AddingProperties.md

TerminalGuiDesigner - Adding new Properties

Making a new Property designable

To add desiging for a new View property update the IEnumerable<Property> LoadDesignableProperties() method.

For example:

if(View is ScrollView)
{
	yield return CreateProperty(nameof(ScrollView.ContentSize));
}

Adding a new 'round trip' test to confirm that the property is serialized/loaded correctly:

[Test]
public void TestRoundTrip_PreserveContentSize()
{
    var scrollViewIn = RoundTrip<ScrollView>((s) =>
            s.ContentSize = new Size(10, 5)
            );

    Assert.AreEqual(10, scrollViewIn.ContentSize.Width);
    Assert.AreEqual(5, scrollViewIn.ContentSize.Height);
}

New Type

To Code

If you need to add support for a new Type of Property (e.g. ContentSize property is of Type Size) then you must do the following:

• Update Property virtual CodeExpression GetRhs():

if(val is Size s)
{
    return new CodeSnippetExpression(s.ToCode());
}

Provide an implementation of ToCode as an Extension Method on the new Type

public static class SizeExtensions
{
    public static string ToCode(this Size s)
    {
        return $"new Size({s.Width},{s.Height})";
    }
}

This should make the 'round trip' test (see above) pass. But you will still need to add designer UI support for editing the Type.

Designer UIs

Create a new Dialog for the new Type in TerminalGuiDesigner.UI.Windows. Use TerminalGuiDesigner to create the form. For example see SizeEditor.Designer.cs / SizeEditor.cs

Update EditDialog.cs method GetNewValue to call the new editor window: