11<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
22<html lang="en">
3- <!-- $Id: ui.src,v 2.7 1998-03-16 14:38:39 ijacobs Exp $ -->
3+ <!-- $Id: ui.src,v 2.8 1998-03-17 01:19:15 ijacobs Exp $ -->
44<HEAD>
55<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
66<TITLE>User interface</TITLE>
77</HEAD>
88<BODY>
99<H1 align="center">User interface</H1>
1010
11- <!-- Not decided yet: Add 'focus-outline' (compound property):
12- <color>||<border-style>||<length>. ChrisW. 26/2/98 -->
13-
1411<H2><a name="cursor-props">Cursors:</a> the <span
1512class="propinst-cursor">'cursor'</span> property</H2>
1613
@@ -66,101 +63,6 @@ at the end of the list.
6663</PRE>
6764</div>
6865
69- <H2><a name="focus-outline">Representing the focus</a></H2>
70-
71- <P>Most computer-human interfaces have the concept of user <span
72- class="index-def" title="focus"><dfn>focus</dfn></span>, the subject
73- of user interaction in a document (e.g., for entering text, selecting
74- a button, etc.). User agents supporting the <a
75- href="media.html#interactive-media-group">interactive media group</a>
76- must keep track of where the focus lies and must also represent
77- the focus. Visual user agents often represent the focus by outlining
78- the relevant control or element.
79-
80- <P>Focus outlines are functionally distinct from normal CSS borders
81- for several reasons:</p>
82-
83- <ul>
84-
85- <li>The focus outline does not change the layout of the page - it is
86- drawn "over" the element, but do not change the position or layout
87- of a box.
88-
89- <li>The focus outline may be drawn around regular CSS borders - e.g., a
90- three-dimensional button (a common user-interface element) may
91- be seen as a text element with an outset border, and when the element has
92- the focus, an additional border is drawn around the outset border.
93-
94- <li>The focus outline does not have to be rectangular. Most of
95- today's user agents are capable of showing the focus around image map
96- areas, which may not be rectangular.
97- </ul>
98-
99- <P>On CSS boxes, focus outlines are drawn directly outside the <a
100- href="visuren.html#border-edge">border edge</a>. If an inline element
101- has a focus border, the border may be drawn as a series of boxes when
102- line breaking occurs. The boxes are closed on all sides.
103-
104- <P>The following properties control the presentation of the focus
105- outline. They may only be used in conjunction with the <a
106- href="selector.html#dynamic-pseudo-classes">:focus</a> pseudo-class.
107-
108- <!-- #include src=properties/focus-outline-width.srb -->
109-
110- <P>This property sets the width of the focus outline. The actual
111- widths of 'thin', 'medium', and 'thick' may vary between user agents,
112- but the values must increase in width from 'thin' to 'medium' to
113- 'thick'. Users may also specify an explicit <span class="index-inst"
114- title="<length>"><span
115- class="value-inst-length"><length></span></span>.
116-
117- <div class="note"><P>
118- <em><strong>Note.</strong>
119- Since the focus outline does not affect formatting (i.e., no
120- space is left for it in the box model), it may well overlap
121- other elements on the page.
122- </em>
123- </div>
124-
125- <!-- #include src=properties/focus-outline-style.srb -->
126-
127- <P>This property sets the style of the focus outline. Values have the
128- same meaning as for <span class="index-inst"
129- title="<border-style>"><span
130- class="value-inst-border-style"><border-style></span></span>
131- except that 'hidden' is not a legal outline style.
132-
133- <!-- #include src=properties/focus-outline-color.srb -->
134-
135- <P>This property sets the color of the focus outline. Values may
136- either be a <span class="index-inst" title="<color>"><span
137- class="value-inst-color"><color></span></span> or 'invert',
138- which is expected to perform a color inversion on the pixels on the
139- screen. This is a common technique ensuring that the focus outline
140- remains visible, regardless of background color.
141-
142- <!-- #include src=properties/focus-outline.srb -->
143-
144- <P>This is a shorthand property for setting the <span
145- class="propinst-focus-outline-width">'focus-outline-width'</span>, <span
146- class="propinst-focus-outline-style">'focus-outline-style'</span>, and <span
147- class="propinst-focus-outline-color">'focus-outline-color'</span> at the same
148- place in the style sheet.
149-
150- <P> For a definition of allowed and initial values, see the previously
151- defined properties. A sub-property for which no value has been
152- specified takes that property's initial value, <em>not</em> the
153- inherited value.
154-
155- <div class="example"><P>
156- The following rule sets three characteristics of the focus
157- outline to follow behavior of some popular user agents:</p>
158-
159- <PRE>
160- :focus { thin dotted invert }
161- </PRE>
162- </div>
163-
16466<H2><a name="system-colors">User preferences for colors</a></H2>
16567
16668<p>In addition to being able to assign pre-defined color values to
@@ -264,21 +166,19 @@ write the following:
264166a user's system resources. Please consult the <span
265167class="propinst-font">'font'</span> property for details.
266168
267- <h2>Dynamic outlines: the <span class="index-def"
268- title="outline">'outline'</span> property</h2>
169+ <h2><a name="dynamic-outlines"> Dynamic outlines:</a> the <span
170+ class="index-def" title="outline">'outline'</span> property</h2>
269171
270172<p>[This section is tentative, awaiting decision on 'outline' by WG.]
271173
272- <!-- include src=properties/outline.srb -->
273- <!-- include src=properties/outline-width.srb -->
274- <!-- include src=properties/outline-style.srb -->
275- <!-- include src=properties/outline-color.srb -->
276-
277- <p>Interactive UAs often draw attention to an element by drawing an
278- outline around it. Most often this is done to indicate that an element
279- has the focus (see the <a
280- href="selector.html#dynamic-pseudo-classes">':focus'</a>
281- pseudo-class).
174+ <P>Most computer-human interfaces have the concept of user <span
175+ class="index-def" title="focus"><dfn>focus</dfn></span>, the subject
176+ of user interaction in a document (e.g., for entering text, selecting
177+ a button, etc.). User agents supporting the <a
178+ href="media.html#interactive-media-group">interactive media group</a>
179+ must keep track of where the focus lies and must also represent
180+ the focus. Visual user agents often represent the focus by outlining
181+ the relevant control or element.
282182
283183<div class="example">
284184<p>For example, to draw a thick black line around an element when it
@@ -291,8 +191,13 @@ rules can be used:
291191</pre>
292192</div>
293193
194+ <!-- #include src=properties/outline.srb -->
195+ <!-- #include src=properties/outline-width.srb -->
196+ <!-- #include src=properties/outline-style.srb -->
197+ <!-- #include src=properties/outline-color.srb -->
198+
294199<p>The outline created with the 'outline' properties is drawn "over"
295- the element, i.e. the outline is always on top, and doesn't influence
200+ the element, i.e., the outline is always on top, and doesn't influence
296201the position or size of the element, or of any other elements.
297202
298203<p>The outline is drawn just outside the <a
@@ -304,29 +209,44 @@ encloses all the element's boxes. In contrast to <a
304209href="visudet.html#border-properties">borders</a>, the outline is not
305210open at the line box's end or start, but is always fully connected.
306211
307- <p>'Outline-width' accepts the same values as <span
308- class="propinst-border-width">'border-width'</span>. 'Outine-style'
309- accepts the same values as <span
310- class="propinst-border-style">'border-style'</span>.
212+ <p>The <span class="propinst-outline-width">'outline-width'</span>
213+ property accepts the same values as <span
214+ class="propinst-border-width">'border-width'</span>.
215+
216+ <P>The <span class="propinst-outline-style">'outline-style'</span>
217+ property accepts the same values as <span
218+ class="propinst-border-style">'border-style'</span>,
219+ except that 'hidden' is not a legal outline style.
311220
312- <p>'Outline-color' accepts all colors, as well as the keyword <span
313- class="index-def" title="invert"><a class="value-def"
221+ <p>The <span class="propinst-outline-color">'outline-color'</span>
222+ accepts all colors, as well as the keyword <span class="index-def"
223+ title="invert"><a class="value-def"
314224name="value-def-invert">'invert'</a></span>. 'Invert' is expected to
315225perform a color inversion on the pixels on the screen. This is a
316226common trick to ensure the focus border is visible, regardless of
317227color background.
318228
319- <p>'Outline' is a shorthand property, and sets all three of
320- 'outline-style', 'outline-width', and 'outline-color'.
229+ <p>The <span class="propinst-outline">'outline'</span> property is a
230+ shorthand property, and sets all three of <span
231+ class="propinst-outline-style">'outline-style'</span>, <span
232+ class="propinst-outline-width">'outline-width'</span>, and <span
233+ class="propinst-outline-color">'outline-color'</span>.
321234
322235<p class="note">Note that the outline is the same on all sides. In
323236contrast to borders, there is no "outline-top" or "outline-left"
324237property.
325238
326- <p>It is undefined how multiple overlapping outlines are drawn, or how
327- outlines are drawn of elements that are partially obscured behind
328- other elements.
239+ <p>This specification does not define how multiple overlapping
240+ outlines are drawn, or how outlines are drawn of elements that are
241+ partially obscured behind other elements.
329242
243+ <div class="note"><P>
244+ <em><strong>Note.</strong>
245+ Since the focus outline does not affect formatting (i.e., no
246+ space is left for it in the box model), it may well overlap
247+ other elements on the page.
248+ </em>
249+ </div>
330250
331251<H2>Magnification</H2>
332252
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