FocusOnLoadBehavior.java

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/dcm4che.
 *
 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
 * Portions created by the Initial Developer are Copyright (C) 2012
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * See @authors listed below
 *
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package org.dcm4chee.wizard.common.behavior;

import java.io.Serializable;

import org.apache.wicket.Component;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.form.FormComponent;
import org.apache.wicket.markup.html.form.TextField;

/**
 * @author Franz Willer <franz.willer@gmail.com>
 */

public class FocusOnLoadBehavior extends Behavior {

    private static final long serialVersionUID = 1L;

    private FocusStrategy focusStrategy;

    public FocusOnLoadBehavior() {
    }

    public FocusOnLoadBehavior(FocusStrategy strategy) {
        focusStrategy = strategy;
    }

    public static FocusOnLoadBehavior newSimpleFocusBehaviour() {
        FocusOnLoadBehavior fb = new FocusOnLoadBehavior();
        fb.focusStrategy = fb.new SimpleFocusStrategy();
        return fb;
    }

    public static FocusOnLoadBehavior newFocusAndSelectBehaviour() {
        FocusOnLoadBehavior fb = new FocusOnLoadBehavior();
        fb.focusStrategy = fb.new FocusAndSelectTextStrategy();
        return fb;
    }

    public void bind(Component component) {
        if (focusStrategy == null) {
            if (component instanceof FormComponent<?>) {
                focusStrategy = new EmptyFocusStrategy();
            } else if (component instanceof Form<?>) {
                focusStrategy = new FirstEmptyTextfieldFocusStrategy();
            }
        }
        component.setOutputMarkupId(true);
    }

    @Override
    public void renderHead(Component component, IHeaderResponse headerResponse) {
        super.renderHead(component, headerResponse);
        focusStrategy.focus(headerResponse, component);
    }

    public boolean isTemporary() {
        return false;
    }

    private boolean setFocusOnEmpty(IHeaderResponse response, Component component) {
        Object object = component.getDefaultModelObject();
        if (object == null || object.toString().length() < 1) {
            response.render(OnDomReadyHeaderItem.forScript(getJavaScriptString(component)));
            return true;
        }
        return false;
    }

    private String getJavaScriptString(Component component) {
        return "self.focus();var elem=document.getElementById('" + component.getMarkupId() + "');elem.focus()";
    }

    public interface FocusStrategy extends Serializable {
        void focus(IHeaderResponse headerResponse, Component component);
    }

    public class SimpleFocusStrategy implements FocusStrategy {

        private static final long serialVersionUID = 1L;

        public void focus(IHeaderResponse response, Component component) {
            response.render(OnDomReadyHeaderItem.forScript(getJavaScriptString(component)));
        }
    }

    public class EmptyFocusStrategy implements FocusStrategy {

        private static final long serialVersionUID = 1L;

        public void focus(IHeaderResponse headerResponse, Component component) {
            setFocusOnEmpty(headerResponse, component);
        }
    }

    public class FocusAndSelectTextStrategy implements FocusStrategy {

        private static final long serialVersionUID = 1L;

        public void focus(IHeaderResponse response, Component component) {
            if (component instanceof TextField<?>) {
                response.render(OnDomReadyHeaderItem.forScript(getJavaScriptString(component) + ";elem.select()"));
            }
        }
    }

    public class FirstEmptyTextfieldFocusStrategy implements FocusStrategy {

        private static final long serialVersionUID = 1L;

        public void focus(IHeaderResponse headerResponse, Component formComponent) {
            Form<?> form = (Form<?>) formComponent;
            Component component;
            for (int i = 0; i < form.size(); i++) {
                component = form.get(i);
                if (component instanceof TextField<?>) {
                    if (setFocusOnEmpty(headerResponse, component)) {
                        component.setOutputMarkupId(true);
                        break;
                    }
                }
            }
        }
    }
}