Horizontal Group Attribute

// The width can either be specified as percentage or pixels.
// All values between 0 and 1 will be treated as a percentage.
// If the width is 0 the column will be automatically sized.

// Auto width
[HorizontalGroup]
public SomeFieldType Left1;

[HorizontalGroup]
public SomeFieldType Right1;

// Margins
[HorizontalGroup("row2", MarginRight = 0.4f)]
public SomeFieldType Left2;

[HorizontalGroup("row2")]
public SomeFieldType Right2;


// Custom width:
[HorizontalGroup("row1", Width = 0.25f)] // 25 %
public SomeFieldType Left3;

[HorizontalGroup("row1", Width = 150)] // 150 px
public SomeFieldType Center3;

[HorizontalGroup("row1")] // Auto / expand
public SomeFieldType Right3;


// Gap Size
[HorizontalGroup("row3", Gap = 3)]
public SomeFieldType Left4;

[HorizontalGroup("row3")]
public SomeFieldType Center4;

[HorizontalGroup("row3")] // Auto / expand
public SomeFieldType Right4;


// Title
[HorizontalGroup("row4", Title = "Horizontal Group Title")]
public SomeFieldType Left5;

[HorizontalGroup("row4")]
public SomeFieldType Center5;

[HorizontalGroup("row4")]
public SomeFieldType Right5;

[HideLabel, Serializable]
public struct SomeFieldType
{
    [LabelText("@$property.Parent.NiceName")]
    [ListDrawerSettings(ShowIndexLabels = true)]
    public float[] x;
}

[Button(ButtonSizes.Large)]
[FoldoutGroup("Buttons in Boxes")]
[HorizontalGroup("Buttons in Boxes/Horizontal")]
[BoxGroup("Buttons in Boxes/Horizontal/One")]
public void Button1() { }

[Button(ButtonSizes.Large)]
[BoxGroup("Buttons in Boxes/Horizontal/Two")]
public void Button2() { }

[Button]
[HorizontalGroup("Buttons in Boxes/Horizontal", Width = 60)]
[BoxGroup("Buttons in Boxes/Horizontal/Double")]
public void Accept() { }

[Button]
[BoxGroup("Buttons in Boxes/Horizontal/Double")]
public void Cancel() { }

[TitleGroup("Multiple Stacked Boxes")]
[HorizontalGroup("Multiple Stacked Boxes/Split")]
[VerticalGroup("Multiple Stacked Boxes/Split/Left")]
[BoxGroup("Multiple Stacked Boxes/Split/Left/Box A")]
public int BoxA;

[BoxGroup("Multiple Stacked Boxes/Split/Left/Box B")]
public int BoxB;

[VerticalGroup("Multiple Stacked Boxes/Split/Right")]
[BoxGroup("Multiple Stacked Boxes/Split/Right/Box C")]
public int BoxC, BoxD, BoxE;