gwt.material.design.components.client.base.mixin.HasValueMixin.java Source code

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Here is the source code for gwt.material.design.components.client.base.mixin.HasValueMixin.java

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/*
 * #%L
 * Gwt Material Design Components
 * %%
 * Copyright (C) 2017 - 2017 Gwt Material Design Components
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package gwt.material.design.components.client.base.mixin;

import com.google.gwt.event.dom.client.ChangeEvent;
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.HandlerRegistration;
import com.google.gwt.user.client.ui.HasValue;

import gwt.material.design.components.client.base.mixin.base.AbstractMixin;
import gwt.material.design.components.client.base.widget.MaterialUIObject;

/**
 * @author Richeli Vargas
 */
public class HasValueMixin<UIO extends MaterialUIObject & HasValue<T>, T> extends AbstractMixin<UIO>
        implements HasValue<T> {

    protected boolean valueChangeHandlerInitialized = false;
    protected T value;

    public HasValueMixin(final UIO widget) {
        super(widget);
    }

    @Override
    public void setValue(final T value) {
        setValue(value, true);
    }

    @Override
    public void setValue(final T value, boolean fireEvents) {
        this.value = value;
        if (fireEvents)
            fireChangeEvent();
    }

    @Override
    public T getValue() {
        return value;
    }

    public void fireChangeEvent() {
        ValueChangeEvent.fire(uiObject, uiObject.getValue());
    }

    @Override
    public HandlerRegistration addValueChangeHandler(final ValueChangeHandler<T> handler) {
        if (!valueChangeHandlerInitialized) {
            valueChangeHandlerInitialized = true;
            uiObject.addDomHandler(event -> {
                event.preventDefault();
                event.stopPropagation();
                fireChangeEvent();
            }, ChangeEvent.getType());
        }
        return uiObject.addHandler(handler, ValueChangeEvent.getType());
    }

    @Override
    public void fireEvent(GwtEvent<?> event) {
        uiObject.fireEvent(event);
    }

}