Devrath Devrath - 23 days ago 11
Java Question

Not able to make click event in android data binding

View.Java

package com.espresso.mvvmtestproject;

import android.content.Context;
import android.databinding.DataBindingUtil;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.espresso.mvvmtestproject.databinding.ActivityMainBinding;


public class View extends AppCompatActivity implements ViewContract.requiredMethods{


ViewModel mModel;
ActivityMainBinding binding;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Setting the layout
binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
mModel=new ViewModel(getContext());
binding.setUser(mModel);
binding.setHandlers(new MyHandlers());

}

@Override
public void onDestroy() {
super.onDestroy();

}

@Override
public Context getContext() {
return View.this;
}


}





ViewContract.java

public interface ViewContract {
interface requiredMethods{
Context getContext();
}
}





activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

<data>
<variable
name="user"
type="com.espresso.mvvmtestproject.ViewModel"/>
<variable
name="handlers"
type="com.espresso.mvvmtestproject.MyHandlers"/>
</data>




<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:gravity="center">
<TextView android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:layout_gravity="center"
android:gravity="center"
android:textColor="@android:color/black"
android:text="First Text"/>
<TextView android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:layout_gravity="center"
android:gravity="center"
android:textColor="@android:color/black"
android:text="Second Text"/>

<Button
android:text="Show Toast"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="@{handlers::onShowToast}"/>
</LinearLayout>

</layout>





MyHandlers.java

public class MyHandlers {

public void onShowToast(View view) {
Toast.makeText(view,"Clicked",Toast.LENGTH_SHORT).show();
}

}


ViewModel.java

public class ViewModel {


private Context mActivity;

public ViewModel(Context context) {
this.mActivity=context;
}

public void onShowToast(View view) {
Toast.makeText(mActivity,"Clicked",Toast.LENGTH_SHORT).show();
}

}





ErrorLog

Information:Gradle tasks [:app:clean, :app:generateDebugSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies, :app:generateDebugAndroidTestSources, :app:assembleDebug]
D:\Projects\Trp\MvvmTestProject\app\src\main\java\com\espresso\mvvmtestproject\View.java
Error:(8, 48) error: package com.espresso.mvvmtestproject.databinding does not exist
Error:(15, 5) error: cannot find symbol class ActivityMainBinding
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
> java.lang.RuntimeException: Found data binding errors.
****/ data binding error ****msg:Listener class android.view.View.OnClickListener with method onClick did not match signature of any method handlers::onShowToast
file:D:\Projects\Trp\MvvmTestProject\app\src\main\res\layout\activity_main.xml
loc:40:31 - 40:51
****\ data binding error ****
Information:BUILD FAILED
Information:Total time: 4.396 secs
Information:3 errors
Information:0 warnings
Information:See complete output in console

Answer

Make your MyHandlers intereface from class.

public class MyHandlers {
    public void onShowToast(View view);
} 

Implement it in your Activity or Fragment, in your case it will be as follows

public class View extends AppCompatActivity implements ViewContract.requiredMethods, MyHanders{

    ViewModel mModel;
ActivityMainBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Setting the layout
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        mModel=new ViewModel(getContext());
        binding.setUser(mModel);
        binding.setHandlers(this);

    }        

    @Override
    public void onShowToast(View view) {
        Toast.makeText(view,"Clicked",Toast.LENGTH_SHORT).show();
    }
}

Override your interface method onShowToast and set handler for your binding, and that's it, you are done with click events

Comments