- From: Markku Hakkinen <markku.hakkinen@gmail.com>
- Date: Fri, 26 Feb 2010 11:35:42 -0600
- To: UAWG list <w3c-wai-ua@w3.org>
Guideline 3.10 Help user to use and orient within viewports. 3.10.1 Highlight Viewport: The viewport with the current focus is highlighted (including any frame that takes current focus) using a highlight mechanism that does not rely on rendered text foreground and background colors alone (e.g., a thick outline). (Level A) Intent of Success Criterion 3.10.1 When a user agent presents content using multiple viewports, users benefit from a clear indication of which viewport has focus. Simply relying upon text foreground and background colors to indicate focus may not provide sufficient, visually perceivable indication for users with low vision. Highlighting of viewport frames using both color, with sufficient contrast, and increase in viewport border thickness can provide multiple visual cues that indicate focus. Examples of Success Criterion 3.10.1 A music Web site allows the user to select which of the top 10 songs are available for listening. Each song is presented in a graphical viewport providing a music player. Using a keyboard based screen magnification tool, a low vision user tabs between songs, with the currently selected player viewport highlighted with a thick, yellow border against a dark grey background. 3.10.2 Move Viewport to Selection: When a viewport's selection changes, the viewport moves as necessary to ensure that the new selection is at least partially in the viewport. (Level A) Intent of Success Criterion 3.10.2 When content is presented within a viewport and the content extends horizontally or vertically beyond the visible bounds of the viewport, the user must be able to move to a selectable element or elements which may be out of view, and to have the selected content automatically move into view. For keyboard based users and users of screen magnification tools, this allows users an efficient means to view selected content without having to utilize scrolling controls to locate and view the selection. Examples of Success Criterion 3.10.2 A screen magnification user is performing a spell check of a blog posting that is contained within a scrollable viewport. The text of the blog posting exceeds the vertical size of the viewport. The blogging software provides a key to move to the first, and then any subsequent, unrecognized words. With two unrecognized words in the posting, the user ignores the first selected word, and presses the keystroke to move to the next which is currently out of view in the last sentence of the posting. As the key is pressed, the viewport scrolls to show the selected word. 3.10.3 Move Viewport to Focus: When a viewport's content focus changes, the viewport moves as necessary to ensure that the new content focus is at least partially in the viewport. (Level A) Intent of Success Criterion 3.10.3 When content is presented within a viewport and the content extends horizontally or vertically beyond the visible bounds of the viewport, the user must be able to move to any focusable elements which may be out of view, and to have the element receiving focus automatically move into view. For keyboard based users and users of screen magnification tools, this allows users an efficient means to view a focused element without having to utilize scrolling controls to locate and view the element with focus. Examples of Success Criterion 3.10.3 A user of a screen reader is showing a sighted colleague how to complete a registration form contained within a viewport. The form exceeds the veritical bounds of the viewport, requiring vertical scrolling to view the complete form content. As the screen reader completes each form entry and presses the tab key, the next form control in the tab order scrolls into view if it is not already visible in the viewport. 3.10.4 Resizable: The user has the option to make graphical viewports resizable, within the limits of the display, overriding any values specified by the author. (Level A) Intent of Success Criterion 3.10.4 If a graphical viewport contains content that exceeds the dimensions of the viewport, users should have the option to increase the size of the viewport to allow the full image to be displayed without scrolling, within the limits of the physical display screen. This benefits keyboard users who may find it difficult to scroll content and users with cognitive or learning disabilities whose understanding of the content is aided by being able to view the complete image. Examples of Success Criterion 3.10.4 A viewport is used to display an image depicting an organization chart. A user with a learning disability has difficulty maintaining a mental representation of the organizational linkages for items out of view. In order to facilitate their understanding of the organization, the user drags the sizing icon on the corners of the viewport to allow the entire chart to be displayed. 3.10.5 Scrollbars: Graphical viewports include scrollbars if the rendered content (including after user preferences have been applied) extends beyond the viewport dimensions, overriding any values specified by the author. (Level A) Intent of Success Criterion 3.10.5 When rendered content exceeds the horizontal and/or vertical bounds of a graphical viewport, scrollbars provide a visible indication that not all of the rendered content is currently visible within the viewport. The scrollbars provide indication to users who may not be able to otherwise recognize that the rendered content is not fully visible. Examples of Success Criterion 3.10.5 A Web site presents a recipe within a viewport, and the length of the recipe exceeds the vertical and horizontal dimension of the viewport, though the step by step graphical depiction of the recipe does not make this obvious. A user following the recipe, uses the scroll bar to recognize that additional steps may be present, and scrolls them into view.
Received on Friday, 26 February 2010 17:36:15 UTC