This Node.js module exports a moveMouse function that moves the mouse cursor to a specified position (x, y) by interacting with a dynamic library file. The module determines the platform-specific path to the dynamic library file and loads a SetMousePosition function from it, which is then called with the provided coordinates.

Cell 2

const {
  equal
} = require('assert')
const {
  load,
  DataType,
  open,
  close,
  arrayConstructor,
  define
} = require('ffi-rs')
const path = require('path')
const {platform} = require('os')

const dynamicLib = platform === 'win32' ? '../mouse.dll' : (platform === 'linux' ? '../mouse.so' : '../mouse.dylib')

function moveMouse(x, y) {
  open({
    library: 'mouse', // key
    path: path.join(__dirname, dynamicLib) // path
  })
  load({
    library: "mouse", // path to the dynamic library file
    funcName: 'SetMousePosition', // the name of the function to call
    retType: DataType.Void, // the return value type
    paramsType: [DataType.Float, DataType.Float], // the parameter types
    paramsValue: [x || 0, y || 0] // the actual parameter values
    // freeResultMemory: true, // whether or not need to free the result of return value memory automatically, default is false
  })
  close('mouse')
}

module.exports = moveMouse

/**
 * Moves the mouse cursor to the specified coordinates.
 * 
 * @param {number} x The x-coordinate of the cursor.
 * @param {number} y The y-coordinate of the cursor.
 */
module.exports = moveMouse;

const { platform } = require('os');
const { join } = require('path');

// Define the path to the dynamic library based on the platform
const dynamicLib = {
  win32: join(__dirname, '../mouse.dll'),
  linux: join(__dirname, '../mouse.so'),
  darwin: join(__dirname, '../mouse.dylib')
}[platform];

// Load the dynamic library and function
const ffi = require('ffi-rs');
const lib = ffi.Library('mouse', {
  SetMousePosition: ['void', ['float', 'float']]
});

/**
 * Closes the dynamic library.
 */
function closeLibrary() {
  ffi.close('mouse');
}

/**
 * The main moveMouse function.
 * 
 * @param {number} x The x-coordinate of the cursor.
 * @param {number} y The y-coordinate of the cursor.
 */
function moveMouse(x, y) {
  try {
    // Load the function
    lib.SetMousePosition(x || 0, y || 0);
  } catch (error) {
    console.error('Error moving mouse:', error);
  } finally {
    closeLibrary();
  }
}

Code Breakdown

This is a Node.js module that exports a function moveMouse to move the mouse cursor to a specified position (x, y).

Requires and Imports

• assert: Required for the equal function, but not used in the provided code.
• ffi-rs: A Rust FOREIGN FUNCTION INTERFACE (FFI) library for Node.js.
• path: A Node.js module for working with file paths.
• os: A Node.js module for platform-specific information.

Dynamic Library Path

The code determines the platform-specific path to a dynamic library file mouse.dll, mouse.so, or mouse.dylib, depending on the platform.

moveMouse Function

The moveMouse function takes x and y coordinates as arguments and performs the following actions:

1. Opens a connection to the dynamic library file mouse using open.
2. Loads a function SetMousePosition from the library using load.
3. Calls the SetMousePosition function with the provided x and y coordinates.
4. Closes the connection to the library using close.

Function Parameters

The function SetMousePosition is expected to have the following parameters:

• x: A floating-point number.
• y: A floating-point number.

Return Type

The SetMousePosition function is expected to return a Void type, indicating that it does not return any value.

Module Exports

The moveMouse function is exported as a module, making it available for use in other Node.js files.