Laying Out Controls in Android Containers
This chapter is from the book
This chapter is from the book
This chapter is from the book
A container is a view used to contain other views. Android offers a collection of view classes that act as containers for views. These container classes are called layouts, and as the name suggests, they decide the organization, size, and position of their children views.
Let’s start the chapter with an introduction to different layouts used in Android applications.
Introduction to Layouts
Layouts are basically containers for other items known as Views, which are displayed on the screen. Layouts help manage and arrange views as well. Layouts are defined in the form of XML files that cannot be changed by our code during runtime.
Table 3.1 shows the layout managers provided by the Android SDK.
Table 3.1. Android Layout Managers
|
Layout Manager |
Description |
|
LinearLayout |
Organizes its children either horizontally or vertically |
|
RelativeLayout |
Organizes its children relative to one another or to the parent |
|
AbsoluteLayout |
Each child control is given a specific location within the bounds of the container |
|
FrameLayout |
Displays a single view; that is, the next view replaces the previous view and hence is used to dynamically change the children in the layout |
|
TableLayout |
Organizes its children in tabular form |
|
GridLayout |
Organizes its children in grid format |
The containers or layouts listed in Table 3.1 are also known as ViewGroups as one or more Views are grouped and arranged in a desired manner through them. Besides the ViewGroups shown here Android supports one more ViewGroup known as ScrollView, which is discussed in Chapter 4, “Utilizing Resources and Media.”