ADD CenterHorizontally and CenterVertically

Author: Christiaan Bloemendaal

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## [2.1.0] - 2020-06-07
+## Added
+- Options to center horizontally and vertically
+
 ## [2.0.2] - 2020-02-19
 ## Fixed
 - Incorrect naming of assembly definitions
@@ -18,4 +22,4 @@
 
 ## [1.0.0] - 2020-02-16
 ### Added
-- Initial version
+- Initial version

Editor/ConstrainedRect.cs

@@ -13,6 +13,9 @@ public class ConstrainedRect
         public Constraint Width { get; }
         public Constraint Height { get; }
 
+        private bool centerHorizontally;
+        private bool centerVertically;
+
         public ConstrainedRect(Rect parent)
         {
             this.parent = parent;
@@ -51,6 +54,15 @@ public Rect ToRect()
 
         private void CalculateHorizontal(out float left, out float right)
         {
+            if (centerHorizontally && Width.IsSet)
+            {
+                float width = Mathf.Abs(Width.RawValue);
+                left = parent.center.x - width * 0.5f;
+                right = width;
+
+                return;
+            }
+
             if (!Width.IsSet || (Left.IsSet && Right.IsSet))
             {
                 left = Left.Apply(parent.xMin);
@@ -77,6 +89,15 @@ private void CalculateHorizontal(out float left, out float right)
 
         private void CalculateVertical(out float top, out float bottom)
         {
+            if (centerVertically && Height.IsSet)
+            {
+                float height = Mathf.Abs(Height.RawValue);
+                top = parent.center.y - height * 0.5f;
+                bottom = height;
+
+                return;
+            }
+
             if (!Height.IsSet || (Top.IsSet && Bottom.IsSet))
             {
                 top = Top.Apply(parent.yMin);
@@ -100,5 +121,17 @@ private void CalculateVertical(out float top, out float bottom)
                 bottom = Height.Apply(parent.height);
             }
         }
+
+        public ConstrainedRect CenterHorizontally()
+        {
+            centerHorizontally = true;
+            return this;
+        }
+
+        public ConstrainedRect CenterVertically()
+        {
+            centerVertically = true;
+            return this;
+        }
     }
-}
+}

Editor/Constraint.cs

@@ -17,6 +17,8 @@ private enum ConstrainMode
 
         private float Value => negateValue ? -value : value;
 
+        internal float RawValue => value;
+
         public bool IsSet => mode != ConstrainMode.NotSet;
 
         public Constraint(ConstrainedRect parent, bool negateValue)
@@ -61,4 +63,4 @@ internal float Apply(float value)
             return value;
         }
     }
-}
+}

Tests/Editor/ConstrainedRectTests.cs

@@ -161,5 +161,31 @@ public void BottomHeightPercentage()
             Assert.AreEqual(120, constrained.yMax);
             Assert.AreEqual(64, constrained.height);
         }
+
+        [Test]
+        public void CenterHorizontally()
+        {
+            var constrained = Constrain.To(rect)
+                .Width.Absolute(20)
+                .CenterHorizontally()
+                .ToRect();
+
+            Assert.AreEqual(20, constrained.width);
+            Assert.AreEqual(128 / 2 - 10, constrained.xMin);
+            Assert.AreEqual(128 / 2 + 10, constrained.xMax);
+        }
+
+        [Test]
+        public void CenterVertically()
+        {
+            var constrained = Constrain.To(rect)
+                .Height.Absolute(20)
+                .CenterVertically()
+                .ToRect();
+
+            Assert.AreEqual(20, constrained.height);
+            Assert.AreEqual(128 / 2 - 10, constrained.yMin);
+            Assert.AreEqual(128 / 2 + 10, constrained.yMax);
+        }
     }
-}
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "net.tnrd.constrainedrect",
-  "version": "2.0.2",
+  "version": "2.1.0",
   "displayName": "Constrained Rect",
   "description": "A simple helper to constrain a Rect to an EditorWindow or another Rect",
   "unity": "2019.1",
@@ -16,4 +16,4 @@
     "url": "https://www.tnrd.net"
   },
   "dependencies": {}
-}
+}