com.google.appinventor.client.widgets.properties.BooleanPropertyEditor.java Source code

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Here is the source code for com.google.appinventor.client.widgets.properties.BooleanPropertyEditor.java

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// -*- mode: java; c-basic-offset: 2; -*-
// Copyright 2009-2011 Google, All Rights reserved
// Copyright 2011-2012 MIT, All rights reserved
// Released under the Apache License, Version 2.0
// http://www.apache.org/licenses/LICENSE-2.0

package com.google.appinventor.client.widgets.properties;

import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.ui.CheckBox;

/**
 * Property editor for boolean values.
 *
 */
public class BooleanPropertyEditor extends PropertyEditor implements ValueChangeHandler<Boolean> {

    // UI for boolean values will be represented by a CheckBox
    private final CheckBox checkbox;

    // Spellings for true and false values (in Java and C++ it is 'true' and 'false', but in Simple
    // it is 'True' and 'False'
    private final String trueValue;
    private final String falseValue;

    /**
     * Creates a new property editor for boolean values.
     *
     * @param trueValue  spelling of true value
     * @param falseValue  spelling of false value
     */
    public BooleanPropertyEditor(String trueValue, String falseValue) {
        this.trueValue = trueValue;
        this.falseValue = falseValue;

        checkbox = new CheckBox();
        checkbox.addValueChangeHandler(this);

        initWidget(checkbox);
    }

    // Updates the property value shown in the editor
    @Override
    protected void updateValue() {
        checkbox.setValue(property.getValue().equals(trueValue));
    }

    // ValueChangeHandler implementation

    @Override
    public void onValueChange(ValueChangeEvent<Boolean> event) {
        property.setValue(checkbox.getValue() ? trueValue : falseValue);
    }
}