From f322877ab571973e14cadbf8e2adf325a84e5a7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Wang?=
Date: Mon, 30 Sep 2024 12:23:07 +0000
Subject: [PATCH] Support CSS width/height properties on MathML elements.
This patch implements support for the width/height properties on
MathML elements [1]. The general algorithm from the spec is as
follows:
(1) The outcome of the math layout is a "math content box".
(2) The content box sets its size from computed width/height values. If
auto, it's the one of the "math content box". This patch ignores
percentage values for now [2] [3].
(3) math content box is shifted so that its inline-start and top edges
aligns with the ones of the content box. There are exceptions
elements like mfrac and munder/mover/munderover which instead
horizontally center the math content box within the content box.
For baseline adjustment, we follow what Chromium does, see [4].
(4) Padding+border are added around the content box. Note that we
ignore the box-sizing property for now [5].
The patch essentially tweaks the various MathML layout algorithms to
perform steps (3) and (4) before the calls to
GetBorderPaddingForPlace and InflateReflowAndBoundingMetrics.
[1] https://w3c.github.io/mathml-core/#layout-algorithms
[2] https://github.com/w3c/mathml-core/issues/76
[3] https://github.com/w3c/mathml-core/issues/77
[4] https://github.com/w3c/mathml-core/issues/259
[5] https://github.com/w3c/mathml-core/issues/257
Below is more information about test coverage:
- width-height-001: Verify that width, height, inline-size and block-size
properties sets the size of the content box. This test used to verify
they are ignored, this patch fixes the `` tag.
It also adds a test for the case the specified size is smaller than the
content (we force non empty descendants to make sure this content is
large enough) and to verify the width is used for the preferred width.
- width-height-002, width-height-003: These are reftests visually checking
offsets of the math content box within a larger content box (specified
by width/height) for the mtext, mrow, mpadded, mfrac, msqrt, mroot,
in LTR/RTL modes. In particular they allow to verify some painted
elements like fraction bar and radical symbols.
- width-height-004: This test more directly checks that the math content
box is horizontally centered within a larger content box for munder,
mover, munderover and mfrac. This patch extends the test to cover the
case when the math content box is wider (i.e. overflowing outside the
content box) and removes unnecessary specified height.
- width-height-005: New test for other layout algorithm that don't
center the math content box, checking inline-start edges of children
when a width is specified. We check both LTR/RTL modes and
wider/narrower content boxes.
- width-height-006: Same but checking the top edges for larger/smaller
height and verifying that baseline is perserved.
Differential Revision: https://phabricator.services.mozilla.com/D221436
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1916988
gecko-commit: dc848382811227e2f040f438794da638b8792f5b
gecko-reviewers: emilio
---
.../css-styling/width-height-001.html | 32 +-
.../css-styling/width-height-004.html | 63 +-
.../css-styling/width-height-005.html | 541 ++++++++++++++++++
.../css-styling/width-height-006.html | 406 +++++++++++++
4 files changed, 1040 insertions(+), 2 deletions(-)
create mode 100644 mathml/relations/css-styling/width-height-005.html
create mode 100644 mathml/relations/css-styling/width-height-006.html
diff --git a/mathml/relations/css-styling/width-height-001.html b/mathml/relations/css-styling/width-height-001.html
index 2deedc3f0b84d4..57cbc1b0ab2788 100644
--- a/mathml/relations/css-styling/width-height-001.html
+++ b/mathml/relations/css-styling/width-height-001.html
@@ -4,7 +4,7 @@
width, height, inline-size and block-size
-
+
@@ -30,6 +30,7 @@
document.body.insertAdjacentHTML("beforeend", ``);
let div = document.body.lastElementChild;
let element = FragmentHelper.element(div.firstElementChild);
+ FragmentHelper.forceNonEmptyDescendants(element);
test(function() {
assert_true(MathMLFeatureDetection[`has_${tag}`](), `${tag} is supported`);
@@ -49,6 +50,35 @@
assert_approx_equals(box.height, 700, epsilon, "height");
}, `inline-size and block-size properties on ${tag}`);
+ // Test that if we specify a size smaller than the content, then
+ // it is used too. Note that we skip mtable, which follows CSS
+ // tables rules and behave differently in that case.
+ if (tag != "mtable") {
+ test(function() {
+ assert_true(MathMLFeatureDetection[`has_${tag}`](), `${tag} is supported`);
+ var style = `width: 2px; height: 1px;`;
+ element.setAttribute("style", style);
+ let box = element.getBoundingClientRect();
+ assert_approx_equals(box.width, 2, epsilon, "width");
+ assert_approx_equals(box.height, 1, epsilon, "height");
+ }, `width and height properties on ${tag} (content overflowing)`);
+ }
+
+ div.style = "display: none;"; // Hide the div after measurement.
+
+ document.body.insertAdjacentHTML("beforeend", `
`);
+ let shrinkWrapDiv = document.body.lastElementChild.firstElementChild;
+ element = FragmentHelper.element(shrinkWrapDiv.firstElementChild);
+ FragmentHelper.forceNonEmptyDescendants(element);
+
+ test(function() {
+ assert_true(MathMLFeatureDetection[`has_${tag}`](), `${tag} is supported`);
+ var style = `width: 300px;`;
+ element.setAttribute("style", style);
+ let box = shrinkWrapDiv.getBoundingClientRect();
+ assert_approx_equals(box.width, 300, epsilon);
+ }, `width property on ${tag} (preferred width)`);
+
div.style = "display: none;"; // Hide the div after measurement.
}
diff --git a/mathml/relations/css-styling/width-height-004.html b/mathml/relations/css-styling/width-height-004.html
index 10ece249ca0b51..e26ebe9682328b 100644
--- a/mathml/relations/css-styling/width-height-004.html
+++ b/mathml/relations/css-styling/width-height-004.html
@@ -20,7 +20,6 @@
}
[data-name] {
width: 7em;
- height: 3em;
border: 1px solid blue;
}
@@ -64,6 +63,18 @@
X
+
+