<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" type="topic" id="interface_viewer_plugin" xml:lang="zh-CN">
  <info>
    <link type="guide" xref="index#examining_a11y"/>
    <title type="sort">2. Interface Viewer Plugin</title>
    <link type="next" xref="validator_plugin"/>
    <desc>
      Examining your accessibility implementation
    </desc>
    <credit type="author">
      <name>Eitan Isaacson</name>
      <email>eitan@ascender.com</email>
    </credit>
    <credit type="author">
      <name>Peter Parente</name>
      <email>pparent@us.ibm.com</email>
    </credit>
    <credit type="author">
      <name>Aline Bessa</name>
      <email>alibezz@gmail.com</email>
    </credit>
    <license>
      <p>Creative Commons Share Alike 3.0</p>
    </license>
  </info>
  <title>Interface Viewer Plugin</title>

  <p>
    The Interface Viewer Plugin shows the information and controls provided by the AT-SPI interfaces
    present in each accessible item from the <link xref="desktop_tree_view">Application Tree View</link>. After
    selecting an item, you can use this plugin to quickly review its supported interfaces, to retrieve 
    each interface's information, and to manipulate the item through all the interface’s methods.
  </p>

  <figure>
    <title>Examining a Menu with the Interface Viewer Plugin</title>
    <desc>
      Given a selected item in the Application Tree View, all of its AT-SPI interfaces will be shown as sensitive
      in the Interface Viewer Plugin. Those unsupported will appear grayed out, such as the Application
      and Collection interfaces in the figure above.
    </desc>
    <media type="image" mime="image/png" width="800" height="450" src="figures/interface_viewer_plugin.png">
      <p>Given a selected item in the Application Tree View, all of its AT-SPI interfaces will be shown as sensitive
      in the Interface Viewer Plugin. Those unsupported will appear grayed out, such as the Application and Collection
      interfaces in the figure above.</p>
    </media>
  </figure>

  <section id="running_interface_viewer">
    <title>Running the Interface Viewer Plugin</title>
    <p>
      The first step to run the Interface Viewer Plugin is to select an item in the <link xref="desktop_tree_view">
      Application Tree View</link>. After that, all AT-SPI interfaces covered by the plugin will be listed in the
      plugin's panel. The interfaces implemented by the selected item will be sensitive, so you can click each one of
      them to either retrieve their provided information or to interact with available methods. The following interfaces 
      can be explored in <app>Accerciser</app>, assuming the selected item implements them:
    </p>
    <list>
      <item>
        <p>
          Accessible - This interface shows the selected item's child count (number of child widgets), description, states,
          relations, and attributes.
        </p>
      </item>
      <item>
        <p>
          Action - This interface shows all the actions that can be performed by the selected item. For each interface,
          you will see its name, such as "press" or "click", followed by a description and a key binding, if there are
          any. If you select an action, a "Perform action" button will become sensitive. Press this button to see the
          item performing the selected action. 
        </p>
      </item>
      <item>
        <p>
          Application - This interface can be implemented by items with role "application". It is worth to point out that
          items with role "application" not necessarily implement this interface. If the selected item implements it, the interface
          will show its ID and, if there are any, its toolkit and version.
        </p>
      </item>
      <item>
        <p>
          Component - This interface shows the selected item's absolute position (with respect to the desktop coordinate system), relative           position (with respect to the window coordinate system), size, layer type, MDI-Z-order (a short integer indicating the
          stacking order of the component in the MDI layer), and alpha (if alpha blending is used).
        </p>
      </item>
      <item>
        <p>
          Document - This interface shows the selected item's document attributes and locale description, if there is one. 
        </p>
      </item>
      <item>
        <p>
          Hypertext - This interface shows a list with all the selected item's hypertext hyperlinks. For each hyperlink, the interface
          provides its name, URI, start (the index in the hypertext at which the hyperlink begins) and end (the index in the hypertext
          at which this hyperlink ends).
        </p>
      </item>
      <item>
        <p>
          Image - This interface shows the selected item's description (or "no description" if unspecified), size, position
          (with respect to the desktop coordinate system), and locale, if there is one. 
        </p>
      </item>
      <item>
        <p>
          Selection - This interface shows all selectable child items of the selected item. If the selected item is a menu bar
          with options "File", "Edit", "View", and "Help", and all of them are selectable, then they will be listed in this
          interface. If you click a listed option - "File", for example - and want to clear it, just press the "Clear" button
          below the list. 
        </p>
      </item>
      <item>
        <p> 
          Streamable Content - This interface shows the selected item's content types and their corresponding URIs.
        </p>
      </item>
      <item>
        <p>
          Table - This interface shows the selected item's caption and summary, rows (number of rows), columns (number of columns),
          selected rows (number of selected rows), and selected columns (number of selected columns). For a selected cell, the 
          interface shows its row's and column's header and extents.
        </p>
      </item>
      <item>
        <p>
          Text - This interface shows the selected item's text content, that can be editable, and its attributes. The basic 
          attributes are offset (the number of characters the text has) and justification. To see possible CSS attributes, 
          click the "Include defaults" check box.
        </p>
      </item>
      <item>
        <p>
          Value - This interface shows the selected item's current value, minimum allowed value, maximum allowed value, and
          the minimum increment by which the value may be changed (or zero if this value cannot be determined). The current
          value can be manually changed via a spin button.
        </p>
      </item> 
    </list>
  </section>
</page>
