Android provides three clock widgets that you can use to implement a clock. They are android.widget.AnalogClock, android.widget.DigitalClock and android.widget.TextClock. The AnalogClock and DigitalClock class have been deprecated since Android SDK version 1.7, but they can still be used. TextClock class is recommended.

android.text.SpannableString is a character sequence type class. You can use it as a String object in android TextView. But SpannableString can make TextView content more colorful and diverse. This article will show you examples about how to use SpannableString with TextView.

android.widget.MultiAutoCompleteTextView class is used to implement multiple auto-complete input text control in android applications. It behaves similar to the class android.widget.AutoCompleteTextView, the difference is that it can let you input text with autocomplete function multiple times. Each text in the input text box is separated by a specified token string.

There are a lot of auto-complete scenarios in the android app. For example, when you use a search engine, you input some characters in the search box then a list of search keywords will pop up. It is not difficult to achieve. This example will show you how to do this use android.widget.AutoCompleteTextView component.

The android class android.graphics.Color provides some color constants which can be used directly in an android application. For example, BLACK, WHITE, RED, GREEN, BLUE, YELLOW, CYAN, MAGENTA, GRAY, LTGRAY (light gray), DKGRAY (dark gray). But you may find that it is not enough, sometimes you need more colors. So this article will show you how

android.view.View component acts like JPanel in Swing programming. It’s just a rectangular blank area, the android.view.View component doesn’t have any content. For built-in UI components of Android applications, they all inherit the class android.view.Viewand then render the appearance on the blank areas provided by the View component.