From a2bb233141692cca30c6eb02e192ea3d5b2cf93e Mon Sep 17 00:00:00 2001
From: Simon Jackson <darkside@zenithmoon.com>
Date: Tue, 25 Jul 2017 18:54:00 +0100
Subject: [PATCH] Merged Stepper control PR #11

---
 Editor/UIExtensionsMenuOptions.cs |  23 +++
 Scripts/Controls/Stepper.cs       | 266 ++++++++++++++++++++++++++++++
 Scripts/Controls/Stepper.cs.meta  |  12 ++
 3 files changed, 301 insertions(+)
 create mode 100644 Scripts/Controls/Stepper.cs
 create mode 100644 Scripts/Controls/Stepper.cs.meta

diff --git a/Editor/UIExtensionsMenuOptions.cs b/Editor/UIExtensionsMenuOptions.cs
index 8e2e97f..da6dd93 100644
--- a/Editor/UIExtensionsMenuOptions.cs
+++ b/Editor/UIExtensionsMenuOptions.cs
@@ -1677,6 +1677,29 @@ namespace UnityEditor.UI
             Selection.activeGameObject = go;
         }
         #endregion
+		
+        #region Stepper
+        [MenuItem("GameObject/UI/Extensions/Stepper", false)]
+        static public void AddStepper(MenuCommand menuCommand)
+        {
+            GameObject go = CreateUIElementRoot("Stepper", menuCommand, new Vector2(42, kThinHeight));
+            Stepper control = go.AddComponent<Stepper>();
+
+            var labels = new string[] { "−", "+" };
+            for (int i = 0; i < 2; i++)
+            {
+                var button = AddButtonAsChild(go);
+				button.gameObject.AddComponent<StepperSide>();
+                button.name = i == 0 ? "Minus" : "Plus";
+                var text = button.GetComponentInChildren<Text>();
+                text.text = labels[i];
+            }
+
+            control.LayoutSides();
+
+            Selection.activeGameObject = go;
+        }
+        #endregion
 
         #region UI Knob
         [MenuItem("GameObject/UI/Extensions/UI Knob", false)]
diff --git a/Scripts/Controls/Stepper.cs b/Scripts/Controls/Stepper.cs
new file mode 100644
index 0000000..e191f6c
--- /dev/null
+++ b/Scripts/Controls/Stepper.cs
@@ -0,0 +1,266 @@
+/// Credit David Gileadi
+/// Sourced from - https://bitbucket.org/UnityUIExtensions/unity-ui-extensions/pull-requests/11
+
+using System;
+using UnityEngine.Events;
+using UnityEngine.EventSystems;
+
+namespace UnityEngine.UI.Extensions
+{
+    // Stepper control
+    [AddComponentMenu("UI/Extensions/Stepper")]
+    [RequireComponent(typeof(RectTransform))]
+    public class Stepper : UIBehaviour
+    {
+        public Button[] sides
+        {
+            get
+            {
+                if (_sides == null || _sides.Length == 0)
+                {
+                    _sides = GetSides();
+                }
+                return _sides;
+            }
+        }
+        private Button[] _sides;
+
+        [SerializeField]
+        private int _value = 0;
+        public int value { get { return _value; } set { _value = value; } }
+
+        [SerializeField]
+        private int _minimum = 0;
+        public int minimum { get { return _minimum; } set { _minimum = value; } }
+
+        [SerializeField]
+        private int _maximum = 100;
+        public int maximum { get { return _maximum; } set { _maximum = value; } }
+
+        [SerializeField]
+        private int _step = 1;
+        public int step { get { return _step; } set { _step = value; } }
+
+        [SerializeField]
+        private bool _wrap = false;
+        public bool wrap { get { return _wrap; } set { _wrap = value; } }
+
+        [SerializeField]
+        private Graphic _separator;
+        public Graphic separator { get { return _separator; } set { _separator = value; _separatorWidth = 0; LayoutSides(sides); } }
+
+        private float _separatorWidth = 0;
+        private float separatorWidth
+        {
+            get
+            {
+                if (_separatorWidth == 0 && separator)
+                {
+                    _separatorWidth = separator.rectTransform.rect.width;
+                    var image = separator.GetComponent<Image>();
+                    if (image)
+                        _separatorWidth /= image.pixelsPerUnit;
+                }
+                return _separatorWidth;
+            }
+        }
+
+        [Serializable]
+        public class StepperValueChangedEvent : UnityEvent<int> { }
+
+        // Event delegates triggered on click.
+        [SerializeField]
+        private StepperValueChangedEvent _onValueChanged = new StepperValueChangedEvent();
+        public StepperValueChangedEvent onValueChanged
+        {
+            get { return _onValueChanged; }
+            set { _onValueChanged = value; }
+        }
+
+        protected Stepper()
+        { }
+
+#if UNITY_EDITOR
+        protected override void OnValidate()
+        {
+            base.OnValidate();
+
+            if (separator)
+                LayoutSides();
+
+            if (!wrap)
+            {
+                DisableAtExtremes(sides);
+            }
+        }
+#endif
+
+        private Button[] GetSides()
+        {
+            var buttons = GetComponentsInChildren<Button>();
+            if (buttons.Length != 2)
+            {
+                throw new InvalidOperationException("A stepper must have two Button children");
+            }
+
+            for (int i = 0; i < 2; i++)
+            {
+                var side = buttons[i].GetComponent<StepperSide>();
+                if (side == null)
+                {
+                    side = buttons[i].gameObject.AddComponent<StepperSide>();
+                }
+            }
+
+            if (!wrap)
+            {
+                DisableAtExtremes(buttons);
+            }
+            LayoutSides(buttons);
+
+            return buttons;
+        }
+
+        public void StepUp()
+        {
+            Step(step);
+        }
+
+        public void StepDown()
+        {
+            Step(-step);
+        }
+
+        private void Step(int amount)
+        {
+            value += amount;
+
+            if (wrap)
+            {
+                if (value > maximum) value = minimum;
+                if (value < minimum) value = maximum;
+            }
+            else
+            {
+                value = Math.Max(minimum, value);
+                value = Math.Min(maximum, value);
+
+                DisableAtExtremes(sides);
+            }
+
+            _onValueChanged.Invoke(value);
+        }
+
+        private void DisableAtExtremes(Button[] sides)
+        {
+            sides[0].interactable = wrap || value > minimum;
+            sides[1].interactable = wrap || value < maximum;
+        }
+
+        private void RecreateSprites(Button[] sides)
+        {
+            for (int i = 0; i < 2; i++)
+            {
+                if (sides[i].image == null)
+                    continue;
+
+                var sprite = sides[i].image.sprite;
+                if (sprite.border.x == 0 || sprite.border.z == 0)
+                    continue;
+
+                var rect = sprite.rect;
+                var border = sprite.border;
+
+                if (i == 0)
+                {
+                    rect.xMax = border.z;
+                    border.z = 0;
+                }
+                else
+                {
+                    rect.xMin = border.x;
+                    border.x = 0;
+                }
+
+                sides[i].image.sprite = Sprite.Create(sprite.texture, rect, sprite.pivot, sprite.pixelsPerUnit, 0, SpriteMeshType.FullRect, border);
+            }
+        }
+
+        public void LayoutSides(Button[] sides = null)
+        {
+            sides = sides ?? this.sides;
+
+            RecreateSprites(sides);
+
+            RectTransform transform = this.transform as RectTransform;
+            float width = (transform.rect.width / 2) - separatorWidth;
+
+            for (int i = 0; i < 2; i++)
+            {
+                float insetX = i == 0 ? 0 : width + separatorWidth;
+
+                var rectTransform = sides[i].GetComponent<RectTransform>();
+                rectTransform.anchorMin = Vector2.zero;
+                rectTransform.anchorMax = Vector2.zero;
+                rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, insetX, width);
+                rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, transform.rect.height);
+
+// TODO: maybe adjust text position
+            }
+
+            if (separator)
+            {
+                var sepTransform = gameObject.transform.Find("Separator");
+                Graphic sep = (sepTransform != null) ? sepTransform.GetComponent<Graphic>() : (GameObject.Instantiate(separator.gameObject) as GameObject).GetComponent<Graphic>();
+                sep.gameObject.name = "Separator";
+                sep.gameObject.SetActive(true);
+                sep.rectTransform.SetParent(this.transform, false);
+                sep.rectTransform.anchorMin = Vector2.zero;
+                sep.rectTransform.anchorMax = Vector2.zero;
+                sep.rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, width, separatorWidth);
+                sep.rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, transform.rect.height);
+            }
+        }
+    }
+
+    [RequireComponent(typeof(Button))]
+    public class StepperSide : UIBehaviour, IPointerClickHandler, ISubmitHandler
+    {
+        Button button { get { return GetComponent<Button>(); } }
+
+        Stepper stepper { get { return GetComponentInParent<Stepper>(); } }
+
+        bool leftmost { get { return button == stepper.sides[0]; } }
+
+        protected StepperSide()
+        { }
+
+        public virtual void OnPointerClick(PointerEventData eventData)
+        {
+            if (eventData.button != PointerEventData.InputButton.Left)
+                return;
+
+            Press();
+        }
+
+        public virtual void OnSubmit(BaseEventData eventData)
+        {
+            Press();
+        }
+
+        private void Press()
+        {
+            if (!button.IsActive() || !button.IsInteractable())
+                return;
+
+            if (leftmost)
+            {
+                stepper.StepDown();
+            }
+            else
+            {
+                stepper.StepUp();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Scripts/Controls/Stepper.cs.meta b/Scripts/Controls/Stepper.cs.meta
new file mode 100644
index 0000000..40387f5
--- /dev/null
+++ b/Scripts/Controls/Stepper.cs.meta
@@ -0,0 +1,12 @@
+fileFormatVersion: 2
+guid: b1867f0d5b751404f86b0e562a3d783b
+timeCreated: 1501004355
+licenseType: Free
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: