In Unity i am using IBeginDragHandler, IDragHandler, IEndDragHandler to drag and drop object. it's working fine. My need is to reset the position of the draggable object to the starting position if it doesn't touch another object that contains IDropHandler. below is my code
Drag script:-
using UnityEngine.EventSystems;
public class Compiler_Drag : MonoBehaviour, IPointerDownHandler, IBeginDragHandler, IEndDragHandler, IDragHandler
{
[SerializeField] private Canvas canvas;
private RectTransform rectTransform;
private CanvasGroup canvasGroup;
Vector3 myPosition;
// Start is called before the first frame update
void Start()
{
myPosition = this.gameObject.transform.position;
}
private void Awake()
{
rectTransform =GetComponent<RectTransform>();
canvasGroup = GetComponent<CanvasGroup>();
}
// Update is called once per frame
void Update()
{
}
public void OnBeginDrag(PointerEventData eventData)
{
Debug.Log("OnBeginDrag");
canvasGroup.alpha = .6f;
canvasGroup.blocksRaycasts = false;
}
public void OnDrag(PointerEventData eventData)
{
Debug.Log("OnDrag");
rectTransform.anchoredPosition +=eventData.delta/ canvas.scaleFactor;
}
public void OnEndDrag(PointerEventData eventData)
{
Debug.Log("OnEndDrag");
canvasGroup.alpha = 1f;
canvasGroup.blocksRaycasts = true;
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("OnPointerDown");
}
}
> Drop object script:-
using UnityEngine.EventSystems;
public class Compiler_Drop_Handler : MonoBehaviour, IDropHandler
{
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
}
public void OnDrop(PointerEventData eventData)
{
Debug.Log("OnDrop");
if(eventData.pointerDrag !=null)
{
eventData.pointerDrag.GetComponent<RectTransform>().anchoredPosition = GetComponent<RectTransform>().anchoredPosition;
}
}
}
what I need is that I should be only able to drop the dragging object, to the object that contains/is attached to the second script.
Related
How to detect UI object on Canvas on Touch in android?
For example, I have a canvas that have 5 objects such as Image, RawImage, Buttons, InputField and so on.
When I touch on Button UI object Then do something. Each button do different process when clicked depending.
The code will look like:
private void Update()
{
if (Input.touches.Length <= 0) return;
for (int i = 0; i < Input.touchCount; i++)
{
if (Button1.touch)
if (Input.GetTouch(i).phase == TouchPhase.Began)
login();
else if (Button2.touch && Input.GetTouch(i).phase == TouchPhase.Began)
LogOut();
}
}
So how to do it?
Second:
How to detect Gameobject get touch? Is it same with that above or not?
You don't use the Input API for the new UI. You subscribe to UI events or implement interface depending on the event.
These are the proper ways to detect events on the new UI components:
1.Image, RawImage and Text Components:
Implement the needed interface and override its function. The example below implements the most used events.
using UnityEngine.EventSystems;
public class ClickDetector : MonoBehaviour, IPointerDownHandler, IPointerClickHandler,
IPointerUpHandler, IPointerExitHandler, IPointerEnterHandler,
IBeginDragHandler, IDragHandler, IEndDragHandler
{
public void OnBeginDrag(PointerEventData eventData)
{
Debug.Log("Drag Begin");
}
public void OnDrag(PointerEventData eventData)
{
Debug.Log("Dragging");
}
public void OnEndDrag(PointerEventData eventData)
{
Debug.Log("Drag Ended");
}
public void OnPointerClick(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Mouse Down: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerEnter(PointerEventData eventData)
{
Debug.Log("Mouse Enter");
}
public void OnPointerExit(PointerEventData eventData)
{
Debug.Log("Mouse Exit");
}
public void OnPointerUp(PointerEventData eventData)
{
Debug.Log("Mouse Up");
}
}
2.Button Component:
You use events to register to Button clicks:
public class ButtonClickDetector : MonoBehaviour
{
public Button button1;
public Button button2;
public Button button3;
void OnEnable()
{
//Register Button Events
button1.onClick.AddListener(() => buttonCallBack(button1));
button2.onClick.AddListener(() => buttonCallBack(button2));
button3.onClick.AddListener(() => buttonCallBack(button3));
}
private void buttonCallBack(Button buttonPressed)
{
if (buttonPressed == button1)
{
//Your code for button 1
Debug.Log("Clicked: " + button1.name);
}
if (buttonPressed == button2)
{
//Your code for button 2
Debug.Log("Clicked: " + button2.name);
}
if (buttonPressed == button3)
{
//Your code for button 3
Debug.Log("Clicked: " + button3.name);
}
}
void OnDisable()
{
//Un-Register Button Events
button1.onClick.RemoveAllListeners();
button2.onClick.RemoveAllListeners();
button3.onClick.RemoveAllListeners();
}
}
If you are detecting something other than Button Click on the Button then use method 1. For example, Button down and not Button Click, use IPointerDownHandler and its OnPointerDown function from method 1.
3.InputField Component:
You use events to register to register for InputField submit:
public InputField inputField;
void OnEnable()
{
//Register InputField Events
inputField.onEndEdit.AddListener(delegate { inputEndEdit(); });
inputField.onValueChanged.AddListener(delegate { inputValueChanged(); });
}
//Called when Input is submitted
private void inputEndEdit()
{
Debug.Log("Input Submitted");
}
//Called when Input changes
private void inputValueChanged()
{
Debug.Log("Input Changed");
}
void OnDisable()
{
//Un-Register InputField Events
inputField.onEndEdit.RemoveAllListeners();
inputField.onValueChanged.RemoveAllListeners();
}
4.Slider Component:
To detect when slider value changes during drag:
public Slider slider;
void OnEnable()
{
//Subscribe to the Slider Click event
slider.onValueChanged.AddListener(delegate { sliderCallBack(slider.value); });
}
//Will be called when Slider changes
void sliderCallBack(float value)
{
Debug.Log("Slider Changed: " + value);
}
void OnDisable()
{
//Un-Subscribe To Slider Event
slider.onValueChanged.RemoveListener(delegate { sliderCallBack(slider.value); });
}
For other events, use Method 1.
5.Dropdown Component
public Dropdown dropdown;
void OnEnable()
{
//Register to onValueChanged Events
//Callback with parameter
dropdown.onValueChanged.AddListener(delegate { callBack(); });
//Callback without parameter
dropdown.onValueChanged.AddListener(callBackWithParameter);
}
void OnDisable()
{
//Un-Register from onValueChanged Events
dropdown.onValueChanged.RemoveAllListeners();
}
void callBack()
{
}
void callBackWithParameter(int value)
{
}
NON-UI OBJECTS:
6.For 3D Object (Mesh Renderer/any 3D Collider)
Add PhysicsRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add PhysicsRaycaster to the main Camera.
public class MeshDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysicsRaycaster();
}
void addPhysicsRaycaster()
{
PhysicsRaycaster physicsRaycaster = GameObject.FindObjectOfType<PhysicsRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<PhysicsRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
7.For 2D Object (Sprite Renderer/any 2D Collider)
Add Physics2DRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add Physics2DRaycaster to the main Camera.
public class SpriteDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysics2DRaycaster();
}
void addPhysics2DRaycaster()
{
Physics2DRaycaster physicsRaycaster = GameObject.FindObjectOfType<Physics2DRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<Physics2DRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
Troubleshooting the EventSystem:
No clicks detected on UI, 2D Objects (Sprite Renderer/any 2D Collider) and 3D Objects (Mesh Renderer/any 3D Collider):
A.Check that you have EventSystem. Without EventSystem it can't detect clicks at-all. If you don't have have it, create it yourself.
Go to GameObject ---> UI ---> Event System. This will create an EventSystem if it doesn't exist yet. If it already exist, Unity will just ignore it.
B.The UI component or GameObject with the UI component must be under a Canvas. It means that a Canvas must be the parent of the UI component. Without this, EventSystem will not function and clicks will not be detected.
This only applies to UI Objects. It doesn't apply to 2D (Sprite Renderer/any 2D Collider) or 3D Objects (Mesh Renderer/any 3D Collider).
C.If this is a 3D Object, PhysicsRaycaster is not attached to the camera. Make sure that PhysicsRaycaster is attached to the camera. See #6 above for more information.
D.If this is a 2D Object, Physics2DRaycaster is not attached to the camera. Make sure that Physics2DRaycaster is attached to the camera. See #7 above for more information.
E.If this is a UI object you want to detect clicks on with the interface functions such as OnBeginDrag, OnPointerClick, OnPointerEnter and other functions mentioned in #1 then the script with the detection code must be attached to that UI Object you want to detect click on.
F.Also, if this is a UI Object you want to detect clicks on, make sure that no other UI Object is in front of it. If there is another UI in front of the one you want to detect click on, it will be blocking that click.
To verify that this is not the issue, disable every object under the Canvas except the one you want to detect click on then see if clicking it works.
You can add an EventTrigger Componenet to Your UI elements that already have these Events you just have to pass method/Function on specific event.
You could use OnMouseDown as well. OnMouseDown is called when the user has pressed the mouse button while over the GUIElement or Collider. This event is sent to all scripts of the Collider or GUIElement.
using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement; // The new load level needs this
public class ExampleClass : MonoBehaviour
{
void OnMouseDown()
{
// Edit:
// Application.LoadLevel("SomeLevel");
// Application.LoadLevel() is depreciating but still works
SceneManager.LoadScene("SomeLevel"); // The new way to load levels
}
}
Do not use OnMouseDown() for mobile performance and multi-touch issues.
This code works on UI Objects for multi-touches
In my answer, I use Image element with a "Button" tag and it has a ButtonController script with a ButtonDown() public method that should be called when user touches the Image element.
Note: Image element has a 2D Collider.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class TouchScript : MonoBehaviour
{
void Update()
{
PointerEventData pointer = new PointerEventData(EventSystem.current);
List<RaycastResult> raycastResult = new List<RaycastResult>();
foreach (Touch touch in Input.touches)
{
if(touch.phase.Equals(TouchPhase.Began))
{
pointer.position = touch.position;
EventSystem.current.RaycastAll(pointer, raycastResult);
foreach(RaycastResult result in raycastResult)
{
if(result.gameObject.tag == "Button")
{
result.gameObject.GetComponent<ButtonController>().ButtonDown();
}
}
raycastResult.Clear();
}
}
}
}
How to detect UI object on Canvas on Touch in android?
For example, I have a canvas that have 5 objects such as Image, RawImage, Buttons, InputField and so on.
When I touch on Button UI object Then do something. Each button do different process when clicked depending.
The code will look like:
private void Update()
{
if (Input.touches.Length <= 0) return;
for (int i = 0; i < Input.touchCount; i++)
{
if (Button1.touch)
if (Input.GetTouch(i).phase == TouchPhase.Began)
login();
else if (Button2.touch && Input.GetTouch(i).phase == TouchPhase.Began)
LogOut();
}
}
So how to do it?
Second:
How to detect Gameobject get touch? Is it same with that above or not?
You don't use the Input API for the new UI. You subscribe to UI events or implement interface depending on the event.
These are the proper ways to detect events on the new UI components:
1.Image, RawImage and Text Components:
Implement the needed interface and override its function. The example below implements the most used events.
using UnityEngine.EventSystems;
public class ClickDetector : MonoBehaviour, IPointerDownHandler, IPointerClickHandler,
IPointerUpHandler, IPointerExitHandler, IPointerEnterHandler,
IBeginDragHandler, IDragHandler, IEndDragHandler
{
public void OnBeginDrag(PointerEventData eventData)
{
Debug.Log("Drag Begin");
}
public void OnDrag(PointerEventData eventData)
{
Debug.Log("Dragging");
}
public void OnEndDrag(PointerEventData eventData)
{
Debug.Log("Drag Ended");
}
public void OnPointerClick(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Mouse Down: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerEnter(PointerEventData eventData)
{
Debug.Log("Mouse Enter");
}
public void OnPointerExit(PointerEventData eventData)
{
Debug.Log("Mouse Exit");
}
public void OnPointerUp(PointerEventData eventData)
{
Debug.Log("Mouse Up");
}
}
2.Button Component:
You use events to register to Button clicks:
public class ButtonClickDetector : MonoBehaviour
{
public Button button1;
public Button button2;
public Button button3;
void OnEnable()
{
//Register Button Events
button1.onClick.AddListener(() => buttonCallBack(button1));
button2.onClick.AddListener(() => buttonCallBack(button2));
button3.onClick.AddListener(() => buttonCallBack(button3));
}
private void buttonCallBack(Button buttonPressed)
{
if (buttonPressed == button1)
{
//Your code for button 1
Debug.Log("Clicked: " + button1.name);
}
if (buttonPressed == button2)
{
//Your code for button 2
Debug.Log("Clicked: " + button2.name);
}
if (buttonPressed == button3)
{
//Your code for button 3
Debug.Log("Clicked: " + button3.name);
}
}
void OnDisable()
{
//Un-Register Button Events
button1.onClick.RemoveAllListeners();
button2.onClick.RemoveAllListeners();
button3.onClick.RemoveAllListeners();
}
}
If you are detecting something other than Button Click on the Button then use method 1. For example, Button down and not Button Click, use IPointerDownHandler and its OnPointerDown function from method 1.
3.InputField Component:
You use events to register to register for InputField submit:
public InputField inputField;
void OnEnable()
{
//Register InputField Events
inputField.onEndEdit.AddListener(delegate { inputEndEdit(); });
inputField.onValueChanged.AddListener(delegate { inputValueChanged(); });
}
//Called when Input is submitted
private void inputEndEdit()
{
Debug.Log("Input Submitted");
}
//Called when Input changes
private void inputValueChanged()
{
Debug.Log("Input Changed");
}
void OnDisable()
{
//Un-Register InputField Events
inputField.onEndEdit.RemoveAllListeners();
inputField.onValueChanged.RemoveAllListeners();
}
4.Slider Component:
To detect when slider value changes during drag:
public Slider slider;
void OnEnable()
{
//Subscribe to the Slider Click event
slider.onValueChanged.AddListener(delegate { sliderCallBack(slider.value); });
}
//Will be called when Slider changes
void sliderCallBack(float value)
{
Debug.Log("Slider Changed: " + value);
}
void OnDisable()
{
//Un-Subscribe To Slider Event
slider.onValueChanged.RemoveListener(delegate { sliderCallBack(slider.value); });
}
For other events, use Method 1.
5.Dropdown Component
public Dropdown dropdown;
void OnEnable()
{
//Register to onValueChanged Events
//Callback with parameter
dropdown.onValueChanged.AddListener(delegate { callBack(); });
//Callback without parameter
dropdown.onValueChanged.AddListener(callBackWithParameter);
}
void OnDisable()
{
//Un-Register from onValueChanged Events
dropdown.onValueChanged.RemoveAllListeners();
}
void callBack()
{
}
void callBackWithParameter(int value)
{
}
NON-UI OBJECTS:
6.For 3D Object (Mesh Renderer/any 3D Collider)
Add PhysicsRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add PhysicsRaycaster to the main Camera.
public class MeshDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysicsRaycaster();
}
void addPhysicsRaycaster()
{
PhysicsRaycaster physicsRaycaster = GameObject.FindObjectOfType<PhysicsRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<PhysicsRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
7.For 2D Object (Sprite Renderer/any 2D Collider)
Add Physics2DRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add Physics2DRaycaster to the main Camera.
public class SpriteDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysics2DRaycaster();
}
void addPhysics2DRaycaster()
{
Physics2DRaycaster physicsRaycaster = GameObject.FindObjectOfType<Physics2DRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<Physics2DRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
Troubleshooting the EventSystem:
No clicks detected on UI, 2D Objects (Sprite Renderer/any 2D Collider) and 3D Objects (Mesh Renderer/any 3D Collider):
A.Check that you have EventSystem. Without EventSystem it can't detect clicks at-all. If you don't have have it, create it yourself.
Go to GameObject ---> UI ---> Event System. This will create an EventSystem if it doesn't exist yet. If it already exist, Unity will just ignore it.
B.The UI component or GameObject with the UI component must be under a Canvas. It means that a Canvas must be the parent of the UI component. Without this, EventSystem will not function and clicks will not be detected.
This only applies to UI Objects. It doesn't apply to 2D (Sprite Renderer/any 2D Collider) or 3D Objects (Mesh Renderer/any 3D Collider).
C.If this is a 3D Object, PhysicsRaycaster is not attached to the camera. Make sure that PhysicsRaycaster is attached to the camera. See #6 above for more information.
D.If this is a 2D Object, Physics2DRaycaster is not attached to the camera. Make sure that Physics2DRaycaster is attached to the camera. See #7 above for more information.
E.If this is a UI object you want to detect clicks on with the interface functions such as OnBeginDrag, OnPointerClick, OnPointerEnter and other functions mentioned in #1 then the script with the detection code must be attached to that UI Object you want to detect click on.
F.Also, if this is a UI Object you want to detect clicks on, make sure that no other UI Object is in front of it. If there is another UI in front of the one you want to detect click on, it will be blocking that click.
To verify that this is not the issue, disable every object under the Canvas except the one you want to detect click on then see if clicking it works.
You can add an EventTrigger Componenet to Your UI elements that already have these Events you just have to pass method/Function on specific event.
You could use OnMouseDown as well. OnMouseDown is called when the user has pressed the mouse button while over the GUIElement or Collider. This event is sent to all scripts of the Collider or GUIElement.
using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement; // The new load level needs this
public class ExampleClass : MonoBehaviour
{
void OnMouseDown()
{
// Edit:
// Application.LoadLevel("SomeLevel");
// Application.LoadLevel() is depreciating but still works
SceneManager.LoadScene("SomeLevel"); // The new way to load levels
}
}
Do not use OnMouseDown() for mobile performance and multi-touch issues.
This code works on UI Objects for multi-touches
In my answer, I use Image element with a "Button" tag and it has a ButtonController script with a ButtonDown() public method that should be called when user touches the Image element.
Note: Image element has a 2D Collider.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class TouchScript : MonoBehaviour
{
void Update()
{
PointerEventData pointer = new PointerEventData(EventSystem.current);
List<RaycastResult> raycastResult = new List<RaycastResult>();
foreach (Touch touch in Input.touches)
{
if(touch.phase.Equals(TouchPhase.Began))
{
pointer.position = touch.position;
EventSystem.current.RaycastAll(pointer, raycastResult);
foreach(RaycastResult result in raycastResult)
{
if(result.gameObject.tag == "Button")
{
result.gameObject.GetComponent<ButtonController>().ButtonDown();
}
}
raycastResult.Clear();
}
}
}
}
I have 2 scenes "GamePlay" and "GameUI".
I load GameUI additively with GamePlay
void Awake () {
if (!instance) {
instance = this;
} else {
Destroy(this.gameObject) ;
}
SceneManager.LoadScene ("GameUI", LoadSceneMode.Additive);
DontDestroyOnLoad(this.gameObject);
}
Now when I reload the "GamePlay" scene using
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
How can I prevent reloading "GameUI" scene?
You could add an MonoBehaviour that is attached to the GameUI which contains a static bool that indicates if the object exists. Make your whole UI Scene a child of one object with the following script.
public class UIExistance : MonoBehaviour
{
public static bool Exists { get; private set; }
void Awake()
{
DontDestroyOnLoad(transform.gameObject);
UIExistance.Exists = true;
}
void OnDestroy()
{
UIExistance.Exists = false;
}
}
When you are in your posted Awake method you can check with if(!UIExistance.Exists) whether the UI is already in the scene.
How to detect UI object on Canvas on Touch in android?
For example, I have a canvas that have 5 objects such as Image, RawImage, Buttons, InputField and so on.
When I touch on Button UI object Then do something. Each button do different process when clicked depending.
The code will look like:
private void Update()
{
if (Input.touches.Length <= 0) return;
for (int i = 0; i < Input.touchCount; i++)
{
if (Button1.touch)
if (Input.GetTouch(i).phase == TouchPhase.Began)
login();
else if (Button2.touch && Input.GetTouch(i).phase == TouchPhase.Began)
LogOut();
}
}
So how to do it?
Second:
How to detect Gameobject get touch? Is it same with that above or not?
You don't use the Input API for the new UI. You subscribe to UI events or implement interface depending on the event.
These are the proper ways to detect events on the new UI components:
1.Image, RawImage and Text Components:
Implement the needed interface and override its function. The example below implements the most used events.
using UnityEngine.EventSystems;
public class ClickDetector : MonoBehaviour, IPointerDownHandler, IPointerClickHandler,
IPointerUpHandler, IPointerExitHandler, IPointerEnterHandler,
IBeginDragHandler, IDragHandler, IEndDragHandler
{
public void OnBeginDrag(PointerEventData eventData)
{
Debug.Log("Drag Begin");
}
public void OnDrag(PointerEventData eventData)
{
Debug.Log("Dragging");
}
public void OnEndDrag(PointerEventData eventData)
{
Debug.Log("Drag Ended");
}
public void OnPointerClick(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Mouse Down: " + eventData.pointerCurrentRaycast.gameObject.name);
}
public void OnPointerEnter(PointerEventData eventData)
{
Debug.Log("Mouse Enter");
}
public void OnPointerExit(PointerEventData eventData)
{
Debug.Log("Mouse Exit");
}
public void OnPointerUp(PointerEventData eventData)
{
Debug.Log("Mouse Up");
}
}
2.Button Component:
You use events to register to Button clicks:
public class ButtonClickDetector : MonoBehaviour
{
public Button button1;
public Button button2;
public Button button3;
void OnEnable()
{
//Register Button Events
button1.onClick.AddListener(() => buttonCallBack(button1));
button2.onClick.AddListener(() => buttonCallBack(button2));
button3.onClick.AddListener(() => buttonCallBack(button3));
}
private void buttonCallBack(Button buttonPressed)
{
if (buttonPressed == button1)
{
//Your code for button 1
Debug.Log("Clicked: " + button1.name);
}
if (buttonPressed == button2)
{
//Your code for button 2
Debug.Log("Clicked: " + button2.name);
}
if (buttonPressed == button3)
{
//Your code for button 3
Debug.Log("Clicked: " + button3.name);
}
}
void OnDisable()
{
//Un-Register Button Events
button1.onClick.RemoveAllListeners();
button2.onClick.RemoveAllListeners();
button3.onClick.RemoveAllListeners();
}
}
If you are detecting something other than Button Click on the Button then use method 1. For example, Button down and not Button Click, use IPointerDownHandler and its OnPointerDown function from method 1.
3.InputField Component:
You use events to register to register for InputField submit:
public InputField inputField;
void OnEnable()
{
//Register InputField Events
inputField.onEndEdit.AddListener(delegate { inputEndEdit(); });
inputField.onValueChanged.AddListener(delegate { inputValueChanged(); });
}
//Called when Input is submitted
private void inputEndEdit()
{
Debug.Log("Input Submitted");
}
//Called when Input changes
private void inputValueChanged()
{
Debug.Log("Input Changed");
}
void OnDisable()
{
//Un-Register InputField Events
inputField.onEndEdit.RemoveAllListeners();
inputField.onValueChanged.RemoveAllListeners();
}
4.Slider Component:
To detect when slider value changes during drag:
public Slider slider;
void OnEnable()
{
//Subscribe to the Slider Click event
slider.onValueChanged.AddListener(delegate { sliderCallBack(slider.value); });
}
//Will be called when Slider changes
void sliderCallBack(float value)
{
Debug.Log("Slider Changed: " + value);
}
void OnDisable()
{
//Un-Subscribe To Slider Event
slider.onValueChanged.RemoveListener(delegate { sliderCallBack(slider.value); });
}
For other events, use Method 1.
5.Dropdown Component
public Dropdown dropdown;
void OnEnable()
{
//Register to onValueChanged Events
//Callback with parameter
dropdown.onValueChanged.AddListener(delegate { callBack(); });
//Callback without parameter
dropdown.onValueChanged.AddListener(callBackWithParameter);
}
void OnDisable()
{
//Un-Register from onValueChanged Events
dropdown.onValueChanged.RemoveAllListeners();
}
void callBack()
{
}
void callBackWithParameter(int value)
{
}
NON-UI OBJECTS:
6.For 3D Object (Mesh Renderer/any 3D Collider)
Add PhysicsRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add PhysicsRaycaster to the main Camera.
public class MeshDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysicsRaycaster();
}
void addPhysicsRaycaster()
{
PhysicsRaycaster physicsRaycaster = GameObject.FindObjectOfType<PhysicsRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<PhysicsRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
7.For 2D Object (Sprite Renderer/any 2D Collider)
Add Physics2DRaycaster to the Camera then use any of the events from Method 1.
The code below will automatically add Physics2DRaycaster to the main Camera.
public class SpriteDetector : MonoBehaviour, IPointerDownHandler
{
void Start()
{
addPhysics2DRaycaster();
}
void addPhysics2DRaycaster()
{
Physics2DRaycaster physicsRaycaster = GameObject.FindObjectOfType<Physics2DRaycaster>();
if (physicsRaycaster == null)
{
Camera.main.gameObject.AddComponent<Physics2DRaycaster>();
}
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
}
//Implement Other Events from Method 1
}
Troubleshooting the EventSystem:
No clicks detected on UI, 2D Objects (Sprite Renderer/any 2D Collider) and 3D Objects (Mesh Renderer/any 3D Collider):
A.Check that you have EventSystem. Without EventSystem it can't detect clicks at-all. If you don't have have it, create it yourself.
Go to GameObject ---> UI ---> Event System. This will create an EventSystem if it doesn't exist yet. If it already exist, Unity will just ignore it.
B.The UI component or GameObject with the UI component must be under a Canvas. It means that a Canvas must be the parent of the UI component. Without this, EventSystem will not function and clicks will not be detected.
This only applies to UI Objects. It doesn't apply to 2D (Sprite Renderer/any 2D Collider) or 3D Objects (Mesh Renderer/any 3D Collider).
C.If this is a 3D Object, PhysicsRaycaster is not attached to the camera. Make sure that PhysicsRaycaster is attached to the camera. See #6 above for more information.
D.If this is a 2D Object, Physics2DRaycaster is not attached to the camera. Make sure that Physics2DRaycaster is attached to the camera. See #7 above for more information.
E.If this is a UI object you want to detect clicks on with the interface functions such as OnBeginDrag, OnPointerClick, OnPointerEnter and other functions mentioned in #1 then the script with the detection code must be attached to that UI Object you want to detect click on.
F.Also, if this is a UI Object you want to detect clicks on, make sure that no other UI Object is in front of it. If there is another UI in front of the one you want to detect click on, it will be blocking that click.
To verify that this is not the issue, disable every object under the Canvas except the one you want to detect click on then see if clicking it works.
You can add an EventTrigger Componenet to Your UI elements that already have these Events you just have to pass method/Function on specific event.
You could use OnMouseDown as well. OnMouseDown is called when the user has pressed the mouse button while over the GUIElement or Collider. This event is sent to all scripts of the Collider or GUIElement.
using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement; // The new load level needs this
public class ExampleClass : MonoBehaviour
{
void OnMouseDown()
{
// Edit:
// Application.LoadLevel("SomeLevel");
// Application.LoadLevel() is depreciating but still works
SceneManager.LoadScene("SomeLevel"); // The new way to load levels
}
}
Do not use OnMouseDown() for mobile performance and multi-touch issues.
This code works on UI Objects for multi-touches
In my answer, I use Image element with a "Button" tag and it has a ButtonController script with a ButtonDown() public method that should be called when user touches the Image element.
Note: Image element has a 2D Collider.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class TouchScript : MonoBehaviour
{
void Update()
{
PointerEventData pointer = new PointerEventData(EventSystem.current);
List<RaycastResult> raycastResult = new List<RaycastResult>();
foreach (Touch touch in Input.touches)
{
if(touch.phase.Equals(TouchPhase.Began))
{
pointer.position = touch.position;
EventSystem.current.RaycastAll(pointer, raycastResult);
foreach(RaycastResult result in raycastResult)
{
if(result.gameObject.tag == "Button")
{
result.gameObject.GetComponent<ButtonController>().ButtonDown();
}
}
raycastResult.Clear();
}
}
}
}
I want to implement drag and drop on contents of scroll view.
The problem is when you try drag items in scroll view you can't scroll the view.
First, I've tried to implement drag and drop by IDragHandler, IBeginDragHandler, IEndDragHandle and IDropHandler interfaces. In a first sight, It worked pretty good but the problem was you can't scroll the ScrollRect.
I think the problem is because of overriding, When I use event triggers that the same as scroll rect like drag, the parent one don't work properly.
So after that, I've thought by myself and implement it by IPointerDown, IPointerUp interfaces and specific time for holding drag-gable UI in ScrollRect and if you don't hold it in specific time the scrolling work well.
But the problem is by enabling DragHandler script that I wrote before the OnDrag, OnBeginDrag and OnEndDrag functions doesn't work when time of holding ended.
First I want to know there is any way to call these functions ?
Second is there any way to implement drag and drop UI without using drag interfaces ?
DragHandler :
using System;
using UnityEngine;
using UnityEngine.EventSystems;
public class DragHandler : MonoBehaviour, IDragHandler, IBeginDragHandler, IEndDragHandler
{
public static GameObject itemBeingDragged;
private Vector3 startPos;
private Transform startParent;
DragHandler dragHandler;
public void Awake()
{
dragHandler = GetComponent<DragHandler>();
}
public void OnBeginDrag(PointerEventData eventData)
{
Debug.Log("Begin");
itemBeingDragged = gameObject;
startPos = transform.position;
startParent = transform.parent;
}
public void OnDrag(PointerEventData eventData)
{
Debug.Log("Drag");
transform.position = Input.mousePosition;
}
public void OnEndDrag(PointerEventData eventData)
{
Debug.Log("End");
itemBeingDragged = null;
if (transform.parent == startParent)
{
dragHandler.enabled = false;
transform.SetParent(startParent);
transform.position = startPos;
}
}
}
ScrollRectController:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class ScrollRectController : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
public float holdTime;
public float maxVelocity;
private Transform scrollRectParent;
private DragHandler dragHandler;
private ScrollRect scrollRect;
private float timer;
private bool isHolding;
void Awake()
{
scrollRectParent = GameObject.FindGameObjectWithTag("rec_dlg").transform;
dragHandler = GetComponent<DragHandler>();
dragHandler.enabled = false;
}
// Use this for initialization
void Start()
{
timer = holdTime;
}
// Update is called once per frame
void Update()
{
}
public void OnPointerDown(PointerEventData eventData)
{
Debug.Log("Down");
scrollRect = scrollRectParent.GetComponent<ScrollRect>();
isHolding = true;
StartCoroutine(Holding());
}
public void OnPointerUp(PointerEventData eventData)
{
Debug.Log("Up");
isHolding = false;
}
IEnumerator Holding()
{
while (timer > 0)
{
//if (scrollRect.velocity.x >= maxVelocity)
//{
// isHolding = false;
//}
if (!isHolding)
{
timer = holdTime;
yield break;
}
timer -= Time.deltaTime;
Debug.Log(timer);
yield return null;
}
dragHandler.enabled = true;
//dragHandler.OnBeginDrag();
}
}
Slot:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class Slot : MonoBehaviour, IDropHandler
{
public void OnDrop(PointerEventData eventData)
{
DragHandler.itemBeingDragged.transform.SetParent(transform);
}
}
Answer:
I wrote some codes that handle drag and drop in scrollRect(scrollView) without using DragHandler interfaces.
DragHandler:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class DragHandler : MonoBehaviour, IPointerExitHandler
{
public static GameObject itemBeingDragged;
public static bool isCustomerDragged;
public Transform customerScrollRect;
public Transform dragParent;
public float holdTime;
public float maxScrollVelocityInDrag;
private Transform startParent;
private ScrollRect scrollRect;
private float timer;
private bool isHolding;
private bool canDrag;
private bool isPointerOverGameObject;
private CanvasGroup canvasGroup;
private Vector3 startPos;
public Transform StartParent
{
get { return startParent; }
}
public Vector3 StartPos
{
get { return startPos; }
}
void Awake()
{
canvasGroup = GetComponent<CanvasGroup>();
}
// Use this for initialization
void Start()
{
timer = holdTime;
}
// Update is called once per frame
void Update()
{
if (Input.GetMouseButtonDown(0))
{
if (EventSystem.current.currentSelectedGameObject == gameObject)
{
//Debug.Log("Mouse Button Down");
scrollRect = customerScrollRect.GetComponent<ScrollRect>();
isPointerOverGameObject = true;
isHolding = true;
StartCoroutine(Holding());
}
}
if (Input.GetMouseButtonUp(0))
{
if (EventSystem.current.currentSelectedGameObject == gameObject)
{
//Debug.Log("Mouse Button Up");
isHolding = false;
if (canDrag)
{
itemBeingDragged = null;
isCustomerDragged = false;
if (transform.parent == dragParent)
{
canvasGroup.blocksRaycasts = true;
transform.SetParent(startParent);
transform.localPosition = startPos;
}
canDrag = false;
timer = holdTime;
}
}
}
if (Input.GetMouseButton(0))
{
if (EventSystem.current.currentSelectedGameObject == gameObject)
{
if (canDrag)
{
//Debug.Log("Mouse Button");
transform.position = Input.mousePosition;
}
else
{
if (!isPointerOverGameObject)
{
isHolding = false;
}
}
}
}
}
public void OnPointerExit(PointerEventData eventData)
{
isPointerOverGameObject = false;
}
IEnumerator Holding()
{
while (timer > 0)
{
if (scrollRect.velocity.x >= maxScrollVelocityInDrag)
{
isHolding = false;
}
if (!isHolding)
{
timer = holdTime;
yield break;
}
timer -= Time.deltaTime;
//Debug.Log("Time : " + timer);
yield return null;
}
isCustomerDragged = true;
itemBeingDragged = gameObject;
startPos = transform.localPosition;
startParent = transform.parent;
canDrag = true;
canvasGroup.blocksRaycasts = false;
transform.SetParent(dragParent);
}
public void Reset()
{
isHolding = false;
canDrag = false;
isPointerOverGameObject = false;
}
}
Some explanation for this piece of code :
Your draggable UI element need intractable option, for me, I used button.
You need to attach this script to your draggable item.
Also you need add Canvas Group component.
customerScrollRect is a ScrollRect parent of your items.
dragParent can be a empty GameObject which is used because of mask of view port.
Slot:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class Slot : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
{
bool isEntered;
public void OnPointerEnter(PointerEventData eventData)
{
isEntered = true;
}
public void OnPointerExit(PointerEventData eventData)
{
isEntered = false;
}
void Update()
{
if (Input.GetMouseButtonUp(0))
{
if (isEntered)
{
if (DragHandler.itemBeingDragged)
{
GameObject draggedItem = DragHandler.itemBeingDragged;
DragHandler dragHandler = draggedItem.GetComponent<DragHandler>();
Vector3 childPos = draggedItem.transform.position;
//Debug.Log("On Pointer Enter");
draggedItem.transform.SetParent(dragHandler.StartParent);
draggedItem.transform.localPosition = dragHandler.StartPos;
draggedItem.transform.parent.SetParent(transform);
draggedItem.transform.parent.position = childPos;
isEntered = false;
}
}
}
}
}
Some explanation for this script:
1.Attach the script to the dropped item.
The easiest solution for this problem is actually to manually call the ScrollRect's events IF the user hasn't pressed long enough using ExecuteEvents.Execute. This solution has the least amount of additional code.
using System.Collections;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class DragAndDropHandler : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler, IDragHandler, IBeginDragHandler, IEndDragHandler
{
// Don't forget to set this to TRUE or expose it to the Inspector else it will always be false and the script will not work
public bool Draggable { get; set; }
private bool draggingSlot;
[SerializeField] private ScrollRect scrollRect;
public void OnPointerDown(PointerEventData eventData)
{
if (!Draggable)
{
return;
}
StartCoroutine(StartTimer());
}
public void OnPointerExit(PointerEventData eventData)
{
StopAllCoroutines();
}
public void OnPointerUp(PointerEventData eventData)
{
StopAllCoroutines();
}
private IEnumerator StartTimer()
{
yield return new WaitForSeconds(0.5f);
draggingSlot = true;
}
public void OnBeginDrag(PointerEventData eventData)
{
ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.beginDragHandler);
}
public void OnDrag(PointerEventData eventData)
{
if (draggingSlot)
{
//DO YOUR DRAGGING HERE
} else
{
//OR DO THE SCROLLRECT'S
ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.dragHandler);
}
}
public void OnEndDrag(PointerEventData eventData)
{
ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.endDragHandler);
if (draggingSlot)
{
//END YOUR DRAGGING HERE
draggingSlot = false;
}
}
}
I've managed to find an easier solution.
Maybe it must be customized by special needs, but if you put this script on your items and make the setup, it should work.
It's not easy from a prefab, but I let a controller make this.
I find all UIElementDragger inside a specified GameObject and add the needed GO instances programmatically.
But can use this code out of the box if you don't use prefabs.
using UnityEngine;
using UnityEngine.EventSystems;
public class UIElementDragger : MonoBehaviour, IPointerUpHandler, IPointerDownHandler
{
/// <summary>
/// Offset in pixels horizontally (positive to right, negative to left)
/// </summary>
[Range(40, 100)]
public float offsetX = 40;
/// <summary>
/// Offset in pixels vertically (positive to right, negative to left)
/// </summary>
[Range(40, 100)]
public float offsetY = 40;
/// <summary>
/// The Panel where the item will set as Child to during drag
/// </summary>
public Transform parentRect;
/// <summary>
/// The GameObject where the item is at start
/// </summary>
public Transform homeWrapper;
/// <summary>
/// The Object where the mouse must be when pointer is up, to put it in this panel
/// </summary>
public Transform targetRect;
/// <summary>
/// The GameObject where the item should live after dropping
/// </summary>
public Transform targetWrapper;
private int siblingIndex;
private bool dragging;
private void Start()
{
siblingIndex = transform.GetSiblingIndex();
}
private void Update()
{
if (dragging)
{
transform.position = new Vector2(Input.mousePosition.x + offsetX, Input.mousePosition.y + offsetY);
}
}
public void OnPointerDown(PointerEventData eventData)
{
transform.parent = parentRect;
dragging = true;
}
public void OnPointerUp(PointerEventData eventData)
{
if (eventData.pointerCurrentRaycast.gameObject.transform.IsChildOf(targetRect))
{
transform.parent = targetWrapper;
}
else
{
transform.parent = homeWrapper;
transform.SetSiblingIndex(siblingIndex);
}
dragging = false;
}
}
Here my solution, thank all.
I have to use a fake instance to keep the object over even if you move it down the list. I post a vertical and a horizontal solution. I hope it help
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class DragController : MonoBehaviour, IPointerDownHandler, IDragHandler, IPointerUpHandler
{
private RectTransform currentTransform;
private GameObject instancePrefab;
private GameObject mainContent;
private Vector3 initialePosition;
private int totalChild;
void Awake()
{
currentTransform = this.GetComponent<RectTransform>();
mainContent = currentTransform.parent.gameObject;
}
public void OnPointerDown(PointerEventData eventData)
{
initialePosition = currentTransform.position;
totalChild = mainContent.transform.childCount;
if (instancePrefab == null)
{
instancePrefab = Instantiate(this.gameObject, mainContent.transform.parent.transform);
instancePrefab.GetComponent<Image>().enabled = false;
}
}
public void OnDrag(PointerEventData eventData)
{
currentTransform.position = new Vector3(eventData.position.x, currentTransform.position.y, currentTransform.position.z);
if (instancePrefab != null)
{
instancePrefab.GetComponent<Image>().enabled = true;
currentTransform.GetComponent<Image>().enabled = false;
instancePrefab.transform.position = currentTransform.position;
}
for (int i = 0; i < totalChild; i++)
{
if (i != currentTransform.GetSiblingIndex())
{
Transform otherTransform = mainContent.transform.GetChild(i);
int distance = (int)Vector3.Distance(currentTransform.position, otherTransform.position);
if (distance <= 20)
{
Vector3 otherTransformOldPosition = otherTransform.position;
// Vertical
/*otherTransform.position = new Vector3(otherTransform.position.x, initialePosition.y,
otherTransform.position.z);
currentTransform.position = new Vector3(currentTransform.position.x, otherTransformOldPosition.y,
currentTransform.position.z);*/
// Horizontal
otherTransform.position = new Vector3(initialePosition.x, otherTransform.position.y,
otherTransform.position.z);
currentTransform.position = new Vector3(otherTransformOldPosition.x, currentTransform.position.y,
currentTransform.position.z);
currentTransform.SetSiblingIndex(otherTransform.GetSiblingIndex());
initialePosition = currentTransform.position;
}
}
}
}
public void OnPointerUp(PointerEventData eventData)
{
currentTransform.position = initialePosition;
instancePrefab.GetComponent<Image>().enabled = false;
currentTransform.GetComponent<Image>().enabled = true;
Destroy(instancePrefab);
instancePrefab = null;
}
}
You can just manually call ScrollRect events, because they are public. Smthing like this:
public void OnDrag(PointerEventData eventData)
{
_scrollRect.OnDrag(eventData);
}