Merge pull request #70 from Yusuke57/add-preview-attribute

Add:  PreviewAttribute

Alchemy/Assets/Alchemy/Editor/BuiltinAttributeDrawers.cs

@@ -239,6 +239,68 @@ public override void OnCreateElement()
         }
     }
 
+    [CustomAttributeDrawer(typeof(PreviewAttribute))]
+    public sealed class PreviewDrawer : TrackSerializedObjectAttributeDrawer
+    {
+        private Image image;
+        private const float PreviewSize = 40f;
+        private const float BorderWidth = 1f;
+        private static readonly Color borderColor = new Color(0f, 0f, 0f, 0.3f);
+
+        public override void OnCreateElement()
+        {
+            if (SerializedProperty.propertyType != SerializedPropertyType.ObjectReference) return;
+
+            image = new Image
+            {
+                scaleMode = ScaleMode.ScaleToFit,
+                style = {
+                    width = PreviewSize,
+                    height = PreviewSize,
+                    marginTop = EditorGUIUtility.standardVerticalSpacing,
+                    marginBottom = EditorGUIUtility.standardVerticalSpacing * 4f,
+                    alignSelf = Align.FlexEnd,
+                    borderTopWidth = BorderWidth,
+                    borderBottomWidth = BorderWidth,
+                    borderLeftWidth = BorderWidth,
+                    borderRightWidth = BorderWidth,
+                    borderBottomColor = borderColor,
+                    borderTopColor = borderColor,
+                    borderLeftColor = borderColor,
+                    borderRightColor = borderColor,
+                }
+            };
+
+            image.RegisterCallback<MouseDownEvent>(x =>
+            {
+                using var mouseDownEvent = MouseDownEvent.GetPooled(x);
+                var objectFieldSelector = TargetElement.Q(className: "unity-object-field__selector");
+                mouseDownEvent.target = objectFieldSelector;
+                objectFieldSelector.SendEvent(mouseDownEvent);
+            });
+
+            var parent = TargetElement.parent;
+            parent.Insert(parent.IndexOf(TargetElement) + 1, image);
+
+            base.OnCreateElement();
+        }
+
+        protected override void OnInspectorChanged()
+        {
+            if (SerializedProperty.objectReferenceValue == null)
+            {
+                image.image = null;
+                return;
+            }
+
+            TargetElement.schedule.Execute(() =>
+            {
+                var texture = AssetPreview.GetAssetPreview(SerializedProperty.objectReferenceValue);
+                image.image = texture;
+            }).Until(() => image.image != null);
+        }
+    }
+
     [CustomAttributeDrawer(typeof(HorizontalLineAttribute))]
     public sealed class HorizontalLineDrawer : AlchemyAttributeDrawer
     {

Alchemy/Assets/Alchemy/Runtime/Inspector/InspectorAttributes.cs

@@ -136,6 +136,9 @@ public HelpBoxAttribute(string message, HelpBoxMessageType messageType = HelpBox
         public HelpBoxMessageType MessageType { get; }
     }
 
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Method)]
+    public sealed class PreviewAttribute : Attribute { }
+
     [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Method)]
     public sealed class HorizontalLineAttribute : Attribute
     {

Alchemy/Assets/Alchemy/Samples~/Samples/Samples.unity

@@ -1120,6 +1120,7 @@ Transform:
   - {fileID: 786074858}
   - {fileID: 306442429}
   - {fileID: 535909118}
+  - {fileID: 2046093442}
   m_Father: {fileID: 0}
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
 --- !u!1 &978336615
@@ -2085,6 +2086,54 @@ Transform:
   - {fileID: 565026220}
   m_Father: {fileID: 0}
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!1 &2046093441
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 2046093442}
+  - component: {fileID: 2046093443}
+  m_Layer: 0
+  m_Name: '[Preview]'
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 1
+--- !u!4 &2046093442
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2046093441}
+  serializedVersion: 2
+  m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: 0}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 0
+  m_Children: []
+  m_Father: {fileID: 801201067}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &2046093443
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2046093441}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 36abc8eeae5f4d0482fe8f93429ee9f7, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  foo: {fileID: 0}
+  bar: {fileID: 0}
+  baz: {fileID: 0}
+  qux: {fileID: 0}
 --- !u!1660057539 &9223372036854775807
 SceneRoots:
   m_ObjectHideFlags: 0

Alchemy/Assets/Alchemy/Samples~/Samples/Scripts/Decorations/PreviewSample.cs

@@ -0,0 +1,13 @@
+using UnityEngine;
+using Alchemy.Inspector;
+
+namespace Alchemy.Samples
+{
+    public class PreviewSample : MonoBehaviour
+    {
+        [Preview] public Sprite foo;
+        [Preview] public Texture bar;
+        [Preview] public Material baz;
+        [Preview] public GameObject qux;
+    }
+}