User Interface and Navigation for ANDROID 

Tooltip

A tooltip is a small descriptive message that appears near a view when users long press the view or hover their mouse over it. This is useful when your app uses an icon to represent an action or piece of information to save space in the layout. This page shows you how to add these tooltips on Android 8.0 (API level 26) and higher.

Toast

A toast provides simple feedback about an operation in a small popup. It only fills the amount of space required for the message and the current activity remains visible and interactive. Toasts automatically disappear after a timeout.

Toasts are not clickable. If user response to a status message is required, consider instead using a Notification.

The app bar

The app bar, also known as the action bar, is one of the most important design elements in your app's activities, because it provides a visual structure and interactive elements that are familiar to users. Using the app bar makes your app consistent with other Android apps, allowing users to quickly understand how to operate your app and have a great experience. The key functions of the app bar are as follows:

A dedicated space for giving your app an identity and indicating the user's location in the app. Access to important actions in a predictable way, such as search. Support for navigation and view switching (with tabs or drop-down lists).

Floating Action Button

A floating action button (FAB) is a circular button that triggers the primary action in your app's UI. 

Search Dialog vs Search Widget 

Before you begin, you should decide whether you'll implement your search interface using the search dialog or the search widget. Both provide the same search features, but in slightly different ways:

• The search dialog is a UI component that's controlled by the Android system. When activated by the user, the search dialog appears at the top of the activity, as shown in figure 1.
  The Android system controls all events in the search dialog. When the user submits a query, the system delivers the query to the activity that you specify to handle searches. The dialog can also provide search suggestions while the user types.

• The search widget is an instance of SearchView that you can place anywhere in your layout. By default, the search widget behaves like a standard EditText widget and doesn't do anything, but you can configure it so that the Android system handles all input events, delivers queries to the appropriate activity, and provides search suggestions (just like the search dialog).

Hide the status bar

This lesson describes how to hide the status bar on different versions of Android. Hiding the status bar (and optionally, the navigation bar) lets the content use more of the display space, thereby providing a more immersive user experience.

Figure 1 shows an app with a visible status bar:

Figure 1. Visible status bar.

Figure 2 shows an app with a hidden status bar. Note that the action bar is hidden too. You should never show the action bar without the status bar.

Figure 2. Hidden status bar.

Hamburger

The hamburger menu is a navigation element you can find on websites, apps, and programs. Its delicious name comes from its design: it’s comprised of three horizontal lines resembling