Before you start your first tutorial, it's important that you understand what it means to develop an accessible application.
An accessible application is an application that can be accessed by people with disabilities, enabling them to retrieve and use information quickly and easily. For example:
For users who have difficulty using a mouse, an accessible application allows them to navigate and control the application entirely by keyboard.
For users with visual impairment, an accessible application leverages operating system color schemes and contrast settings to improve readability.
For users with visual impairment or blindness, an accessible application integrates with screen reader technology.
Accessibility standards are largely driven by the US Federal Government's Section 508 amendment to the Rehabilitation Act, which requires that federal agencies, and the companies that provide technology to federal agencies, make their technology accessible to people with disabilities. For more information on Section 508 standards, visit the www.section508.gov website.
For the user who has difficulty using a mouse and thus relies entirely on the keyboard, it's important that an application allow full keyboard navigation and control. That is, the user should be able to press the Tab key to navigate through each element in the application in a logical sequence. In addition, the user should be able to use standard keyboard shortcuts, such as "Ctrl+P" to print or "Ctrl+C" to copy.
As the developer, in order to enable full keyboard control, you must specify the tab sequence for the elements in your application, and you must program the appropriate keyboard shortcuts. For more information, refer to the Volle Tastaturavigation aktivieren section of this appendix.
For users who are visually impaired, Microsoft Windows provide a "high contrast mode" that presents applications in high contrast color combinations in order to improve readability. The Boxely UI Toolkit automatically detects if a user's operating system is running in high contrast and attempts to present applications using the same color settings as those specified at the operating system level.
As the developer, it is your job to style applications with system color settings in mind. If you use system colors, the user's default settings for both regular and high contrast mode automatically propagate to your application. If you use custom fill colors or if you use images as fills, you may need to do additional development work to ensure your application displays appropriately in high contrast mode. For more information, refer to the Styling Zugreifbarer Anwendungen section of this appendix.
For users who are visually impaired or blind, screen reader software, such as JAWS from Freedom Scientific, is available to read information from the screen aloud.
As the developer, it is your job to ensure that your application provides text equivalents for all graphics, as well as text labels for all objects and controls, so that a screen reader can adequately interpret the application.
All of the gadgets available in the Boxely Toolkit are already accessible; that is, each gadget is "pre-programmed" to tell the screen reader how to interpret it to the user. If you choose to incorporate a non-gadget element into your scene, of if you choose to build a custom gadget, you must include specific code to describe the element to the screen reader. For more information, refer to the Integrieren mit Bildschirmlesertechnik section of this appendix.