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

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Here is the source code for com.sencha.gxt.core.client.util.Util.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.ArrayList;
import java.util.List;

import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.dom.client.Style.Overflow;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.client.ui.AbstractImagePrototype;

/**
 * Various utility functions.
 */
public class Util {

    /**
     * A non-breaking space in SafeHtml form.
     */
    public static final SafeHtml NBSP_SAFE_HTML = SafeHtmlUtils.fromSafeConstant(" ");

    /**
     * Constrains the value by a minimum and max value.
     * 
     * @param value the value
     * @param min the minimum
     * @param max the maximum
     * @return the adjusted value
     */
    public static int constrain(int value, int min, int max) {
        value = Math.max(value, min);
        value = Math.min(value, max);
        return value;
    }

    /**
     * Creates a new list and adds the element(s).
     * 
     * @param element the item to add to the list
     * @return the new list
     */
    public static <T> List<T> createList(T... element) {
        List<T> list = new ArrayList<T>();
        fill(list, element);
        return list;
    }

    /**
     * Does an equals check by first checking identity, then equality.
     * 
     * @param obj1 object 1
     * @param obj2 object 2
     * @return boolean if equal
     */
    public static boolean equalWithNull(Object obj1, Object obj2) {
        if (obj1 == obj2) {
            return true;
        } else if (obj1 == null) {
            return false;
        } else {
            return obj1.equals(obj2);
        }
    }

    /**
     * Populates a list with an array of elements.
     * 
     * @param list the list
     * @param elements the elements to be added to the list
     */
    public static <T> void fill(List<T> list, T[] elements) {
        for (int i = 0; i < elements.length; i++) {
            list.add(elements[i]);
        }
    }

    /**
     * Returns an element for the given image.
     * 
     * @param ir the image resource
     * @return the element
     */
    public static Element getImage(ImageResource ir) {
        return AbstractImagePrototype.create(ir).createElement();
    }

    /**
     * Returns true if the string is null or equals to the empty string.
     * 
     * @param string the string to test
     * @return true if the string is empty
     */
    public static boolean isEmptyString(String string) {
        return string == null || "".equals(string);
    }

    /**
     * Tests if the value is an integer.
     * 
     * @param value the value to test
     * @return the integer state
     */
    public static boolean isInteger(String value) {
        try {
            Integer.parseInt(value);
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * Parses a string value and returns an integer.
     * 
     * @param value the string value
     * @param defaultValue the default value
     * @return the integer value
     */
    public static native int parseInt(String value, int defaultValue) /*-{
                                                                      var v = parseInt(value, 10);
                                                                      if (v === 0) {
                                                                      return 0;
                                                                      }
                                                                      return v || defaultValue;
                                                                      }-*/;

    /**
     * Parses a string value and returns the applicable {@link Overflow} object.
     * 
     * @param value the string value
     * @return the {@link Overflow} object
     */
    public static Overflow parseOverflow(String value) {
        if (value.equals(Overflow.AUTO.getCssName())) {
            return Overflow.AUTO;
        } else if (value.equals(Overflow.HIDDEN.getCssName())) {
            return Overflow.HIDDEN;
        } else if (value.equals(Overflow.SCROLL.getCssName())) {
            return Overflow.SCROLL;
        } else if (value.equals(Overflow.VISIBLE.getCssName())) {
            return Overflow.VISIBLE;
        } else {
            return null;
        }
    }

    /**
     * Converts a node list to an element array.
     * 
     * @param nodes the nodes
     * @return the element array
     */
    public static Element[] toElementArray(List<Element> nodes) {
        Element[] e = new Element[nodes.size()];
        for (int i = 0; i < nodes.size(); i++) {
            e[i] = nodes.get(i);
        }
        return e;
    }

    /**
     * Converts a node list to an element array.
     * 
     * @param nodes the nodes
     * @return the element array
     */
    public static Element[] toElementArray(NodeList<Element> nodes) {
        Element[] e = new Element[nodes.getLength()];
        for (int i = 0; i < nodes.getLength(); i++) {
            e[i] = nodes.getItem(i);
        }
        return e;
    }

}