selenium webdriver: upload file by drag and drop

To perform an HTML5 file drop with Selenium:

static final String JS_DROP_FILE =
    "var tgt=arguments[0],e=document.createElement('input');e.type='" +
    "file';e.addEventListener('change',function(event){var dataTrans" +
    "fer={dropEffect:'',effectAllowed:'all',files:e.files,items:{},t" +
    "ypes:[],setData:function(format,data){},getData:function(format" +
    "){}};var emit=function(event,target){var evt=document.createEve" +
    "nt('Event');evt.initEvent(event,true,false);evt.dataTransfer=da" +
    "taTransfer;target.dispatchEvent(evt);};emit('dragenter',tgt);em" +
    "it('dragover',tgt);emit('drop',tgt);document.body.removeChild(e" +
    ");},false);document.body.appendChild(e);return e;";

WebDriver driver = new FirefoxDriver();
driver.get("http://html5demos.com/file-api");

WebElement drop_area = driver.findElement(By.id("holder"));

JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript(JS_DROP_FILE, new Object[] {
        drop_area
    }).sendKeys("C:\\image.png");

AutoIt has the DLL wrapper. I use it directly from C#/Selenium code.

Drop file using jsExecutor

public void dropFile(File filePath, WebElement target) {
    if (!filePath.exists())
        throw new WebDriverException("File not found: " + filePath.toString());

    JavascriptExecutor jse = (JavascriptExecutor) getDriver();

    String JS_DROP_FILE =
        "var target = arguments[0]," +
        "    offsetX = arguments[1]," +
        "    offsetY = arguments[2]," +
        "    document = target.ownerDocument || document," +
        "    window = document.defaultView || window;" +
        "" +
        "var input = document.createElement('INPUT');" +
        "input.type = 'file';" +
        "input.style.display = 'none';" +
        "input.onchange = function () {" +
        "  var rect = target.getBoundingClientRect()," +
        "      x = rect.left + (offsetX || (rect.width >> 1))," +
        "      y = rect.top + (offsetY || (rect.height >> 1))," +
        "      dataTransfer = { files: this.files };" +
        "" +
        "  ['dragenter', 'dragover', 'drop'].forEach(function (name) {" +
        "    var evt = document.createEvent('MouseEvent');" +
        "    evt.initMouseEvent(name, !0, !0, window, 0, 0, 0, x, y, !1, !1, !1, !1, 0, null);" +
        "    evt.dataTransfer = dataTransfer;" +
        "    target.dispatchEvent(evt);" +
        "  });" +
        "" +
        "  setTimeout(function () { document.body.removeChild(input); }, 25);" +
        "};" +
        "document.body.appendChild(input);" +
        "return input;";

    WebElement input = (WebElement) jse.executeScript(JS_DROP_FILE, target, 0, 0);
    input.sendKeys(filePath.getAbsoluteFile().toString());
    waitFor(ExpectedConditions.stalenessOf(input));
}

Use AWT Robot class for performing drag and drop:

Robot robot=new Robot();
// drag
robot.mouseMove(x1, y1);
robot.mousePress(InputEvent.BUTTON1_MASK);
// drop
robot.mouseMove(x2, y2);
robot.mouseRelease(InputEvent.BUTTON1_MASK);