//----------------------------------------------
// NGUI: Next-Gen UI kit
// Copyright © 2011-2015 Tasharen Entertainment
//----------------------------------------------
using UnityEngine;
using System.Collections;
/// <summary>
/// UIDragDropItem is a base script for your own Drag & Drop operations.
/// </summary>
[AddComponentMenu("NGUI/Interaction/Drag and Drop Item")]
public class UIDragDropItem : MonoBehaviour
{
public enum Restriction
{
None,
Horizontal,
Vertical,
PressAndHold,
}
/// <summary>
/// What kind of restriction is applied to the drag & drop logic before dragging is made possible.
/// </summary>
public Restriction restriction = Restriction.None;
/// <summary>
/// Whether a copy of the item will be dragged instead of the item itself.
/// </summary>
public bool cloneOnDrag = false;
/// <summary>
/// How long the user has to press on an item before the drag action activates.
/// </summary>
[HideInInspector]
public float pressAndHoldDelay = 1f;
#region Common functionality
[System.NonSerialized] protected Transform mTrans;
[System.NonSerialized] protected Transform mParent;
[System.NonSerialized] protected Collider mCollider;
[System.NonSerialized] protected Collider2D mCollider2D;
[System.NonSerialized] protected UIButton mButton;
[System.NonSerialized] protected UIRoot mRoot;
[System.NonSerialized] protected UIGrid mGrid;
[System.NonSerialized] protected UITable mTable;
[System.NonSerialized] protected float mDragStartTime = 0f;
[System.NonSerialized] protected UIDragScrollView mDragScrollView = null;
[System.NonSerialized] protected bool mPressed = false;
[System.NonSerialized] protected bool mDragging = false;
[System.NonSerialized] protected UICamera.MouseOrTouch mTouch;
/// <summary>
/// Cache the transform.
/// </summary>
protected virtual void Start ()
{
mTrans = transform;
#if UNITY_4_3 || UNITY_4_5 || UNITY_4_6
mCollider = collider;
mCollider2D = collider2D;
#else
mCollider = gameObject.GetComponent<Collider>();
mCollider2D = gameObject.GetComponent<Collider2D>();
#endif
mButton = GetComponent<UIButton>();
mDragScrollView = GetComponent<UIDragScrollView>();
}
/// <summary>
/// Record the time the item was pressed on.
/// </summary>
protected void OnPress (bool isPressed)
{
if (isPressed)
{
mTouch = UICamera.currentTouch;
mDragStartTime = RealTime.time + pressAndHoldDelay;
mPressed = true;
}
else
{
mPressed = false;
mTouch = null;
}
}
/// <summary>
/// Start the dragging operation after the item was held for a while.
/// </summary>
protected virtual void Update ()
{
if (restriction == Restriction.PressAndHold)
{
if (mPressed && !mDragging && mDragStartTime < RealTime.time)
StartDragging();
}
}
/// <summary>
/// Start the dragging operation.
/// </summary>
protected void OnDragStart ()
{
if (!enabled || mTouch != UICamera.currentTouch) return;
// If we have a restriction, check to see if its condition has been met first
if (restriction != Restriction.None)
{
if (restriction == Restriction.Horizontal)
{
Vector2 delta = mTouch.totalDelta;
if (Mathf.Abs(delta.x) < Mathf.Abs(delta.y)) return;
}
else if (restriction == Restriction.Vertical)
{
Vector2 delta = mTouch.totalDelta;
if (Mathf.Abs(delta.x) > Mathf.Abs(delta.y)) return;
}
else if (restriction == Restriction.PressAndHold)
{
// Checked in Update instead
return;
}
}
StartDragging();
}
/// <summary>
/// Start the dragging operation.
/// </summary>
protected virtual void StartDragging ()
{
if (!mDragging)
{
if (cloneOnDrag)
{
mPressed = false;
GameObject clone = NGUITools.AddChild(transform.parent.gameObject, gameObject);
clone.transform.localPosition = transform.localPosition;
clone.transform.localRotation = transform.localRotation;
clone.transform.localScale = transform.localScale;
UIButtonColor bc = clone.GetComponent<UIButtonColor>();
if (bc != null) bc.defaultColor = GetComponent<UIButtonColor>().defaultColor;
if (mTouch != null && mTouch.pressed == gameObject)
{
mTouch.current = clone;
mTouch.pressed = clone;
mTouch.dragged = clone;
mTouch.last = clone;
}
UIDragDropItem item = clone.GetComponent<UIDragDropItem>();
item.mTouch = mTouch;
item.mPressed = true;
item.mDragging = true;
item.Start();
item.OnDragDropStart();
if (UICamera.currentTouch == null)
UICamera.currentTouch = mTouch;
mTouch = null;
UICamera.Notify(gameObject, "OnPress", false);
UICamera.Notify(gameObject, "OnHover", false);
}
else
{
mDragging = true;
OnDragDropStart();
}
}
}
/// <summary>
/// Perform the dragging.
/// </summary>
protected void OnDrag (Vector2 delta)
{
if (!mDragging || !enabled || mTouch != UICamera.currentTouch) return;
OnDragDropMove(delta * mRoot.pixelSizeAdjustment);
}
/// <summary>
/// Notification sent when the drag event has ended.
/// </summary>
protected void OnDragEnd ()
{
if (!enabled || mTouch != UICamera.currentTouch) return;
StopDragging(UICamera.hoveredObject);
}
/// <summary>
/// Drop the dragged item.
/// </summary>
public void StopDragging (GameObject go)
{
if (mDragging)
{
mDragging = false;
OnDragDropRelease(go);
}
}
#endregion
/// <summary>
/// Perform any logic related to starting the drag & drop operation.
/// </summary>
protected virtual void OnDragDropStart ()
{
// Automatically disable the scroll view
if (mDragScrollView != null) mDragScrollView.enabled = false;
// Disable the collider so that it doesn't intercept events
if (mButton != null) mButton.isEnabled = false;
else if (mCollider != null) mCollider.enabled = false;
else if (mCollider2D != null) mCollider2D.enabled = false;
mParent = mTrans.parent;
mRoot = NGUITools.FindInParents<UIRoot>(mParent);
mGrid = NGUITools.FindInParents<UIGrid>(mParent);
mTable = NGUITools.FindInParents<UITable>(mParent);
// Re-parent the item
if (UIDragDropRoot.root != null)
mTrans.parent = UIDragDropRoot.root;
Vector3 pos = mTrans.localPosition;
pos.z = 0f;
mTrans.localPosition = pos;
TweenPosition tp = GetComponent<TweenPosition>();
if (tp != null) tp.enabled = false;
SpringPosition sp = GetComponent<SpringPosition>();
if (sp != null) sp.enabled = false;
// Notify the widgets that the parent has changed
NGUITools.MarkParentAsChanged(gameObject);
if (mTable != null) mTable.repositionNow = true;
if (mGrid != null) mGrid.repositionNow = true;
}
/// <summary>
/// Adjust the dragged object's position.
/// </summary>
protected virtual void OnDragDropMove (Vector2 delta)
{
mTrans.localPosition += (Vector3)delta;
}
/// <summary>
/// Drop the item onto the specified object.
/// </summary>
protected virtual void OnDragDropRelease (GameObject surface)
{
if (!cloneOnDrag)
{
// Re-enable the collider
if (mButton != null) mButton.isEnabled = true;
else if (mCollider != null) mCollider.enabled = true;
else if (mCollider2D != null) mCollider2D.enabled = true;
// Is there a droppable container?
UIDragDropContainer container = surface ? NGUITools.FindInParents<UIDragDropContainer>(surface) : null;
if (container != null)
{
// Container found -- parent this object to the container
mTrans.parent = (container.reparentTarget != null) ? container.reparentTarget : container.transform;
Vector3 pos = mTrans.localPosition;
pos.z = 0f;
mTrans.localPosition = pos;
}
else
{
// No valid container under the mouse -- revert the item's parent
mTrans.parent = mParent;
}
// Update the grid and table references
mParent = mTrans.parent;
mGrid = NGUITools.FindInParents<UIGrid>(mParent);
mTable = NGUITools.FindInParents<UITable>(mParent);
// Re-enable the drag scroll view script
if (mDragScrollView != null)
StartCoroutine(EnableDragScrollView());
// Notify the widgets that the parent has changed
NGUITools.MarkParentAsChanged(gameObject);
if (mTable != null) mTable.repositionNow = true;
if (mGrid != null) mGrid.repositionNow = true;
// We're now done
OnDragDropEnd();
}
else NGUITools.Destroy(gameObject);
}
/// <summary>
/// Function called when the object gets reparented after the drop operation finishes.
/// </summary>
protected virtual void OnDragDropEnd () { }
/// <summary>
/// Re-enable the drag scroll view script at the end of the frame.
/// Reason: http://www.tasharen.com/forum/index.php?topic=10203.0
/// </summary>
protected IEnumerator EnableDragScrollView ()
{
yield return new WaitForEndOfFrame
(); if (mDragScrollView != null) mDragScrollView.enabled = true;
}
}
