Sencha GXT 3.0 how to capture grid checkbox deselection

Question

All I want to do is capture an event every time an item in a Grid using CheckBoxSelectionModel is either checked or unchecked. The checked/selected part is easy using the SelectionHandler. I'm not seeing anything that fires a deselection event in a multi-select mode though. I have a grid with 1000 items or so, and I let users multi-select items to track on a map. It's not giong to perform well to scan the entire model whenever a selection changes so I'm wondering how to handle this.

Answer 1

You are correct. SelectionHandler will only provide checked/selected status. I had a similar requirement and I solved it by overriding the onSelectChange() method of CheckBoxSelectionModel.

Here is the sample code for your reference.

IdentityValueProvider<VO> identity = new IdentityValueProvider<VO>();
CheckBoxSelectionModel<VO> sm = new CheckBoxSelectionModel<VO>(identity) {

    protected void onSelectChange(VO model, boolean select) {

        super.onSelectChange(model, select);
        if (select) {
            // Do something on select ...
        } else {
            // Do something on deselect ...
        }
    };
};

Hope this helps.