EDIT: In an effort to make this question not as unpleasant, I have continued working on this and have something to actually show for now. I completely removed all previous content and am completely rewriting my question.
My end goal is to have a MainActivity screen with multiple buttons that each perform different actions. Two example buttons are 1) to view device build information, and 2) to view installed applications. When a button is clicked, I want the Activity to switch to the RecyclerView and present that information. The user should be able to press the back button and click on another button.
I believe I have the structure ready but cannot figure out how to integrate the function to read packages. For that fact, where would I create the functions themselves and how can I pass the results to be viewed within RecyclerView?
Here is "MainActivity.java":
package com.emil.proofofconcepts.anothergo;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
//Variables
private TextView mTv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initRecyclerView();
}
private void initRecyclerView() {
RecyclerView recyclerView = findViewById(R.id.recycler_view);
RecyclerViewAdapter adapter = new RecyclerViewAdapter(this, mTv);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
}
}
This is my "RecyclerViewAdapter.java":
package com.emil.proofofconcepts.anothergo;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import org.w3c.dom.Text;
import java.util.ArrayList;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>{
private static final String TAG = "RecyclerViewAdapter";
private TextView mTv;
private Context mContext;
public RecyclerViewAdapter(Context context, TextView mTv) {
mTv = mTv;
mContext = context;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_list, parent, false);
ViewHolder holder = new ViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
Log.d(TAG, "onBindViewHolder: called.");
//holder.tv.setText("what");
holder.tv.setText(readPackages());
}
@Override
public int getItemCount() {
return 1;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView tv;
RelativeLayout parentLayout;
public ViewHolder(@NonNull View itemView) {
super(itemView);
tv = itemView.findViewById(R.id.tv_display);
parentLayout = itemView.findViewById(R.id.parent_layout);
}
}
private String readPackages() {
PackageManager pm = getPackageManager();
String ret = "";
for (ApplicationInfo app : pm.getInstalledApplications(0)){
if(app.className != null && !app.className.equals("Null")){
if(!ret.equals("")) ret = ret + "\n";
ret = ret + app.className;
}
}
return ret;
}
}
Here is my "layout_list.xml":
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:id="@+id/parent_layout"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/tv_display"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sample Text"/>
</RelativeLayout>
And last but not least, this is my "activity_main.xml":
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical">
</androidx.recyclerview.widget.RecyclerView>
</RelativeLayout>
