using System;
using System.Linq.Expressions;
using UnityEngine.Assertions;
namespace UnityEditor.Rendering
{
/// <summary>
/// Serialized property fetcher.
/// </summary>
/// <typeparam name="T">Serialized object type.</typeparam>
public sealed class PropertyFetcher<T> : IDisposable
{
/// <summary>
/// Serialized object associated with the fetcher.
/// </summary>
public readonly SerializedObject obj;
/// <summary>
/// Constructor
/// </summary>
/// <param name="obj">Serialized object containing properties to fetch.</param>
public PropertyFetcher(SerializedObject obj)
{
Assert.IsNotNull(obj);
this.obj = obj;
}
/// <summary>
/// Find a property by name.
/// </summary>
/// <param name="str">Property name.</param>
/// <returns>Required property if it exists, null otherwise.</returns>
public SerializedProperty Find(string str)
{
return obj.FindProperty(str);
}
/// <summary>
/// Find a property based on an expression.
///
/// To use with extreme caution. It not really get the property but try to find a field with similar name
/// Hence inheritance override of property is not supported.
/// Also variable rename will silently break the search.
/// </summary>
/// <typeparam name="TValue">Type of the serialized object.</typeparam>
/// <param name="expr">Expression for the property.</param>
/// <returns>Required property if it exists, null otherwise.</returns>
public SerializedProperty Find<TValue>(Expression<Func<T, TValue>> expr)
{
string path = CoreEditorUtils.FindProperty(expr);
return obj.FindProperty(path);
}
/// <summary>
/// Disposable pattern implementation.
/// </summary>
public void Dispose()
{
// Nothing to do here, still needed so we can rely on the using/IDisposable pattern
}
}
/// <summary>
/// Relative property fetcher.
/// </summary>
/// <typeparam name="T">SerializedObject type.</typeparam>
public sealed class RelativePropertyFetcher<T> : IDisposable
{
/// <summary>
/// Serialized object associated with the fetcher.
/// </summary>
public readonly SerializedProperty obj;
/// <summary>
/// Constructor
/// </summary>
/// <param name="obj">Serialized object containing properties to fetch.</param>
public RelativePropertyFetcher(SerializedProperty obj)
{
Assert.IsNotNull(obj);
this.obj = obj;
}
/// <summary>
/// Find a property by name.
/// </summary>
/// <param name="str">Property name.</param>
/// <returns>Required property if it exists, null otherwise.</returns>
public SerializedProperty Find(string str)
{
return obj.FindPropertyRelative(str);
}
/// <summary>
/// Find a property based on an expression.
///
/// Use with extreme caution as this method does not directly retrieve the property but instead searches for a field with a similar name.
/// Inheritance and property overrides are not supported, and renaming a variable may break the linkage without warning.
/// </summary>
/// <typeparam name="TValue">Type of the serialized object.</typeparam>
/// <param name="expr">Expression for the property.</param>
/// <returns>Required property if it exists, null otherwise.</returns>
public SerializedProperty Find<TValue>(Expression<Func<T, TValue>> expr)
{
string path = CoreEditorUtils.FindProperty(expr);
return obj.FindPropertyRelative(path);
}
/// <summary>
/// Disposable pattern implementation.
/// </summary>
public void Dispose()
{
// Nothing to do here, still needed so we can rely on the using/IDisposable pattern
}
}
/// <summary>
/// Property fetcher extension class.
/// </summary>
public static class PropertyFetcherExtensions
{
/// <summary>
/// Retrieves a <see cref="SerializedProperty"/> by using a lambda expression to reference its containing class and field.
/// </summary>
/// <typeparam name="TSource">The class type containing the field.</typeparam>
/// <typeparam name="TValue">The field type.</typeparam>
/// <param name="obj">The <see cref="SerializedObject"/> being searched.</param>
/// <param name="expr">A lambda expression pointing to the field within the source class.</param>
/// <returns>The corresponding <see cref="SerializedProperty"/>, or null if not found.</returns>
public static SerializedProperty Find<TSource, TValue>(this SerializedObject obj, Expression<Func<TSource, TValue>> expr)
{
var path = CoreEditorUtils.FindProperty(expr);
return obj.FindProperty(path);
}
/// <summary>
/// Retrieves a relative <see cref="SerializedProperty"/> based on a lambda expression pointing to a specific field within the source object.
/// </summary>
/// <typeparam name="TSource">The class type containing the field.</typeparam>
/// <typeparam name="TValue">The field type.</typeparam>
/// <param name="obj">The instance of <see cref="SerializedProperty"/> to begin the search from.</param>
/// <param name="expr">>A lambda expression pointing to the field within the source class.</param>
/// <returns>The relative <see cref="SerializedProperty"/> if found; otherwise, null.</returns>
public static SerializedProperty Find<TSource, TValue>(this SerializedProperty obj, Expression<Func<TSource, TValue>> expr)
{
var path = CoreEditorUtils.FindProperty(expr);
return obj.FindPropertyRelative(path);
}
}
}