Element Interaction

/**
 * WebElement interface for HTML element interaction
 * Extends SearchContext for finding child elements and TakesScreenshot for element screenshots
 */
interface WebElement extends SearchContext, TakesScreenshot {
    /**
     * Click the element
     */
    void click();
    
    /**
     * Submit a form containing this element
     */
    void submit();
    
    /**
     * Type text into the element (usually input fields)
     * @param keysToSend - Text and special keys to send
     */
    void sendKeys(CharSequence... keysToSend);
    
    /**
     * Clear the content of the element (input fields and text areas)
     */
    void clear();
    
    /**
     * Get the HTML tag name of the element
     * @return Tag name in lowercase (e.g., "input", "div", "span")
     */
    String getTagName();
    
    /**
     * Get DOM attribute value
     * @param name - Attribute name
     * @return Attribute value or null if not present
     */
    String getDomAttribute(String name);
    
    /**
     * Get DOM property value
     * @param name - Property name  
     * @return Property value or null if not present
     */
    String getDomProperty(String name);
    
    /**
     * Get attribute value (legacy method, use getDomAttribute for new code)
     * @param name - Attribute name
     * @return Attribute value or null if not present
     */
    String getAttribute(String name);
    
    /**
     * Get ARIA role of the element
     * @return ARIA role or null if not present
     */
    String getAriaRole();
    
    /**
     * Get accessible name of the element
     * @return Accessible name or null if not present
     */
    String getAccessibleName();
    
    /**
     * Check if the element is selected (checkboxes, radio buttons, options)
     * @return true if selected, false otherwise
     */
    boolean isSelected();
    
    /**
     * Check if the element is enabled for interaction
     * @return true if enabled, false if disabled
     */
    boolean isEnabled();
    
    /**
     * Check if the element is visible on the page
     * @return true if displayed, false if hidden
     */
    boolean isDisplayed();
    
    /**
     * Get the visible text content of the element
     * @return Text content as seen by the user
     */
    String getText();
    
    /**
     * Get computed CSS property value
     * @param propertyName - CSS property name (e.g., "color", "font-size")
     * @return Computed CSS value
     */
    String getCssValue(String propertyName);
    
    /**
     * Get element position relative to top-left of page
     * @return Point with x,y coordinates
     */
    Point getLocation();
    
    /**
     * Get element dimensions
     * @return Dimension with width and height
     */
    Dimension getSize();
    
    /**
     * Get element position and dimensions combined  
     * @return Rectangle with position and size
     */
    Rectangle getRect();
}

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.By;
import org.openqa.selenium.Keys;
import org.openqa.selenium.chrome.ChromeDriver;

WebDriver driver = new ChromeDriver();

try {
    driver.get("https://example.com/form");
    
    // Find and interact with input elements
    WebElement usernameField = driver.findElement(By.id("username"));
    WebElement passwordField = driver.findElement(By.id("password"));
    WebElement submitButton = driver.findElement(By.xpath("//button[@type='submit']"));
    
    // Type into input fields
    usernameField.sendKeys("testuser");
    passwordField.sendKeys("password123");
    
    // Clear field and retype
    usernameField.clear();
    usernameField.sendKeys("newuser");
    
    // Use special keys
    usernameField.sendKeys(Keys.CONTROL, "a"); // Select all
    usernameField.sendKeys("replacedtext");
    
    // Check element properties
    System.out.println("Tag name: " + usernameField.getTagName()); // "input"
    System.out.println("Type attribute: " + usernameField.getDomAttribute("type")); // "text"
    System.out.println("Value property: " + usernameField.getDomProperty("value"));
    System.out.println("Placeholder: " + usernameField.getAttribute("placeholder"));
    
    // Check element state
    if (submitButton.isEnabled() && submitButton.isDisplayed()) {
        submitButton.click();
    }
    
    // Work with checkboxes and radio buttons
    WebElement checkbox = driver.findElement(By.id("terms"));
    if (!checkbox.isSelected()) {
        checkbox.click();
    }
    
    // Get element information
    Rectangle rect = usernameField.getRect();
    System.out.println("Element position: " + rect.getX() + "," + rect.getY());
    System.out.println("Element size: " + rect.getWidth() + "x" + rect.getHeight());
    
    // Get CSS properties
    String color = usernameField.getCssValue("color");
    String fontSize = usernameField.getCssValue("font-size");
    
    // Get accessible information
    String ariaRole = submitButton.getAriaRole();
    String accessibleName = submitButton.getAccessibleName();
    
} finally {
    driver.quit();
}

/**
 * SearchContext interface for element finding
 * Implemented by WebDriver (searches entire page) and WebElement (searches within element)
 */
interface SearchContext {
    /**
     * Find the first element matching the given locator
     * @param by - Element locator strategy
     * @return First matching WebElement
     * @throws NoSuchElementException if no element found
     */
    WebElement findElement(By by);
    
    /**  
     * Find all elements matching the given locator
     * @param by - Element locator strategy
     * @return List of matching WebElements (empty list if none found)
     */
    List<WebElement> findElements(By by);
}

// Find elements from driver (entire page)
WebElement form = driver.findElement(By.id("loginForm"));
List<WebElement> allInputs = driver.findElements(By.tagName("input"));

// Find child elements within a parent element
WebElement navigation = driver.findElement(By.className("navbar"));
List<WebElement> navLinks = navigation.findElements(By.tagName("a"));
WebElement homeLink = navigation.findElement(By.linkText("Home"));

// Chain element searches
WebElement table = driver.findElement(By.id("dataTable"));
WebElement firstRow = table.findElement(By.xpath(".//tr[1]"));
List<WebElement> cells = firstRow.findElements(By.tagName("td"));

/**
 * TakesScreenshot interface for capturing screenshots
 * Implemented by WebDriver (full page) and WebElement (element only)
 */
interface TakesScreenshot {
    /**
     * Capture screenshot in specified output format
     * @param target - Output format (BASE64, BYTES, or FILE)
     * @return Screenshot data in requested format
     */
    <X> X getScreenshotAs(OutputType<X> target);
}

import org.openqa.selenium.OutputType;
import org.openqa.selenium.TakesScreenshot;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

// Full page screenshot
TakesScreenshot screenshot = (TakesScreenshot) driver;
File fullPageFile = screenshot.getScreenshotAs(OutputType.FILE);
Files.copy(fullPageFile.toPath(), Paths.get("fullpage.png"));

// Element screenshot
WebElement loginForm = driver.findElement(By.id("loginForm"));
File elementFile = loginForm.getScreenshotAs(OutputType.FILE);
Files.copy(elementFile.toPath(), Paths.get("loginform.png"));

// Screenshot as base64 string (useful for embedding in reports)
String base64Screenshot = screenshot.getScreenshotAs(OutputType.BASE64);

// Screenshot as byte array
byte[] screenshotBytes = screenshot.getScreenshotAs(OutputType.BYTES);

WebElement element = driver.findElement(By.id("myElement"));

// Comprehensive element state check
public boolean isElementInteractable(WebElement element) {
    return element.isDisplayed() && element.isEnabled();
}

// Check if element has specific CSS class
public boolean hasClass(WebElement element, String className) {
    String classes = element.getAttribute("class");
    return classes != null && classes.contains(className);
}

// Get element text with fallback to value attribute
public String getElementText(WebElement element) {
    String text = element.getText();
    if (text.isEmpty()) {
        text = element.getAttribute("value");
    }
    return text;
}

// Check if input field is empty
public boolean isInputEmpty(WebElement input) {
    return input.getDomProperty("value").isEmpty();
}

// Wait for element to be clickable
WebElement button = driver.findElement(By.id("submitButton"));
WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));
wait.until(ExpectedConditions.elementToBeClickable(button));
button.click();

// Text input
WebElement textInput = driver.findElement(By.id("textField"));
textInput.clear();
textInput.sendKeys("New text value");

// Password input  
WebElement passwordInput = driver.findElement(By.id("password"));
passwordInput.sendKeys("secretpassword");

// Textarea
WebElement textarea = driver.findElement(By.tagName("textarea"));
textarea.clear();
textarea.sendKeys("Line 1\nLine 2\nLine 3");

// Checkbox
WebElement checkbox = driver.findElement(By.id("agreeTerms"));
if (!checkbox.isSelected()) {
    checkbox.click();
}

// Radio button
WebElement radioButton = driver.findElement(By.id("option1"));
radioButton.click();

// File upload
WebElement fileInput = driver.findElement(By.id("fileUpload"));
fileInput.sendKeys("/path/to/file.txt");

// Select dropdown (use Select class for better support)
WebElement selectElement = driver.findElement(By.id("country"));
Select select = new Select(selectElement);
select.selectByVisibleText("United States");
select.selectByValue("us");
select.selectByIndex(0);

/**
 * Color class for CSS color parsing and manipulation
 * Converts between different color representations
 */
class Color {
    /**
     * Create Color from CSS color string
     * @param cssColorString - CSS color value (hex, rgb, rgba, name, etc.)
     * @return Color instance
     */
    static Color fromString(String cssColorString);
    
    /**
     * Get color as hex string
     * @return Hex color string (e.g., "#ff0000")
     */
    String asHex();
    
    /**
     * Get color as RGB string
     * @return RGB color string (e.g., "rgba(255, 0, 0, 1)")
     */
    String asRgb();
    
    /**
     * Get color as RGBA string
     * @return RGBA color string with alpha channel
     */
    String asRgba();
    
    /**
     * Get red component (0-255)
     * @return Red value
     */
    short getRed();
    
    /**
     * Get green component (0-255)
     * @return Green value
     */
    short getGreen();
    
    /**
     * Get blue component (0-255)
     * @return Blue value
     */
    short getBlue();
    
    /**
     * Get alpha/opacity component (0.0-1.0)
     * @return Alpha value
     */
    float getAlpha();
}

import org.openqa.selenium.support.Color;

// Get element color and parse it
WebElement element = driver.findElement(By.id("colorful-element"));
String cssColor = element.getCssValue("color");
Color color = Color.fromString(cssColor);

// Convert between color formats
String hexColor = color.asHex();        // "#ff0000"
String rgbColor = color.asRgb();        // "rgb(255, 0, 0)"
String rgbaColor = color.asRgba();      // "rgba(255, 0, 0, 1)"

// Get individual color components
short red = color.getRed();      // 255
short green = color.getGreen();  // 0
short blue = color.getBlue();    // 0
float alpha = color.getAlpha();  // 1.0

// Parse different CSS color formats
Color hexColor1 = Color.fromString("#ff0000");
Color hexColor2 = Color.fromString("#f00");
Color rgbColor1 = Color.fromString("rgb(255, 0, 0)");
Color rgbaColor1 = Color.fromString("rgba(255, 0, 0, 0.5)");
Color namedColor = Color.fromString("red");

// Verify element colors in tests
WebElement errorMessage = driver.findElement(By.className("error"));
Color errorColor = Color.fromString(errorMessage.getCssValue("color"));
assert errorColor.asHex().equals("#ff0000"); // Verify red color