Hotkey detection for UI elements

Question

I have several UI elements that can be opened using hotkeys for example the settings menu's key is Escape. The problem is that I have the Keycode stored in Dictionary along with an Action or a Button.ButtonClickedEvent here's how the two dictionaries are declared:

 public static readonly Dictionary<KeyCode, Button.ButtonClickedEvent> KeysUIElementsWithButtonEvents = new Dictionary<KeyCode, Button.ButtonClickedEvent>
 {
 { KeyCode.P, SpellbookButton.onClick },
 { KeyCode.Escape, SettingsMenuButton.onClick },
 };
 public static readonly Dictionary<KeyCode, Action> KeysUIElementsWithActions = new Dictionary<KeyCode, Action>
 {
 { KeyCode.LeftAlt, SwitchCursorState},
 };

And here's how I used to invoke them :

 foreach (var item in Settings.Settings.KeysUIElementsWithButtonEvents)
 {
 if(Input.GetKeyDown(item.Key))
 {
 if(Cursor.lockState == CursorLockMode.Locked)
 {
 Settings.Settings.SwitchCursorState();
 }
 item.Value.Invoke();
 }
 }
 foreach (var item in Settings.Settings.KeysUIElementsWithActions)
 {
 if (Input.GetKeyDown(item.Key))
 {
 if (Cursor.lockState == CursorLockMode.Locked)
 {
 Settings.Settings.SwitchCursorState();
 }
 item.Value.Invoke();
 }
 }

I didn't like the repetitive code in here so I decided to create a function which solves the problem:

 CheckUIKeysCollection(Settings.Settings.KeysUIElementsWithButtonEvents); 
 CheckUIKeysCollection(Settings.Settings.KeysUIElementsWithActions);
 private void CheckUIKeysCollection<T>(Dictionary<KeyCode, T> collection)
 {
 foreach (var item in collection)
 {
 if (Input.GetKeyDown(item.Key))
 {
 if (Cursor.lockState == CursorLockMode.Locked)
 {
 Settings.Settings.SwitchCursorState();
 }
 if (item.Value is Action)
 {
 (item.Value as Action).Invoke();
 continue;
 }
 (item.Value as Button.ButtonClickedEvent).Invoke();
 }
 }
 }

However I'm not sure if the method is efficient enough it involves some casting here and there and it's also being called in the Update function (every frame) and if I have big collections it might hurt the performance. What can I do to improve the method?

• Stud: Maybe you could wrap your Button.ButtonClickedEvent and Action in a class that would do the work. This solution would allow you to have one dictionary instead of two and a simpler invoke process in the iteration.

Answer 1

The easiest way to solve this with one dictionary is to simply create an action for the Button.ButtonClickedEvent calls:

public static readonly Dictionary<KeyCode, Button.ButtonClickedEvent> KeysUIElementsWithButtonEvents = new Dictionary<KeyCode, Button.ButtonClickedEvent>
{
 { KeyCode.P, SpellbookButton.onClick },
 { KeyCode.Escape, SettingsMenuButton.onClick },
};
public static readonly Dictionary<KeyCode, Action> KeysUIElementsWithActions = new Dictionary<KeyCode, Action>
{
 { KeyCode.LeftAlt, SwitchCursorState},
};

Can be one Dictionary<KeyCode, Action>:

public static readonly Dictionary<KeyCode, Action> KeysUIElementsWithActions = new Dictionary<KeyCode, Action>
{
 { KeyCode.P, () => SpellbookButton.onClick.Invoke() },
 { KeyCode.Escape, () => SettingsMenuButton.onClick.Invoke() },
 { KeyCode.LeftAlt, SwitchCursorState }
}

Then this:

private void CheckUIKeysCollection<T>(Dictionary<KeyCode, T> collection)
{
 foreach (var item in collection)
 {
 if (Input.GetKeyDown(item.Key))
 {
 if (Cursor.lockState == CursorLockMode.Locked)
 {
 Settings.Settings.SwitchCursorState();
 }
 if (item.Value is Action)
 {
 (item.Value as Action).Invoke();
 continue;
 }
 (item.Value as Button.ButtonClickedEvent).Invoke();
 }
 }
}

Becomes this:

private void CheckUIKeysCollection(Dictionary<KeyCode, Action> collection)
{
 foreach (var item in collection)
 {
 if (Input.GetKeyDown(item.Key))
 {
 if (Cursor.lockState == CursorLockMode.Locked)
 {
 Settings.Settings.SwitchCursorState();
 }
 item.Value.Invoke();
 }
 }
}

No more generics, no more casting, no more inferences. Simply create an action that calls the ButtonClickedEvent.Invoke() method for the appropriate Button.

You could, also, create a method that does that for you:

public void ClickButton(Button button)
{
 button.onClick.Invoke();
}

Then make your dictionary:

public static readonly Dictionary<KeyCode, Action> KeysUIElementsWithActions = new Dictionary<KeyCode, Action>
{
 { KeyCode.P, ClickButton(SpellbookButton) },
 { KeyCode.Escape, ClickButton(SettingsMenuButton) },
 { KeyCode.LeftAlt, SwitchCursorState }
}

This also means it's simpler to click buttons from anywhere in your code: simply call ClickButton(Button), instead of Button.onClick.Invoke().

---

Apart from that:

Using is then as is not recommended, simply use as then check if it's null:

var temp = value as string;
if (temp != null)
{
 Console.WriteLine(temp.Length);
}