Added comments and summaries to MainActivity.java and changed variable names

app/src/main/java/com/MartyrPher/smapiandroidinstaller/MainActivity.java

@@ -2,86 +2,119 @@ package com.MartyrPher.smapiandroidinstaller;
 
 import android.Manifest;
 import android.content.pm.PackageManager;
+import android.os.Environment;
 import android.support.annotation.NonNull;
+import android.support.design.widget.TabLayout;
 import android.support.v4.app.ActivityCompat;
 import android.support.v4.content.ContextCompat;
+import android.support.v4.view.ViewPager;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
-import android.view.View;
+import android.util.Log;
-import android.widget.Button;
 import android.widget.Toast;
 
+import java.io.File;
+import java.io.FileOutputStream;
+
 public class MainActivity extends AppCompatActivity {
 
+    //Tag used for debugging
     private static final String TAG = "MainActivity";
 
-    private static final int MY_PERMISSION_REQUEST_STORAGE = 2;
+    //Override int for onRequestionPermssionResult to ensure the right permssion
+    private static final int PERMISSION_REQUEST_STORAGE = 2;
 
-    private boolean hasPermissions = false;
+    //Whether the user has permissions
+    public static boolean mHasPermissions = false;
 
+    //Whether ConfigEditorFragment has found the mods in the mod folder
+    public static boolean mHasFoundMods = false;
+
+    //TabAdapter to allow changes to the tabs
+    private TabAdapter mTabAdapter;
+
+    //TabLayout to control the tabs at the top of the screen
+    private TabLayout mTabLayout;
+
+    //ViewPager that allows switching between fragments
+    private ViewPager mViewPager;
+
+    /**
+     * Override that create the initial view and sets up the layout
+     * @param savedInstanceState = The savedInstanceState
+     */
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
+        try {
-        setContentView(R.layout.activity_main);
+            super.onCreate(savedInstanceState);
+            setContentView(R.layout.view_pager);
 
-        requestPermissions();
+            //Find the ViewPager and TabLayout ids
+            mViewPager = findViewById(R.id.view_pager);
+            mTabLayout = findViewById(R.id.tab_layout);
 
-        final Button start_button = findViewById(R.id.start_button);
+            //Get the fragment manager and add the fragments
-        start_button.setOnClickListener(new View.OnClickListener() {
+            mTabAdapter = new TabAdapter(getSupportFragmentManager());
-            @Override
+            if (mTabAdapter.getCount() < 1)
-            public void onClick(View v) {
+            {
-                start_button.setBackgroundColor(getResources().getColor(R.color.colorAccent));
+                mTabAdapter.addFragment(new InstallFragment(), "Install");
-                if (hasPermissions)
+                mTabAdapter.addFragment(new ConfigEditorFragment(), "Configs");
-                {
-                    boolean[] foundGame;
-                    ApkExtractor apkExtractor = new ApkExtractor(MainActivity.this);
-
-                    foundGame = apkExtractor.checkForInstallOrUpgrade();
-
-                    if(foundGame[1] || foundGame[2])
-                    {
-                        BackgroundTask backgroundTask = new BackgroundTask(MainActivity.this, apkExtractor, foundGame[0]);
-                        backgroundTask.execute();
-                    }
-                    else
-                    {
-                        DialogFrag.showDialog(MainActivity.this, R.string.cant_find, 1);
-                        start_button.setBackgroundColor(getResources().getColor(R.color.colorPrimary));
-                    }
-
-                }
-                else
-                {
-                    requestPermissions();
-                }
             }
-        });
+
+            //Setup the ViewPager adapter and TabLayout with ViewPager
+            mViewPager.setAdapter(mTabAdapter);
+            mTabLayout.setupWithViewPager(mViewPager);
+
+            //Request the permissions for storage access
+            requestPermissions();
+        }
+        catch (Exception e)
+        {
+            //Try to log a crash in onCreate()
+            File logFile = new File(Environment.getExternalStorageDirectory() + "/SMAPI Installer/crash.txt");
+            try {
+                FileOutputStream stream = new FileOutputStream(logFile);
+                stream.write(e.getMessage().getBytes());
+                stream.close();
+            }
+            catch(Exception er)
+            {
+                Log.e(TAG, er.toString());
+            }
+        }
     }
 
-
+    /**
-    //Request permissions to be able to read/write external storage
+     * Request permissions to be able to read/write external storage
+     */
     public void requestPermissions()
     {
         if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE)
                 != PackageManager.PERMISSION_GRANTED) {
             ActivityCompat.requestPermissions(MainActivity.this,
                     new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE},
-                    MY_PERMISSION_REQUEST_STORAGE);
+                    PERMISSION_REQUEST_STORAGE);
         }
         else
         {
-            hasPermissions = true;
+            mHasPermissions = true;
         }
     }
 
+    /**
+     * Override to handle the result of the permission request
+     * @param requestCode = The request code
+     * @param permissions = An array of Strings for needed permissions
+     * @param grantResults = The results of the permissions
+     */
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         switch(requestCode)
         {
-            case MY_PERMISSION_REQUEST_STORAGE:
+            case PERMISSION_REQUEST_STORAGE:
                 if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
                 {
-                    hasPermissions = true;
+                    mHasPermissions = true;
                     Toast.makeText(this, R.string.permission, Toast.LENGTH_SHORT).show();
                 }
                 break;