[optimize][painter] add upper and top painter layer

Runtime/Component/Child/Padding.cs

@@ -0,0 +1,79 @@
+using System;
+using UnityEngine;
+
+namespace XCharts.Runtime
+{
+    /// <summary>
+    /// padding setting of item or text.
+    /// |边距设置。
+    /// </summary>
+    [Serializable]
+    public class Padding : ChildComponent
+    {
+        [SerializeField] protected bool m_Show = true;
+        [SerializeField] protected float m_Top = 2;
+        [SerializeField] protected float m_Right = 4;
+        [SerializeField] protected float m_Left = 4;
+        [SerializeField] protected float m_Bottom = 2;
+
+        public Padding() { }
+
+        public Padding(float top, float right, float bottom, float left)
+        {
+            SetPadding(top, right, bottom, left);
+        }
+
+        public void SetPadding(float top, float right, float bottom, float left)
+        {
+            m_Top = top;;
+            m_Right = right;
+            m_Bottom = bottom;
+            m_Left = left;
+        }
+        /// <summary>
+        /// show padding.
+        /// 是否显示。
+        /// </summary>
+        public bool show
+        {
+            get { return m_Show; }
+            set { if (PropertyUtil.SetStruct(ref m_Show, value)) SetComponentDirty(); }
+        }
+        /// <summary>
+        /// padding of top.
+        /// |顶部间距。
+        /// </summary>
+        public float top
+        {
+            get { return m_Top; }
+            set { if (PropertyUtil.SetStruct(ref m_Top, value)) SetComponentDirty(); }
+        }
+        /// <summary>
+        /// padding of right.
+        /// |右部间距。
+        /// </summary>
+        public float right
+        {
+            get { return m_Right; }
+            set { if (PropertyUtil.SetStruct(ref m_Right, value)) SetComponentDirty(); }
+        }
+        /// <summary>
+        /// padding of bottom.
+        /// |底部间距。
+        /// </summary>
+        public float bottom
+        {
+            get { return m_Bottom; }
+            set { if (PropertyUtil.SetStruct(ref m_Bottom, value)) SetComponentDirty(); }
+        }
+        /// <summary>
+        /// padding of left.
+        /// |左边间距。
+        /// </summary>
+        public float left
+        {
+            get { return m_Left; }
+            set { if (PropertyUtil.SetStruct(ref m_Left, value)) SetComponentDirty(); }
+        }
+    }
+}