Change the modes of Volume Expander to make them analogous to Volume Creation Wizard

[thericle]

When you try to create a new container you are given 3 choices:

1. Full Format: VeraCrypt fills the entire file with random data
2. Quick Format: Windows populates the file with zeros
3. Fast Create: Windows fills the file with lingering disk content (previously deleted data that's still in the disk sectors).

When you try to expand an existing container with Volume Expander, there are two settings you can enable or disable:

1. Fill new space with random data
2. Quick Expand

If my understanding is correct, to achieve the behaviors of Volume Creation Wizard in Volume Expander you must do the following:

1. For "Full Format", you must enable "Fill new space with random data" and disable "Quick Expand".
2. For "Quick Format", you must disable both "Fill new space with random data" and "Quick Expand".
3. For "Fast Create", you must disable "Fill new space with random data" and enable "Quick Expand".

I believe it would be easier to understand and more self-consistent if you replaced the 2 options in Volume Expander with 3 choices, in the same way the Volume Creation Wizard works:

1. "Full Expand", to replace the data in the relevant sectors with random data.
2. "Quick Expand", to fill the relevant sectors with zeros.
3. "Fast Expand", to leave previous data as it is.

Of course "Quick expand" and "Fast expand" sound a little too similar, so you could change the name although I'd try to keep the connection with Volume Creation Wizard options as obvious as possible.

Please allow me to take my thoughts a step further. I'd suggest entirely getting rid of "Quick Format" everywhere and just renaming "Fast Create" to "Quick Format", at least for Windows. Wasn't the "Fast Create" a workaround because in Windows "Quick Format" wasn't working as intended? I personally don't see the point of filling the file with zeros, to be honest. It complicates things without adding anything. You either want to replace previous data, in which case it's best to do it with random data, or you don't care about previous data so you leave them there. There is a reason only these two options exist when encrypting a disk or partition.

IMHO, it would be much preferable and easier to understand for the user if there were only two options everywhere (Disk/Partition Encryption, Container Creation, Volume Expander):

1. Full: replace with random data
2. Quick: leave previous data as it is

Keep in mind I only use the Windows version so that's the version I'm talking about.