# Blitz

[github.com/DioxusLabs/blitz](https://github.com/DioxusLabs/blitz) · MIT OR Apache-2.0

## For hotty-blitz

32 patches on `674d7d2`. hotty-blitz is HOTTY's renderer: it lays out and paints a terminal program's HTML surfaces with Blitz, behind the C ABI that hottyterm links and in the polyfill for other terminals. A HOTTY program changes its documents by small deltas many times a second, and expects of them what a browser does: layout that costs the change rather than the document, form controls in the page's colour scheme, `srcset`, password inputs and selects, a user stylesheet, and SVG that reads no files. We mod Blitz rather than fork it so that each of those stays one change on a pinned commit, written as a browser behaviour Blitz could take as it is.

The patches, each with its upstream fit:

1. [A delta costs the change, not the document](https://neuroplast.io/modding/blitz#a-delta-costs-the-change-not-the-document) — **maybe**
2. [Inline SVG follows its preserveAspectRatio](https://neuroplast.io/modding/blitz#inline-svg-follows-its-preserveaspectratio) — **yes**
3. [A control in the disabled state acts disabled](https://neuroplast.io/modding/blitz#a-control-in-the-disabled-state-acts-disabled) — **yes**
4. [Outlines take outline-offset and every border style](https://neuroplast.io/modding/blitz#outlines-take-outline-offset-and-every-border-style) — **yes**
5. [A box whose layout changed gets its overflow and transform again](https://neuroplast.io/modding/blitz#a-box-whose-layout-changed-gets-its-overflow-and-transform-again) — **yes**
6. [An SVG's image loads a data: URL and no file](https://neuroplast.io/modding/blitz#an-svgs-image-loads-a-data-url-and-no-file) — **yes**
7. [A request says what it is for: image, style, font, iframe or document](https://neuroplast.io/modding/blitz#a-request-says-what-it-is-for-image-style-font-iframe-or-document) — **yes**
8. [An img shows the source that srcset, sizes and picture choose](https://neuroplast.io/modding/blitz#an-img-shows-the-source-that-srcset-sizes-and-picture-choose) — **yes**
9. [An inline SVG's image draws what the document fetches for it](https://neuroplast.io/modding/blitz#an-inline-svgs-image-draws-what-the-document-fetches-for-it) — **yes**
10. [An img chooses its source again when the device changes](https://neuroplast.io/modding/blitz#an-img-chooses-its-source-again-when-the-device-changes) — **yes**
11. [Form controls follow the used color scheme](https://neuroplast.io/modding/blitz#form-controls-follow-the-used-color-scheme) — **yes**
12. [Text controls are as wide as size and cols, and as tall as rows](https://neuroplast.io/modding/blitz#text-controls-are-as-wide-as-size-and-cols-and-as-tall-as-rows) — **yes**
13. [A scroll container's client rect doesn't move with its own scroll](https://neuroplast.io/modding/blitz#a-scroll-containers-client-rect-doesnt-move-with-its-own-scroll) — **yes**
14. [A document can lock scrolling along an axis](https://neuroplast.io/modding/blitz#a-document-can-lock-scrolling-along-an-axis) — **maybe**
15. [A scroll container is hit only within its box](https://neuroplast.io/modding/blitz#a-scroll-container-is-hit-only-within-its-box) — **yes**
16. [Stylesheets of the user origin](https://neuroplast.io/modding/blitz#stylesheets-of-the-user-origin) — **yes**
17. [:focus-visible matches, and a click shows the ring only on a text field](https://neuroplast.io/modding/blitz#focus-visible-matches-and-a-click-shows-the-ring-only-on-a-text-field) — **yes**
18. [Selected text takes the colours of its ::selection](https://neuroplast.io/modding/blitz#selected-text-takes-the-colours-of-its-selection) — **yes**
19. [Backspace edits a text input on macOS too](https://neuroplast.io/modding/blitz#backspace-edits-a-text-input-on-macos-too) — **maybe**
20. [An embedder can hide the caret, to blink it](https://neuroplast.io/modding/blitz#an-embedder-can-hide-the-caret-to-blink-it) — **maybe**
21. [A password input shows a mask and edits its value](https://neuroplast.io/modding/blitz#a-password-input-shows-a-mask-and-edits-its-value) — **yes**
22. [An embedder can edit a text input: its value, selection and rows](https://neuroplast.io/modding/blitz#an-embedder-can-edit-a-text-input-its-value-selection-and-rows) — **maybe**
23. [A select has a selected option, submits it, and draws closed](https://neuroplast.io/modding/blitz#a-select-has-a-selected-option-submits-it-and-draws-closed) — **yes**
24. [A table emptied of its rows forgets them](https://neuroplast.io/modding/blitz#a-table-emptied-of-its-rows-forgets-them) — **yes**
25. [A box gone display: none forgets the boxes built under it](https://neuroplast.io/modding/blitz#a-box-gone-display-none-forgets-the-boxes-built-under-it) — **yes**
26. [Speculative relayout leaves nodes out of the layout tree alone](https://neuroplast.io/modding/blitz#speculative-relayout-leaves-nodes-out-of-the-layout-tree-alone) — **maybe**
27. [A mutation's queued work skips the nodes it freed](https://neuroplast.io/modding/blitz#a-mutations-queued-work-skips-the-nodes-it-freed) — **yes**
28. [An inline svg is built again when its source changes](https://neuroplast.io/modding/blitz#an-inline-svg-is-built-again-when-its-source-changes) — **maybe**
29. [An inline svg's currentColor is written as rgb()](https://neuroplast.io/modding/blitz#an-inline-svgs-currentcolor-is-written-as-rgb) — **yes**
30. [A row move can extend the selection](https://neuroplast.io/modding/blitz#a-row-move-can-extend-the-selection) — **yes**
31. [A double click selects a word, and a triple click its block](https://neuroplast.io/modding/blitz#a-double-click-selects-a-word-and-a-triple-click-its-block) — **yes**
32. [A double click in a password input selects all of it](https://neuroplast.io/modding/blitz#a-double-click-in-a-password-input-selects-all-of-it) — **yes**

### A delta costs the change, not the document

> Upstream fit: **maybe** · [patch 0001](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0001-blitz-dom-patch-cost-proportional-to-depth-not-docum.patch)

**What it changes:** one changed node cost every phase of `resolve` a walk
of the whole document. Each phase now stops where the change stops.
Construction skips elements with no damage below them. Each node's layout
cache grows past taffy's 9 entries, up to 64, since a content-sized
container k levels deep is measured under about 3 + 5k constraints a pass
and the entries evicted each other. A flex or grid container keeps its
cache when every changed item, asked again what the container asked it
last time, answers the same (`layout/speculate.rs`). Rounding visits only
the nodes whose layout changed and the subtrees that moved, and everything
when more than a quarter changed. Debug builds compare every incremental
rounding with `taffy::round_layout`, and Blitz's 299 tests pass.

**Why we carry it:** HOTTY programs send deltas many times a second; a
one-cell change to a large dashboard cost the whole document.

**For upstream:** maybe. The cache and the rounding are generic, but the
speculation is a large change to how layout settles, and upstream's own
damage tracking has moved since our base, so it would need rework there.

### Inline SVG follows its preserveAspectRatio

> Upstream fit: **yes** · [patch 0002](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0002-blitz-paint-inline-SVG-follows-its-preserveAspectRat.patch)

**What it changes:** an inline `<svg>` was always painted as `object-fit:
contain`. A browser fits the viewBox to the element's box as
`preserveAspectRatio` says (SVG 2, 8.6): `none` stretches it, `slice`
covers the box, and the default fits inside. 14 lines in blitz-paint.

**Why we carry it:** charts drawn in a fixed viewBox and stretched to their
box came out narrow and centred.

**For upstream:** yes. It is what browsers do, and small.

### A control in the disabled state acts disabled

> Upstream fit: **yes** · [patch 0003](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0003-blitz-dom-blitz-paint-a-control-in-the-disabled-stat.patch)

**What it changes:** pointer handling and form-control painting asked for
the `disabled` attribute. Blitz already keeps a control's disabled state in
its `ElementState`, which `:disabled` matches; they now ask
`ElementData::is_disabled`, the attribute or the state. Nothing changes for
a document whose state comes from its attributes. An embedder that
disables a control with `Node::disable`, leaving the attributes alone, gets
what the attribute gives: no focus, no toggle, no submit, no selection, and
a grey checkbox.

**Why we carry it:** a detached HOTTY surface's controls act disabled
(SPEC §5.5) while the document keeps the program's attributes.

**For upstream:** yes. It is small, and makes the state and the attribute
agree everywhere.

### Outlines take outline-offset and every border style

> Upstream fit: **yes** · [patch 0004](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0004-blitz-paint-outlines-take-outline-offset-and-every-b.patch)

**What it changes:** an outline was drawn solid, just outside the border
box: `outline-offset` was ignored, and dashed, dotted, double, groove,
ridge, inset and outset outlines came out solid. The outline is now the
border of a box of its own, offset from the border box (inside it when the
offset is negative), drawn with the border's edge code, so it takes every
border style. It is painted after the element's content, as CSS 2.1
Appendix E does, so the element's background doesn't cover one inside it.
Dotted outlines have round dots, as Blitz's dotted borders do.

**Why we carry it:** a surface's root fills the surface, so an outline on
it has to come inside with a negative offset, and was drawn off the
surface.

**For upstream:** yes. It is CSS as browsers draw it.

### A box whose layout changed gets its overflow and transform again

> Upstream fit: **yes** · [patch 0005](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0005-blitz-dom-a-box-whose-layout-changed-gets-its-overfl.patch)

**What it changes:** Blitz computed a node's transform and scrollable
overflow again only when its own style damage asked for it. Damage flows up
the tree, so a box resized only because an ancestor changed kept its old
overflow, and paint, which culls a box by its overflow, could drop it on
every later paint. Every node whose final layout changed is now recorded
(`set_final_layout`), with the boxes that reach it in `resolve_transforms`,
and those are computed again too.

**Why we carry it:** a delta to a custom property that set a ring's height
and `translateY` left its stretched child culled off the surface.

**For upstream:** yes. It is a bug in incremental updates that any
embedder changing a document can hit.

### An SVG's image loads a data: URL and no file

> Upstream fit: **yes** · [patch 0006](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0006-blitz-dom-an-SVG-s-image-loads-a-data-URL-and-no-fil.patch)

**What it changes:** Blitz parses every SVG (an `<img>`, a CSS image and an
inline `<svg>` alike) with usvg's default options, whose image resolver
reads any `<image href>` that isn't a `data:` URL as a path on the disk. A
page could draw any image the user's files hold, without asking the
`NetProvider`. The resolver now loads `data:` URLs, and (with a later
patch) what the document fetched for an inline SVG's `<image>`, and
nothing else. A test in blitz-dom checks it.

**Why we carry it:** HOTTY documents come from programs, and a surface
must never read the user's files (SPEC §12).

**For upstream:** yes. It closes a file read that browsers never allow.

### A request says what it is for: image, style, font, iframe or document

> Upstream fit: **yes** · [patch 0007](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0007-blitz-traits-blitz-dom-a-request-carries-its-destina.patch)

**What it changes:** a `NetProvider` got a URL and nothing about what it
was for. `Request` now has fetch's `destination`, and every request a
document makes sets it: `Image` for `<img>` and CSS images, `Style` for
stylesheets, their reload and `@import`, `Font` for `@font-face`,
`Iframe` for an iframe's document, and `Document` for a navigation.
`Request::get` leaves it `Empty`. The struct was `non_exhaustive`
already.

**Why we carry it:** HOTTY applies a fetch policy per kind of resource, as
CSP's `img-src`, `style-src` and `font-src` do (SPEC §7.2).

**For upstream:** yes. It is fetch's own field, and any embedder with a
content policy needs it.

### An img shows the source that srcset, sizes and picture choose

> Upstream fit: **yes** · [patch 0008](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0008-blitz-dom-an-img-shows-the-source-srcset-sizes-and-p.patch)

**What it changes:** Blitz loaded an `<img>`'s `src` and nothing else.
`BaseDocument::image_source` now selects a source as HTML does: the first
`<source>` of its `<picture>` whose `type` this build decodes and whose
`media` matches the device, else its own `srcset`, else its `src`. Of a
`srcset`, it takes the candidate with the smallest density at or above the
device's, else the densest; a `w` candidate's density is its width over
the size `sizes` gives it, with Stylo's `SourceSizeList`. Changing the
attributes loads the image again.

**Why we carry it:** HOTTY surfaces are drawn at the terminal's scale and
theme, and programs send images for each.

**For upstream:** yes. It is HTML's image source selection.

### An inline SVG's image draws what the document fetches for it

> Upstream fit: **yes** · [patch 0009](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0009-blitz-dom-an-inline-SVG-s-image-draws-what-the-docum.patch)

**What it changes:** usvg resolves an `<image>`'s href synchronously while
it parses, and Blitz parses an inline `<svg>` while it constructs boxes,
so nothing could be fetched for it. An SVG `<image>` is now fetched as an
`<img>` is, through the `NetProvider` as an `Image` request, when it joins
the document or its `href` changes. The bytes are kept by URL; when they
arrive, the outermost `<svg>` is built again, and the resolver hands usvg
those bytes. An SVG that is itself an image still loads only `data:`, as
in a browser.

**Why we carry it:** `cid:` resources in an SVG `href` (HOTTY SPEC §7.1),
and `img-src` reaching images in SVG (§7.2).

**For upstream:** yes. Inline SVG images then load as in a browser.

### An img chooses its source again when the device changes

> Upstream fit: **yes** · [patch 0010](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0010-blitz-dom-an-img-chooses-its-source-again-when-the-d.patch)

**What it changes:** when the viewport's size, scale or colour scheme, or
the media type, changes, every `<img>` whose source the device chose
chooses again, and loads what it chose if that differs. The old image shows
until the new one arrives, and one chosen for an old device that arrives
late isn't shown.

**Why we carry it:** a terminal's scale and theme change under a live
document, as a browser window's do.

**For upstream:** yes, with "An img shows the source that srcset, sizes
and picture choose".

### Form controls follow the used color scheme

> Upstream fit: **yes** · [patch 0011](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0011-blitz-dom-blitz-paint-form-controls-follow-the-used-.patch)

**What it changes:** the UA stylesheet made fields white and buttons light
grey, and checkboxes and radio buttons were painted white, so a page with
`color-scheme: dark` showed light controls. Fields now take `Field` and
`FieldText`, and buttons `ButtonFace` and `ButtonText`, system colours
that Stylo already resolves in the element's used colour scheme, with
Chromium's borders in each scheme (`light-dark()`). Checkboxes and radio
buttons are drawn in the used scheme (`BaseDocument::used_color_scheme`),
with Chromium's colours for `accent-color: auto` and its 13px geometry. A
document's own colours still win.

**Why we carry it:** surfaces on a dark terminal are dark (HOTTY SPEC
§8).

**For upstream:** yes. Browsers draw controls this way; the shades are
Stylo's system colours, a little off Chromium's.

### Text controls are as wide as size and cols, and as tall as rows

> Upstream fit: **yes** · [patch 0012](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0012-blitz-dom-text-controls-are-as-wide-as-size-and-cols.patch)

**What it changes:** a text input was 300px wide (or the available width)
whatever its `size`, and a textarea 300px unless it had `cols`. Controls
now count characters as Chromium does: one character is the font's
average width (OS/2 `xAvgCharWidth`), or the advance of `0`; an input is
`size` characters wide (20 by default) plus the widest glyph less one
character; a textarea is `cols` characters (20) with no scrollbar gutter,
since Blitz's scrollbars are overlays; a row is the line height, the
font's own for `line-height: normal`. For Noto Sans and Noto Sans Mono at
16px, every width matches Chromium's to the pixel.

**Why we carry it:** forms in surfaces are laid out by their attributes.

**For upstream:** yes. It is HTML's sizing.

### A scroll container's client rect doesn't move with its own scroll

> Upstream fit: **yes** · [patch 0013](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0013-blitz-dom-a-scroll-container-s-client-rect-does-not-.patch)

**What it changes:** `get_client_bounding_rect` is the border box, which a
scroll container's own scroll offset doesn't move, but the position walk
subtracted that offset, so a scrolled box reported itself moved.
`scroll_into_view` already made up for it.

**Why we carry it:** HOTTY's `area` and bringing a focused element into
view went wrong inside a scrolled box.

**For upstream:** yes. It is a bug fix.

### A document can lock scrolling along an axis

> Upstream fit: **maybe** · [patch 0014](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0014-blitz-dom-blitz-paint-a-document-can-lock-scrolling-.patch)

**What it changes:** `BaseDocument::set_scroll_axes` locks an axis: every
scroll target's range along it is empty, whoever scrolls (the user, a
fragment link, a fling, a thumb), locking puts the offsets back to zero,
and no scrollbar is drawn or hit there. A text input still scrolls its own
text to follow the caret.

**Why we carry it:** HOTTY scrolls a document only along the axes it asks
for (SPEC §5.1, §5.3).

**For upstream:** maybe. It is an embedder API shaped by HOTTY's model;
another embedder might want it, but nothing in the web platform asks for
it.

### A scroll container is hit only within its box

> Upstream fit: **yes** · [patch 0015](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0015-blitz-dom-a-scroll-container-is-hit-only-within-its-.patch)

**What it changes:** hit testing added a node's scroll offset to the point
before testing it against the node's box, so a box scrolled down took
points above itself and handed them to the children it had scrolled out of
view. The point is now tested against the box first, the scroll offset
moves only the content, and content a box clips isn't hit outside its
padding box, where it isn't drawn.

**Why we carry it:** a press above a scrolled list landed on the items it
had scrolled away.

**For upstream:** yes. It is a bug fix.

### Stylesheets of the user origin

> Upstream fit: **yes** · [patch 0016](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0016-blitz-dom-stylesheets-of-the-user-origin.patch)

**What it changes:** `DocumentConfig::user_stylesheets`, and
`BaseDocument::add_user_stylesheet` and `remove_user_stylesheet`. A user
stylesheet wins over the user agent's and loses to the document's own,
whatever the selectors' specificity, as the CSS cascade orders its
origins.

**Why we carry it:** HOTTY's host stylesheet (SPEC §8) dresses controls,
focus, links and selection in the terminal's colours with
zero-specificity `:where()` rules, which must beat the UA sheet and lose to
the document. As a second UA sheet it lost to `input { background-color:
Field }`.

**For upstream:** yes. User stylesheets are part of CSS, and any embedder
with a theme can use them.

### :focus-visible matches, and a click shows the ring only on a text field

> Upstream fit: **yes** · [patch 0017](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0017-blitz-dom-focus-visible-matches-the-focus-ring-a-cli.patch)

**What it changes:** `:focus-visible` matched nothing. It now matches the
focus ring (`ElementState::FOCUSRING`), which focus from the keyboard or a
script sets. Focus moved by the pointer (`set_focus_by_pointer`, which
Blitz's own click handling now calls) keeps the ring only on a text field,
as browsers do.

**Why we carry it:** HOTTY's host stylesheet draws focus rings with
`:focus-visible` (SPEC §8).

**For upstream:** yes. It is the selector as browsers match it.

### Selected text takes the colours of its ::selection

> Upstream fit: **yes** · [patch 0018](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0018-blitz-dom-blitz-paint-selected-text-takes-the-colour.patch)

**What it changes:** a selection was a fixed light blue under text in its
own colours. The highlight is now the inline root's, or the text field's,
`::selection` background, or that blue when it sets none, and the selected
text is drawn again over it, clipped to it, in each run's `::selection`
colour.

**Why we carry it:** HOTTY's host stylesheet colours selections with the
terminal's palette (SPEC §8).

**For upstream:** yes. It is `::selection` as CSS has it.

### Backspace edits a text input on macOS too

> Upstream fit: **maybe** · [patch 0019](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0019-blitz-dom-Backspace-edits-a-text-input-on-macOS-too.patch)

**What it changes:** the text input's Backspace arm was compiled out on
macOS, where Cocoa's text system turns the key into a `deleteBackward:`
keybinding that does the deleting. The arm now applies on every platform.
It is the only key the text input left to Cocoa: Delete, the arrows, Home
and End take the same path everywhere.

**Why we carry it:** a terminal has no Cocoa text system and hotty-blitz
sends no keybindings, so on macOS Backspace did nothing in a field.

**For upstream:** maybe. An embedder without Cocoa needs it, but
upstream's own macOS shell would then delete twice unless it is made
conditional on the embedder.

### An embedder can hide the caret, to blink it

> Upstream fit: **maybe** · [patch 0020](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0020-blitz-dom-blitz-paint-an-embedder-can-hide-the-caret.patch)

**What it changes:** a focused text input's caret was painted solid.
`BaseDocument::set_caret_shown` turns it off and on, and the painter
honours it.

**Why we carry it:** hotty-blitz blinks the caret on the frame clock that
plays animated images, repainting only the input, as a browser blinks it.

**For upstream:** maybe. Blinking is wanted, but upstream may prefer to
blink the caret itself rather than leave it to the embedder.

### A password input shows a mask and edits its value

> Upstream fit: **yes** · [patch 0021](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0021-blitz-dom-a-password-input-shows-a-mask-and-edits-it.patch)

**What it changes:** an `<input type=password>` was edited as a text field
and showed the password. Its value is now kept beside the editor
(`TextInputData::password`), and the editor holds a bullet, U+2022 as in
Chrome, for each character, so the caret, selection and hit testing work on
what is shown. Each edit of the mask is made to the value too. The input
event, form submission and `TextInputData::value` carry the value, and the
`value` attribute sets it. As in a browser, the value isn't copied or cut,
the field composes nothing, and changing `type` to or from `password` masks
or shows the value, which is how a page makes a reveal toggle.

**Why we carry it:** HOTTY forms ask for passwords.

**For upstream:** yes. It is what browsers do, with tests in blitz-dom.

### An embedder can edit a text input: its value, selection and rows

> Upstream fit: **maybe** · [patch 0022](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0022-blitz-dom-an-embedder-can-edit-a-text-input-its-valu.patch)

**What it changes:** on `BaseDocument`: `text_input_selection` reads a text
input's value and selection; `set_text_input` sets both (a password
field's value too, its mask following) and redraws; `move_text_input_rows`
moves the caret by laid-out rows from Parley's selection; and
`text_input_rows_shown` counts the rows the field shows, for a page.

**Why we carry it:** a text field's keys are its program's keymap (HOTTY
SPEC §10.2), so hotty-blitz does the editing itself rather than send keys
Blitz's editor would read its own way.

**For upstream:** maybe. An embedder with its own keymap needs this, but
its shape follows hotty-blitz's.

### A select has a selected option, submits it, and draws closed

> Upstream fit: **yes** · [patch 0023](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0023-blitz-dom-a-select-has-a-selected-option-submits-it-.patch)

**What it changes:** every `<option>` was hidden and nothing kept
selectedness, so a select drew as an empty box and never reached form
data. An option's selectedness is now its `ElementState::CHECKED` bit, as
in Gecko, so `option:checked` matches it, and the mutator settles it with
HTML's selectedness algorithm as options come, go, or have `selected` set
or removed. Form data has the selected options. A select without
`multiple` draws closed, as a browser draws it: the selected option and an
arrow, as wide as its widest option. `BaseDocument::pick_option` picks.
Its list isn't drawn, nor is a `multiple` select or one with `size` above
1.

**Why we carry it:** HOTTY lets a host show no list, and hotty-blitz
picks with the keys (SPEC §10.2).

**For upstream:** yes. Selectedness and the closed select are HTML's, and
a list could come later.

### A table emptied of its rows forgets them

> Upstream fit: **yes** · [patch 0024](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0024-blitz-dom-a-table-emptied-of-its-rows-forgets-them.patch)

**What it changes:** construction returned before the table branch for a
node with no children, so a table emptied of its rows kept its table
context, and paint read the freed rows from it ("invalid SlotMap key
used"). The context now goes with the inline layout, first, and is built
again while the node is a table with children.

**Why we carry it:** a delta that emptied a table panicked, and in
hottyterm that turned HOTTY off for the terminal. hotty-blitz's fuzz test
found it.

**For upstream:** yes. It is a crash fix.

### A box gone display: none forgets the boxes built under it

> Upstream fit: **yes** · [patch 0025](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0025-blitz-dom-a-box-gone-display-none-forgets-the-boxes-.patch)

**What it changes:** a box that goes `display: none` isn't constructed
again, and its unstyled subtree reports no damage, not even a removal. It
kept its layout children, anonymous blocks, inline layout, hoisted
out-of-flow boxes and paint tree, as did the boxes under it, and Taffy and
paint still visited it. Damage propagation now has a hidden box forget all
of it, for its former subtree too; shown again, the subtree is built
afresh. Blitz's own `assert_layout_parents_consistent`, which failed after
such a delta, holds again.

**Why we carry it:** a delta under a box that went `display: none`
panicked on freed nodes. hotty-blitz's fuzz test found it.

**For upstream:** yes. It is a crash fix.

### Speculative relayout leaves nodes out of the layout tree alone

> Upstream fit: **maybe** · [patch 0026](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0026-blitz-dom-speculative-relayout-leaves-nodes-out-of-t.patch)

**What it changes:** the speculative relayout of "A delta costs the change,
not the document" asked nodes that had just left the layout tree about
their layout parent, and laid out their children, both possibly freed. It
now passes over a node unless each layout parent up to the root element
lists it; its old container lays out again, as for any unsettled child.

**Why we carry it:** a crash on freed nodes, found by hotty-blitz's fuzz
test.

**For upstream:** maybe, as part of "A delta costs the change, not the
document": it fixes that patch, and goes wherever it goes.

### A mutation's queued work skips the nodes it freed

> Upstream fit: **yes** · [patch 0027](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0027-blitz-dom-a-mutation-s-queued-work-skips-the-nodes-i.patch)

**What it changes:** the mutator queues work for its flush (a form
control's form owner, a style element's sheet, a select's selectedness),
and a control inserted and freed by the same mutation stayed queued, so
the flush touched a freed node. The flush now skips nodes no longer there.

**Why we carry it:** a delta that inserted a form control and removed it
again panicked. hotty-blitz's fuzz test found it.

**For upstream:** yes. It is a crash fix.

### An inline svg is built again when its source changes

> Upstream fit: **maybe** · [patch 0028](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0028-blitz-dom-an-inline-svg-is-built-again-when-its-sour.patch)

**What it changes:** an inline `<svg>` is drawn from one usvg parse of its
markup, made while boxes are constructed, with `currentColor` resolved to
each element's colour then. A colour change later is only style damage, so
an icon drawn with `fill="currentColor"` kept its first colour through a
parent's class, a theme, `:hover` and `:focus`. A hash of the source each
inline svg was built from is now kept, and when an svg or anything under
it is damaged and its source differs, that svg alone is constructed again.

**Why we carry it:** the HOTTY UI kit draws its icons in `currentColor`.

**For upstream:** maybe. The bug is real, but Blitz has since rebuilt
inline SVG when its styles change in its own way, after our base, which
may make this patch unnecessary once the base moves.

### An inline svg's currentColor is written as rgb()

> Upstream fit: **yes** · [patch 0029](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0029-blitz-dom-an-inline-svg-s-currentColor-is-written-as.patch)

**What it changes:** `outer_html` wrote an inline svg's `currentColor` with
`to_css_string`, so a colour that computes to anything but legacy sRGB
(`color-mix()`, oklab, display-p3) came out as `color(srgb …)`, which usvg
doesn't parse, and the icon drew black. It is now written as `rgb()` or
`rgba()` (`into_srgb_legacy`).

**Why we carry it:** every icon in the HOTTY UI kit's muted text, a
`color-mix()`, drew black.

**For upstream:** yes. It is small, and any page with modern colours hits
it.

### A row move can extend the selection

> Upstream fit: **yes** · [patch 0030](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0030-blitz-dom-a-row-move-can-extend-the-selection.patch)

**What it changes:** `TextInputData::move_rows`, and
`move_text_input_rows`, take `extend`: with it, the selection's anchor
stays and the caret moves, as Shift+ArrowDown does in a browser's
textarea. Without it, a selection collapses first, as before. Parley's
`move_lines` already extends; this passes the flag through.

**Why we carry it:** HOTTY text fields select by rows with the keymap.

**For upstream:** yes. It is small and generic.

### A double click selects a word, and a triple click its block

> Upstream fit: **yes** · [patch 0031](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0031-blitz-dom-a-double-click-selects-a-word-and-a-triple.patch)

**What it changes:** in a page's text, as a browser does: a double click
selects the word under the pointer (`Selection::word_from_point`), and a
triple click the inline root's whole text. A text input already did both.

**Why we carry it:** HOTTY documents are read and copied from like pages
(SPEC §9).

**For upstream:** yes. It is what browsers do.

### A double click in a password input selects all of it

> Upstream fit: **yes** · [patch 0032](https://github.com/neuroplastio/hotty-blitz/blob/079f6ae967aed32326797f8b7423d0f073aa4550/mods/blitz/0032-blitz-dom-a-double-click-in-a-password-input-selects.patch)

**What it changes:** a password input's mask has no words: to UAX #29 each
bullet is a word of its own, so a double click selected one. As in a
browser, a double click selects the whole value, as a triple click does.

**Why we carry it:** password inputs in HOTTY forms.

**For upstream:** yes, with "A password input shows a mask and edits its
value".

---

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