bond-wm/xutils.ts

An X Window Manager built on web technologies.

import { Atom, IXClient, XEventMask, XGetPropertyCallbackProps } from "@bond-wm/shared";
import { log, logError } from "./log";
import { ExtraAtoms } from "./wm";

export function internAtomAsync(X: IXClient, name: string): Promise<number> {
  return new Promise((resolve, reject) => {
    X.InternAtom(false, name, (err, atom) => {
      if (err) {
        reject(err);
      } else {
        resolve(atom);
      }
    });
  });
}

export async function getPropertyValue<TValue>(
  X: IXClient,
  wid: number,
  nameAtom: Atom,
  typeAtom: Atom
): Promise<TValue> {
  const prop = await getRawPropertyValue(X, wid, nameAtom, typeAtom);

  switch (prop.type) {
    case X.atoms.STRING:
      return prop.data.toString() as unknown as TValue;

    case ExtraAtoms.UTF8_STRING:
      return prop.data.toString() as unknown as TValue;

    case X.atoms.WINDOW:
      if (prop.data && prop.data.length >= 4) {
        return prop.data.readInt32LE(0) as unknown as TValue;
      }
      return undefined as unknown as TValue;

    default:
      log("Unhandled atom property type", prop);
      return undefined as unknown as TValue;
  }
}

export function getRawPropertyValue(
  X: IXClient,
  wid: number,
  nameAtom: Atom,
  typeAtom: Atom
): Promise<XGetPropertyCallbackProps> {
  return new Promise((resolve, reject) => {
    X.GetProperty(0, wid, nameAtom, typeAtom, 0, 10000000, function (err, prop) {
      if (err) {
        reject(err);
        return;
      }

      log("Got property value response", prop);
      resolve(prop);
    });
  });
}

export function changeWindowEventMask(X: IXClient, wid: number, eventMask: XEventMask): boolean {
  let failed;
  log("Changing event mask for", wid, eventMask);
  X.ChangeWindowAttributes(wid, { eventMask }, (err) => {
    if (err && err.error === 10) {
      logError(
        `Error while changing event mask for for ${wid} to ${eventMask}: Another window manager already running.`,
        err
      );
      failed = true;
      return;
    }
    logError(`Error while changing event mask for for ${wid} to ${eventMask}`, err);
    failed = true;
  });
  return !failed;
}

/**
 * Converts an array of numbers into a Buffer holding those numbers.
 * @param nums Numbers to put in the buffer (as 32 bit ints)
 * @returns Buffer filled with nums.
 */
export function numsToBuffer(nums: number[]): Buffer {
  const buffer = Buffer.alloc(nums.length * 4);
  for (let i = 0; i < nums.length; i++) {
    buffer.writeInt32LE(nums[i], i * 4);
  }
  return buffer;
}