Events

Zaffre uses Clojure's core.async pub-sub metaphor for event handling. A terminal's publication is available through the Terminal protocol's (pub [terminal]) method.

Typically, an application will use zaffre.events/add-event-listener to add event listeners.

(zevents/add-event-listener terminal :keypress
  (fn [ev] ...))

However there may be cases when working directly with core.async/sub is preferred.

(let [term-pub (pub terminal)
      key-chan (core.async/chan)]
  (core.async/sub :keypress key-chan)
  (core.async/go-loop []
     (let [new-key (core.async/<! key-chan)]
        ; Do something with new-key

Event Types

:keypress

Keypress messages are simply characters.

:mouse-down

Mouse down messages are maps.

Example:

{:type :mouse-down
 :button :left ; :left/:right/:middle
 :col 21
 :row 44
 :group-id :app}

One :mouse-down message will be received for each layer group intersecting the mouse cursor. If using pub/sub you may find clojure.core.async/filter< useful to filter messages of a certain :group-id. Otherwise, be careful and remember to check the :group-id in the event handler if necessary.

:mouse-up

Mouse up messages are maps.

Example:

{:type :mouse-up
 :button :left ; :left/:right/:middle
 :col 21
 :row 44
 :group-id :app}

Like :mouse-down, one :mouse-up message will be received for each layer group intersecting the mouse cursor. If using pub/sub you may find clojure.core.async/filter< useful to filter messages of a certain :group-id. Otherwise, be careful and remember to check the :group-id in the event handler if necessary.

:click

Click messages are maps.

Example:

{:type :click
 :button :left ; :left/:right/:middle
 :col 21
 :row 44
 :group-id :app}

Click messages are generated on mouse up for every (group,col,row) that matches to the corresponding mouse down. Ie: the mouse cursor may drag a bit, but as long as the cursor is inside the same grid cell when the button is release, a click message will be generated.

Like :mouse-down and :mouse-up, one :click message will be received for each layer group intersecting the mouse cursor. If using pub/sub you may find clojure.core.async/filter< useful to filter messages of a certain :group-id. Otherwise, be careful and remember to check the :group-id in the event handler if necessary.

:mouse-leave

Mouse leave messages are maps.

Example:

{:type :mouse-leave
 :col 21
 :row 44
 :group-id :app}

:mouse-enter

Mouse enter messages are maps.

Example:

{:type :mouse-enter
 :col 21
 :row 44
 :group-id :app}

:close

The close message value is the keyword :close. Close messages are generated when the window is dismissed or destroy! is called on the terminal.