ZK Component Reference/Base Components/LabelImageElement

Label Image Element

• Demonstration: N/A
• Java API: LabelImageElement
• JavaScript API: LabelImageWidget

Employment/Purpose

An HTML element with a label and an image.

Preload Image

Since 6.0.0

The feature is applied to all of the LabelImageElement and Image components.

By default the preload function is disabled, so users have to specify the custom-attributes and set it to true. For example,

<button image="xxx.png">
  <custom-attributes org.zkoss.zul.image.preload="true"/>
</button>

Or specify it just below the root component.

For example,

<window>
  <custom-attributes org.zkoss.zul.image.preload="true"/>
  <button image="xxx.png"/>
  <image src="xxx.png"/>
</window>

As you can see, the custom-attributes will be checked recursively (see also Scope.getAttribute(String, boolean)).

Since 6.5.2

The feature can also applied from zk.xml as a library property.

For example,

<!-- zk.xml -->
<zk>
    <library-property>
        <name>org.zkoss.zul.image.preload</name>
        <value>true</value>
    </library-property>
</zk>

IconSclass

Font Awesome Bundled

Since 7.0.0

ZK 7.0.0 integrates Font Awesome 4.0.1 with the prefix z-icon. To use it, just specify the iconSclass attribute. For a complete list of icons, please refer to FontAwesome Cheatsheet.

For example, to add a home icon on a Button,

<window>
    <button iconSclass="z-icon-home" />
</window>

If you want to use other Font Awesome functions such as the animation icon, you can include the external font awesome CSS link and add the CSS class to iconSclass. For example,

<?link href="http://netdna.bootstrapcdn.com/font-awesome/4.0.1/css/font-awesome.css" rel="stylesheet"?>
<window>
    <button iconSclass="z-icon-bell fa-spin" />
    <button iconSclass="z-icon-home fa-2x fa-rotate-90" />
</window>

Since 8.0.0

ZK 8.0.0 integrates Font Awesome 4.3.0. Also, with ZK 8 there is no need to include external font awesome CSS link to use an animation icon. Therefore the example above becomes

<window>
    <button iconSclass="z-icon-bell z-icon-spin" />
    <button iconSclass="z-icon-home z-icon-2x z-icon-rotate-90" />
</window>

Since 8.5.2

ZK 8.5.2 integrates Font Awesome 4.7.0.

Since 10.0.0

ZK 10.0.0 integrates Font Awesome 6.4.2 free icons and supports both Font Awesome 4 syntax and Font Awesome 6 syntax with styles specified:

<window>
    <!--Font Awesome 4 syntax-->
    <button iconSclass="z-icon-bell" />
    <!--Font Awesome 6 syntax-->
    <button iconSclass="z-icon-bell z-icon-solid" />
    <button iconSclass="z-icon-bell z-icon-regular" />
</window>

Use Other Icons

The iconSclass not only applies to font awesome icons ("z-icon-" classes): Any css class can be applied to customize. Notice you need to manually include related CSS or font file. For example, the bootstrap glyphicons can be used here too:

<window>
    <button iconSclass="glyphicon glyphicon-envelope" />
</window>

Since the web font is loaded after the character is being displayed if there is no cache, ZK doesn't know if the web font is ready when initializing. Therefore using hflex="min" with iconSclass may not get the desired result. Moreover, the final width of icons might not be the same. To make the width of icons always be fixed, add z-icon-fw.

<window hflex="min">
    <button iconSclass="z-icon-fw z-icon-home" />
    <button iconSclass="z-icon-fw z-icon-bell z-icon-spin" />
</window>

IconTooltip

Since 10.0.0 The iconTooltip attribute is introduced for adding a tooltip to an icon.

    <button iconSclass="z-icon-home" iconTooltip="home"/>

Multiple icons and tooltips

Since 10.0.0 One LabelImageElement can have multiple icons and tooltips set using Java API:

    e.setIconSclasses(new String[] {"z-icon-home", "z-icon-podcast"});
    e.setIconTooltips(new String[] {"tooltip1", "tooltip2"});

Please note that this is only supported through Java API but not Zul attributes.

Not Supported Usages

The following usages mentioned in Font Awesome official document are not supported:

• Duotone
• Stacking icons
• Layering Text & Counters
• Power Transforms

Supported Events

Name	Event Type
None	None

• Inherited Supported Events: LabelElement

Supported Children

*All

Version History

Version	Date	Content
8.6.2	May 2019	ZK-4243: The result of hflex="min" is not sufficient if the content has Font Awesome icons
7.0.0	October 2012	Add iconSclass attribute with FontAwesome supported.
6.0.0	September 2011	ZK-314: A way to pre-load images since many UIs depend on the size of an image
10.0.0	August 2023	ZK-5502: Allow users to customize tooltip on the icon
10.0.0	August 2023	ZK-5503: Allow users to set multiple icons and tooltips on the same LabelImageElement
10.0.0	September 2023	ZK-5119: Integrate Font Awesome 6 free icons