Trying to write a function that checks if 2 keys are pressed

Questions & Answers
1

So I’m trying to write a function that checks if 2 keys are pressed within 1 second if each other:

bool IfTwoKeysPressed(string Key1, string Key2)
{
    float FirstKeyPress = 20;
    float SecondKeyPress = 50;
    float TimePressedDelay = 1;
    bool KeysPressed = false;

    if (Input.GetKeyDown(Key1))
    {
        FirstKeyPress = Time.time;
    }
    if (Input.GetKeyDown(Key2))
    {
        SecondKeyPress = Time.time;
    }
    if (Mathf.Abs(SecondKeyPress - FirstKeyPress) <= TimePressedDelay)
    {
        FirstKeyPress = 20;
        SecondKeyPress = 50;
        KeysPressed = true;
    }
    Debug.Log(KeysPressed);
    return KeysPressed;
}

Problem is when I call this function in Update(), checking the delay between the 2 presses doesn’t work since the function happens within 1 frame and resets.
Transferring the code into Update() works but in my game I’m going to have to check a lot of key combinations and would prefer not having to creating all the variables and writing this code every time.

2

You have to store the last times the keys have been pressed manually. Then, each time a new key has been pressed, check if all the keys have been presses in your time frame (1 second). Let me give you a helper class that manages that:

using System;
using System.Collections.Generic;
using UnityEngine;

[Serializable]
public class MultiKeyPressChecker
{
    [Serializable]
    private class KeyData
    {
        [SerializeField, Tooltip("key that has to be pressed to trigger")] private KeyCode key = KeyCode.A;

        [SerializeField]private float lastPressTime = float.NegativeInfinity;

        public void Update()
        {
            if (Input.GetKeyDown(key))
            {
                lastPressTime = Time.time;
            }
        }

        public bool GetWasPressed(float timeFrame)
        {
            return Time.time - timeFrame < lastPressTime;
        }

        public void ClearLastKeyPressTime()
        {
            lastPressTime = float.NegativeInfinity;
        }
    }


    [SerializeField, Tooltip("keys that have to be pressed in the timeframe to make the check trigger")]
    private List<KeyData> keys;

    [SerializeField, Tooltip("duration in which all specified keys have to be pressed")]
    private float timeFrame = 1f;

    public bool Check()
    {
        foreach (KeyData key in keys)
        {
            //update last press times of keys
            key.Update();
        }

        foreach (KeyData key in keys)
        {
            //if any of the keys was not pressed in the timeframe, return false
            if (!key.GetWasPressed(timeFrame))
            {
                return false;
            }
        }

        //else clear last key presses and return true (all keys have been pressed in the timeframe)
        foreach (KeyData key in keys)
        {
            key.ClearLastKeyPressTime();
        }
        return true;
    }
}

You can use this helper class like in this example script:

using UnityEngine;

public class MultiKeyPressExample : MonoBehaviour
{
    [SerializeField] private MultiKeyPressChecker keyPressChecker;

    private void Update()
    {
        if (keyPressChecker.Check())
        {
            Debug.Log("all the specified keys have been pressed in the timeframe");
        }
    }
}

Just assign the keys you are interested in and the allowed timeframe in the inspector and you are good to go.

3

I created a double key press script. Thus, if other scripts need to use it, just add it and check for the keys you need. I also changed a few lines of code as well, as I don’t think you need to keep time for each button press.

using UnityEngine;

// I wouldn't worry about time for each key.  You just need a global time from the last one clicked
public class DoubleKeyPress : MonoBehaviour
{
    bool key1Pressed;
    bool key2Pressed;
    float countDownSinceKeyPressed = 0;
    float TimePressedDelay = 1;


    public bool IfTwoKeysPressed(KeyCode key1, KeyCode key2)
    {
        countDownSinceKeyPressed -= Time.deltaTime;
        if (countDownSinceKeyPressed <= 0)
        {
            key1Pressed = false;
            key2Pressed = false;
        }

        if (Input.GetKeyDown(key1))
        {
            countDownSinceKeyPressed = TimePressedDelay;
            key1Pressed = true;
        }

        if (Input.GetKeyDown(key2))
        {
            countDownSinceKeyPressed = TimePressedDelay;
            key2Pressed = true;
        }

        if (key1Pressed && key2Pressed) countDownSinceKeyPressed = 0f;

        return key1Pressed && key2Pressed;
    }
}

Here is a random script that adds it and uses it.

using UnityEngine;

public class UseDoubleKeyPress : MonoBehaviour
{
    DoubleKeyPress keyPress;


	void Awake ()
    {
        keyPress = gameObject.AddComponent<DoubleKeyPress>();
	}
	

	void Update ()
    {
        if (keyPress.IfTwoKeysPressed(KeyCode.A, KeyCode.B))
        {
            Debug.LogError("Buttons Pressed");
        }
	}
}