Package com.google.gwt.aria.client

Class Roles

  • public final class Roles
extends java.lang.Object

    A factory providing each concrete role in the ARIA specification. Each role implements methods that a GWT application can use to modify the appropriate DOM attributes for that role.

    For example, suppose our GWT app has a image button and we want to make it visible in screen readers as a button with some help text. To do this, we add a button role to the image and set the ARIA label property to the help text that the screen reader can use:

        Roles.getButtonRole().set(img.getElement());
    Roles.getButtonRole().setAriaLabelProperty(img.getElement(), "some help text");

    Most ARIA properties have a prefix of "aria-" and only affect screen readers, but there is one exception: the "tabindex" property is the same one used for tab order in regular widgets. For example, to set tabindex to 0 for the button: 

       Roles.getButtonRole().setTabindexExtraAttribute(img.getElement(), 0);

    When the button changes state (it's enabled or disabled), we can change the ARIA enabled state to match, like this:

       Roles.getButtonRole().setAriaEnabledState(img.getElement(), isEnabled);

    ARIA distinguishes between properties (which change rarely and could be set in static HTML) and states (which need to be updated in response to user input). This distinction can get a bit blurry when a GWT app updates the DOM dynamically. Generally you should update ARIA attributes at the same time that you change the CSS styles on a DOM node, so that a screen reader will see the same state as someone viewing the page visually.

    The role interfaces form a hierarchy whose root is the Role interface, which contains generic methods that aren't specific to a role. Some abstract roles include:

    1. WidgetRole, for DOM elements that represent either standalone or composite widgets.
    2. CompositeRole, for widgets that contain other widgets.
    3. StructureRole, for DOM elements that are part of the page layout.
    4. LandmarkRole, for DOM elements defining common regions of a page.
    5. WindowRole, for DOM elements that define windows and dialogs.

    See Also:
    the W3C specification

    • Constructor Detail

      • Roles

        public Roles()

    • Method Detail

      • getAlertRole

        public static AlertRole getAlertRole()

      • getArticleRole

        public static ArticleRole getArticleRole()

      • getBannerRole

        public static BannerRole getBannerRole()

      • getButtonRole

        public static ButtonRole getButtonRole()

      • getCheckboxRole

        public static CheckboxRole getCheckboxRole()

      • getComboboxRole

        public static ComboboxRole getComboboxRole()

      • getDefinitionRole

        public static DefinitionRole getDefinitionRole()

      • getDialogRole

        public static DialogRole getDialogRole()

      • getDirectoryRole

        public static DirectoryRole getDirectoryRole()

      • getDocumentRole

        public static DocumentRole getDocumentRole()

      • getFormRole

        public static FormRole getFormRole()

      • getGridcellRole

        public static GridcellRole getGridcellRole()

      • getGridRole

        public static GridRole getGridRole()

      • getGroupRole

        public static GroupRole getGroupRole()

      • getHeadingRole

        public static HeadingRole getHeadingRole()

      • getImgRole

        public static ImgRole getImgRole()

      • getLinkRole

        public static LinkRole getLinkRole()

      • getListboxRole

        public static ListboxRole getListboxRole()

      • getListitemRole

        public static ListitemRole getListitemRole()

      • getListRole

        public static ListRole getListRole()

      • getLogRole

        public static LogRole getLogRole()

      • getMainRole

        public static MainRole getMainRole()

      • getMarqueeRole

        public static MarqueeRole getMarqueeRole()

      • getMathRole

        public static MathRole getMathRole()

      • getMenubarRole

        public static MenubarRole getMenubarRole()

      • getMenuitemRole

        public static MenuitemRole getMenuitemRole()

      • getMenuRole

        public static MenuRole getMenuRole()

      • getNavigationRole

        public static NavigationRole getNavigationRole()

      • getNoteRole

        public static NoteRole getNoteRole()

      • getOptionRole

        public static OptionRole getOptionRole()

      • getRadiogroupRole

        public static RadiogroupRole getRadiogroupRole()

      • getRadioRole

        public static RadioRole getRadioRole()

      • getRegionRole

        public static RegionRole getRegionRole()

      • getRowgroupRole

        public static RowgroupRole getRowgroupRole()

      • getRowheaderRole

        public static RowheaderRole getRowheaderRole()

      • getRowRole

        public static RowRole getRowRole()

      • getScrollbarRole

        public static ScrollbarRole getScrollbarRole()

      • getSearchRole

        public static SearchRole getSearchRole()

      • getSeparatorRole

        public static SeparatorRole getSeparatorRole()

      • getSliderRole

        public static SliderRole getSliderRole()

      • getSpinbuttonRole

        public static SpinbuttonRole getSpinbuttonRole()

      • getStatusRole

        public static StatusRole getStatusRole()

      • getTablistRole

        public static TablistRole getTablistRole()

      • getTabpanelRole

        public static TabpanelRole getTabpanelRole()

      • getTabRole

        public static TabRole getTabRole()

      • getTextboxRole

        public static TextboxRole getTextboxRole()

      • getTimerRole

        public static TimerRole getTimerRole()

      • getToolbarRole

        public static ToolbarRole getToolbarRole()

      • getTooltipRole

        public static TooltipRole getTooltipRole()

      • getTreegridRole

        public static TreegridRole getTreegridRole()

      • getTreeitemRole

        public static TreeitemRole getTreeitemRole()

      • getTreeRole

        public static TreeRole getTreeRole()

      • roleOf

        public static Role roleOf​(Element element)
        Returns the WAI-ARIA role for the element. If no 'role' attribute is set to the element or if the set role tokens do not include a WAI-ARIA role, null is returned. Otherwise, if a WAI_ARIA role is among the role tokens in the 'role' attribute token list, a Role corresponding the WAI-ARIA role is returned.