CODEWITHSUNDEEP
gwtsuggestbox
AndreiXwe
AndreiXwe

Reputation: 763

How to show suggestions in a GWT SuggestBox only after 2 characters have been typed?

I am trying to make a SuggestBox showing suggestions only after 2 characters have been typed. My idea was to hide the suggestions when the text length is 1, using the class DefaultSuggestionDisplay. I have tried to attach different handlers like KeyPressHandler and KeyUpHandler on the SuggestionBox itself and its TextBox, but none of them seemed to work. Do you have any "suggestions"? :D

Upvotes: 0

Views: 1196

Answers (2)

Andrei Volgin
Andrei Volgin

Reputation: 41099

You can extend SuggestBox and override showSuggestionList() method.

Adding KeyUpHandler is not working because you add another KeyUpHandler, not replacing the one that SuggestBox added to its own TextBox.

EDIT:

@Override
showSuggestionList() {
    if (getTextBox().getValue().length() > 1) {
        super.showSuggestionList();
    }
}

Upvotes: 0

Adam
Adam

Reputation: 5599

You can extend DefaultSuggestionDisplay and override showSuggestions method:

public class MySuggestionDisplay extends DefaultSuggestionDisplay {
    @Override
    protected void showSuggestions(SuggestBox suggestBox, Collection<? extends Suggestion> suggestions, boolean isDisplayStringHTML, boolean isAutoSelectEnabled, SuggestionCallback callback) {
        if(suggestBox.getText().length() > 1)
            super.showSuggestions(suggestBox, suggestions, isDisplayStringHTML, isAutoSelectEnabled, callback);
    }
}

You have to pass your new display to the SuggestBox constructor:

public class MySuggestBox extends SuggestBox {
    public MySuggestBox() {
        super(
            new MySuggestOracle(),
            new TextBox(), 
            new MySuggestionDisplay());
    }
}

In this constructor you should provide:

  • your own SuggestOracle class (here named MySuggestOracle) - I suppose you have one
  • TextBox - it is the default widget to enter text (you can provide your own, it just needs to implement HasText)
  • SuggestionDisplay - use the one with showSuggestions method overridden.

This is full working example code showing suggestions on at least 2 characters typed:

import java.util.ArrayList;
import java.util.Collection;

import com.google.gwt.user.client.ui.SuggestBox;
import com.google.gwt.user.client.ui.SuggestOracle;
import com.google.gwt.user.client.ui.SuggestOracle.Suggestion;
import com.google.gwt.user.client.ui.TextBox;

public class MySuggestBox extends SuggestBox {

    public MySuggestBox() {
        super(
            new SuggestOracle() {
                @Override
                public void requestSuggestions(Request request, Callback callback) {
                    ArrayList<Suggestion> suggestions = new ArrayList<Suggestion>();
                    suggestions.add(new MySuggestion("aaa"));
                    suggestions.add(new MySuggestion("bbb"));
                    suggestions.add(new MySuggestion("ccc"));
                    suggestions.add(new MySuggestion("ddd"));

                    Response response = new Response();
                    response.setSuggestions(suggestions);
                    callback.onSuggestionsReady(request, response);
                }
            }, 
            new TextBox(), 
            new MySuggestionDisplay());
    }

    public static class MySuggestionDisplay extends DefaultSuggestionDisplay {
        @Override
        protected void showSuggestions(SuggestBox suggestBox, Collection<? extends Suggestion> suggestions, boolean isDisplayStringHTML, boolean isAutoSelectEnabled, SuggestionCallback callback) {
            if(suggestBox.getText().length() > 1)
                super.showSuggestions(suggestBox, suggestions, isDisplayStringHTML, isAutoSelectEnabled, callback);
        }
    }

    public static class MySuggestion implements Suggestion {

        private String text;

        public MySuggestion(String text) {
            this.text = text;
        }

        @Override
        public String getDisplayString() {
            return text;
        }

        @Override
        public String getReplacementString() {
            return text;
        }
    }
}

Upvotes: 2

Related Questions