TelegramPWA/src/util/selection.ts

100 lines
2.6 KiB
TypeScript

const extractorEl = document.createElement('div');
export function insertHtmlInSelection(html: string) {
const selection = window.getSelection();
if (selection?.getRangeAt && selection.rangeCount) {
const range = selection.getRangeAt(0);
range.deleteContents();
const fragment = range.createContextualFragment(html);
const lastInsertedNode = fragment.lastChild;
range.insertNode(fragment);
if (lastInsertedNode) {
range.setStartAfter(lastInsertedNode);
range.setEndAfter(lastInsertedNode);
} else {
range.collapse(false);
}
selection.removeAllRanges();
selection.addRange(range);
}
}
export function getHtmlBeforeSelection(container?: HTMLElement, useCommonAncestor?: boolean) {
if (!container) {
return '';
}
const sel = window.getSelection();
if (!sel || !sel.rangeCount) {
return container.innerHTML;
}
const range = sel.getRangeAt(0).cloneRange();
if (!range.intersectsNode(container)) {
return container.innerHTML;
}
if (!useCommonAncestor && !container.contains(range.commonAncestorContainer)) {
return '';
}
range.collapse(true);
range.setStart(container, 0);
extractorEl.innerHTML = '';
extractorEl.appendChild(range.cloneContents());
return extractorEl.innerHTML;
}
// https://stackoverflow.com/a/3976125
export function getCaretPosition(element: HTMLElement) {
let caretPosition = 0;
const selection = window.getSelection();
if (!selection || selection.rangeCount === 0) {
return caretPosition;
}
const range = selection.getRangeAt(0);
const caretRange = range.cloneRange();
caretRange.selectNodeContents(element);
caretRange.setEnd(range.endContainer, range.endOffset);
caretPosition = caretRange.toString().length;
return caretPosition;
}
// https://stackoverflow.com/a/36953852
export function setCaretPosition(element: Node, position: number) {
for (const node of element.childNodes) {
if (node.nodeType === Node.TEXT_NODE) {
if ((node as Text).length >= position) {
const range = document.createRange();
const selection = window.getSelection()!;
range.setStart(node, position);
range.collapse(true);
selection.removeAllRanges();
selection.addRange(range);
return -1;
} else {
position -= 'length' in node ? node.length as number : 0;
}
} else {
position = setCaretPosition(node, position);
if (position === -1) {
return -1;
}
}
}
return position;
}
export function removeAllSelections() {
const selection = window.getSelection();
selection?.removeAllRanges();
}