Merge pull request #300 from w3c/mjm-target-size-changes

Changes to 2.5.8 Target size notes

comments-by-guideline-and-success-criterion.md

@@ -248,6 +248,9 @@ Except for parts of the content which require two-dimensional layout for usage o
 <div class="note">
 
 Examples of content which requires two-dimensional layout are images required for understanding (such as maps and diagrams), video, games, presentations, data tables (not individual cells), and interfaces where it is necessary to keep toolbars in view while manipulating content. It is acceptable to provide two-dimensional scrolling for such parts of the content.</div>
+<div class="note">
+
+In technologies where CSS is not used, the definition of 'CSS pixel' applies as described in [Applying “CSS pixel” to Non-Web Documents and Software](#applying-css-pixel-to-non-web-documents-and-software).</div>
 
 (non-web documents)
 
@@ -739,10 +742,12 @@ The size of the [target](#dfn-target) for [pointer inputs](https://www.w3.org/TR
 <div class="note">
 
 Targets that allow for values to be selected spatially based on position within the target are considered one target for the purpose of the success criterion. Examples include sliders with granular values, color pickers displaying a gradient of colors, or editable areas where you position the cursor.</div>
-
 <div class="note">
 
 For inline targets the line-height should be interpreted as perpendicular to the flow of text. For example, in a language displayed vertically, the line-height would be horizontal.</div>
+<div class="note">
+
+In technologies where CSS is not used, the definition of 'CSS pixel' applies as described in [Applying “CSS pixel” to Non-Web Documents and Software](#applying-css-pixel-to-non-web-documents-and-software).</div>
 
 (for non-web documents)
 

comments-on-definitions-in-wcag-2.2-glossary-in-appendix-a.md

@@ -381,6 +381,9 @@ continuous line forming the boundary of a shape not including shared pixels, or
 <div class="example">
 
 The perimeter calculation for a 2 **<INS>[platform-defined density-independent pixel]</INS>** perimeter around a rectangle is 4h+4w, where h is the height and w is the width. For a 2 **<INS>[platform-defined density-independent pixel]</INS>** perimeter around a circle it is 4𝜋r.</div>
+<div class="note">
+
+In technologies where CSS is not used, the definition of 'CSS pixel' applies as described in [Applying “CSS pixel” to Non-Web Documents and Software](#applying-css-pixel-to-non-web-documents-and-software).</div>
 </DD></DL>
 
 #### dfn-programmatically-determined

success-criteria-problematic-for-closed-functionality.md

@@ -40,6 +40,9 @@ There are Success Criteria that can be problematic for developers of closed func
 <li><a href="#multiple-ways">2.4.5 Multiple Ways</a>—The WCAG2ICT interpretation of this Success Criterion replaces "set of Web pages" with "set of software programs." Such sets, particularly in the context of closed functionality software, are exceedingly rare. There are a number of notes in the section <a href="#applying-sc-2-4-5-multiple-ways-to-non-web-documents-and-software">Applying SC 2.4.5 Multiple Ways to Non-Web Documents and Software</a> that are applicable to closed functionality software.</li>  
 <li><a href="#pointer-cancellation">2.5.2 Pointer Cancellation</a>—As noted in the section <a href="#applying-sc-2-5-2-pointer-cancellation-to-non-web-documents-and-software">Applying SC 2.5.2 Pointer Cancellation to Non-Web Documents and Software</a>, examples of 'essential' functionality are features for meeting environmental energy usage requirements (like waking a device from sleep, power saver mode, and low power state).</li>  
 <li><a href="#label-in-name">2.5.3 Label in Name</a>—Requires information in a programmatically determinable form; specifically, the programmatic name contains the text of the visual label.</li>
+<li><a href="#target-size-minimum">2.5.8 Target Size (Minimum)</a>—2.5.8 Target Size (Minimum) - This Success Criterion uses CSS pixels for defining the target size. Closed functionality may not use CSS pixels as a standard measurement, but the definition of 'CSS pixel' still applies as described in <a href="#applying-css-pixel-to-non-web-documents-and-software">Applying “CSS pixel” to Non-Web Documents and Software</a>. If the system supports a density-independent pixel measurement, it should be used in place of CSS pixels.
+<div class="note">If the viewing distance and pixel density of the system are unknown, approximating the reference pixel as described in Applying “CSS pixel” to Non-Web Documents and Software is not possible.</div>
+<div class="note">For software designed to run on specific known hardware, a physical size standard would be more straightforward to apply, as calculations for a CSS pixel are dependent on the viewing distance or pixel density of the display.</div></li>
 <li><a href="#language-of-page">3.1.1 Language of Page</a>—Requires language information in a programmatically determinable form intended to drive correct pronunciation. Where another mechanism achieves correct pronunciation for closed functionality, such as self-voicing, the intent of this success criterion would be met.</li>
 <li><a href="#language-of-parts">3.1.2 Language of Parts</a>—Requires language information in a programmatically determinable form intended to drive correct pronunciation. Where another mechanism achieves correct pronunciation for closed functionality, such as self-voicing, the intent of this success criterion would be met.</li>
 <li><a href="#consistent-navigation">3.2.3 Consistent Navigation</a>—This Success Criterion is interpreted to only apply to "sets of software programs" which are very rare. See the second note in the section <a href="#applying-sc-3-2-3-consistent-navigation-to-non-web-documents-and-software">Applying SC 3.2.3 Consistent Navigation to Non-Web Documents and Software</a>.</li>