[Eto Dialogs] New Item Dialog

[harry-cpp]

Discussed in #4238

Replaces new item/new template dialog.

Stuff done to the dialog:

• redesigned the layout
  • headerbar and normal version can now use the same layout
  • less pointless empty space
• implement check for if the file exists in target directory
• always shows the extension that's gonna be added to the name

Before left, after right:

[tomspilman]

Why is the new dialog a different size on Mac/Linux than Windows?

[tomspilman]

Also are header bar buttons a very common thing on these platforms? Seems weird to me. Don't want MonoGame tools to be the weirdo tool that does things different from all other tools.

[harry-cpp]

Why is the new dialog a different size on Mac/Linux than Windows?

They are actually pretty similar in sizes, headerbar counts into client size so it eats up a bit of height (and a bit of width), look at bellow image.

Also are header bar buttons a very common thing on these platforms?

Common on GNOME, not common for the rest, so depending on if it's running under GNOME it will decided if it will use it: https://github.com/mono/MonoGame/blob/develop/Tools/Pipeline/Eto/Global.cs#L19

This is what it looks like if it's not running under GNOME:

[tomspilman]

They are actually pretty similar in sizes

The dialogs are clearly different sizes... but I guess the smaller font size on Windows is fooling me a bit too.

This is what it looks like if it's not running under GNOME:

Ok... as long as it is only different in places where it is expected.

[harry-cpp]

The dialogs are clearly different sizes... but I guess the smaller font size on Windows is fooling me a bit too.

Different DPI more likely.

[tomspilman]

True.