some cleanup and fix for back button in ImportKeysActivity (fixes #1372)

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptActivity.java

@@ -49,13 +49,7 @@ public class DecryptActivity extends BaseActivity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        setFullScreenDialogClose(new View.OnClickListener() {
+        setFullScreenDialogClose(Activity.RESULT_CANCELED, false);
-            @Override
-            public void onClick(View v) {
-                setResult(Activity.RESULT_CANCELED);
-                finish();
-            }
-        }, false);
 
         // Handle intent actions
         handleActions(savedInstanceState, getIntent());

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DisplayTextActivity.java

@@ -41,13 +41,7 @@ public class DisplayTextActivity extends BaseActivity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        setFullScreenDialogClose(new View.OnClickListener() {
+        setFullScreenDialogClose(Activity.RESULT_CANCELED, false);
-            @Override
-            public void onClick(View v) {
-                setResult(Activity.RESULT_CANCELED);
-                finish();
-            }
-        }, false);
 
         // Handle intent actions
         handleActions(savedInstanceState, getIntent());

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptFilesActivity.java

@@ -18,6 +18,7 @@
 
 package org.sufficientlysecure.keychain.ui;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -41,12 +42,7 @@ public class EncryptFilesActivity extends EncryptActivity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        setFullScreenDialogClose(new View.OnClickListener() {
+        setFullScreenDialogClose(Activity.RESULT_OK, false);
-            @Override
-            public void onClick(View v) {
-                finish();
-            }
-        }, false);
 
         Intent intent = getIntent();
         String action = intent.getAction();

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptTextActivity.java

@@ -18,6 +18,7 @@
 
 package org.sufficientlysecure.keychain.ui;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.app.FragmentTransaction;
@@ -39,12 +40,7 @@ public class EncryptTextActivity extends EncryptActivity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        setFullScreenDialogClose(new View.OnClickListener() {
+        setFullScreenDialogClose(Activity.RESULT_OK, false);
-            @Override
-            public void onClick(View v) {
-                finish();
-            }
-        }, false);
 
         Intent intent = getIntent();
         String action = intent.getAction();

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ImportKeysActivity.java

@@ -17,6 +17,7 @@
 
 package org.sufficientlysecure.keychain.ui;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -95,6 +96,8 @@ public class ImportKeysActivity extends BaseNfcActivity
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        setFullScreenDialogClose(Activity.RESULT_CANCELED, true);
+
         mProxyPrefs = Preferences.getPreferences(this).getProxyPrefs();
 
         mImportButton = findViewById(R.id.import_import);

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ImportKeysProxyActivity.java

@@ -257,7 +257,6 @@ public class ImportKeysProxyActivity extends FragmentActivity
         Intent data = new Intent();
         data.putExtras(returnData);
         returnResult(data);
-        return;
     }
 
     @Override

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseActivity.java

@@ -87,9 +87,7 @@ public abstract class BaseActivity extends AppCompatActivity {
         mToolbar.setNavigationOnClickListener(cancelOnClickListener);
     }
 
-    /**
+    /** Close button only */
-     * Close button only
-     */
     protected void setFullScreenDialogClose(View.OnClickListener cancelOnClickListener, boolean white) {
         if (white) {
             setActionBarIcon(R.drawable.ic_close_white_24dp);
@@ -104,6 +102,17 @@ public abstract class BaseActivity extends AppCompatActivity {
         setFullScreenDialogClose(cancelOnClickListener, true);
     }
 
+    /** Close button only, with finish-action and given return status, white. */
+    protected void setFullScreenDialogClose(final int result, boolean white) {
+        setFullScreenDialogClose(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                setResult(result);
+                finish();
+            }
+        }, white);
+    }
+
     /**
      * Inflate custom design with two buttons using drawables.
      * This does not conform to the Material Design Guidelines, but we deviate here as this is used