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/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
export var LayoutUtils = {
/**
* For a given DOM element, returns its position in screen coordinates of CSS units
*/
getElementBoundingScreenRect(aElement) {
let rect = aElement.getBoundingClientRect();
let win = aElement.ownerGlobal;
const { x, y, width, height } = this._rectToClientRect(win, rect);
return win.windowUtils.toScreenRectInCSSUnits(x, y, width, height);
},
/**
* Similar to getElementBoundingScreenRect using window and rect,
* returns screen coordinates in screen units.
*/
rectToScreenRect(win, rect) {
const { x, y, width, height } = this._rectToClientRect(win, rect);
return win.ownerGlobal.windowUtils.toScreenRect(x, y, width, height);
},
_rectToClientRect(win, rect) {
// We need to compensate the position for ancestor iframes in the same
// process that might shift things over. Those might have different CSS
// pixel scales, so we compute the position in device pixels and then go
// back to css pixels at the end.
let winDpr = win.devicePixelRatio;
let x = rect.left * winDpr;
let y = rect.top * winDpr;
let parentFrame = win.browsingContext?.embedderElement;
while (parentFrame) {
win = parentFrame.ownerGlobal;
let cstyle = win.getComputedStyle(parentFrame);
let framerect = parentFrame.getBoundingClientRect();
let xDelta =
framerect.left +
parseFloat(cstyle.borderLeftWidth) +
parseFloat(cstyle.paddingLeft);
let yDelta =
framerect.top +
parseFloat(cstyle.borderTopWidth) +
parseFloat(cstyle.paddingTop);
x += xDelta * win.devicePixelRatio;
y += yDelta * win.devicePixelRatio;
parentFrame = win.browsingContext?.embedderElement;
}
return {
x: x / winDpr,
y: y / winDpr,
width: rect.width,
height: rect.height,
};
},
};