Different Layout Types

# [CSE 340](/courses/cse340/23wi/schedule.html) Lab 2 Winter 23
## Week 2: Finishing Doodle, Introducing Layout

.title-slide-logo[
![:img Android phone showing a linear layout of TODOs on a calendar, 15%, width](img/android-linear.png)
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# FrameLayout
- FrameLayout is designed to block out an area on the screen to display a single item.
- Can add multiple children to a FrameLayout and control their position by assigning gravity to each child (android:layout_gravity attribute)
- Child views are drawn in a stack, with the most recently added child on top

![:img Challenge for buttons in XML, 20%, width](img/framelayout_1.png)
![:img Challenge with buttons to be added programatically, 10%, width](img/framelayout_2.png)

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# LinearLayout
- LinearLayout organizes its children into a single horizontal or vertical row.
- Wrap it in a `ScrollView` to create a scrollbar if the length of the window exceeds the length of the screen.

![:img Linear layout of an email message with to line subject line and message arranged vertically, 15%, width](img/linearlayout.png)
![:img Horizontal Linear Layout where the screen shows several bars stacked in a horizontal line, 15%, width](img/horizontal_linlayout.png)
![:img Vertical Linear Layout where the screen shows several bars stacked on top of each other vertically, 15%, width](img/vert_linlayout.png)

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# RelativeLayout
- Enables you to specify the location of child objects relative to each other (child A to the left of child B) or to the parent (aligned to the top of the parent).

![:img Challenge for buttons in XML, 15%, width](img/relativelayout_1.png)
![:img Challenge with buttons to be added programatically, 17%, width](img/relativelayout_2.png)

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# TableLayout
- Added in API 1
- TableLayout arranges its children into rows and columns
  - Can leave the cells empty
- Found in the Accessibility assignment base code

![:img Challenge for buttons in XML, 35%, width](img/tablelayout_1.png)
![:img Challenge with buttons to be added programatically, 20%, width](img/tablelayout_2.png)

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# GridLayout
- Places its children in a rectangular grid
- Must define the number of rows and columns first, then populate with Views
- Why choose this over TableLayout?
  - Easy to arrange lots of data because you don’t need to specify each View’s width and height
  - [Preferable](https://android-developers.googleblog.com/2011/11/new-layout-widgets-space-and-gridlayout.html) to TableLayout (GridLayout added API 14)

![:img Challenge for buttons in XML, 10%, width](img/gridlayout_1.png)
![:img Challenge with buttons to be added programatically, 30%, width](img/gridlayout_2.png)

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# Constraint Layout
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![:img A simple layout on an android watch with a textview and two
buttons (save and discard) and the constraints highlighted,150%,width](img/constraint-editor.png)
]
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- ViewGroup that allows you to position widgets in a flexible way
- Useful for building responsive interfaces in Android.
- You can see little lines connecting the `textView` to its container and it's sibling (the `linearLayout`).
  - This specifies how it's attached (can change type by clicking on right)
  - If you were to change the interface (e.g. a different sized screen), it would stay attached and keep filling the space
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