Reactor.Events

optionallyPreventDefault :: forall m. MonadEffect m => DefaultBehavior -> Event -> HookM m Unit

Used internally.

data DefaultBehavior

This datatype is used internally to signal to the reactor whether you want to prevent the default behavior that would normally happen as a response to the event.

In more detail: Some events have default behaviors associated with them; for example, pressing Ctrl+F shows the find on the page dialog for the current page. When handling events, we often want to 'consume' them, and prevent the default behavior from happening — maybe Ctrl+F is used for the 'fire' command in your game, and you don't want the find on the page dialog to show.

The default behavior is prevented automatically in your event handler. If you want to execture the default behavior for certain events, you have to explicitly call Reactor.Action.executeDefaultBehavior.

Constructors

• Prevent
• Execute

Instances

• Eq DefaultBehavior

mouseEventFromDOM :: { height :: Int, tileSize :: Int, width :: Int } -> MouseInteractionType -> MouseEvent -> Event

Convert a DOM mouse event into our custom event type. Used internally, you shouldn't need it.

data MouseInteractionType

The main mouse event types, from the point of view of the rendered grid. A Drag occurs when the mouse button is down during a Move. Right-button clicks are not handled, those get handled by the browser.

Constructors

• ButtonUp
• ButtonDown
• Drag
• Enter
• Leave
• Move

Instances

• Eq MouseInteractionType
• Generic MouseInteractionType _
• Show MouseInteractionType

keypressEventFromDOM :: KeyboardEvent -> Event

Convert a DOM keyboard event into our custom event type. Used internally, you shouldn't need it.

data Event

This type describes the different events that occur during the life of a reactor. You pattern match on this in the handleEvent function.

Tick Event

This event is fired on every clock-tick in the reactor. The attribute delta is the time from the last tick, in seconds. There's approximately 60 ticks per second, however, the number can vary depending on the browser's current available resources.

Mouse Event

This event is fired whenever the user presses a button on their mouse, or moves the mouse over the rendering grid. Explanation of each of the fields:

• type is the type of the event (drag, button up, etc.)
• position is the position of the event relative to the rendering grid (i.e. in tiles).
• positionOnCanvas is the position of the event relative to the rendering canvas (i.e. in pixels).
• for more information on modifiers see the documentation of the type Modifiers.

Keypress Event

This event is fired whenever the user presses down a key on the keyboard. The key is passed in the event as a String, with the following rules:

• Numbers, letters, and symbols all have intuitive codes (type A → get "A", type ů → get "ů"). Notably, pressing space produces an event with a literal space, " ".
• Any modifier keys that were pressed simultaneously with the main key are passed in the record modifiers.
• Common special keys have intuitive names. For example: ArrowLeft, ArrowRight, ArrowUp, ArrowDown. Full list can be seen on MDN Web Docs.

Constructors

• Tick { delta :: Number }
• Mouse { modifiers :: Modifiers, position :: Coordinates, positionOnCanvas :: { x :: Number, y :: Number }, type :: MouseInteractionType }
• KeyPress { key :: String, modifiers :: Modifiers }

Instances

• Generic Event _
• Show Event

type Modifiers = { alt :: Boolean, control :: Boolean, meta :: Boolean, shift :: Boolean }

Mouse and KeyPress events carry the info about modifier keys that were pressed when the event happened. A meta key is the Windows button on Windows, and the Command button on the Mac. The rest are the common modifier keys.

windowPerformanceNow :: Window -> Effect Number