html2canvas/src/clone.js

101 lines
3.6 KiB
JavaScript

var log = require('./log');
var Promise = require('./promise');
function restoreOwnerScroll(ownerDocument, x, y) {
if (ownerDocument.defaultView && (x !== ownerDocument.defaultView.pageXOffset || y !== ownerDocument.defaultView.pageYOffset)) {
ownerDocument.defaultView.scrollTo(x, y);
}
}
function cloneCanvasContents(canvas, clonedCanvas) {
try {
if (clonedCanvas) {
clonedCanvas.width = canvas.width;
clonedCanvas.height = canvas.height;
clonedCanvas.getContext("2d").putImageData(canvas.getContext("2d").getImageData(0, 0, canvas.width, canvas.height), 0, 0);
}
} catch(e) {
log("Unable to copy canvas content from", canvas, e);
}
}
function cloneNode(node, javascriptEnabled) {
var clone = node.nodeType === 3 ? document.createTextNode(node.nodeValue) : node.cloneNode(false);
var child = node.firstChild;
while(child) {
if (javascriptEnabled === true || child.nodeType !== 1 || child.nodeName !== 'SCRIPT') {
clone.appendChild(cloneNode(child, javascriptEnabled));
}
child = child.nextSibling;
}
if (node.nodeType === 1) {
clone._scrollTop = node.scrollTop;
clone._scrollLeft = node.scrollLeft;
if (node.nodeName === "CANVAS") {
cloneCanvasContents(node, clone);
} else if (node.nodeName === "TEXTAREA" || node.nodeName === "SELECT") {
clone.value = node.value;
}
}
return clone;
}
function initNode(node) {
if (node.nodeType === 1) {
node.scrollTop = node._scrollTop;
node.scrollLeft = node._scrollLeft;
var child = node.firstChild;
while(child) {
initNode(child);
child = child.nextSibling;
}
}
}
module.exports = function(ownerDocument, containerDocument, width, height, options, x ,y) {
var documentElement = cloneNode(ownerDocument.documentElement, options.javascriptEnabled);
var container = containerDocument.createElement("iframe");
container.className = "html2canvas-container";
container.style.visibility = "hidden";
container.style.position = "fixed";
container.style.left = "-10000px";
container.style.top = "0px";
container.style.border = "0";
container.width = width;
container.height = height;
container.scrolling = "no"; // ios won't scroll without it
containerDocument.body.appendChild(container);
return new Promise(function(resolve) {
var documentClone = container.contentWindow.document;
/* Chrome doesn't detect relative background-images assigned in inline <style> sheets when fetched through getComputedStyle
if window url is about:blank, we can assign the url to current by writing onto the document
*/
container.contentWindow.onload = container.onload = function() {
var interval = setInterval(function() {
if (documentClone.body.childNodes.length > 0) {
initNode(documentClone.documentElement);
clearInterval(interval);
if (options.type === "view") {
container.contentWindow.scrollTo(x, y);
}
resolve(container);
}
}, 50);
};
documentClone.open();
documentClone.write("<!DOCTYPE html><html></html>");
// Chrome scrolls the parent document for some reason after the write to the cloned window???
restoreOwnerScroll(ownerDocument, x, y);
documentClone.replaceChild(documentClone.adoptNode(documentElement), documentClone.documentElement);
documentClone.close();
});
};