[html5] r6177 - [e] (0) Add a note about HAVE_METADATA vs HAVE_CURRENT_DATA

[whatwg at whatwg.org]

Author: ianh
Date: 2011-06-02 16:53:44 -0700 (Thu, 02 Jun 2011)
New Revision: 6177

Modified:
   complete.html
   index
   source
Log:
[e] (0) Add a note about HAVE_METADATA vs HAVE_CURRENT_DATA

Modified: complete.html
===================================================================
--- complete.html	2011-06-02 22:40:53 UTC (rev 6176)
+++ complete.html	2011-06-02 23:53:44 UTC (rev 6177)
@@ -28196,8 +28196,14 @@
    playback rate</a>, would not overtake the available data before
    playback reaches the end of the <a href=#media-resource>media resource</a>.</dd>
 
-  </dl><div class=impl>
+  </dl><p class=note>In practice, the difference between <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> and <code title=dom-media-HAVE_CURRENT_DATA><a href=#dom-media-have_current_data>HAVE_CURRENT_DATA</a></code> is
+  negligible. Really the only time the difference is relevant is when
+  painting a <code><a href=#the-video-element>video</a></code> element onto a <code><a href=#the-canvas-element>canvas</a></code>,
+  where it distinguishes the case where something will be drawn (<code title=dom-media-HAVE_CURRENT_DATA><a href=#dom-media-have_current_data>HAVE_CURRENT_DATA</a></code> or
+  greater) from the case where nothing is drawn (<code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> or less).</p>
 
+  <div class=impl>
+
   <p>When the ready state of a <a href=#media-element>media element</a> whose <code title=dom-media-networkState><a href=#dom-media-networkstate>networkState</a></code> is not <code title=dom-media-NETWORK_EMPTY><a href=#dom-media-network_empty>NETWORK_EMPTY</a></code> changes, the
   user agent must follow the steps given below:</p>
 

Modified: index
===================================================================
--- index	2011-06-02 22:40:53 UTC (rev 6176)
+++ index	2011-06-02 23:53:44 UTC (rev 6177)
@@ -28185,8 +28185,14 @@
    playback rate</a>, would not overtake the available data before
    playback reaches the end of the <a href=#media-resource>media resource</a>.</dd>
 
-  </dl><div class=impl>
+  </dl><p class=note>In practice, the difference between <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> and <code title=dom-media-HAVE_CURRENT_DATA><a href=#dom-media-have_current_data>HAVE_CURRENT_DATA</a></code> is
+  negligible. Really the only time the difference is relevant is when
+  painting a <code><a href=#the-video-element>video</a></code> element onto a <code><a href=#the-canvas-element>canvas</a></code>,
+  where it distinguishes the case where something will be drawn (<code title=dom-media-HAVE_CURRENT_DATA><a href=#dom-media-have_current_data>HAVE_CURRENT_DATA</a></code> or
+  greater) from the case where nothing is drawn (<code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> or less).</p>
 
+  <div class=impl>
+
   <p>When the ready state of a <a href=#media-element>media element</a> whose <code title=dom-media-networkState><a href=#dom-media-networkstate>networkState</a></code> is not <code title=dom-media-NETWORK_EMPTY><a href=#dom-media-network_empty>NETWORK_EMPTY</a></code> changes, the
   user agent must follow the steps given below:</p>
 

Modified: source
===================================================================
--- source	2011-06-02 22:40:53 UTC (rev 6176)
+++ source	2011-06-02 23:53:44 UTC (rev 6177)
@@ -30738,6 +30738,16 @@
 
   </dl>
 
+  <p class="note">In practice, the difference between <code
+  title="dom-media-HAVE_METADATA">HAVE_METADATA</code> and <code
+  title="dom-media-HAVE_CURRENT_DATA">HAVE_CURRENT_DATA</code> is
+  negligible. Really the only time the difference is relevant is when
+  painting a <code>video</code> element onto a <code>canvas</code>,
+  where it distinguishes the case where something will be drawn (<code
+  title="dom-media-HAVE_CURRENT_DATA">HAVE_CURRENT_DATA</code> or
+  greater) from the case where nothing is drawn (<code
+  title="dom-media-HAVE_METADATA">HAVE_METADATA</code> or less).</p>
+
   <div class="impl">
 
   <p>When the ready state of a <span>media element</span> whose <code