Class SvgAbstract

Marks an element as created (and therefore owned) by MAIDR. Public so trace code that clones or synthesizes highlight elements outside this utility can participate in ownership-aware disposal.

Returns true if the element was created by MAIDR (safe to remove on disposal). Original chart elements referenced for in-place highlighting are not owned and must never be removed.

Converts an SVG element to a Base64-encoded JPEG data URL.

Selects all SVG elements matching a query and optionally clones them.

Selects a single SVG element matching a query and optionally clones it.

Clones an element, hides the copy, and inserts it straight after the original.

This is the side effect selectElement performs once it has found its element, split out so a caller can do the finding first. Resolving a positional* selector -- :nth-child(N) and friends -- while earlier clones are already in the DOM counts siblings the chart never drew, and answers with the clone of an earlier element; a caller with a list of such selectors has to look them all up before inserting anything (#1004).

Select the Nth element matching a query, in document order.

Useful when a single CSS selector matches multiple sibling elements (e.g. multi-series Vega-Lite line charts where each series renders as a separate <g class="mark-line role-mark layer_0_marks"> group, all with the same class). CSS :nth-child(N) cannot address the Nth matching group when classes differ; this helper does it via JS.

Always returns the live DOM element (no cloning side-effects), since the indexed-selection use case is for resolving live DOM nodes that downstream code (highlight pipeline, etc.) operates on directly.

Creates an empty, hidden, transparent SVG element of the specified type.

Creates one circle element per centre, styled to match the parent element's stroke or fill.

A whole series at once rather than a point at a time, because the two expensive parts of the job are per-series rather than per-point: the paint is one computed style for a line all of whose markers share it, and the insertion is one fragment. Reading a style back after inserting an element is what forces the browser to recalculate it, so a loop alternating the two paid a recalculation per point of every line, at construction and again on every live-data rebuild.

Builds one line per request, each along one edge of one element's bounding box, and returns them detached.

A whole batch at once rather than a line at a time, for the reason given on createCircleElements: measuring an element after inserting a node beside it is what forces the browser to lay the chart out again, and a loop that alternated the two paid a layout per line. Reading every anchor first and building from the numbers costs one layout for the batch however many lines it holds -- and a candlestick or a box plot builds two per candle or per box, at construction and again on every live-data rebuild.

Building is split from inserting because where a line lands among its siblings is behaviour, not bookkeeping: an anchor that is also the original of a hidden clone pairs with that clone by previousElementSibling, so a line inserted between them changes which elements a trace reports as its originals and therefore what a high-contrast reader is shown. The caller inserts with insertDerived, at the point in its own writes where the line belongs.

Each anchor is measured and styled once even when several lines are drawn along it: inserting a hidden sibling does not move the anchor, so the second read only ever returned what the first did.

When a bounding box has zero width (vertical path) or zero height (horizontal path), a minimum span is used so the resulting line is visible.

Puts derived nodes into the document directly after the element they were derived from, one at a time and in the order they were built.

insertAdjacentElement(AFTER_END, ...) puts each node straight after the anchor, so building a then b and inserting both leaves [anchor, b, a]. That reversal is the child order every renderer, highlight and high-contrast pass has always seen, so it is reproduced exactly rather than tidied: the caller passes the nodes in the order it built them.

Where the caller makes this call matters as much as the order within it. A node inserted after an anchor that is itself the original of a hidden clone lands between the two, and AbstractTrace.getAllOriginalElements pairs a clone to its original by previousElementSibling; inserting earlier or later than the chart's own clones therefore changes which elements HighContrastService recolours. Callers insert at the point their one-at-a-time predecessor did.

An anchor with no parent inserts nothing, exactly as insertAdjacentElement does.

Draws the whiskers between box plots' caps and their boxes.

A box plot's selectors name the caps and the box, and a highlight only ever needs those. A renderer showing the chart's shape needs the whisker between them as well, or a box arrives as a rectangle with two detached dashes floating beyond it. The whisker runs from the cap's centre to the nearer edge of the box, and it is hidden: it is geometry for a renderer to read, not a mark for the chart to show.

A whole batch at once for the reason given on buildLineElements: one box plot's whiskers used to be measured after the previous one's had been inserted, so every box cost the browser two more layouts. The same element is measured once however many whiskers touch it -- a box and both its caps were read four times per box. The whiskers come back detached, for the caller to insert with insertDerived where its one-at-a-time predecessor did.

Creates a highlighted clone of an SVG element with enhanced visibility.

When the element has a zero-size bounding box (e.g. a single-point <path d="M x y"> used for median markers in violin plots), a visible <circle> is created at that position instead.

Calculates a contrasting color (black or white) based on the element's fill color.

Applies CSS outline styling to highlight a subplot element.

Removes CSS outline highlighting from a subplot element.

Applies SVG stroke highlighting to a subplot with adaptive color based on background.

Removes SVG stroke highlighting from a subplot element.