How to detect left mouse click but not when the click occur on a UI Button component [closed]

Answer 1

I guess you are using Update() method to handle mouse input with no proper conditions. I suggest you to change your code as use interaction with a UI element instead of mouse button down etc.

Example: create a big invisible UI Panel on all over the screen but must be behind everything else in UI Canvas. Then add a button component on it and control your gameObject movement by OnClick() event of this button. (please vote up to help others if it solves problem)

Answer 2

I bet there are better solutions, but the first thing that comes to my mind is that:

Check if you are clicking an UI element, bevor moving your object on mouse up event.

You can check if you hit an UI element by using a GraphicsRaycaster to cast a ray on your mouse position. If it hits anything, then you are clicking on any canvas.

See: https://docs.unity3d.com/Manual/script-GraphicRaycaster.html

Answer 3

After reading your comment. What you need is EventSystem.current.IsPointerOverGameObject() which checks if pointer is over UI. true when pointer is over UI, otherwise false. You can use it with '!' and run your rotation code only if the mouse is not over the UI.

For Desktop

if(Input.GetMouseButtonUp(0) && !EventSystem.current.IsPointerOverGameObject())
{
    //Your code here
}

// For Mobile

if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Ended && !EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
{
    //Your code here
}   

The solution above should work but there is a bug. When the mouse button is pressed over the UI Button then released outside of the UI Button, it will register as a click. So, basically, the solution works only when you click on UI Button and release on UI Button. If you release outside the U Button, the original problem will be back again.

The best solution is to use a temporary boolean value and check if button was originally pressed on a UI with Input.GetMouseButtonDown. That saved boolean, you can then use when the Button is released with Input.GetMouseButtonUp(0). The solution below is provided to work with both Mobile and Desktop. Mobile tested and it works.

bool validInput = true;

private void Update()
{
    validateInput();

    #if UNITY_STANDALONE || UNITY_EDITOR

    //DESKTOP COMPUTERS
    if (Input.GetMouseButtonUp(0) && validInput)
    {
        //Put your code here
        Debug.Log("Valid Input");
    }
    #else

    //MOBILE DEVICES
    if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Ended && validInput)
    {
        //Put your code here
        Debug.Log("Valid Input");
    }
    #endif
}

void validateInput()
{
    #if UNITY_STANDALONE || UNITY_EDITOR
    //DESKTOP COMPUTERS
    if (Input.GetMouseButtonDown(0))
    {
        if (EventSystem.current.IsPointerOverGameObject())
            validInput = false;
        else
            validInput = true;
    }
    #else
    //MOBILE DEVICES
    if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
    {
        if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
            validInput = false;
        else
            validInput = true;
    }
    #endif
}