Android Studio has some great tooling support for previewing layouts, but sometimes we need to provide it with some extra help to really make good use of it.
If we take a look at the preview it generates for fragment_job_list.xml right now, we'll see that it only displays our RecyclerView as a couple simple lines of text.
We can provide the information about which layout we'll use in our rows by adding the tools:listitem attribute to the RecyclerView, like this:
<android.support.v7.widget.RecyclerView
android:id="@+id/jobListings"
android:layout_width="0dp"
android:layout_height="0dp"
android:orientation="vertical"
app:layoutManager="android.support.v7.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="@layout/row_job_listing" />
This is much better, but we can do even more by editing the row_job_listing.xml layout as well. In there, we can use built-in sample data to populate avatars as well as locations in our rows (only in the layout previews, not at runtime!).
To our ImageView, we can add the following attribute:
tools:src="@tools:sample/avatars"And to the TextView displaying location information (locationText), this one:
tools:text="@tools:sample/cities"There are a number of sample data sets available, which you can find quite easily by just browsing them in code completion while adding the attributes above. We can find names, zip codes, lorem ipsum text, and more.
What we can't find, however, are good job titles. We'll have to provide these ourselves, and the tooling thankfully lets us do this as well.
Let's right click on the app module in the Project view, and choose New -> Sample Data Directory. This will create a directory called sampledata within app. Create a file within this directory called jobtitles. In each line of the file, add a job title, for example:
Junior Mobile Developer
Senior Spring Developer
We can use this the same way as the sample data from before, the only difference being one less tools: prefix. Set the following attribute on the TextView with the ID titleText:
tools:text="@sample/jobtitles"You should now have this preview for your list screen, populated with all this great looking sample data:
