Add message explaining storage permission

If the storage permission is denied, display a message
explaining the need for the permission, and that the
app can do nothing without it.

Author: brarcher

app/src/main/java/protect/videotranscoder/activity/MainActivity.java

@@ -209,6 +209,29 @@ public void onRequestPermissionsResult(int requestCode,
             {
                 uploadVideo();
             }
+            else
+            {
+                new AlertDialog.Builder(MainActivity.this)
+                    .setMessage(R.string.writePermissionExplanation)
+                    .setCancelable(true)
+                    .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener()
+                    {
+                        public void onClick(DialogInterface dialog, int which)
+                        {
+                            dialog.dismiss();
+                        }
+                    })
+                    .setNegativeButton(R.string.permissionRequestAgain, new DialogInterface.OnClickListener()
+                    {
+                        @Override
+                        public void onClick(DialogInterface dialog, int which)
+                        {
+                            dialog.dismiss();
+                            getPermission();
+                        }
+                    })
+                    .show();
+            }
         }
     }
 

app/src/main/res/values/strings.xml

@@ -19,6 +19,9 @@
     <string name="transcodeSuccess">Encoding completed successfully. The file was written to:\n<xliff:g id="path">%s</xliff:g></string>
     <string name="transcodeFailed">Encoding failed, see logs for details.</string>
 
+    <string name="writePermissionExplanation">This application needs access to storage in order to read and write media files. Without this access, the application cannot transcode.</string>
+    <string name="permissionRequestAgain">Request again</string>
+
     <string name="about">About</string>
     <string name="app_copyright_fmt">Copyright 2018-<xliff:g>%d</xliff:g> Branden Archer</string>
     <string name="app_license">Licensed under the GPLv2.</string>