Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add a lang IDL Attribute to CanvasTextDrawingStyles, and clarify "direction" on same #10873

Merged
merged 24 commits into from
Mar 4, 2025
Merged

Add a lang IDL Attribute to CanvasTextDrawingStyles, and clarify "direction" on same #10873

Changes from 6 commits
Commits
Show all changes
24 commits
Select commit Hold shift + click to select a range
eba506c
Add the lang IDL attribute to CanvasTextDrawingStyles
schenney-chromium Dec 18, 2024
caa22ca
Merge branch 'whatwg:main' into main
schenney-chromium Dec 18, 2024
488b95b
Fix Developer info
schenney-chromium Dec 18, 2024
01e6185
Merge branch 'whatwg:main' into main
schenney-chromium Jan 10, 2025
b6df5ee
Merge branch 'whatwg:main' into main
schenney-chromium Jan 22, 2025
1b5a1df
Post review revisions
schenney-chromium Jan 22, 2025
152e3a4
Clean up offscreen snapshot behavior
schenney-chromium Jan 23, 2025
60a5971
Fix the setter/getter for lang.
schenney-chromium Jan 23, 2025
720ff90
Next round of edits.
schenney-chromium Jan 23, 2025
c131fd6
Merge branch 'whatwg:main' into main
schenney-chromium Feb 3, 2025
119a4c5
Update the offscreen transfer steps, and clarify lang rules.
schenney-chromium Feb 3, 2025
25efd43
Text cleanup
schenney-chromium Feb 4, 2025
369688c
Post-review update
schenney-chromium Feb 5, 2025
7e5c880
Update link to content language
schenney-chromium Feb 5, 2025
37d7233
Minor cleanup
schenney-chromium Feb 14, 2025
e999e9e
Merge branch 'whatwg:main' into main
schenney-chromium Feb 21, 2025
f129f9b
Next iteration
schenney-chromium Feb 22, 2025
bf760d7
Update with latest review fixes.
schenney-chromium Feb 24, 2025
12d6c1f
Extract OffscreenCanvas constructor steps.
schenney-chromium Feb 25, 2025
779363e
Next round of edits.
schenney-chromium Feb 26, 2025
cdd56da
Fix annotaton of direction inherit.
schenney-chromium Feb 26, 2025
2e79feb
More formatting cleanup and text improvements.
schenney-chromium Feb 26, 2025
c19feba
More cleanup.
schenney-chromium Feb 27, 2025
ef5c3bd
Final edit.
schenney-chromium Feb 27, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
164 changes: 127 additions & 37 deletions source
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -65549,6 +65549,7 @@ interface mixin <dfn interface>CanvasPathDrawingStyles</dfn> {

interface mixin <dfn interface>CanvasTextDrawingStyles</dfn> {
// text
attribute DOMString <span data-x="dom-context-2d-lang">lang</span>; // (default: "inherit")
attribute DOMString <span data-x="dom-context-2d-font">font</span>; // (default 10px sans-serif)
attribute <span>CanvasTextAlign</span> <span data-x="dom-context-2d-textAlign">textAlign</span>; // (default: "start")
attribute <span>CanvasTextBaseline</span> <span data-x="dom-context-2d-textBaseline">textBaseline</span>; // (default: "alphabetic")
Expand Down Expand Up @@ -66022,6 +66023,7 @@ context.fillRect(100,0,50,50); // only this square remains</code></pre>
data-x="dom-context-2d-shadowOffsetX">shadowOffsetX</code>, <code
data-x="dom-context-2d-shadowOffsetY">shadowOffsetY</code>, <code
data-x="dom-context-2d-shadowBlur">shadowBlur</code>, <code
data-x="dom-context-2d-lang">lang</code>, <code
data-x="dom-context-2d-font">font</code>, <code
data-x="dom-context-2d-textAlign">textAlign</code>, <code
data-x="dom-context-2d-textBaseline">textBaseline</code>, <code
Expand Down Expand Up @@ -66516,13 +66518,26 @@ transform. ack Shaun Morris. -->
<h6>Text styles</h6>

<dl class="domintro">
<dt><code data-x=""><var>context</var>.<span subdfn data-x="dom-context-2d-lang">lang</span> [ = <var>value</var> ]</code></dt>
<dt><code data-x=""><var>styles</var>.<span data-x="dom-context-2d-lang">lang</span> [ = <var>value</var> ]</code></dt>
<dd>
<p>Returns the current language setting.</p>

<p>Can be set, to change the language used when resolving fonts. The syntax and valid values
are the same as those for the <span data-x="attr-lang">lang</span> element attribute, or the
value "<code data-x="dom-context-2d-direction-inherit">inherit</code>" which is described
below.</p>

<p>The default is "<code data-x="dom-context-2d-direction-inherit">inherit</code>".</p>
</dd>

<dt><code data-x=""><var>context</var>.<span subdfn data-x="dom-context-2d-font">font</span> [ = <var>value</var> ]</code></dt>
<dt><code data-x=""><var>styles</var>.<span data-x="dom-context-2d-font">font</span> [ = <var>value</var> ]</code></dt>
<dd>
<p>Returns the current font settings.</p>

<p>Can be set, to change the font. The syntax is the same as for the CSS <span>'font'</span>
property; values that cannot be parsed as CSS font values are ignored.</p>
property; values that cannot be parsed as CSS font values are ignored. The default is "10px sans-serif".</p>

<p>Relative keywords and lengths are computed relative to the font of the <code>canvas</code>
element.</p>
Expand Down Expand Up @@ -66694,15 +66709,72 @@ worker.postMessage(offscreenCanvas, [offscreenCanvas]);</code></pre>
Notice that the font is only loaded inside the worker, and not in the document context.</p>
</div>

<p>The choice of fonts and glyphs within a font may vary according to the <dfn
attribute for="CanvasTextDrawingStyles"><code data-x="dom-context-2d-lang">lang</code></dfn>
IDL attribute. On setting, <code data-x="dom-context-2d-lang">lang</code> must be
a <span data-x="attr-lang">valid BCP 47 language tag</span> or the string "inherit".
To determine the <dfn data-x="dom-context-2d-font-language">language for the font</dfn> from
the <code data-x="dom-context-2d-lang">lang</code> IDL attribute, use the following steps:</p>

<ol>
<li><p>If <var>object</var>'s <code data-x="dom-context-2d-lang">lang</code> value is
"inherit", then</p>
<ol>
<li><p>If <var>object</var>'s <span>font style source object</span> is a <code>canvas</code>
element, then set the <span data-x="dom-context-2d-font-language">language for the
font</span> to the element's <span data-x="language">language</span>. The <span
data-x="dom-context-2d-font-language">language for the font</span> must be updated when the
rendering context is created and each time the
<code data-x="dom-context-2d-lang">lang</code> attribute is
set to "inherit" (not on all changes to the element's <span
data-x="language">language</span>).</p></li>

<li><p>Otherwise, if <var>object</var>'s <span>font style source object</span> is an
<code>OffscreenCanvas</code> object created via <span
data-x="dom-canvas-transferControlToOffscreen">transferControlToOffscreen</span>,
then set the <span data-x="dom-context-2d-font-language">language for the font</span> to
the source canvas element's <span data-x="language">language</span>. The source
canvas's language should be snapshot at the time of transfer and the value used
whenever the <code data-x="dom-context-2d-lang">lang</code> value is "inherit".</p></li>

<li>
<p>Otherwise, <var>object</var>'s <span>font style source object</span> is an
<code>OffscreenCanvas</code> object:</p>
<ol>
<li><p>Let <var>global</var> be <var>object</var>'s <span>relevant global
object</span>.</p></li>

<li><p>If <var>global</var> is a <code>Window</code> object, then set the <span
data-x="dom-context-2d-font-language">language for the font</span> to the
<span data-x="language">language</span> from <var>global</var>'s
<span data-x="concept-document-window">associated <code>Document</code></span>.
The <span data-x="concept-document-window">associated <code>Document</code></span>'s
language should be snapshot when the <code>OffscreenCanvas</code> is
created and the value used whenever the <code data-x="dom-context-2d-lang">lang</code>
value is "inherit".</p></li>

<li><p>Otherwise, the <span data-x="dom-context-2d-font-language">language for the
font</span> is explicitly unknown.</p></li>
</ol>
</li>
</ol>
<li><p>Otherwise, the <span data-x="dom-context-2d-font-language">language for the font</span> is the <code data-x="dom-context-2d-lang">lang</code> value.</p></li>
</ol>

<p>The <code data-x="dom-context-2d-lang">lang</code> IDL attribute, on getting, must return
the current value.</p>

<p>The <dfn attribute for="CanvasTextDrawingStyles"><code
data-x="dom-context-2d-font">font</code></dfn> IDL attribute, on setting, must be <span
data-x="parse something according to a CSS grammar">parsed as a CSS &lt;'font'> value</span> (but
without supporting property-independent style sheet syntax like 'inherit'), and the resulting font
must be assigned to the context, with the <span>'line-height'</span> component forced to 'normal',
with the <span>'font-size'</span> component converted to <span data-x="'px'">CSS pixels</span>,
and with system fonts being computed to explicit values. If the new value is syntactically
incorrect (including using property-independent style sheet syntax like 'inherit' or 'initial'),
then it must be ignored, without assigning a new font value. <ref>CSS</ref></p>
must be assigned to the context, with the <span data-x="dom-context-2d-font-language">language
for the font</span> as determined above, with the <span>'line-height'</span>
component forced to 'normal', with the <span>'font-size'</span> component converted to <span
data-x="'px'">CSS pixels</span>, and with system fonts being computed to explicit values. If the
new value is syntactically incorrect (including using property-independent style sheet syntax
like 'inherit' or 'initial'), then it must be ignored, without assigning a new font value.
<ref>CSS</ref></p>

<p>Font family names must be interpreted in the context of the <span>font style source
object</span> when the font is to be used; any fonts embedded using <code
Expand Down Expand Up @@ -66900,16 +66972,54 @@ worker.postMessage(offscreenCanvas, [offscreenCanvas]);</code></pre>

<dd><p>Treat input to the <span>text preparation algorithm</span> as right-to-left text.</p></dd>

<!--
<dt><dfn><code data-x="dom-context-2d-direction-auto">auto</code></dfn>
<dt><dfn enum-value for="CanvasDirection"><code data-x="dom-context-2d-direction-inherit">inherit</code></dfn>

<dd><p>Determine the direction from the input to the <span>text preparation algorithm</span>.</p></dd>
-->
<dd><p>Use the following process to determine the value for the
<dfn for="CanvasDirection"><code data-x="dom-context-2d-inherited-direction">inherited direction</code></dfn> referred to in the <span>text preparation algorithm</span></p>

<dt><dfn enum-value for="CanvasDirection"><code data-x="dom-context-2d-direction-inherit">inherit</code></dfn>
<ol>
<li><p>If <var>object</var>'s <span>font style source object</span> is a <code>canvas</code>
element:</p>

<ol>
<li><p>If the element has a <span>computed value</span> for
<span>'direction'</span> use that as the <span data-x="dom-context-2d-inherited-direction">inherited direction</span>.</p></li>

<li><p>Otherwise, use the <span data-x="the directionality">directionality</span>
of the element as the <span data-x="dom-context-2d-inherited-direction">inherited direction</span>.</p></li>
</ol>

<li>
<p>Otherwise, <var>object</var>'s <span>font style source object</span> is an
<code>OffscreenCanvas</code> object, set the
<span data-x="dom-context-2d-inherited-direction">inherited direction</span> when
the <code>OffscreenCanvas</code> is created and use the same value through the
life of the <code>OffscreenCanvas</code>:</p>

<ol>
<li><p>If the <code>OffscreenCanvas</code> was created via <span
data-x="dom-canvas-transferControlToOffscreen">transferControlToOffscreen</span>,
then set the <span data-x="dom-context-2d-inherited-direction">inherited direction
</span> to that of source canvas element's as described in the case above.</p></li>

<li><p>Otherwise, if <var>global</var> is a <code>Window</code> object:</p>
<ol>
<li><p>Let <var>Document</var> be the <var>global</var>'s
<span data-x="concept-document-window">associated <code>Document</code></span>.</p></li>

<dd><p>Default to the directionality of the <code>canvas</code> element or <code>Document</code>
as appropriate.</p></dd>
<li><p>Use the <span data-x="the directionality">directionality</span> of the
<var>Document</var> as the <span
data-x="dom-context-2d-inherited-direction">inherited direction</span>.</p></li>
</ol>
</li>

<li><p>Otherwise, set the <span
data-x="dom-context-2d-inherited-direction">inherited direction</span> to
"ltr".</p></li>
</ol>
</li>
</ol>
</dd>
</dl>

<p>The <code data-x="dom-context-2d-fontKerning">fontKerning</code> attribute's allowed keywords
Expand Down Expand Up @@ -67033,32 +67143,11 @@ worker.postMessage(offscreenCanvas, [offscreenCanvas]);</code></pre>
data-x="dom-context-2d-direction-rtl">rtl</code>"</dt>
<dd>Let <var>direction</var> be '<span data-x="concept-rtl">rtl</span>'.</dd>

<!--
<dt>If the <var>target</var> object's <code
data-x="dom-context-2d-direction">direction</code> attribute has the value "<code
data-x="dom-context-2d-direction-auto">auto</code>"</dt>
<dd>
Find the first character in <var>text</var> of bidirectional character type L, AL, or
R, if any. If such a character is found and it is of bidirectional character type AL or R,
then let <var>direction</var> be '<span data-x="concept-rtl">rtl</span>'; otherwise,
let <var>direction</var> be '<span data-x="concept-rtl">rtl</span>'. <ref>BIDI</ref>
</dd>
-->

<dt>If the <var>target</var> object's <span>font style source object</span> is an
element</dt>

<dd>Let <var>direction</var> be <span>the directionality</span> of the <var>target</var> object's <span>font style source object</span>.</dd>

<dt>If the <var>target</var> object's <span>font style source object</span> is a
<code>Document</code> with a non-null <span>document element</span></dt>

<dd>Let <var>direction</var> be <span>the directionality</span> of the <var>target</var>
object's <span>font style source object</span>'s <span>document element</span>.</dd>

<dt>Otherwise</dt>

<dd>Let <var>direction</var> be '<span data-x="concept-ltr">ltr</span>'.</dd>
data-x="dom-context-2d-direction-inherit">inherit</code>"</dt>
<dd>Let <var>direction</var> be the <var>target</var>'s <span
data-x="dom-context-2d-inherited-direction">inherited direction</span>.</dd>
</dl>
</li>

Expand Down Expand Up @@ -146999,6 +147088,7 @@ INSERT INTERFACES HERE
Ştefan Vargyas,
Stefan Weiss,
Steffen Meschkat,
Stephen Chenney,
Stephen Ma,
Stephen Stewart,
Stephen White,
Expand Down