ActionDrawer

Generic Odin property drawer for all Action-derived types. Renders a toolbar header with a polymorphic type selector, a foldable body displaying action variables, and an optional progress indicator that animates while the action is running.

Definition

Namespace: Paragon.Core.ActionSystem.Editor Assembly: Paragon.Editor.dll

[DrawerPriority(0.0, 0.0, 3000.0)]
[DrawerIndentation]
public class ActionDrawer<TAction> : OdinValueDrawer<TAction>
    where TAction : Action

Inherits: OdinValueDrawer<TAction> (Sirenix.OdinInspector.Editor) Type Constraint: TAction : Action

Remarks

This is the base editor drawer for the entire Action System hierarchy. It handles three responsibilities:

1. Header — A horizontal toolbar containing a foldout toggle and a PolymorphicObjectField for type selection. This allows users to pick any concrete Action subclass from a dropdown.

2. Progress Indicator — An animated bar that pulses while IsRunning is true, providing visual feedback during Play Mode.

3. Body — A foldable section that draws the action's actionVariables child property (the fields marked with [Variable]).

The drawer uses DrawerPriority(0, 0, 3000) so it takes precedence over Odin's default drawers. Subclass drawers (e.g., ActionSequenceDrawer) use higher priorities to override this drawer for more specific types.

Quick Lookup

Goal	How
Customize the foldout label	Override defaultLabel property
Change header rendering	Override DrawHeader(GUIContent)
Change body rendering	Override DrawBody()
Hide progress indicator	Set showProgressIndicator = false in Initialize()
Check if action is running	Read isRunning property

Properties

defaultLabel

The default GUIContent label shown when no label is provided by the property. Defaults to "Action".

protected virtual GUIContent defaultLabel { get; }

isRunning

Returns whether the drawn action is currently executing. Reads from ValueEntry.SmartValue.IsRunning.

protected bool isRunning { get; }

Fields

isExpanded

Controls whether the body foldout is expanded. Defaults to true.

protected bool isExpanded;

showProgressIndicator

Controls whether the animated progress indicator is shown. Defaults to true. Set to false in Initialize() to hide it.

protected bool showProgressIndicator;

Methods

DrawPropertyLayout

Main entry point called by Odin. Draws the header, optional progress indicator, and body in a vertical layout.

protected override void DrawPropertyLayout(GUIContent label)

Parameter	Type	Description
label	GUIContent	Label from the serialized property. Falls back to defaultLabel if null.

DrawHeader

Draws the toolbar header containing the foldout toggle and polymorphic object field.

protected virtual void DrawHeader(GUIContent label)

Parameter	Type	Description
label	GUIContent	Label to display. Automatically nicified via ObjectNames.NicifyVariableName().

Behavior:

• If SmartValue is null: shows a prefix label with no foldout (collapsed).

• If SmartValue is set: shows a SirenixEditorGUI.Foldout controlling isExpanded.

• Always renders SirenixEditorFields.PolymorphicObjectField for type selection/assignment.

DrawBody

Draws the foldable body containing the action's actionVariables child property.

protected virtual void DrawBody()

Behavior:

• Wraps content in a SirenixEditorGUI.BeginFadeGroup / EndFadeGroup controlled by isExpanded.

• Draws the actionVariables child property inside a horizontal toolbar with indentation.

Extension Points

Required Overrides

None — ActionDrawer is a concrete class.

Optional Overrides

Method / Property	Purpose
defaultLabel	Change the default foldout label text
DrawHeader(GUIContent)	Customize the toolbar header (type selector, foldout, extra buttons)
DrawBody()	Customize what is drawn inside the foldable body
Initialize()	One-time setup (e.g., set showProgressIndicator = false)

Implementation Requirements

When subclassing ActionDrawer<TAction>, you MUST:

1. Use a higher DrawerPriority than 3000 (otherwise Odin will pick this drawer instead)

2. Constrain TAction to your custom Action subclass (e.g., where T : MyAction)

You SHOULD:

• Call base.DrawHeader(label) if you only want to append to the header

• Call base.DrawBody() if you want to extend (not replace) the body

• Set showProgressIndicator in Initialize(), not in DrawPropertyLayout()

Common Pitfalls

Drawer priority collision If your custom drawer has the same or lower priority than 3000, Odin may still select ActionDrawer instead. Always use a priority above 3000.

Null SmartValue DrawPropertyLayout returns early if SmartValue is null (after drawing the header). Any code in DrawBody() will not execute for unassigned action fields. Do not assume SmartValue is always set.

FadeGroup key uniqueness DrawBody() uses UniqueDrawerKey.Create(actionVariables, this) to generate a unique key for the fade group. If you override DrawBody() and use your own fade groups, ensure unique keys to avoid animation conflicts.

Examples

Custom Drawer for a Specific Action Type

using UnityEngine;
using Sirenix.OdinInspector.Editor;
using Paragon.Core.ActionSystem.Editor;
using Paragon.Editor;

[DrawerPriority(0.0, 0.0, 3010.0)]
[JetBrains.Annotations.UsedImplicitly]
public class MoveToActionDrawer<T> : ActionDrawer<T> where T : MoveToAction
{
    protected override GUIContent defaultLabel { get; } = new GUIContent("Move To");

    protected override void DrawBody()
    {
        base.DrawBody();

        // Add a preview button after the default body
        if (SirenixEditorGUI.BeginFadeGroup(this, isExpanded))
        {
            using (DrawGUI.HorizontalToolbar())
            {
                if (DrawGUI.Button("Preview Path"))
                {
                    // Custom preview logic
                }
            }
        }
        SirenixEditorGUI.EndFadeGroup();
    }
}

Drawer Without Progress Indicator

[DrawerPriority(0.0, 0.0, 3010.0)]
[JetBrains.Annotations.UsedImplicitly]
public class InstantActionDrawer<T> : ActionDrawer<T> where T : InstantAction
{
    protected override void Initialize()
    {
        base.Initialize();
        showProgressIndicator = false; // No progress bar for instant actions
    }
}

See Also

• Action — runtime class this drawer renders

• ActionSequenceDrawer — subclass that draws ActionSequence

• ActionPlayerEditor — custom inspector for ActionPlayer

• Action System Editor — editor tooling overview