Custom ExpectedConditions

WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));

// Wait until an element's attribute has a specific value
wait.until(driver -> {
    WebElement el = driver.findElement(By.id("progress-bar"));
    String width = el.getCssValue("width");
    return width.equals("100%");
});

// Wait until dropdown options are loaded
wait.until(driver -> {
    List<WebElement> options = driver.findElements(
        By.cssSelector("#country-select option"));
    return options.size() > 1; // More than just "Select..."
});

import org.openqa.selenium.support.ui.ExpectedCondition;
import org.openqa.selenium.JavascriptExecutor;

public class CustomConditions {

    public static ExpectedCondition<Boolean> attributeToBe(
            By locator, String attribute, String value) {
        return driver -> {
            try {
                String actual = driver.findElement(locator)
                    .getAttribute(attribute);
                return value.equals(actual);
            } catch (Exception e) {
                return false;
            }
        };
    }

    public static ExpectedCondition<Boolean> pageLoadComplete() {
        return driver -> {
            JavascriptExecutor js = (JavascriptExecutor) driver;
            return js.executeScript("return document.readyState")
                      .equals("complete");
        };
    }
}

// Usage:
wait.until(CustomConditions.attributeToBe(
    By.id("status"), "class", "completed"));
wait.until(CustomConditions.pageLoadComplete());