SplitLayout.cs

using System.Collections.Generic;
using BepInEx.Logging;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace MoveControllerAxisSplit
{
    internal enum Axis
    {
        X,
        Z
    }

    internal sealed class SplitLayout
    {
        private sealed class TextState
        {
            internal Text Text;
            internal bool Enabled;
        }

        private readonly ManualLogSource _logger;
        private readonly MoveControllerBridge _bridge;
        private readonly List<TextState> _originalTextStates = new List<TextState>();
        private Button _sourceButton;
        private Button _zButton;
        private GameObject _xLabel;
        private Vector2 _originalSizeDelta;
        private Vector2 _originalAnchoredPosition;

        internal bool IsApplied
        {
            get { return _sourceButton != null; }
        }

        internal bool IsAlive
        {
            get { return _sourceButton != null && _sourceButton.gameObject != null; }
        }

        internal SplitLayout(ManualLogSource logger, MoveControllerBridge bridge)
        {
            _logger = logger;
            _bridge = bridge;
        }

        internal bool Apply(Button sourceButton, float gap)
        {
            if (sourceButton == null || IsApplied)
                return false;

            RectTransform sourceRect = sourceButton.transform as RectTransform;
            if (sourceRect == null)
                return false;

            try
            {
                _sourceButton = sourceButton;
                _originalSizeDelta = sourceRect.sizeDelta;
                _originalAnchoredPosition = sourceRect.anchoredPosition;
                CaptureAndHideOriginalText(sourceButton);

                GameObject clone = Object.Instantiate(sourceButton.gameObject) as GameObject;
                if (clone == null)
                    throw new UnityException("Could not clone the Move XZ control.");

                clone.name = "MoveZ";
                clone.transform.SetParent(sourceRect.parent, false);
                _zButton = clone.GetComponent<Button>();
                if (_zButton == null)
                    throw new UnityException("The cloned Move Z control has no Button component.");

                RectTransform zRect = clone.transform as RectTransform;
                CopyRectTransform(sourceRect, zRect);
                RemoveEventTriggers(sourceButton.gameObject);
                RemoveEventTriggers(clone);
                ClearButtonClick(sourceButton);
                ClearButtonClick(_zButton);
                HideAllText(_zButton);

                SplitVertically(sourceRect, zRect, gap);
                _xLabel = CreateLabel(sourceButton, "\u2190  Move X  \u2192");
                CreateLabel(_zButton, "\u2190  Move Z  \u2192");

                if (!_bridge.BindAxisButton(sourceButton, Axis.X) ||
                    !_bridge.BindAxisButton(_zButton, Axis.Z))
                {
                    throw new UnityException("Could not bind one or more split controls.");
                }

                Canvas.ForceUpdateCanvases();
                return true;
            }
            catch (System.Exception ex)
            {
                _logger.LogError("Could not split the Move XZ control: " + ex.Message);
                RestoreOriginal();
                return false;
            }
        }

        internal void RestoreOriginal()
        {
            if (_sourceButton == null)
            {
                ForgetDestroyedLayout();
                return;
            }

            try
            {
                if (_zButton != null)
                    Object.DestroyImmediate(_zButton.gameObject);

                if (_xLabel != null)
                    Object.DestroyImmediate(_xLabel);

                RectTransform sourceRect = _sourceButton.transform as RectTransform;
                if (sourceRect != null)
                {
                    sourceRect.sizeDelta = _originalSizeDelta;
                    sourceRect.anchoredPosition = _originalAnchoredPosition;
                }

                RestoreOriginalText();
                RemoveEventTriggers(_sourceButton.gameObject);
                ClearButtonClick(_sourceButton);
                _bridge.BindOriginalXZ(_sourceButton);
                Canvas.ForceUpdateCanvases();
            }
            catch (System.Exception ex)
            {
                _logger.LogWarning("Could not fully restore the original Move XZ control: " + ex.Message);
            }
            finally
            {
                ForgetDestroyedLayout();
            }
        }

        internal void ForgetDestroyedLayout()
        {
            _sourceButton = null;
            _zButton = null;
            _xLabel = null;
            _originalTextStates.Clear();
        }

        private void CaptureAndHideOriginalText(Button button)
        {
            _originalTextStates.Clear();
            Text[] texts = button.GetComponentsInChildren<Text>(true);
            for (int i = 0; i < texts.Length; i++)
            {
                TextState state = new TextState();
                state.Text = texts[i];
                state.Enabled = texts[i].enabled;
                _originalTextStates.Add(state);
                texts[i].enabled = false;
            }
        }

        private void RestoreOriginalText()
        {
            for (int i = 0; i < _originalTextStates.Count; i++)
            {
                TextState state = _originalTextStates[i];
                if (state.Text != null)
                    state.Text.enabled = state.Enabled;
            }
        }

        private static void HideAllText(Button button)
        {
            Text[] texts = button.GetComponentsInChildren<Text>(true);
            for (int i = 0; i < texts.Length; i++)
                texts[i].enabled = false;
        }

        private static GameObject CreateLabel(Button button, string label)
        {
            Text template = null;
            Text[] texts = button.GetComponentsInChildren<Text>(true);
            if (texts.Length > 0)
                template = texts[0];

            GameObject labelObject = new GameObject("AxisSplitLabel", typeof(RectTransform), typeof(Text));
            RectTransform rect = labelObject.GetComponent<RectTransform>();
            rect.SetParent(button.transform, false);
            rect.anchorMin = Vector2.zero;
            rect.anchorMax = Vector2.one;
            rect.offsetMin = new Vector2(2f, 1f);
            rect.offsetMax = new Vector2(-2f, -1f);
            rect.localScale = Vector3.one;

            Text text = labelObject.GetComponent<Text>();
            text.text = label;
            text.alignment = TextAnchor.MiddleCenter;
            text.raycastTarget = false;
            text.color = template != null ? template.color : Color.black;
            text.font = template != null ? template.font : Resources.GetBuiltinResource<Font>("Arial.ttf");
            text.fontStyle = template != null ? template.fontStyle : FontStyle.Normal;
            text.fontSize = template != null ? template.fontSize : 12;
            text.resizeTextForBestFit = true;
            text.resizeTextMinSize = 7;
            text.resizeTextMaxSize = Mathf.Max(10, text.fontSize);
            return labelObject;
        }

        private static void SplitVertically(RectTransform xRect, RectTransform zRect, float gap)
        {
            float originalHeight = xRect.rect.height;
            if (originalHeight <= 1f)
                originalHeight = Mathf.Abs(xRect.sizeDelta.y);
            float splitHeight = Mathf.Max(8f, (originalHeight - gap) * 0.5f);
            float pivotY = xRect.pivot.y;
            float originalTop = xRect.anchoredPosition.y + ((1f - pivotY) * originalHeight);
            float originalBottom = xRect.anchoredPosition.y - (pivotY * originalHeight);

            xRect.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, splitHeight);
            zRect.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, splitHeight);

            Vector2 xPosition = xRect.anchoredPosition;
            xPosition.y = originalTop - ((1f - pivotY) * splitHeight);
            xRect.anchoredPosition = xPosition;

            Vector2 zPosition = zRect.anchoredPosition;
            zPosition.y = originalBottom + (pivotY * splitHeight);
            zRect.anchoredPosition = zPosition;
        }

        private static void CopyRectTransform(RectTransform source, RectTransform target)
        {
            target.anchorMin = source.anchorMin;
            target.anchorMax = source.anchorMax;
            target.pivot = source.pivot;
            target.sizeDelta = source.sizeDelta;
            target.anchoredPosition = source.anchoredPosition;
            target.localScale = source.localScale;
            target.localRotation = source.localRotation;
        }

        private static void RemoveEventTriggers(GameObject gameObject)
        {
            EventTrigger[] triggers = gameObject.GetComponents<EventTrigger>();
            for (int i = 0; i < triggers.Length; i++)
                Object.DestroyImmediate(triggers[i]);
        }

        private static void ClearButtonClick(Button button)
        {
            button.onClick = new Button.ButtonClickedEvent();
        }
    }
}