9) Dialog Fragment – Dr James Froggatt

A Dialog box is like a prompt for user decisions/information for an app to continue a task (e.g. deleting a record in a database)

A Dialog Box is composed of 3 parts:

1) Optional title
2) Content Area (can contain sliders/lists/ checkboxes etc)
3) Action Buttons (e.g. Cancel & OK). Keep dismissive actions on the left, and affirmative action on the right.

Construct/create a DialogFragment

Define the appearance of the layout

Create a class that extends DialogFragment

Use onCreateView to link the appearance

Displaying a DialogFragment

MyDialog d= new Dialog();

d.show(manager,”test”);

Note: the fragment manager object is managed in the show() method. We don’t call commit() after show either as that too is managed within the show() method.

show Dialog must be the last call if we are carrying out fragment transactions

e.g.
// Add a
// Replace a with b

because commit() as mentioned above is WITHIN the show() method.

MainActivity.java

package com.jamesfroggatt.dialogsdemo.app;

import android.app.Activity;
import android.app.FragmentManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import static android.widget.Toast.LENGTH_SHORT;

public class MainActivity extends Activity implements MyDialog.Communicator{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void showDialog(View v){
        FragmentManager manager=getFragmentManager();
        MyDialog myDialog=new MyDialog();
        myDialog.show(manager,"MyDialog");
    }

    @Override
    public void onDialogMessage(String message) {
        Toast.makeText(this,message, LENGTH_SHORT).show();
    }
}

MyDialog.java

package com.jamesfroggatt.dialogsdemo.app;

import android.app.Activity;
import android.app.DialogFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

public class MyDialog extends DialogFragment implements View.OnClickListener{

   Button yes,no;

    // create a reference to the communicator interface
    Communicator comm;


    // link the xml appearance with java
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.my_dialog, null);

        // set the title of the dialog
        getDialog().setTitle("Hello");

        yes= (Button) view.findViewById(R.id.yes);
        no= (Button) view.findViewById(R.id.no);

        // set the onclick listeners
        yes.setOnClickListener(this);
        no.setOnClickListener(this);

        // stops user clicking off the Dialog and it dissapearing
        setCancelable(false);

        return view;
    }



    @Override
    public void onClick(View v) {
        if (v.getId()==R.id.yes){

            comm.onDialogMessage("Yes was clicked");
            // makes the dialog go away when button is selected
            dismiss();
            //Toast.makeText(getActivity(), "Yes button clicked", Toast.LENGTH_SHORT).show();
        }else{

            comm.onDialogMessage("No was clicked");
            // makes the dialog go away when button is selected
            dismiss();

            //Toast.makeText(getActivity(),"No button clicked",Toast.LENGTH_SHORT).show();
        }
    }

    interface Communicator
    {
        public void onDialogMessage(String message);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        comm= (Communicator) activity;
    }
}

my_dialog.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="This is a dialog"
        android:id="@+id/textView" />


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="No"
        android:id="@+id/no"
        android:layout_below="@+id/textView" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Yes"
        android:id="@+id/yes"
        android:layout_below="@+id/textView"
        android:layout_toRightOf="@+id/no"/>

</RelativeLayout>

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${packageName}.${activityClass}">


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show dialog"
        android:onClick="showDialog"
         />
</RelativeLayout>