeleteRowAction) {
             System.out.println("Row deleted");
        } else {
             System.out.println("Action triggered with sender: " + sender + " and target: " + target)
        }       
);
requirementRulesSpreadsheet.addActionHandler(actionHandler);