So I have to convert an activity into a fragment. I followed some basic principles however the app still crashes.
The converted activity code:
package com.example.computerscienceiawithtablayout;
import android.support.annotation.NonNull;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import java.io.File;
import java.util.*;
public class FragmentHome extends Fragment implements AddBookDialogue.AddBookDialogueListener{
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
return inflater.inflate(R.layout.fragment_home, container, false);
}
@Override
public void onStart() {
super.onStart();
}
public void onBigButtonClick(View w) {
AddBookDialogue addBookDialogue = new AddBookDialogue();
addBookDialogue.show(getChildFragmentManager(), "add book dialogue");
}
@Override
public void getTexts(String bookAuthor, String bookTitle, String bookBarcode, String bookCourse, String selectedBookshelf) {
if(bookAuthor.isEmpty() || bookTitle.isEmpty() || bookBarcode.isEmpty() || bookCourse.isEmpty()){
Toast.makeText(getActivity(), "You didn't enter all necessary data", Toast.LENGTH_LONG).show();
}else{
if(bookBarcode.length()!=8){
Toast.makeText(getActivity(), "Barcodes should be eight digits long", Toast.LENGTH_LONG).show();
}else{ if(selectedBookshelf.equals("Withdrawn")){
Book a = new Book(bookAuthor, bookTitle, bookBarcode, bookCourse, selectedBookshelf);
Toast.makeText(getActivity(), a.toString(), Toast.LENGTH_LONG).show();
}else{
Book a = new Book(bookAuthor, bookTitle, bookBarcode, bookCourse, selectedBookshelf);
Toast.makeText(getActivity(), a.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
}
The fragment call upon an addBookDialogue, which is a dialoguefragment, code here:
package com.example.computerscienceiawithtablayout;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatDialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
public class AddBookDialogue extends AppCompatDialogFragment{
private EditText editTextBookAuthor;
private EditText editTextBookTitle;
private EditText editTextBookCourse;
private EditText editTextBookBarcode;
private Spinner spinnerBookshelf;
private AddBookDialogueListener listener;
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getParentFragment().getActivity());
LayoutInflater inflater = getParentFragment().getActivity().getLayoutInflater();
View view = inflater.inflate(R.layout.dialogue_addbook, null);
builder.setView(view)
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
})
.setPositiveButton("Add", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
String bookAuthor = editTextBookAuthor.getText().toString();
String bookTitle = editTextBookTitle.getText().toString();
String bookBarcode = editTextBookBarcode.getText().toString();
String bookCourse = editTextBookCourse.getText().toString();
String seletecBookshelf = spinnerBookshelf.getSelectedItem().toString();
listener.getTexts( bookAuthor, bookTitle, bookBarcode, bookCourse, seletecBookshelf);
}
});
editTextBookAuthor = view.findViewById(R.id.author);
editTextBookTitle= view.findViewById(R.id.bookTitle);
editTextBookBarcode= view.findViewById(R.id.bookBarcode);
editTextBookCourse= view.findViewById(R.id.bookBarcode);
spinnerBookshelf= view.findViewById(R.id.spinnerBookshelf);
ArrayAdapter<CharSequence> spinnerAdapter = ArrayAdapter.createFromResource(getActivity(), R.array.addBookBookshelfsAvailable, android.R.layout.simple_spinner_item);
spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerBookshelf.setAdapter(spinnerAdapter);
return builder.create();
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
listener = (AddBookDialogueListener) context;
} catch(ClassCastException e){
throw new ClassCastException(context.toString() + "no listener");
}
}
public interface AddBookDialogueListener{
void getTexts(String bookAuthor, String bookTitle, String bookBarcode, String bookCourse, String selectedBookshelf);
}
}
I am huge newbie and basing some of this code on intuition. The major flaws that I can think of are calling the addBookDialogue with .show(getChildFragmentManager) and in AddBookDialogue file setting the builder to getParentFragment.getActivity This probably isn't the correct approach, but I am having difficulties understanding the interactions between fragments. The book object is a simple java class with a constructor and a few setters/getters
So yeah, idk where to problem is, all help appreciated :)
For more reference here is the xml file for the main activity
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FragmentHome">
<fragment
android:id="@+id/fragmentHome"
android:name="com.example.computerscienceiawithtablayout.FragmentHome"
android:layout_height="match_parent"
android:layout_width="match_parent"/>
</android.support.constraint.ConstraintLayout>
and here is the xml for the fragment
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FragmentHome">
<Button
android:text="@string/Add"
android:textStyle="bold"
android:textColor="#ffffff"
android:background="@drawable/button_states"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/button"
android:onClick="onBigButtonClick"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="480dp" app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="164dp" style="@style/Widget.AppCompat.Button"/>
</android.support.constraint.ConstraintLayout>
