Abstract setting the thread priority away into ProgressDialogTask

app/src/main/java/me/impy/aegis/ui/tasks/DerivationTask.java

@@ -1,10 +1,6 @@
 package me.impy.aegis.ui.tasks;
 
 import android.content.Context;
-import android.os.Process;
-
-import java.security.NoSuchAlgorithmException;
-import java.security.spec.InvalidKeySpecException;
 
 import javax.crypto.SecretKey;
 
@@ -22,9 +18,9 @@ public class DerivationTask extends ProgressDialogTask<DerivationTask.Params, Se
 
     @Override
     protected SecretKey doInBackground(DerivationTask.Params... args) {
-        Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE);
+        setPriority();
 
-        DerivationTask.Params params = args[0];
+        Params params = args[0];
         try {
             byte[] salt = CryptoUtils.generateSalt();
             return params.Slot.deriveKey(params.Password, salt, CryptoUtils.CRYPTO_SCRYPT_N, CryptoUtils.CRYPTO_SCRYPT_r, CryptoUtils.CRYPTO_SCRYPT_p);

app/src/main/java/me/impy/aegis/ui/tasks/ProgressDialogTask.java

@@ -3,6 +3,7 @@ package me.impy.aegis.ui.tasks;
 import android.app.ProgressDialog;
 import android.content.Context;
 import android.os.AsyncTask;
+import android.os.Process;
 import android.support.annotation.CallSuper;
 
 public abstract class ProgressDialogTask<Params, Result> extends AsyncTask<Params, Void, Result> {
@@ -28,6 +29,10 @@ public abstract class ProgressDialogTask<Params, Result> extends AsyncTask<Param
         }
     }
 
+    protected void setPriority() {
+        Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE);
+    }
+
     protected final ProgressDialog getDialog() {
         return _dialog;
     }

app/src/main/java/me/impy/aegis/ui/tasks/SlotCollectionTask.java

@@ -1,7 +1,6 @@
 package me.impy.aegis.ui.tasks;
 
 import android.content.Context;
-import android.os.Process;
 
 import java.lang.reflect.UndeclaredThrowableException;
 
@@ -28,9 +27,9 @@ public class SlotCollectionTask<T extends Slot> extends ProgressDialogTask<SlotC
 
     @Override
     protected MasterKey doInBackground(SlotCollectionTask.Params... args) {
-        Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE);
+        setPriority();
 
-        SlotCollectionTask.Params params = args[0];
+        Params params = args[0];
         try {
             if (!params.Slots.has(_type)) {
                 throw new RuntimeException();