de.alpharogroup.wicket.behaviors.FocusRequestBehavior.java Source code

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Here is the source code for de.alpharogroup.wicket.behaviors.FocusRequestBehavior.java

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/**
 * Copyright (C) 2010 Asterios Raptis
 *
 * 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 de.alpharogroup.wicket.behaviors;

import org.apache.wicket.Component;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.OnLoadHeaderItem;

/**
 * The class {@link FocusRequestBehavior} set the focus on a component when the page is load.
 */
public class FocusRequestBehavior extends Behavior {

    /**
     * The serialVersionUID.
     */
    private static final long serialVersionUID = 1L;

    /**
     * The Constant DEFAULT_ID is the default id that will be set if the id is not set explicit.
     */
    public static final String DEFAULT_ID = FocusRequestBehavior.class.getSimpleName();

    /**
     * Factory method to create a new {@link FocusRequestBehavior} object for the component that is
     * added.
     *
     * @return the new {@link FocusRequestBehavior} object
     */
    public static FocusRequestBehavior of() {
        return new FocusRequestBehavior();
    }

    /**
     * Factory method to create a new {@link FocusRequestBehavior} object from the given clearValue
     * parameter for the component that is added.
     *
     * @param clearValue
     *            the clear value
     * @return the new {@link FocusRequestBehavior} object
     */
    public static FocusRequestBehavior of(final boolean clearValue) {
        return new FocusRequestBehavior(clearValue);
    }

    /**
     * Factory method to create a new {@link FocusRequestBehavior} object from the given clearValue
     * and delay parameter for the component that is added.
     *
     * @param clearValue
     *            the clear value
     * @param delay
     *            the delay
     * @return the new {@link FocusRequestBehavior} object
     */
    public static FocusRequestBehavior of(final boolean clearValue, final Integer delay) {
        return new FocusRequestBehavior(clearValue, delay);
    }

    /**
     * Factory method to create a new {@link FocusRequestBehavior} object from the given delay
     * parameter for the component that is added.
     *
     * @param delay
     *            the delay
     * @return the new {@link FocusRequestBehavior} object
     */
    public static FocusRequestBehavior of(final Integer delay) {
        return new FocusRequestBehavior(delay);
    }

    /** The flag if the value may be clear. */
    private final boolean clearValue;

    /** The delay that is set in the setTimeout method. */
    private final int delay;

    /**
     * Instantiates a new request focus behavior.
     */
    public FocusRequestBehavior() {
        this(false);
    }

    /**
     * Instantiates a new {@link FocusRequestBehavior} object.
     *
     * @param clearValue
     *            The flag if the value may be clear.
     */
    public FocusRequestBehavior(final boolean clearValue) {
        this(clearValue, 1);
    }

    /**
     * Instantiates a new {@link FocusRequestBehavior} object.
     *
     * @param clearValue
     *            The flag if the value may be clear.
     * @param delay
     *            the delay
     */
    public FocusRequestBehavior(final boolean clearValue, final Integer delay) {
        this.clearValue = clearValue;
        this.delay = delay;
    }

    /**
     * Instantiates a new {@link FocusRequestBehavior} object.
     *
     * @param delay
     *            the delay
     */
    public FocusRequestBehavior(final Integer delay) {
        this(false, delay);
    }

    /**
     * Factory method that creates the java script code for request focus.
     *
     * @param component
     *            the component
     * @return the string
     */
    protected String newJavaScript(final Component component) {
        final StringBuilder sb = new StringBuilder();
        sb.append("setTimeout(" + "function() {" + "var component = document.getElementById(\"")
                .append(component.getMarkupId()).append("\");");
        if (clearValue) {
            sb.append("component.value = \"\";");
        }
        sb.append("component.focus();");
        sb.append("}, " + this.delay + ")");
        return sb.toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void renderHead(final Component component, final IHeaderResponse response) {
        super.renderHead(component, response);
        component.setOutputMarkupId(true);
        response.render(OnLoadHeaderItem.forScript(newJavaScript(component)));
    }

}