Recycler-Core
Recycler-Core provides a clean MVC framework for managing your RecyclerView Adapters.
Motivation
Blindly dealing with multiple view types in a RecyclerView.Adapter can frequently lead to unmaintainable source code. The standard pattern of managing multiple views also does not promote reusability between multiple adapters.
Recycler-Core attempts to solve the maintainability and reusability problems that are ran into when dealing with multiple views in a RecyclerView.Adapter by creating an MVC pattern for RecyclerViews.
Download
Configure the project-level build.gradle to include the 'android-apt' plugin
buildscript {
repositories {
jcenter()
}
dependencies {
...
classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
}
}
Then, apply the 'android-apt' plugin in the module-level build.gradle and add the Recycler-Core dependencies:
Gradle:
apply plugin: 'com.neenbedankt.android-apt' android {
...
}
dependencies {
compile 'com.carrotcreative.recyclercore:recycler-core:2.0-alpha'
apt 'com.carrotcreative.recyclercore:recyclercore-compiler:2.0-alpha'
}
Usage
The View
To create a View Type for your RecyclerView, you're going to have to build out a component for the Model, View, and Controller.
In this example, we will build out an element that will display basic information about a user.
The View is a standard Layout XML file with nothing special about it.
element_user.xml:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="32dp"
>
<TextView
android:id="@+id/name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
/>
<TextView
android:id="@+id/email"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
/> </LinearLayout>The Model
Next I create the model.
The model is a standard POJO class, which is responsible for storing all of the data that defines our views.
When defining the model, we need to declare a class level annotation InjectController and pass in the controller and the layout.
UserModel.java:
// ... @RCModel(controller = UserController.class) public class UserModel {
public String mName;
public String mEmail;
// ... Setters + Getters
}
The Controller
Now we create the controller.
This class must extend RecyclerCoreController with the generic of the model that was just created.
The magic happens in the bind method, where this object will be passed an instance of the model.
UserController.java:
// ... @RCController(layout = R.layout.element_user_list) public class UserController extends RecyclerCoreController<UserModel> {
private TextView mName;
private TextView mEmail;
public UserController(View itemView, Activity activity)
{
super(itemView, activity);
mName = (TextView) itemView.findViewById(R.id.name);
mEmail = (TextView) itemView.findViewById(R.id.email);
}
@Override
public void bind(UserModel model)
{
mName.setText(model.getName());
mEmail.setText(model.getEmail());
}
}
In use
MainActivity.java:
// ... ArrayList<RecyclerCoreModel> models = new ArrayList<>();
UserModel brandon = new UserModel()
.setEmail("[email protected]")
.setName("Brandon");
models.add(brandon);
UserModel rob = new UserModel()
.setEmail("[email protected]")
.setName("Rob");
models.add(rob);
RecyclerCoreAdapter adapter = new RecyclerCoreAdapter(models);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setAdapter(adapter);
And now you have:
Extras
ProgressRecyclerViewLayout
RecyclerCore also provides a custom view called ProgressRecyclerViewLayout. This is just a RecyclerView with a ProgressBar inside of a RelativeLayout and it manages displaying the ProgressBar when the adapter is set.
I pretty much never use RecyclerViews that aren't encapsulated inside this pattern so I decided to include it in this library.
SwipeRefreshProgressRecyclerView
We also have a SwipeRefreshProgressRecyclerView that is same as SwipeRefreshLayout with ProgressRecyclerViewLayout as a child. So it encapsulates the features or SwipeRefreshLayout, RecyclerView in one View.
OnLoadPointListener
ProgressRecyclerViewLayout also provides us interfaces that can allow us to add unlimited scroll.
/**
* An interface to add a callback that gets called when the load point is reached.
* For the load point callback to work, we need to set
* {
@link #setDistanceFromBottomToLoadMore(int)
}
and the
* {
@link #setOnLoadPointListener(OnLoadPointListener)
}
* <p>
* This currently only supports {
@link android.support.v7.widget.LinearLayoutManager
}
,
* {
@link android.support.v7.widget.StaggeredGridLayoutManager
}
,
* {
@link android.support.v7.widget.GridLayoutManager
}
*/
public interface OnLoadPointListener
{
void onReachedLoadPoint();
}
In order to get that working, we need to set distanceFromBottomToLoadMore attribute value, which can be set either in the Layout or programmatically.
<com.carrotcreative.recyclercore.widget.ProgressRecyclerViewLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/recycler_view_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:distanceFromBottomToLoadMore="0"
/> OR
/**
* Helper method to set the distance from bottom value programmatically, if its not set in
* the layout file.
* <p>
* A value of 0, means the #onReachedLoadPoint is called when the last child starts becoming
* visible.
* <p>
* A value of 1 means the #onReachedLoadPoint is called when the secnd last child starts
* becoming visible
* <p>
* A Negative value is considered and invalid value
*
* @param distanceFromBottomToLoadMore The no of item from the bottom of the recycler view,
*
after which #OnLoadPointListener is called
*/
public void setDistanceFromBottomToLoadMore(int distanceFromBottomToLoadMore) Once this is done, we need to set a listener that will be called when the recycler view reached the load point
mRecyclerViewLayout.setOnLoadPointListener(new ProgressRecyclerViewLayout
.OnLoadPointListener()
{
@Override
public void onReachedLoadPoint()
{
loadMoreData();
}
}
);