com.sencha.gxt.core.client.util.ToggleGroup.java Source code

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Here is the source code for com.sencha.gxt.core.client.util.ToggleGroup.java

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/**
 * Sencha GXT 4.0.0 - Sencha for GWT
 * Copyright (c) 2006-2015, Sencha Inc.
 *
 * licensing@sencha.com
 * http://www.sencha.com/products/gxt/license/
 *
 * ================================================================================
 * Open Source License
 * ================================================================================
 * This version of Sencha GXT is licensed under the terms of the Open Source GPL v3
 * license. You may use this license only if you are prepared to distribute and
 * share the source code of your application under the GPL v3 license:
 * http://www.gnu.org/licenses/gpl.html
 *
 * If you are NOT prepared to distribute and share the source code of your
 * application under the GPL v3 license, other commercial and oem licenses
 * are available for an alternate download of Sencha GXT.
 *
 * Please see the Sencha GXT Licensing page at:
 * http://www.sencha.com/products/gxt/license/
 *
 * For clarification or additional options, please contact:
 * licensing@sencha.com
 * ================================================================================
 *
 *
 * ================================================================================
 * Disclaimer
 * ================================================================================
 * THIS SOFTWARE IS DISTRIBUTED "AS-IS" WITHOUT ANY WARRANTIES, CONDITIONS AND
 * REPRESENTATIONS WHETHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE
 * IMPLIED WARRANTIES AND CONDITIONS OF MERCHANTABILITY, MERCHANTABLE QUALITY,
 * FITNESS FOR A PARTICULAR PURPOSE, DURABILITY, NON-INFRINGEMENT, PERFORMANCE AND
 * THOSE ARISING BY STATUTE OR FROM CUSTOM OR USAGE OF TRADE OR COURSE OF DEALING.
 * ================================================================================
 */
package com.sencha.gxt.core.client.util;

import java.util.AbstractSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.HasValue;

/**
 * Group HasValue<Boolean> implementers like checkboxes and radios so they can be controlled as a group.
 * <p/>
 * Note: to reset all the items in a group to false use {@link #reset()}.
 */
public class ToggleGroup extends AbstractSet<HasValue<Boolean>> implements HasValue<HasValue<Boolean>> {

    protected ValueChangeHandler<Boolean> handler = new ValueChangeHandler<Boolean>() {
        @SuppressWarnings("unchecked")
        @Override
        public void onValueChange(ValueChangeEvent<Boolean> event) {
            if (event.getValue() && getValue() != event.getSource()) {
                setValue((HasValue<Boolean>) event.getSource(), true);
            }
        }
    };

    protected Map<HasValue<Boolean>, HandlerRegistration> toggles = new HashMap<HasValue<Boolean>, HandlerRegistration>();
    protected HasValue<Boolean> value;

    private HandlerManager handlerManager;

    @Override
    public boolean add(HasValue<Boolean> toggle) {
        if (toggles.containsKey(toggle)) {
            return false;
        } else {
            return toggles.put(toggle, toggle.addValueChangeHandler(handler)) == null;
        }
    }

    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<HasValue<Boolean>> handler) {
        return ensureHandlers().addHandler(ValueChangeEvent.getType(), handler);
    }

    /**
     * Remove all of the items added to this toggle group. This calls {@link java.util.AbstractSet#clear()}.
     * <p>
     * To Reset all of the toggle group HasValue<Boolean> items to false use {@link #reset()}.
     */
    @Override
    public void clear() {
        super.clear();
    }

    @Override
    public void fireEvent(GwtEvent<?> event) {
        if (handlerManager != null) {
            handlerManager.fireEvent(event);
        }
    }

    @Override
    public HasValue<Boolean> getValue() {
        return value;
    }

    @Override
    public Iterator<HasValue<Boolean>> iterator() {
        return toggles.keySet().iterator();
    }

    @Override
    public boolean remove(Object toggle) {
        HandlerRegistration reg = toggles.remove(toggle);
        if (reg != null) {
            reg.removeHandler();
            return true;
        }
        return false;

    }

    /**
     * Reset all of the toggle group HasValue<Boolean> items to false.
     * <p>
     * To remove all of the items use {@link #clear()}.
     */
    public void reset() {
        this.value = null;

        Iterator<HasValue<Boolean>> it = iterator();
        while (it.hasNext()) {
            HasValue<Boolean> item = it.next();
            item.setValue(false, false);
        }
    }

    @Override
    public void setValue(HasValue<Boolean> value) {
        setValue(value, false);
    }

    @Override
    public void setValue(HasValue<Boolean> value, boolean fireEvents) {
        if (!contains(value)) {
            value = null;
        }
        HasValue<Boolean> oldValue = getValue();
        this.value = value;
        if (value != null && !value.getValue()) {
            value.setValue(true, fireEvents);
        }

        for (HasValue<Boolean> toggle : ToggleGroup.this) {
            if (toggle != value) {
                toggle.setValue(false, fireEvents);
            }
        }
        if (fireEvents) {
            ValueChangeEvent.fireIfNotEqual(this, oldValue, value);
        }
    }

    @Override
    public int size() {
        return toggles.size();
    }

    protected HandlerManager ensureHandlers() {
        return handlerManager == null ? handlerManager = new HandlerManager(this) : handlerManager;
    }

}