Fixes #2575 - TableView to use interface instead of System.Data.DataTable

[tznind]

Fixes #2575 - Changes TableView from being based on System.Data.DataTable to ITableDataSource

This PR makes it super easy to create TableView that presents any arbitrary collection. The user is no longer required to mess about converting their data into System.Data.DataTable in order to render.

[Fact,AutoInitShutdown]
public void TestEnumerableDataSource_BasicTypes()
{
	var tv = new TableView ();
	tv.ColorScheme = Colors.TopLevel;
	tv.Bounds = new Rect (0, 0, 50, 6);

	tv.Table = new EnumerableTableSource<Type> (
		new Type [] { typeof (string), typeof (int), typeof (float) },
		new () {
			{ "Name", (t)=>t.Name},
			{ "Namespace", (t)=>t.Namespace},
			{ "BaseType", (t)=>t.BaseType}
		});

	tv.LayoutSubviews ();

	tv.Redraw (tv.Bounds);

	string expected =
		@"
┌──────┬─────────┬───────────────────────────────┐
│Name  │Namespace│BaseType                       │
├──────┼─────────┼───────────────────────────────┤
│String│System   │System.Object                  │
│Int32 │System   │System.ValueType               │
│Single│System   │System.ValueType               │";

	TestHelpers.AssertDriverContentsAre (expected, output);
}

ProcessTable scenario

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[tznind]

Marking this ready for review as it is good to merge. I do want to update FileDialog to use the new interface but since it was all written with DataTable in mind it will be a bit of work to back that out and probably makes sense to do that as a seperate PR.

[tig]

See my PR.

[tznind]

I am not a fan of how the columns change width as one scrolls. It's disconcerting:

This is currently 'by design'.

• It is both for performance (not measuring all the data in the table up front)
• Defensive, it prevents 1 long value in a column pushing out all the other columns (potentially off the screen so that horizontal scrolling is required).

The current way of dealing with this is to use the ColumnStyle to configure min/max widths etc

I mentioned in your PR about maybe adding something like SizeColumnsToAllData or something but that I think should be a seperate PR?

[tig]

I get it now. I think we should add your explanation in uicatalog.cs where I put all the setup code.

[tznind]

I get it now. I think we should add your explanation in uicatalog.cs where I put all the setup code.

Cool that makes sense, how does this read?
c767aeb

[tig]

Oops. As soon as I merged this, i realized moving to TableView broke CollectionNavigator for the scenario list.

@tznind how hard it is to make CollectionNavigator work with tableview?

[tznind]

Oops. As soon as I merged this, i realized moving to TableView broke CollectionNavigator for the scenario list.

@tznind how hard it is to make CollectionNavigator work with tableview?

Its doable because I did a 'good enough' implementation for FileDialog (see UpdateCollectionNavigator method).

But to add it as a core feature of TableView would require some care as we don't want to compromise performance when working with large tables.

For example if you have 1 million rows then you don't want to be regularly passing them to a new navigator just because the user changed columns.

And you don't want to duplicate all the data at all really because it can change.

I think we would want an interface ICollectionNavigator and then implement GetNextMatchingItem to search the ITableSource data directly (starting at the current offset).

Its definitely doable but requires care.

I am refactoring FileDialog to use ITableSource at the moment (its making the code much cleaner). I can look into the collection navigation next.

[tznind]

I have documented the breaking change in the breaking changes thread: #2448 (comment)