 Hello everyone. Today, we are going to discuss on the topic Android user interface design. First, we will see learning outcome. At the end of the session, students will be able to describe different user interface components of Android screen. First about, we will talk user interface resources. A mobile user interface is the graphical and usually touch sensitive display on a mobile device. Such as a smartphone or tablet that allows the user to interact with the device app, features, content and functions. Here, Android provides a variety of pre-built user interface components such as structured layout objects and user interface controls. For example, dialogues, notifications and menus. As a developer, developer thinks two user interface approaches always while developing the mobile app. One is procedural and second is declarative. If he thinks about procedural, user has to write a Java code first. And if he thinks on declarative, then user has to write XML code which is similar to HTML of a web page. It is up to the user, user has to decide in which approach he has to adopt. So, user can also select two styles can be mixed in developing user interface approaches. One is start with XML and declare most of user interface. Second is switch to the Java and implement user interface logic. Next is user interface control. Here, we say user interface consists of a variety of objects called views. Every element of the screen is a view. Here the view class represents the basis building block for UI components. And user interface controls always contains a view which is represented as a class. And the base class for the classes which provide interactive user interface components such as buttons, checkboxes, text, spinner and text entry fields. A view has a location expressed as a pair of left and top coordinates. And two dimensions expressed as a width and height. The unit for location and dimensions is the density independent pixel that is called as a dipping. When user has to think text view, so text view is used for displaying a text. Edit text is used to enable the user to enter an edit text. Button and other clickable elements such as radio button, checkbox, spinner to provide interactive behavior. So user has to apply all these interface controls while developing apps. So from the user point of view, user interface controls are vital in developing the mobile app. This is one of the user interface control which contains two text boxes, then two radio buttons, three checkboxes and two buttons. So this is all user interface controls will place on one view. Just we talked about a view. Then we go for menu and toast. Android menu is a user interface component used in many types of applications. To provide a familiar user experience, you should use the menu APIs for user actions. In Android applications, menu is an important user interface entity which provides action options for Android applications. Here we see the types of menus. First one is option menu, primary collections of menu items for an activity. Second context menu, floating menu that appears when the user performs a lock leak on an element. Pop-up menu displays a list of items in a vertical list that invoked the menu. And the toast provides some simple feedback about an operation in a small pop-up. This is the diagram of option menu. Here option menu is a collection of menu items required for an activity. This is where you place actions having the global impact like search, compose, mail and settings. In the diagram, they have shown all the menus which is a user is going to select options from the options menu. The second diagram is context menu. Here the context menu uses contextual action mode. It is a system implementation of action mode class to enable actions on selected contents. This mode displays action items that affect the selected content in a bar. The user has to use context menu in the application where user is required to develop a mobile app. Third example using pop-up menu in Android. So there are three diagrams. In the first diagram, user has to create a button called as a show pop-up. When the user clicks on the show pop-up, all the menu items will be displayed from the pop-up menu. That is shown in the second diagram, middle diagram. So 1, 2 and 3 options are there, menu items. And in the third diagram, when user clicks on any menu item in the pop-up menu, so that toast will be displayed at the bottom of the mobile screen that is shown in the third diagram. So this is called as a pop-up menu in the Android. Next we go for list view. List view is a view group that displays a list of scrollable items. Because list view is an important component in the form of developers developers always use the list view to display the various options for selection for a user. So that's why it is a view group which displays a list of scrollable items. Atoms in the list are automatically inserted into the list using an adapter. Adapter is a class in Android. With the help of adapter, we can grab all the menu items from the list view which is required for the developer. So adapter pools contain from a source such as an array or database query and converts each atom selection result into a view that is placed into the list. This is a simple example of list view which displays all the city names. When the user add all the options in the list with the help of adapter, so these options will appear in the list view like in this way. So user has to select one of the options from the list view and perform the action. When the user select a particular option, the toast message will appear on the mobile screen that is shown in the example of list view. Very important user interface control is a dialogue because user has to face different dialogues during the developing code and user has to decide which options user has to select. For this reason, dialogue box is a small window that prompts the user to make a decision or enter additional information. A dialogue does not fill the screen and is normally used for a model event that requires users to take an action before they can proceed. A small window that prompts the user to make a decision or enter additional information. Normally used for model events that require users to take an action before they can proceed. This is one of the dialogue box which shows the android alert message which has a two button OK and cancel. So user has to take a decision either he has to press OK or cancel depends on the user's decision. So this is one of the examples of android alert dialogue box. Second dialogue box is alert dialogue box. This is shown as again a second example which shows the title and user has to press yes or no depends on the user's decision. After all these discussions pause the video for a while and answer the question. The question is dialogue loss in android are dash dash dash dash. First answer alert dialogue. Second answer progress dialogue. Third answer red picker dialogue. Fourth answer time picker dialogue. These are all the data classes which are used in android for mobile app development. These are the references for this topic. Thank you.