Technique FLASH30:Specifying accessible names for image buttons
About this Technique
This technique is not referenced from any Understanding document.
This technique applies to content implemented in Adobe Flash.
Description
For image based Button components the accessible name needs to be set to provide a functional label. This label indicates the button's function, but does not attempt to describe the image. The label is especially important if there are multiple buttons on the page that each lead to different results.
The accessible name for a button may need to be updated if the button changes during the use of the Flash movie.
Examples
Example 1: Accessible name for a simple image button
In this example, an icon based button is given an accessible name through scripting. When the button is clicked a web page is opened.
//provide text equivalent for image button this.check_btn.accessibilityProperties = new AccessibilityProperties(); this.check_btn.accessibilityProperties.name = "Check page validation"; //set up event listener and function to navigate to URL this.check_btn.addEventListener(MouseEvent.CLICK, onClickHandler); function onClickHandler(e: MouseEvent): void { var btn = e.target; var url: String = "http://validator.w3.org"; var request: URLRequest = new URLRequest(url); navigateToURL(request, '_blank'); }
The result is demonstrated in the working version of Accessible name for a simple image button. The source of Accessible name for a simple image button is available.
Example 2: Accessible name for a dynamic image button
import fl.controls.Button; import fl.accessibility.ButtonAccImpl; ButtonAccImpl.enableAccessibility(); var soundIsMuted = false; var myButton: Button = new Button(); myButton.label = ""; myButton.x = myButton.y = 10; myButton.width = myButton.height = 50; updateAccName(myButton, "mute sound"); myButton.setStyle("icon", unmuted); myButton.addEventListener(MouseEvent.CLICK, handleBtnClick); addChild(myButton); function handleBtnClick(e) { soundIsMuted = ! soundIsMuted; myButton.setStyle("icon", soundIsMuted? muted: unmuted); updateAccName(myButton, soundIsMuted? "unmute sound": "mute sound"); } function updateAccName(obj, newName: String) { if (! obj.accessibilityProperties) obj.accessibilityProperties = new AccessibilityProperties(); obj.accessibilityProperties.name = newName; if (Capabilities.hasAccessibility) Accessibility.updateProperties(); }
The result is demonstrated in the working version of Accessible name for a dynamic image button. The source of Accessible name for a dynamic image button is available.
Tests
Procedure
When a Flash Movie contains image based buttons, confirm that:
- An accessible name is provided for the button that describes the button's action
- If the button's action changes (for example when it is clicked) the accessible name changes correspondingly
Expected Results
- #1 and #2 are true