Entering text in pop up and saving it on TestNG - selenium

Question

I'm new to automation testing. I'm using twitter as a test website to learn selenium.
I want to create a new tweet and for doing that I'm using the below scenario. I'm able to open the 'New tweet' pop-up but still can't enter text in its text box. Please help.
Pre-Requisite: Login into Twitter
Click on the button (for creating new tweet) on top right side of screen.
The pop up opens up
Click on the text box present on pop-up to enter text.
The cursor gets highlighted in text box and save button enables
Enter some text
Click on Save button
For me it's working till point 2 and after that it doesn't enter text in textbox
See my code below:
String popUpHandle = driver.getWindowHandle();
driver.switchTo().window(popUpHandle);
driver.findElement(By.id("global-new-tweet-button")).click();
driver.findElement(By.xpath("(//button[#type='button'])[123]")).click();
driver.findElement(By.xpath("(//button[#type='button'])[123]")).sendKeys("test tweet");
driver.findElement(By.xpath("//button[#type='button'])[106]")).click();

Answer 1

#user3241182
I just tested this myself. You do not need to use any window handling.
Code Below is a provided solution and works great.
WebDriver driver = new FirefoxDriver();
driver.get("https://twitter.com/");
WebElement username = driver.findElement(By.id("signin-email"));
username.clear();
username.sendKeys("your_twitter_handle");
WebElement pass = driver.findElement(By.id("signin-password"));
pass.clear();
pass.sendKeys("your_twitter_passwd");
WebElement signInButton = driver.findElement(By.xpath("/html/body/div/div[2]/div/div[2]/div[2]/div[2]/form/table/tbody/tr/td[2]/button"));
signInButton.click();
WebElement tweetButton = driver.findElement(By.id("global-new-tweet-button"));
tweetButton.click();
WebElement tweetBox = driver.findElement(By.id("tweet-box-global"));
tweetBox.clear();
tweetBox.sendKeys("This is an automated tweet!");
WebElement tweetSubmit = driver.findElement(By.xpath("/html/body/div[9]/div[2]/div[2]/div[2]/form/div[2]/div[2]/button"));
tweetSubmit.click();