Image

LIVE DEMO

Image component is designed for displaying images from different sources. The component can be bound to a data container or configured programmatically.

Component’s XML-name: image.

Basics

The Image component can display the value of an entity attribute of FileRef or byte[] type. In the example below, the entity has the image attribute which is a reference to a file in file storage:

@JmixEntity
@Table(name = "UIEX1_PERSON")
@Entity(name = "uiex1_Person")
public class Person {

    /* other attributes */

    @Column(name = "IMAGE", length = 1024)
    private FileRef image;

In the simplest case, the component can be declaratively associated with data using the dataContainer and property attributes:

<data readOnly="true">
    <instance id="personDc"
              class="ui.ex1.entity.Person">
        <fetchPlan extends="_base"/>
        <loader/>
    </instance>
</data>
<layout spacing="true">
    <image id="fileRefImage"
           dataContainer="personDc"
           property="image"/>
</layout>

In the example above, the component displays the image attribute of the Person entity located in the personDc data container.

Resources

Alternatively, the Image component can display images from different resources. You can set the resource type declaratively using the nested XML elements described below, or programmatically using the setSource() method.

ClasspathResource

A resource that is located in the classpath.

  • In XML: classpath element with the path attribute.

    For example, if your image is located at ui/ex1/screen/component/image/jmix-logo.png under src/main/resources, you can specify the displayed resource as follows:

    <image scaleMode="SCALE_DOWN"
       width="20%"
       height="20%">
    <resource>
        <classpath path="ui/ex1/screen/component/image/jmix-logo.png"/>
    </resource>
</image>

  • In Java: ClasspathResource interface.

    image.setSource(ClasspathResource.class)
        .setPath("ui/ex1/screen/component/image/jmix-logo.png");

FileResource

A resource that is stored in the server file system.

  • In XML: file element with the path attribute.

    <image scaleMode="SCALE_DOWN"
       width="20%"
       height="20%">
    <resource>
        <file path="D:\JMIX\jmix-logo.png"/>
    </resource>
</image>

  • In Java: FileResource interface.

    image.setSource(FileResource.class)
        .setFile(file);

FileStorageResource

An image stored in the file storage.

  • In XML: property attribute of image.

    <image id="fileRefImage"
       dataContainer="personDc"
       property="image"/>

  • In Java: FileStorageResource interface.

    image.setSource(FileStorageResource.class)
        .setFileReference(person.getImage());

RelativePathResource

An image served statically by the application.

By default, static content is served from /static, /public, /resources, or /META-INF/resources directories of the classpath (see details in the Spring Boot documentation).

  • In XML: relativePath element with the path attribute.

    For example, an image located at src/main/resources/static/images/jmix-icon-login.svg can be displayed as follows:

    <image>
    <resource>
        <relativePath path="images/jmix-icon-login.svg"/>
    </resource>
</image>

    The image will also be available at http://{host}:{port}/images/jmix-icon-login.svg.

  • In Java: RelativePathResource interface.

    image.setSource(RelativePathResource.class)
        .setPath("images/jmix-icon-login.svg");

StreamResource

An image provided by an InputStream.

  • In Java: StreamResource interface.

    byte[] picture;
// picture = ...
image.setSource(StreamResource.class)
        .setStreamSupplier(() -> new ByteArrayInputStream(picture));

ThemeResource

An image located in the current theme.

In the example below, an image is located in the images directory of the helium-ext custom theme:

images theme resources

Then you can use it in the Image component as follows:

  • In XML: theme element with the path attribute.

    <image>
    <resource>
        <theme path="images/jmix-icon-login.svg"/>
    </resource>
</image>

  • In Java: ThemeResource interface:

    image.setSource(ThemeResource.class)
        .setPath("images/jmix-icon-login.svg");

UrlResource

An image that can be loaded from an arbitrary URL.

  • In XML: url element with the url attribute.

    <image scaleMode="SCALE_DOWN"
       width="20%"
       height="20%">
    <resource>
        <url url="https://www.jmix.io/uploads/framework_image_9efadbc372.svg"/>
    </resource>
</image>

  • In Java: UrlResource interface.

    try {
    image.setSource(UrlResource.class)
            .setUrl(new URL("https://www.jmix.io/images/jmix-logo.svg"));
} catch (MalformedURLException e) {
    log.error("Invalid URL format", e);
}

Resource Settings

  • bufferSize - size of the download buffer in bytes used for this resource.

  • cacheTime - length of cache expiration time in milliseconds.

  • mimeType - MIME type of the resource.

For example:

<image>
    <resource>
        <url url="https://avatars3.githubusercontent.com/u/17548514?v=4&#38;s=200"
             mimeType="image/png"/>
    </resource>
</image>

Attributes

  • alternateText - sets an alternate text for an image in case the resource is not set or unavailable.

  • scaleMode - applies the scale mode to the image. It corresponds to the object-fit CSS property. The following scale modes are available:

    • FILL - the image is stretched according to the size of the component.

    • CONTAIN - the image is compressed or stretched to fit the component dimensions while preserving the proportions.

    • COVER - the image is compressed or stretched to fill the entire component while preserving the proportions. If the image proportions do not match the component’s proportions then the image will be clipped to fit.

    • SCALE_DOWN - the image is sized as if NONE or CONTAIN were specified, whichever would result in a smaller concrete object size.

    • NONE - the image is not resized.

Methods

To programmatically manage the Image component, use the following methods:

  • setValueSource() - sets the data container, and the entity attribute name. Only FileRef and byte[] type of attributes are supported.

    The data container can be set programmatically, for example, to display images in table cells:

    <data readOnly="true">
    <collection id="personsDc"
                class="ui.ex1.entity.Person">
        <fetchPlan extends="_base"/>
        <loader id="personsDl">
            <query>
                <![CDATA[select e from uiex1_Person e]]>
            </query>
        </loader>
    </collection>
</data>
<layout spacing="true">
    <groupTable id="personsTable"
                width="100%"
                dataContainer="personsDc">
        <columns>
            <column id="name"/>
        </columns>
    </groupTable>
</layout>
    @Autowired
private GroupTable<Person> personsTable;
@Autowired
private UiComponents uiComponents;

@Subscribe
public void onInit(InitEvent event) {
    personsTable.addGeneratedColumn("image", entity -> {
        Image<FileRef> image = uiComponents.create(Image.NAME);
        image.setValueSource(
                new ContainerValueSource<>(
                        personsTable.getInstanceContainer(entity),
                        "image"));
        image.setHeight("100px");
        image.setScaleMode(Image.ScaleMode.CONTAIN);
        return image;
    });
}

  • setSource() - sets the resource for the component. The method accepts the resource type and returns the resource object that can be configured using the fluent interface.

    <layout spacing="true">
    <image id="programmaticImage"/>
</layout>
    @Autowired
private Image<FileRef> programmaticImage;

@Subscribe
public void onInit(InitEvent event) {
    try {
        URL url = new URL("https://www.jmix.io/images/jmix-logo.svg");
        programmaticImage.setSource(UrlResource.class).setUrl(url);
    } catch (MalformedURLException e) {
        log.error("Error", e);
    }
}

Events and Handlers

To generate a handler stub in Jmix Studio, select the component in the screen descriptor XML or in the Component Hierarchy panel and use the Handlers tab of the Component Inspector panel.

Alternatively, you can use the Generate Handler button in the top panel of the screen controller.

ClickEvent

See ClickEvent.

ContextHelpIconClickEvent

See ContextHelpIconClickEvent.

SourceChangeEvent

SourceChangeEvent is sent when a source of an image is changed. SourceChangeEvent has the following methods:

  • getNewSource()

  • getOldSource()

@Subscribe("image")
public void onImageSourceChange(ResourceView.SourceChangeEvent event) {
    notifications.create()
            .withCaption("Old source was: " + event.getOldSource() +
                    "; new source is: " + event.getNewSource());
}

To register the event handler programmatically, use the addSourceChangeListener() component method.

All XML Attributes

You can view and edit attributes applicable to the component using the Component Inspector panel of the Studio’s Screen Designer.

Image XML Attributes

align - alternateText - box.expandRatio - caption - captionAsHtml - colspan - contextHelpText - contextHelpTextHtmlEnabled - css - dataContainer - description - descriptionAsHtml - editable - enable - height - htmlSanitizerEnabled - icon - id - property - required - requiredMessage - property - required - requiredMessage - rowspan - scaleMode - stylename - visible - width

Image XML Elements

resource

Resources XML Elements

classpath - file - relativePath - theme - url