date: 2019/08/15 17:44:30
- user: cg
- file: GraphicsDevice.st directory: libview
- module: stx stc-classLibrary: libview
- Claus Gittinger
this abstract class was inserted to provide a home for ST-80 classes
(previously, DeviceWorkstation was directly under Object).
In ST/X, this is mostly dummy.
displayId <Handle> the device handle
screen any another some device specific id
eventListeners <Collection> | nil bunch of objects interested in events.
deviceType <Symbol> some arbitrary symbol, used to choose windowSpecs.
accessing & queries
creating graphics contexts
add a local eventListener (with new protocol - #processEvent:)
This one gets a chance to intercept all events for this device
I am not a WebService pseudo-device
(comment from inherited method)
generate a literalArrayEncoding array for myself.
This uses #literalArrayEncodingSlotOrder which defines the slots and
order and #skippedInLiteralEncoding which defines slots to skip.
In addition, an object may define virtualSlotsInLiteralEncoding for slots
which are not really instvars, but should be fetched via getters.
For most subclasses, there is no need to redefine those.
remove a local eventListener (with new protocol - #processEvent:)
return true, if this device supports alpha information.
Currently none does
create a new graphics context.
The default is to use the inherited graphics context.
Subclasses may redefine this to use their own graphics context
notify all eventHandlers about an incoming event.
If any returns true, it is assumed to be eaten by the handler and not
enqueued (i.e. not passed to the windowGroup process)
answer the round trip time in milliseconds.
May be used to detect slow device connections.
Subclasses redefine this. Assume a fast Diplay connection
and answer 0 here
Screen current roundTripTime