//-------------------------------------------------
//            NGUI: Next-Gen UI kit
// Copyright © 2011-2019 Tasharen Entertainment Inc
//-------------------------------------------------

using UnityEngine;
using System.Collections;

/// <summary>
/// Allows dragging of the specified scroll view by mouse or touch.
/// </summary>

[AddComponentMenu("NGUI/Interaction/Drag Scroll View")]
public class UIDragScrollView_Ex : MonoBehaviour
{
    /// <summary>
    /// Reference to the scroll view that will be dragged by the script.
    /// </summary>

    //UIScrollView scrollView;

    public UIScrollView scrollView_W;
    public UIScrollView scrollView_H;
    public UICenterOnChild centerOn;

    // Legacy functionality, kept for backwards compatibility. Use 'scrollView' instead.
    [HideInInspector] [SerializeField] UIScrollView draggablePanel;

    Transform mTrans;
    UIScrollView mScroll;
    bool mAutoFind = false;
    bool mStarted = false;
    int iDirection = 0;
    Vector2 vTset2 = Vector2.zero;
    /// <summary>
    /// Automatically find the scroll view if possible.
    /// </summary>

    void OnEnable()
    {
        mTrans = transform;
        // Auto-upgrade
        if (scrollView_W == null && draggablePanel != null)
        {
            scrollView_W = draggablePanel;
            draggablePanel = null;
        }

        if (mStarted && (mAutoFind || mScroll == null))
            FindScrollView();
    }

    /// <summary>
    /// Find the scroll view.
    /// </summary>

    void Start()
    {
        mStarted = true;
        FindScrollView();
    }

    /// <summary>
    /// Find the scroll view to work with.
    /// </summary>

    void FindScrollView()
    {
        // If the scroll view is on a parent, don't try to remember it (as we want it to be dynamic in case of re-parenting)
        UIScrollView sv = NGUITools.FindInParents<UIScrollView>(mTrans);

        if (sv != null && (scrollView_H == null || (mAutoFind && sv != scrollView_H)))
        {
            scrollView_H = sv;
            mAutoFind = true;

            if (scrollView_W == null)
            {
                sv = NGUITools.FindInParents<UIScrollView>(scrollView_H.gameObject.transform.parent.gameObject);
                scrollView_W = sv;
            }

            if (centerOn == null)
            {
                centerOn = NGUITools.FindInParents<UICenterOnChild>(mTrans);
            }
        }
        else if (scrollView_H == sv)
        {
            mAutoFind = true;
        }
        mScroll = scrollView_H;

        if (scrollView_H == null || scrollView_H == null || centerOn == null)
        {
             enabled = false;
          //  GameObject.Destroy(this);
        }
    }

    [System.NonSerialized] bool mPressed = false;

    /// <summary>
    /// Stop the active dragging operation.
    /// </summary>

    void OnDisable()
    {
        if (mPressed && mScroll != null && mScroll.GetComponentInChildren<UIWrapContent>() == null)
        {
            mScroll.Press(false);
            mScroll = null;
        }
    }

    /// <summary>
    /// Create a plane on which we will be performing the dragging.
    /// </summary>

    void OnPress(bool pressed)
    {
        if (centerOn == null)
            return;

        iDirection = 0;
        vTset2 = Vector2.zero;
        mPressed = pressed;
        //if (pressed)
            //centerOn.bCenterOn = false;
        // If the scroll view has been set manually, don't try to find it again
        if (mAutoFind && mScroll != scrollView_W)
        {
            mScroll = scrollView_W;
            mAutoFind = false;
        }

        if (scrollView_W && enabled && NGUITools.GetActive(gameObject))
        {
            scrollView_W.Press(pressed);
            scrollView_H.Press(pressed);

            if (!pressed && mAutoFind)
            {
                scrollView_W = NGUITools.FindInParents<UIScrollView>(mTrans);
                mScroll = scrollView_W;
            }
        }
    }

    /// <summary>
    /// Drag the object along the plane.
    /// </summary>

    void OnDrag(Vector2 delta)
    {
        if (iDirection == 0)
        {
            vTset2 += delta;
            if (Mathf.Abs(vTset2.x) - Mathf.Abs(vTset2.y) > 10)
            {
                centerOn.bCenterOn = true;
                iDirection = 1;
            }
            else if (Mathf.Abs(vTset2.y) - Mathf.Abs(vTset2.x) > 10)
            {
                // centerOn.bCenterOn = false;
                iDirection = 2;
            }
        }

        if (scrollView_W && NGUITools.GetActive(this))
        {
            if (iDirection == 1)
                scrollView_W.Drag();
            else if (iDirection == 2)
                scrollView_H.Drag();
        }
    }

    /// <summary>
    /// If the object should support the scroll wheel, do it.
    /// </summary>

    void OnScroll(float delta)
    {
        if (scrollView_W && NGUITools.GetActive(this))
        {
            if (iDirection == 1)
                scrollView_W.Scroll(delta);
            else if (iDirection == 2)
                scrollView_H.Scroll(delta);
        }

    }

    /// <summary>
    /// Pan the scroll view.
    /// </summary>

    public void OnPan(Vector2 delta)
    {
        if (scrollView_W && NGUITools.GetActive(this))
        {
            if (iDirection == 1)
                scrollView_W.OnPan(delta);
            else if (iDirection == 2)
                scrollView_H.OnPan(delta);
        }
    }
}