Glide and Image Display Codelab

Question 1

What four things does Glide do with an image?

What two things does Glide need?

Answer 1

Glide is used to

• download
• buffer
• decode
• cache images.

Glide needs

• the url of the image
• an ImageView to display the image

Question 2

What is the implementation for the Glide dependency?

Answer 2

implementation “com.github.bumptech.glide:glide:$version_glide”

Question 3

Define a function that loads an image from its url to an ImageView

Answer 3

fun bindImage(imgView: ImageView, imgUrl: String?) {
imgUrl?.let {
val imgUri = imgUrl.toUri().buildUpon().scheme(“https”).build()
Glide.with(imgView.context)
.load(imgUri)
.apply(RequestOptions()
.placeholder(R.drawable.loading_animation)
.error(R.drawable.ic_broken_image)
)
.into(imgView)
}
}

Question 4

What is the codelabs strategy for handling loading / error states on the UI?

Answer 4

1. Create an enum for LOADING, ERROR, DONE
2. Use a LiveData to track the status
3. Update the network calls in the ViewModel to set the LiveData when the status changes
4. Create a binding adapter that changes an ImageView based on the status
5. Add an ImageView that can be substituted in for the RecyclerView when in LOADING / ERROR state.

Question 5

In addition to ^variable^, what needs to go in the data element of a layout xml in order to perform logic using another class (e.g. set a view to View.VISIBLE or View.GONE)?

How do you then define the View’s visibility value in the xml?

Answer 5

^data^
^variable
name=”property”
type=”com.example.android.marsrealestate.network.MarsProperty” /^
^import type=”android.view.View” /^
^/data^

android:visibility=”@{property.rental ? View.GONE : View.VISIBLE}”

Question 6

How can you display one ImageView over the top of another?

Answer 6

Wrap both in a FrameLayout.

The topmost ImageView in code will appear as the bottommost layer.

Question 7

What parameter can be passed to a CRUD function calling an endpoint that applies “?filter=value”?

Answer 7

@Query(“filter”) type:String

type can be an enum value based on available endpoint filters