com.github.nmorel.gwtjackson.benchmark.client.ui.InputCheckbox.java Source code

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Here is the source code for com.github.nmorel.gwtjackson.benchmark.client.ui.InputCheckbox.java

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/*
 * Copyright 2014 Nicolas Morel
 *
 * 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.
 */

package com.github.nmorel.gwtjackson.benchmark.client.ui;

import com.google.gwt.dom.client.InputElement;
import com.google.gwt.editor.client.IsEditor;
import com.google.gwt.editor.client.LeafValueEditor;
import com.google.gwt.editor.client.adapters.TakesValueEditor;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.ui.FocusWidget;
import com.google.gwt.user.client.ui.HasValue;

/**
 * @author Nicolas Morel
 */
public class InputCheckbox extends FocusWidget implements HasValue<Boolean>, IsEditor<LeafValueEditor<Boolean>> {

    private LeafValueEditor<Boolean> editor;

    private boolean valueChangeHandlerInitialized;

    private final InputElement inputElem;

    public InputCheckbox() {
        super(DOM.createInputCheck());
        inputElem = getElement().cast();
    }

    @Override
    public Boolean getValue() {
        if (isAttached()) {
            return inputElem.isChecked();
        } else {
            return inputElem.isDefaultChecked();
        }
    }

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

    @Override
    public void setValue(Boolean value, boolean fireEvents) {
        if (value == null) {
            value = Boolean.FALSE;
        }

        Boolean oldValue = getValue();
        inputElem.setChecked(value);
        inputElem.setDefaultChecked(value);
        if (value.equals(oldValue)) {
            return;
        }
        if (fireEvents) {
            ValueChangeEvent.fire(this, value);
        }
    }

    public void setForId(String id) {
        inputElem.setPropertyString("id", id);
    }

    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
        // Is this the first value change handler? If so, time to add handlers
        if (!valueChangeHandlerInitialized) {
            ensureDomEventHandlers();
            valueChangeHandlerInitialized = true;
        }
        return addHandler(handler, ValueChangeEvent.getType());
    }

    protected void ensureDomEventHandlers() {
        addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                // Checkboxes always toggle their value, no need to compare
                // with old value. Radio buttons are not so lucky, see
                // overrides in RadioButton
                ValueChangeEvent.fire(InputCheckbox.this, getValue());
            }
        });
    }

    @Override
    public LeafValueEditor<Boolean> asEditor() {
        if (editor == null) {
            editor = TakesValueEditor.of(this);
        }
        return editor;
    }
}