- From: Ian Hickson via cvs-syncmail <cvsmail@w3.org>
- Date: Mon, 25 May 2009 23:31:46 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/spec
In directory hutz:/tmp/cvs-serv27969
Modified Files:
Overview.html
Log Message:
Try to make the definitions of 'available', 'supported', image.width, image.height, and image.complete more correct. (whatwg r3126)
Index: Overview.html
===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.2283
retrieving revision 1.2284
diff -u -d -r1.2283 -r1.2284
--- Overview.html 25 May 2009 22:10:45 -0000 1.2283
+++ Overview.html 25 May 2009 23:31:43 -0000 1.2284
@@ -294,7 +294,8 @@
<li><a href="#dom-trees"><span class="secno">2.1.2 </span>DOM trees</a></li>
<li><a href="#scripting-0"><span class="secno">2.1.3 </span>Scripting</a></li>
<li><a href="#plugins"><span class="secno">2.1.4 </span>Plugins</a></li>
- <li><a href="#character-encodings"><span class="secno">2.1.5 </span>Character encodings</a></ol></li>
+ <li><a href="#character-encodings"><span class="secno">2.1.5 </span>Character encodings</a></li>
+ <li><a href="#resources"><span class="secno">2.1.6 </span>Resources</a></ol></li>
<li><a href="#conformance-requirements"><span class="secno">2.2 </span>Conformance requirements</a>
<ol>
<li><a href="#dependencies"><span class="secno">2.2.1 </span>Dependencies</a></li>
@@ -1462,7 +1463,20 @@
the set 0x09, 0x0A, 0x0C, 0x0D, 0x20 - 0x22, 0x26, 0x27, 0x2C -
0x3F, 0x41 - 0x5A, and 0x61 - 0x7A<!-- is that list ok? do any
character sets we want to support do things outside that range?
- -->. <!-- XXX #refs RFC1345 ? --><h3 id="conformance-requirements"><span class="secno">2.2 </span>Conformance requirements</h3><p>All diagrams, examples, and notes in this specification are
+ -->. <!-- XXX #refs RFC1345 ? --><h4 id="resources"><span class="secno">2.1.6 </span>Resources</h4><p>The specification uses the term <i>supported</i> when referring
+ to whether a user agent has an implementation capable of decoding
+ the semantics of an external resource. A format or type is said to
+ be <i>supported</i> if the implementation can process an external
+ resource of that format or type without critical aspects of the
+ resource being ignored. Whether a specific resource is
+ <i>supported</i> can depend on what features of the resource's
+ format are in use.<p class="example">For example, a PNG image would be considered to
+ be in a supported format if its pixel data could be decoded and
+ rendered, even if, unbeknownst to the implementation, the image
+ actually also contained animation data.<p class="example">A MPEG4 video file would not be considered to be
+ in a supported format if the compression format used was not
+ supported, even if the implementation could determine the dimensions
+ of the movie from the file's metadata.<h3 id="conformance-requirements"><span class="secno">2.2 </span>Conformance requirements</h3><p>All diagrams, examples, and notes in this specification are
non-normative, as are all sections explicitly marked non-normative.
Everything else in this specification is normative.<p>The key words "MUST", "MUST NOT", "REQUIRED", <!--"SHALL", "SHALL
NOT",--> "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
@@ -15099,29 +15113,30 @@
<a href="#origin-0" title="origin">cross-origin</a> access control policies
that mitigate this attack.</p>
- <p>If the image's type is a supported image type, and the image is a
- valid image of that type, then the image is said to be
- <i>available</i> (this affects exactly what the element represents,
- as defined below). This can be true even before the image is
- completely downloaded, if the user agent supports incremental
- rendering of images; in such cases, each <a href="#concept-task" title="concept-task">task</a> that is <a href="#queue-a-task" title="queue a
+ <p>If the image is in a supported image type and its dimensions are
+ known, then the image is said to be <dfn id="img-available" title="img-available"><i>available</i></dfn> (this affects exactly
+ what the element represents, as defined below). This can be true
+ even before the image is completely downloaded, if the user agent
+ supports incremental rendering of images; in such cases, each <a href="#concept-task" title="concept-task">task</a> that is <a href="#queue-a-task" title="queue a
task">queued</a> by the <a href="#networking-task-source">networking task source</a> while
the image is being <a href="#fetch" title="fetch">fetched</a> must update
- the presentation of the image appropriately.</p>
+ the presentation of the image appropriately. It can also stop being
+ true, e.g. if the user agent finds, after obtaining the image's
+ dimensions, that the image data is actually fatally corrupted.</p>
<p>If the image was not fetched (e.g. because the UA's image support
is disabled, or because the <code title="attr-img-src"><a href="#attr-img-src">src</a></code>
attribute's value is an <i>ignored self-reference</i>), or if the
conditions in the previous paragraph are not met, then the image is
- <em>not</em> <i>available</i>.</p>
+ <em>not</em> <i title="img-available"><a href="#img-available">available</a></i>.</p>
- <p class="note">An image might be <i>available</i> in one
- <a href="#view">view</a> but not another. For instance, a
- <code>Document</code> could be rendered by a screen reader providing
- a speech synthesis view of the output of a Web browser using the
- screen media. In this case, the image would be <i>available</i> in
- the Web browser's screen view, but <em>not</em> <i>available</i> in
- the screen reader's view.</p>
+ <p class="note">An image might be <i title="img-available"><a href="#img-available">available</a></i> in one <a href="#view">view</a> but not
+ another. For instance, a <code>Document</code> could be rendered by
+ a screen reader providing a speech synthesis view of the output of a
+ Web browser using the screen media. In this case, the image would be
+ <i title="img-available"><a href="#img-available">available</a></i> in the Web browser's screen
+ view, but <em>not</em> <i title="img-available"><a href="#img-available">available</a></i> in the
+ screen reader's view.</p>
<p>Whether the image is fetched successfully or not (e.g. whether
the response code was a 2xx code <a href="#concept-http-equivalent-codes" title="concept-http-equivalent-codes">or equivalent</a>) must be
@@ -15152,8 +15167,8 @@
<p>The <a href="#concept-task" title="concept-task">task</a> that is <a href="#queue-a-task" title="queue a task">queued</a> by the <a href="#networking-task-source">networking task
source</a> once the resource has been <a href="#fetch" title="fetch">fetched</a>, must, if the download was successful
- and the image is <i>available</i>, <a href="#queue-a-task">queue a task</a> to
- <a href="#fire-a-simple-event">fire a simple event</a> called <code title="event-load"><a href="#event-load">load</a></code> at the <code><a href="#the-img-element">img</a></code> element (this
+ and the image is <i title="img-available"><a href="#img-available">available</a></i>, <a href="#queue-a-task">queue
+ a task</a> to <a href="#fire-a-simple-event">fire a simple event</a> called <code title="event-load"><a href="#event-load">load</a></code> at the <code><a href="#the-img-element">img</a></code> element (this
happens after <code title="dom-img-complete"><a href="#dom-img-complete">complete</a></code> starts
returning true); and otherwise, if the fetching process fails
without a response from the remote server, or completes but the
@@ -15176,8 +15191,8 @@
the content, redundant with some other information in the
document.</p>
- <p>If the image is <i>available</i> and the user agent is
- configured to display that image, then the element
+ <p>If the image is <i title="img-available"><a href="#img-available">available</a></i> and the
+ user agent is configured to display that image, then the element
<a href="#represents">represents</a> the image specified by the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute.</p>
<p>Otherwise, the element <a href="#represents">represents</a> nothing, and may
@@ -15196,8 +15211,8 @@
<p>The image is a key part of the content; the <code title="attr-img-alt"><a href="#attr-img-alt">alt</a></code> attribute gives a textual
equivalent or replacement for the image.</p>
- <p>If the image is <i>available</i> and the user agent is
- configured to display that image, then the element
+ <p>If the image is <i title="img-available"><a href="#img-available">available</a></i> and the
+ user agent is configured to display that image, then the element
<a href="#represents">represents</a> the image specified by the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute.</p>
<p>Otherwise, the element <a href="#represents">represents</a> the text given
@@ -15219,16 +15234,16 @@
is a key part of the content but that a textual replacement for
the image was not available when the image was generated.</p>
- <p>If the image is <i>available</i>, the element
- <a href="#represents">represents</a> the image specified by the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute.</p>
+ <p>If the image is <i title="img-available"><a href="#img-available">available</a></i>, the
+ element <a href="#represents">represents</a> the image specified by the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute.</p>
- <p>If the image is not <i>available</i> or if the user agent is
- not configured to display the image, then the user agent should
- display some sort of indicator that there is an image that is not
- being rendered, and may, if requested by the user, or if so
- configured, or when required to provide contextual information in
- response to navigation, provide caption information for the image,
- derived as follows:</p>
+ <p>If the image is not <i title="img-available"><a href="#img-available">available</a></i> or
+ if the user agent is not configured to display the image, then the
+ user agent should display some sort of indicator that there is an
+ image that is not being rendered, and may, if requested by the
+ user, or if so configured, or when required to provide contextual
+ information in response to navigation, provide caption information
+ for the image, derived as follows:</p>
<ol><li><p>If the image has a <code title="attr-title"><a href="#the-title-attribute">title</a></code>
attribute whose value is not the empty string, then the value of
@@ -15346,17 +15361,18 @@
rendered width and height of the image, in CSS pixels, if the image
is being rendered, and is being rendered to a visual medium; or else
the intrinsic width and height of the image, in CSS pixels, if the
- image is <i>available</i> but not being rendered to a visual medium;
- or else 0, if the image is not <i>available</i> or its dimensions
- are not known. <a href="#references">[CSS21]</a></p>
+ image is <i title="img-available"><a href="#img-available">available</a></i> but not being
+ rendered to a visual medium; or else 0, if the image is not <i title="img-available"><a href="#img-available">available</a></i> or its dimensions are not
+ known. <a href="#references">[CSS21]</a></p>
<p>On setting, they must act as if they <a href="#reflect" title="reflect">reflected</a> the respective content attributes
of the same name.</p>
<p>The DOM attribute <dfn id="dom-img-complete" title="dom-img-complete"><code>complete</code></dfn> must return
- true if the user agent has fetched the image specified in the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute, and it is a valid image,
- even if the final <a href="#concept-task" title="concept-task">task</a> queued by
- the <a href="#networking-task-source">networking task source</a> for the <a href="#fetch" title="fetch">fetching</a> of the image resource has not yet been
+ true if the user agent has fetched the image specified in the <code title="attr-img-src"><a href="#attr-img-src">src</a></code> attribute, and it is in a supported
+ image type (i.e. it was decoded without fatal errors), even if the
+ final <a href="#concept-task" title="concept-task">task</a> queued by the
+ <a href="#networking-task-source">networking task source</a> for the <a href="#fetch" title="fetch">fetching</a> of the image resource has not yet been
processed. Otherwise, the attribute must return false.</p>
<p class="note">The value of <code title="dom-img-complete"><a href="#dom-img-complete">complete</a></code> can thus change while a
@@ -15679,9 +15695,9 @@
at least that would look good on the cover of a blue book.</p></pre>
<p>This example shows how the alternative text should be written
- such that if the image isn't <i>available</i>, and the text is used
- instead, the text flows seamlessly into the surrounding text, as
- if the image had never been there in the first place.</p>
+ such that if the image isn't <i title="img-available"><a href="#img-available">available</a></i>, and the text is used instead,
+ the text flows seamlessly into the surrounding text, as if the
+ image had never been there in the first place.</p>
</div><h6 id="text-that-has-been-rendered-to-a-graphic-for-typographical-effect"><span class="secno">4.8.2.1.4 </span>Text that has been rendered to a graphic for typographical effect</h6><p>Sometimes, an image just consists of text, and the purpose of the
image is not to highlight the actual typographic effects used to
@@ -28803,12 +28819,11 @@
<p>If the image was successfully obtained, with no network errors,
and the image's type is a supported image type, and the image is a
- valid image of that type, then the image is said to be
- <i>available</i>. If this is true before the image is completely
- downloaded, each <a href="#concept-task" title="concept-task">task</a> that is
- <a href="#queue-a-task" title="queue a task">queued</a> by the <a href="#networking-task-source">networking
- task source</a> while the image is being <a href="#fetch" title="fetch">fetched</a> must update the presentation of the
- image appropriately.</p>
+ valid image of that type, then the image is said to be <dfn id="input-img-available" title="input-img-available"><i>available</i></dfn>. If this is true
+ before the image is completely downloaded, each <a href="#concept-task" title="concept-task">task</a> that is <a href="#queue-a-task" title="queue a
+ task">queued</a> by the <a href="#networking-task-source">networking task source</a> while
+ the image is being <a href="#fetch" title="fetch">fetched</a> must update
+ the presentation of the image appropriately.</p>
<p>The user agents should apply the <a href="#content-type-sniffing:-image" title="Content-Type
sniffing: image">image sniffing rules</a> to determine the type
@@ -28826,13 +28841,14 @@
<p>The <a href="#concept-task" title="concept-task">task</a> that is <a href="#queue-a-task" title="queue a task">queued</a> by the <a href="#networking-task-source">networking task
source</a> once the resource has been <a href="#fetch" title="fetch">fetched</a>, must, if the download was successful
- and the image is <i>available</i>, <a href="#queue-a-task">queue a task</a> to
- <a href="#fire-a-simple-event">fire a simple event</a> called <code title="event-load"><a href="#event-load">load</a></code> at the <code><a href="#the-input-element">input</a></code> element;
- and otherwise, if the fetching process fails without a response from
- the remote server, or completes but the image is not a valid or
- supported image, <a href="#queue-a-task">queue a task</a> to <a href="#fire-a-simple-event">fire a simple
- event</a> called <code title="event-error"><a href="#event-error">error</a></code> on the
- <code><a href="#the-input-element">input</a></code> element.</p>
+ and the image is <i title="input-img-available"><a href="#input-img-available">available</a></i>,
+ <a href="#queue-a-task">queue a task</a> to <a href="#fire-a-simple-event">fire a simple event</a> called
+ <code title="event-load"><a href="#event-load">load</a></code> at the <code><a href="#the-input-element">input</a></code>
+ element; and otherwise, if the fetching process fails without a
+ response from the remote server, or completes but the image is not a
+ valid or supported image, <a href="#queue-a-task">queue a task</a> to <a href="#fire-a-simple-event">fire a
+ simple event</a> called <code title="event-error"><a href="#event-error">error</a></code> on
+ the <code><a href="#the-input-element">input</a></code> element.</p>
<hr></div><p>The <dfn id="attr-input-alt" title="attr-input-alt"><code>alt</code></dfn> attribute
provides the textual label for the alternative button for users and
@@ -28841,9 +28857,9 @@
attributes</a>.<div class="impl">
<hr><p>If the <code title="attr-input-src"><a href="#attr-input-src">src</a></code> attribute is set,
- and the image is <i>available</i> and the user agent is configured
- to display that image, then: The element <a href="#represents">represents</a> a
- control for selecting a <a href="#concept-input-type-image-coordinate" title="concept-input-type-image-coordinate">coordinate</a> from
+ and the image is <i title="input-img-available"><a href="#input-img-available">available</a></i> and
+ the user agent is configured to display that image, then: The
+ element <a href="#represents">represents</a> a control for selecting a <a href="#concept-input-type-image-coordinate" title="concept-input-type-image-coordinate">coordinate</a> from
the image specified by the <code title="attr-input-src"><a href="#attr-input-src">src</a></code>
attribute; if the element is <i title="concept-input-mutable"><a href="#concept-input-mutable">mutable</a></i>, the user agent should
allow the user to select this <a href="#concept-input-type-image-coordinate" title="concept-input-type-image-coordinate">coordinate</a>. The
@@ -62632,14 +62648,14 @@
does not <a href="#represents" title="represents">represent</a> an image, but the
element already has intrinsic dimensions (e.g. from the
<a href="#dimension-attributes">dimension attributes</a> or CSS rules), and either the user
- agent has reason to believe that the image will become
- <i>available</i> and be rendered in due course or the
- <code>Document</code> is in <a href="#quirks-mode">quirks mode</a>, the element is
- expected to be treated as a replaced element whose content is the
- text that the element represents, if any, optionally alongside an
- icon indicating that the image is being obtained. For
- <code><a href="#the-input-element">input</a></code> elements, the text is expected to appear
- button-like to indicate that the element is a <a href="#concept-button" title="concept-button">button</a>.</p>
+ agent has reason to believe that the image will become <i title="img-available"><a href="#img-available">available</a></i><!--input-img-available also-->
+ and be rendered in due course or the <code>Document</code> is in
+ <a href="#quirks-mode">quirks mode</a>, the element is expected to be treated as a
+ replaced element whose content is the text that the element
+ represents, if any, optionally alongside an icon indicating that the
+ image is being obtained. For <code><a href="#the-input-element">input</a></code> elements, the text
+ is expected to appear button-like to indicate that the element is a
+ <a href="#concept-button" title="concept-button">button</a>.</p>
<p>When an <code><a href="#the-img-element">img</a></code> element <a href="#represents">represents</a> some
text and the user agent does not expect this to change, the element
Received on Monday, 25 May 2009 23:31:57 UTC