View Binding

Intro

A lightweight library aiming to speed up Android app development by leveraging the new Android Data Binding and taking the best from the Model-View-ViewModel design pattern.

Getting Started

For information on how to get started with View Binding, take a look at our Getting Started guide.

Submitting Bugs or Feature Requests

Bugs or feature requests should be submitted at our GitHub Issues section.

Why should I use it?

1. Data Binding Android Data Binding is great and if you're not, you should start using it today.
2. You don't need to care about screen rotation (configuration change) at all. Most of the screen lifecycle is moved to ViewModel where the lifecycle is dramatically easier to understand and to use. The ViewModel instance outlives it's Activity/Fragment during configuration change so no more hassle with onSaveInstanceState() or using retained Fragments.
3. ViewModel as the only variable in the layout ViewModel serves as the data provider in layout's binding as well as handler for click or other methods common fro Data Binding. With a construct like android:onClick="@{viewBinding.onClickedPlayButton}" you will never have to set an OnClickListener anymore. Also, each ViewModel extends BaseObservable so you have a choice between using BaseObservable approach or ObservableField approach within the DataBinding. (see Data Binding Guide)

How does it work?

The framework extensively uses Java Generics to provide a type-safe link between Activity/Fragment and ViewModel and its binding.

ViewModel instances are stored in a global static Map and reattached automatically to corresponding Activity/Fragment. When there is no need for the ViewModel anymore (Activity finished) the instance is destroyed.

1. Depend on our library

View Binding for Android is available through Google's Maven Repository. To use it:

1. Open the build.gradle file for your application.

2. Make sure that the repositories section includes Google's Maven Repository google(). For example:

     allprojects {
       repositories {
         google()
         jcenter()
       }
     }

3. Add the library to the dependencies section:

     dependencies {
       // ...
       implementation 'com.zeoflow:view-binding:<version>'
       // ...
     }

2. Activity/Fragment Class

MainActivity.java

public class MainActivity extends BindAppActivity<ActivityMainBinding, MainViewBinding>
{
    //..
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState)
    {
        //..
        setupViewBinding(R.layout.activity_main, MainViewBinding.class);
        //..
        super.onCreate(savedInstanceState);
        //..
        MainViewBinding mMainViewBinding = getViewBinding();
        //..
    }
    //..
}

3. Activity/Fragment Layout

activity_main.xml

<layout xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto">

	<data>

        <variable
            name="viewBinding"
            type="com.zeoflow.view.binding.sample.MainViewBinding" />
	</data>

	<LinearLayout
		android:layout_width="match_parent"
		android:layout_height="match_parent"
		android:padding="@dimen/activity_padding"
		android:orientation="vertical">

		<android.support.design.widget.TextInputLayout
			android:layout_width="match_parent"
			android:layout_height="wrap_content">

			<EditText
				android:layout_width="match_parent"
				android:layout_height="wrap_content"
				android:text="@={viewBinding.name}"
				android:inputType="textPersonName|textCapWords"
				android:hint="@string/hint_enter_your_name" />
		</android.support.design.widget.TextInputLayout>


		<FrameLayout
			android:layout_width="match_parent"
			android:layout_height="0dp"
			android:layout_weight="1"
			android:animateLayoutChanges="true">

			<TextView
				android:layout_width="wrap_content"
				android:layout_height="wrap_content"
				android:layout_gravity="center"
				android:textAppearance="@style/Base.TextAppearance.AppCompat.Headline"
				android:textColor="@color/colorPrimary"
				android:text="@{@string/hello(viewBinding.name)}"
				app:show="@{viewBinding.name != null &amp;&amp; !viewBinding.name.empty}"
				tools:text="@string/hello" />
		</FrameLayout>


		<Button
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_gravity="center"
			android:onClick="@{() -> viewBinding.showDialog()}"
			android:text="@string/button_dialog_fragment"
			style="@style/Widget.AppCompat.Button.Colored" />
	</LinearLayout>
</layout>

4. ViewModel

MainViewModel.java

public class MainViewBinding extends ViewBinding
{

	public final ObservableField<String> name = new ObservableField<>();

	@Override
	public void onViewModelCreated()
	{
		super.onViewModelCreated();
		// Do API calls etc.
	}

	@Override
	public void onViewAttached(boolean firstAttachment)
	{
		super.onViewAttached(firstAttachment);
		// manipulate with the view
	}
}

License

Copyright 2020 ZeoFlow

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.