gitea/web_src/js/features/comp/EditorMarkdown.ts

198 lines
7.3 KiB
TypeScript

export const EventEditorContentChanged = 'ce-editor-content-changed';
export function triggerEditorContentChanged(target) {
target.dispatchEvent(new CustomEvent(EventEditorContentChanged, {bubbles: true}));
}
export function textareaInsertText(textarea, value) {
const startPos = textarea.selectionStart;
const endPos = textarea.selectionEnd;
textarea.value = textarea.value.substring(0, startPos) + value + textarea.value.substring(endPos);
textarea.selectionStart = startPos;
textarea.selectionEnd = startPos + value.length;
textarea.focus();
triggerEditorContentChanged(textarea);
}
type TextareaValueSelection = {
value: string;
selStart: number;
selEnd: number;
}
function handleIndentSelection(textarea: HTMLTextAreaElement, e) {
const selStart = textarea.selectionStart;
const selEnd = textarea.selectionEnd;
if (selEnd === selStart) return; // do not process when no selection
e.preventDefault();
const lines = textarea.value.split('\n');
const selectedLines = [];
let pos = 0;
for (let i = 0; i < lines.length; i++) {
if (pos > selEnd) break;
if (pos >= selStart) selectedLines.push(i);
pos += lines[i].length + 1;
}
for (const i of selectedLines) {
if (e.shiftKey) {
lines[i] = lines[i].replace(/^(\t| {1,2})/, '');
} else {
lines[i] = ` ${lines[i]}`;
}
}
// re-calculating the selection range
let newSelStart, newSelEnd;
pos = 0;
for (let i = 0; i < lines.length; i++) {
if (i === selectedLines[0]) {
newSelStart = pos;
}
if (i === selectedLines[selectedLines.length - 1]) {
newSelEnd = pos + lines[i].length;
break;
}
pos += lines[i].length + 1;
}
textarea.value = lines.join('\n');
textarea.setSelectionRange(newSelStart, newSelEnd);
triggerEditorContentChanged(textarea);
}
type MarkdownHandleIndentionResult = {
handled: boolean;
valueSelection?: TextareaValueSelection;
}
type TextLinesBuffer = {
lines: string[];
lengthBeforePosLine: number;
posLineIndex: number;
inlinePos: number
}
export function textareaSplitLines(value: string, pos: number): TextLinesBuffer {
const lines = value.split('\n');
let lengthBeforePosLine = 0, inlinePos = 0, posLineIndex = 0;
for (; posLineIndex < lines.length; posLineIndex++) {
const lineLength = lines[posLineIndex].length + 1;
if (lengthBeforePosLine + lineLength > pos) {
inlinePos = pos - lengthBeforePosLine;
break;
}
lengthBeforePosLine += lineLength;
}
return {lines, lengthBeforePosLine, posLineIndex, inlinePos};
}
function markdownReformatListNumbers(linesBuf: TextLinesBuffer, indention: string) {
const reDeeperIndention = new RegExp(`^${indention}\\s+`);
const reSameLevel = new RegExp(`^${indention}([0-9]+)\\.`);
let firstLineIdx: number;
for (firstLineIdx = linesBuf.posLineIndex - 1; firstLineIdx >= 0; firstLineIdx--) {
const line = linesBuf.lines[firstLineIdx];
if (!reDeeperIndention.test(line) && !reSameLevel.test(line)) break;
}
firstLineIdx++;
let num = 1;
for (let i = firstLineIdx; i < linesBuf.lines.length; i++) {
const oldLine = linesBuf.lines[i];
const sameLevel = reSameLevel.test(oldLine);
if (!sameLevel && !reDeeperIndention.test(oldLine)) break;
if (sameLevel) {
const newLine = `${indention}${num}.${oldLine.replace(reSameLevel, '')}`;
linesBuf.lines[i] = newLine;
num++;
if (linesBuf.posLineIndex === i) {
// need to correct the cursor inline position if the line length changes
linesBuf.inlinePos += newLine.length - oldLine.length;
linesBuf.inlinePos = Math.max(0, linesBuf.inlinePos);
linesBuf.inlinePos = Math.min(newLine.length, linesBuf.inlinePos);
}
}
}
recalculateLengthBeforeLine(linesBuf);
}
function recalculateLengthBeforeLine(linesBuf: TextLinesBuffer) {
linesBuf.lengthBeforePosLine = 0;
for (let i = 0; i < linesBuf.posLineIndex; i++) {
linesBuf.lengthBeforePosLine += linesBuf.lines[i].length + 1;
}
}
export function markdownHandleIndention(tvs: TextareaValueSelection): MarkdownHandleIndentionResult {
const unhandled: MarkdownHandleIndentionResult = {handled: false};
if (tvs.selEnd !== tvs.selStart) return unhandled; // do not process when there is a selection
const linesBuf = textareaSplitLines(tvs.value, tvs.selStart);
const line = linesBuf.lines[linesBuf.posLineIndex] ?? '';
if (!line) return unhandled; // if the line is empty, do nothing, let the browser handle it
// parse the indention
let lineContent = line;
const indention = /^\s*/.exec(lineContent)[0];
lineContent = lineContent.slice(indention.length);
if (linesBuf.inlinePos <= indention.length) return unhandled; // if cursor is at the indention, do nothing, let the browser handle it
// parse the prefixes: "1. ", "- ", "* ", there could also be " [ ] " or " [x] " for task lists
// there must be a space after the prefix because none of "1.foo" / "-foo" is a list item
const prefixMatch = /^([0-9]+\.|[-*])(\s\[([ x])\])?\s/.exec(lineContent);
let prefix = '';
if (prefixMatch) {
prefix = prefixMatch[0];
if (prefix.length > linesBuf.inlinePos) prefix = ''; // do not add new line if cursor is at prefix
}
lineContent = lineContent.slice(prefix.length);
if (!indention && !prefix) return unhandled; // if no indention and no prefix, do nothing, let the browser handle it
if (!lineContent) {
// clear current line if we only have i.e. '1. ' and the user presses enter again to finish creating a list
linesBuf.lines[linesBuf.posLineIndex] = '';
linesBuf.inlinePos = 0;
} else {
// start a new line with the same indention
let newPrefix = prefix;
if (/^\d+\./.test(prefix)) newPrefix = `1. ${newPrefix.slice(newPrefix.indexOf('.') + 2)}`;
newPrefix = newPrefix.replace('[x]', '[ ]');
const inlinePos = linesBuf.inlinePos;
linesBuf.lines[linesBuf.posLineIndex] = line.substring(0, inlinePos);
const newLineLeft = `${indention}${newPrefix}`;
const newLine = `${newLineLeft}${line.substring(inlinePos)}`;
linesBuf.lines.splice(linesBuf.posLineIndex + 1, 0, newLine);
linesBuf.posLineIndex++;
linesBuf.inlinePos = newLineLeft.length;
recalculateLengthBeforeLine(linesBuf);
}
markdownReformatListNumbers(linesBuf, indention);
const newPos = linesBuf.lengthBeforePosLine + linesBuf.inlinePos;
return {handled: true, valueSelection: {value: linesBuf.lines.join('\n'), selStart: newPos, selEnd: newPos}};
}
function handleNewline(textarea: HTMLTextAreaElement, e: Event) {
const ret = markdownHandleIndention({value: textarea.value, selStart: textarea.selectionStart, selEnd: textarea.selectionEnd});
if (!ret.handled) return;
e.preventDefault();
textarea.value = ret.valueSelection.value;
textarea.setSelectionRange(ret.valueSelection.selStart, ret.valueSelection.selEnd);
triggerEditorContentChanged(textarea);
}
export function initTextareaMarkdown(textarea) {
textarea.addEventListener('keydown', (e) => {
if (e.key === 'Tab' && !e.ctrlKey && !e.metaKey && !e.altKey) {
// use Tab/Shift-Tab to indent/unindent the selected lines
handleIndentSelection(textarea, e);
} else if (e.key === 'Enter' && !e.shiftKey && !e.ctrlKey && !e.metaKey && !e.altKey) {
// use Enter to insert a new line with the same indention and prefix
handleNewline(textarea, e);
}
});
}