Modding:Modder Guide/APIs/Input

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Modding:Index

The input API lets you check and suppress controller/keyboard/mouse state.

APIs

Check button state

IsDown
You can check if any controller/keyboard/mouse button is currently pressed by calling the IsDown(button) method. For example:
bool isShiftPressed = this.Helper.Input.IsDown(SButton.LeftShift) || this.Helper.Input.IsDown(SButton.RightShift);
GetState
For more finetuned control, you can check the button state relative to the previous game tick:
SButtonState state = this.Helper.Input.GetState(SButton.LeftShift);
bool isDown = (state == SButtonState.Pressed || state == SButtonState.Held);

Available button states:

previous tick current tick resulting state
up up None
up down Pressed
down down Held
down up Released

Check cursor position

The GetCursorPosition() method provides the cursor position in three coordinate systems|ICursorPosition.

For example:

// draw text at the cursor position
ICursorPosition cursorPos = this.Helper.Input.GetCursorPosition();
Game1.spriteBatch.DrawString(Game1.smallFont, "some text", cursorPos.ScreenPixels, Color.Black);

Suppress input

You can prevent the game from handling any controller/keyboard/mouse button press (including clicks) by suppressing it. This suppression will remain in effect until the player releases the button. This won't prevent other mods from handling it.

method effect
Suppress Suppress the specified SButton value.
SuppressActiveKeybinds For the given KeybindList, suppress every button that's part of an activated keybind.
IsSuppressed Get whether the specified SButton value is currently suppressed.

For example:

// prevent game from seeing that LeftShift is pressed
this.Helper.Input.Suppress(SButton.LeftShift);

// that works for clicks too:
this.Helper.Input.Suppress(SButton.MouseLeft);

// check if a button is being suppressed:
bool suppressed = this.Helper.Input.IsSuppressed(SButton.LeftShift);

Side-effects:

  • The ButtonReleased event will be raised on the next tick for the suppressed input.
  • Methods like helper.Input.IsDown(button) and helper.Input.GetState(button) will show the button as released for the duration of the suppression, even if it's physically still pressed. You can use helper.Input.IsSuppressed(button) to check if that's the case (it will only be true until the button is physically released):
    bool isPhysicallyDown = helper.Input.IsDown(button) || helper.Input.IsSuppressed(button);
    

Data structures

SButton

SMAPI's SButton is a constant which includes every controller, keyboard, and mouse button. SMAPI events use this to let you handle button presses without needing separate code for each. See Modding:Player Guide/Key Bindings for a list of values.

SMAPI provides extensions to convert any of the other constants to SButton:

SButton key = Keys.A.ToSButton(); // SButton.A
SButton button = Buttons.A.ToSButton(); // SButton.ControllerA
SButton input = new InputButton(true).ToSButton(); // SButton.MouseLeft

You can also convert SButton to the other constants. This uses a TryGet approach since SButton is a superset of the others (e.g. you can't convert SButton.ControllerA to a keyboard value):

SButton value = SButton.A;
if (value.TryGetKeyboard(out Keys key))
   ...;
if (value.TryGetController(out Buttons button))
   ...;
if (value.TryGetStardewInput(out InputButton input))
   ...;

Two last extensions let you check how the button is mapped in the game:

SButton button = SButton.MouseLeft;
if (button.IsUseToolButton())
   // use tool
else if (button.IsActionButton())
   // perform action

You can use SButton values directly in your config model, but KeybindList is recommended instead in most cases.

KeybindList

SMAPI's KeybindList utility lets you manage an arbitrary set of keybindings. A keybind list has any number of keybinds, each of which has any number of button codes. For example, the keybind list "F2, LeftShift + S" would be pressed if (a) F2 is pressed, or (b) both LeftShift and S are pressed.

You can use a KeybindList directly in your config.json model:

C# model   JSON file
class ModConfig
{
   public KeybindList ToggleKey { get; set; } = KeybindList.Parse("Shift + F2");
}
{
   "ToggleKey": "Shift + F2"
}

And you can then check whether it's pressed directly in your code. For example, in a ButtonsChanged event handler:

private void OnButtonsChanged(object sender, ButtonsChangedEventArgs e)
{
   if (this.Config.ToggleKey.JustPressed())
   {
      // perform desired action
   }
}

The KeybindList provides a number of methods depending on your use case:

member description
KeybindList.Parse(…)
KeybindList.TryParse(…)
Parse a keybind string like "F2, LeftShift + S" into a keybind list.
IsBound Whether the keybind list has any keys bound. For example, this would be false for the strings "None" or "".
Keybinds The individual keybinds. In most cases you shouldn't use these directly.
GetState() Get the overall keybind state relative to the previous tick. This state is transitive across keybinds; e.g. if the player releases one keybind and immediately presses another within the list, the overall state is Held.
IsDown() Get whether any keybind in the list is currently down (i.e. the player pressed or is holding down the keys).
JustPressed() Get whether the player just activated the keybind during the current tick (i.e. GetState() returns Pressed instead of Held).
GetKeybindCurrentlyDown() Get the individual Keybind in the list which is currently down, if any. If there are multiple keybinds down, the first one is returned.
ToString() Get a string representation of the input binding (e.g. "F2, LeftShift + S").

Caveats:

  • Don't use the ButtonPressed event to check keybinds, since it's raised once for each button pressed. If the player presses two keys at once, your keybind would be activated twice. Use ButtonsChanged instead.

ICursorPosition

SMAPI's ICursorPosition provides the cursor position in four coordinate systems:

  • AbsolutePixels is the pixel position relative to the top-left corner of the in-game map, adjusted for zoom but not UI scaling.
  • ScreenPixels is the pixel position relative to the top-left corner of the visible screen, adjusted for zoom but not UI scaling.
  • Tile is the tile position under the cursor.
  • GrabTile is the tile position that the game considers under the cursor for the purposes of clicking actions. This automatically accounts for controller mode. This may be different than Tile if that's too far from the player.

This is returned by the this.Helper.Input.GetCursorPosition() method and in the event args for some input events.

The pixel positions are not adjusted for UI scaling (i.e. they're non-UI mode). Whether you need UI or non-UI positions depends how you're using them, so you can use cursorPos.GetScaledAbsolutePixels() or cursorPos.GetScaledScreenPixels() to adjust them automatically for the current mode or Utility.ModifyCoordinatesForUIScale to always get UI mode coordinates.

See also