Custom layouts in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom layout in Android development?

A custom layout is a user-defined ViewGroup that arranges child views in a specific way not provided by standard layouts like LinearLayout or RelativeLayout.

beginner

Which method must you override to define how child views are positioned in a custom layout?

You must override the onLayout method to specify the exact position and size of each child view within the custom layout.

intermediate

What is the purpose of the onMeasure method in a custom layout?

onMeasure calculates the size requirements for the layout and its children, ensuring the layout knows how much space it needs.

intermediate

Why is it important to call measureChild or measureChildWithMargins inside onMeasure?

These methods measure each child view with the correct size constraints, so the parent layout can properly calculate its own size and layout children correctly.

beginner

How does a custom layout improve app UI design?

It allows developers to create unique arrangements of views tailored to specific design needs, beyond what standard layouts offer.

Which method do you override to position child views in a custom Android layout?

A onCreate

B onDraw

C onLayout

D onStart

The onLayout method is where you set the position and size of each child view inside your custom layout.

What does the onMeasure method do in a custom layout?

A Calculates the size requirements of the layout and its children

B Draws the layout on screen

C Handles user input events

D Starts the activity

onMeasure calculates how big the layout and its children want to be.

Which method helps measure child views with margins inside onMeasure?

A measureChildWithMargins

B layoutChild

C drawChild

D requestLayout

measureChildWithMargins measures child views considering their margins.

What is the base class you extend to create a custom layout in Android?

A Fragment

B ViewGroup

C View

D Activity

Custom layouts extend ViewGroup because they contain and manage child views.

Why might you create a custom layout instead of using standard layouts?

A To change app permissions

B To handle network requests

C To improve battery life

D To create unique view arrangements not possible with standard layouts

Custom layouts allow unique arrangements of views tailored to your design needs.

Explain the roles of onMeasure and onLayout when creating a custom layout in Android.

Think about measuring first, then placing views.

Describe why and when you would create a custom layout instead of using built-in layouts.

Consider a real app design that standard layouts can't handle.