From 680076b631d67fb2a7a5cbcbc03e0ee100885505 Mon Sep 17 00:00:00 2001
From: David Gileadi <gileadis@gmail.com>
Date: Sun, 23 Jul 2017 21:48:38 -0700
Subject: [PATCH] Create segmented control

---
 Editor/UIExtensionsMenuOptions.cs         |  26 ++
 Scripts/Controls/SegmentedControl.cs      | 434 ++++++++++++++++++++++
 Scripts/Controls/SegmentedControl.cs.meta |  12 +
 3 files changed, 472 insertions(+)
 create mode 100644 Scripts/Controls/SegmentedControl.cs
 create mode 100644 Scripts/Controls/SegmentedControl.cs.meta

diff --git a/Editor/UIExtensionsMenuOptions.cs b/Editor/UIExtensionsMenuOptions.cs
index ec94484..8e2e97f 100644
--- a/Editor/UIExtensionsMenuOptions.cs
+++ b/Editor/UIExtensionsMenuOptions.cs
@@ -1652,6 +1652,32 @@ namespace UnityEditor.UI
 
         #endregion
 
+        #region Segmented Control
+        [MenuItem("GameObject/UI/Extensions/Segmented Control", false)]
+        static public void AddSegmentedControl(MenuCommand menuCommand)
+        {
+            GameObject go = CreateUIElementRoot("Segmented Control", menuCommand, s_ThinGUIElementSize);
+            SegmentedControl control = go.AddComponent<SegmentedControl>();
+
+            Color selectedColor = new Color(0f, 0.455f, 0.894f);
+            control.selectedColor = selectedColor;
+
+            var labels = new string[] { "This", "That", "Other" };
+            for (int i = 0; i < 3; i++)
+			{
+                var button = AddButtonAsChild(go);
+                button.name = "Segment " + (i + 1);
+                var text = button.GetComponentInChildren<Text>();
+                text.text = labels[i];
+                text.color = selectedColor;
+            }
+
+            control.LayoutSegments();
+
+            Selection.activeGameObject = go;
+        }
+        #endregion
+
         #region UI Knob
         [MenuItem("GameObject/UI/Extensions/UI Knob", false)]
 		static public void AddUIKnob(MenuCommand menuCommand)
diff --git a/Scripts/Controls/SegmentedControl.cs b/Scripts/Controls/SegmentedControl.cs
new file mode 100644
index 0000000..4486643
--- /dev/null
+++ b/Scripts/Controls/SegmentedControl.cs
@@ -0,0 +1,434 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine.Events;
+using UnityEngine.EventSystems;
+using UnityEngine.Serialization;
+
+namespace UnityEngine.UI.Extensions
+{
+    // Segmented control, like a group of buttons
+    [AddComponentMenu("UI/Extensions/Segmented Control")]
+    [RequireComponent(typeof(RectTransform))]
+    public class SegmentedControl : UIBehaviour
+    {
+        public Button[] segments
+        {
+            get
+            {
+                if (_segments == null || _segments.Length == 0)
+                {
+                    _segments = GetChildSegments();
+                }
+                return _segments;
+            }
+        }
+        private Button[] _segments;
+
+        [SerializeField]
+        public Color selectedColor;
+
+        [SerializeField]
+        private Graphic _separator;
+        public Graphic separator { get { return _separator; } set { _separator = value; _separatorWidth = 0; LayoutSegments(); } }
+
+        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;
+            }
+        }
+
+        [SerializeField] private bool _allowSwitchingOff = false;
+        public bool allowSwitchingOff { get { return _allowSwitchingOff; } set { _allowSwitchingOff = value; } }
+
+        protected internal Button selectedSegment;
+
+        [SerializeField]
+        private int _selectedSegmentIndex = -1;
+        public int selectedSegmentIndex
+        {
+            get { return Array.IndexOf(segments, selectedSegment); }
+            set
+            {
+                value = Math.Max(value, -1);
+                value = Math.Min(value, segments.Length - 1);
+                _selectedSegmentIndex = value;
+                if (value == -1)
+                {
+                    if (selectedSegment)
+                    {
+                        selectedSegment.GetComponent<Segment>().selected = false;
+                        selectedSegment = null;
+                    }
+                }
+                else
+                {
+#if UNITY_EDITOR
+                    segments[value].GetComponent<Segment>().StoreTextColor();
+#endif
+                    segments[value].GetComponent<Segment>().selected = true;
+                }
+            }
+        }
+
+        [Serializable]
+        public class SegmentSelectedEvent : UnityEvent<int> { }
+
+        // Event delegates triggered on click.
+        [SerializeField]
+        private SegmentSelectedEvent _onValueChanged = new SegmentSelectedEvent();
+
+        public SegmentSelectedEvent onValueChanged
+        {
+            get { return _onValueChanged; }
+            set { _onValueChanged = value; }
+        }
+
+        protected SegmentedControl()
+        { }
+
+        protected override void Start()
+        {
+            base.Start();
+
+            LayoutSegments();
+
+            if (_selectedSegmentIndex != -1)
+                selectedSegmentIndex = _selectedSegmentIndex;
+        }
+
+#if UNITY_EDITOR
+        protected override void OnValidate()
+        {
+            base.OnValidate();
+
+            if (separator)
+                LayoutSegments();
+
+            if (_selectedSegmentIndex != -1)
+                selectedSegmentIndex = _selectedSegmentIndex;
+        }
+#endif
+
+        private Button[] GetChildSegments()
+        {
+            var buttons = GetComponentsInChildren<Button>();
+            if (buttons.Length < 2)
+            {
+                throw new InvalidOperationException("A segmented control must have at least two Button children");
+            }
+
+            for (int i = 0; i < buttons.Length; i++)
+            {
+                var segment = buttons[i].GetComponent<Segment>();
+                if (segment == null)
+                {
+                    segment = buttons[i].gameObject.AddComponent<Segment>();
+                }
+                segment.index = i;
+            }
+
+            return buttons;
+        }
+
+        public void SetAllSegmentsOff()
+        {
+            selectedSegment = null;
+        }
+
+        public void LayoutSegments()
+        {
+            RectTransform transform = this.transform as RectTransform;
+            float width = (transform.rect.width / segments.Length) - (separatorWidth * (segments.Length - 1));
+
+            for (int i = 0; i < segments.Length; i++)
+            {
+                float leftX = 0;
+                float rightX = 0;
+                if (segments[i].image != null && segments[i].image.hasBorder)
+                {
+                    if (i > 0)
+                    {
+                        leftX = segments[i].image.sprite.border.x / segments[i].image.pixelsPerUnit;
+                    }
+                    if (i < segments.Length - 1)
+                    {
+                        rightX = segments[i].image.sprite.border.z / segments[i].image.pixelsPerUnit;
+                    }
+                }
+
+                float insetX = ((width + separatorWidth) * i) - leftX;
+
+                var rectTransform = segments[i].GetComponent<RectTransform>();
+                rectTransform.anchorMin = Vector2.zero;
+                rectTransform.anchorMax = Vector2.zero;
+                rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, insetX, width + leftX + rightX);
+                rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, transform.rect.height);
+
+                if (separator && i > 0)
+                {
+                    var sepTransform = gameObject.transform.Find("Separator " + i);
+                    Graphic sep = (sepTransform != null) ? sepTransform.GetComponent<Graphic>() : (GameObject.Instantiate(separator.gameObject) as GameObject).GetComponent<Graphic>();
+                    sep.gameObject.name = "Separator " + i;
+                    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, insetX + leftX - separatorWidth, separatorWidth);
+                    sep.rectTransform.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, transform.rect.height);
+                }
+// TODO: maybe adjust text position
+            }
+        }
+    }
+
+    [RequireComponent(typeof(Button))]
+    public class Segment :
+        UIBehaviour,
+        IMeshModifier,
+        IPointerClickHandler,
+        ISubmitHandler,
+        IPointerEnterHandler, IPointerExitHandler,
+        IPointerDownHandler, IPointerUpHandler,
+        ISelectHandler, IDeselectHandler
+    {
+        internal int index;
+
+        internal bool leftmost
+        {
+            get { return index == 0; }
+        }
+        internal bool rightmost
+        {
+            get { return index == segmentControl.segments.Length - 1; }
+        }
+
+        public bool selected
+        {
+            get { return segmentControl.selectedSegment == this.button; }
+            set { SetSelected(value); }
+        }
+
+        internal SegmentedControl segmentControl
+        {
+            get { return GetComponentInParent<SegmentedControl>(); }
+        }
+
+        internal Button button
+        {
+            get { return GetComponent<Button>(); }
+        }
+
+        [SerializeField]
+        Color textColor;
+
+        protected Segment()
+        { }
+
+        public virtual void OnPointerClick(PointerEventData eventData)
+        {
+            if (eventData.button != PointerEventData.InputButton.Left)
+                return;
+
+            selected = true;
+        }
+
+        public virtual void OnPointerEnter(PointerEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnPointerExit(PointerEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnPointerDown(PointerEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnPointerUp(PointerEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnSelect(BaseEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnDeselect(BaseEventData eventData)
+        {
+            MaintainSelection();
+        }
+
+        public virtual void OnSubmit(BaseEventData eventData)
+        {
+            selected = true;
+        }
+
+        private void SetSelected(bool value)
+        {
+            if (value && button.IsActive() && button.IsInteractable())
+            {
+                if (segmentControl.selectedSegment == this.button)
+                {
+                    if (segmentControl.allowSwitchingOff)
+                    {
+                        Deselect();
+                    }
+                    else
+                    {
+                        MaintainSelection();
+                    }
+                }
+                else
+                {
+                    if (segmentControl.selectedSegment)
+                    {
+                        var segment = segmentControl.selectedSegment.GetComponent<Segment>();
+                        segmentControl.selectedSegment = null;
+                        segment.TransitionButton();
+                    }
+
+                    segmentControl.selectedSegment = this.button;
+                    StoreTextColor();
+                    TransitionButton();
+                    segmentControl.onValueChanged.Invoke(index);
+                }
+            }
+            else if (segmentControl.selectedSegment == this.button)
+            {
+                Deselect();
+            }
+        }
+
+        private void Deselect()
+        {
+            segmentControl.selectedSegment = null;
+            TransitionButton();
+            segmentControl.onValueChanged.Invoke(-1);
+        }
+
+        void MaintainSelection()
+        {
+            if (button != segmentControl.selectedSegment)
+                return;
+
+            TransitionButton(true);
+        }
+
+        internal void TransitionButton()
+        {
+            TransitionButton(false);
+        }
+
+        internal void TransitionButton(bool instant)
+        {
+            Color tintColor = selected ? segmentControl.selectedColor : button.colors.normalColor;
+            Color textColor = selected ? button.colors.normalColor : this.textColor;
+            Sprite transitionSprite = selected ? button.spriteState.pressedSprite : null;
+            string triggerName = selected ? button.animationTriggers.pressedTrigger : button.animationTriggers.normalTrigger;
+
+            switch (button.transition)
+            {
+                case Selectable.Transition.ColorTint:
+                    StartColorTween(tintColor * button.colors.colorMultiplier, instant);
+                    ChangeTextColor(textColor * button.colors.colorMultiplier);
+                    break;
+                case Selectable.Transition.SpriteSwap:
+                    DoSpriteSwap(transitionSprite);
+                    break;
+                case Selectable.Transition.Animation:
+                    TriggerAnimation(triggerName);
+                    break;
+            }
+        }
+
+        void StartColorTween(Color targetColor, bool instant)
+        {
+            if (button.targetGraphic == null)
+                return;
+
+            button.targetGraphic.CrossFadeColor(targetColor, instant ? 0f : button.colors.fadeDuration, true, true);
+        }
+
+        internal void StoreTextColor()
+        {
+            var text = GetComponentInChildren<Text>();
+            if (!text)
+                return;
+
+            textColor = text.color;
+        }
+
+        void ChangeTextColor(Color targetColor)
+        {
+            var text = GetComponentInChildren<Text>();
+            if (!text)
+                return;
+
+            text.color = targetColor;
+        }
+
+        void DoSpriteSwap(Sprite newSprite)
+        {
+            if (button.image == null)
+                return;
+
+            button.image.overrideSprite = newSprite;
+        }
+
+        void TriggerAnimation(string triggername)
+        {
+            if (button.animator == null || !button.animator.isActiveAndEnabled || !button.animator.hasBoundPlayables || string.IsNullOrEmpty(triggername))
+                return;
+
+            button.animator.ResetTrigger(button.animationTriggers.normalTrigger);
+            button.animator.ResetTrigger(button.animationTriggers.pressedTrigger);
+            button.animator.ResetTrigger(button.animationTriggers.highlightedTrigger);
+            button.animator.ResetTrigger(button.animationTriggers.disabledTrigger);
+
+            button.animator.SetTrigger(triggername);
+        }
+
+        public void ModifyMesh(Mesh mesh)
+        {
+            throw new NotSupportedException();
+        }
+
+        public void ModifyMesh(VertexHelper verts)
+        {
+            if (verts.currentIndexCount != 54)
+            {
+                return;
+            }
+
+            List<UIVertex> vertexList = new List<UIVertex>();
+            verts.GetUIVertexStream(vertexList);
+
+            if (!leftmost)
+            {
+                vertexList.RemoveRange(0, 18);
+            }
+            if (!rightmost)
+            {
+                vertexList.RemoveRange(vertexList.Count - 18, 18);
+            }
+
+            verts.Clear();
+            verts.AddUIVertexTriangleStream(vertexList);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Scripts/Controls/SegmentedControl.cs.meta b/Scripts/Controls/SegmentedControl.cs.meta
new file mode 100644
index 0000000..c857a57
--- /dev/null
+++ b/Scripts/Controls/SegmentedControl.cs.meta
@@ -0,0 +1,12 @@
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+guid: 439b3dcc2b7714c1e91776a9d161f6ee
+timeCreated: 1498517608
+licenseType: Free
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
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