Class: SynchronousWindowSensor

• Inheritance
• Description
• Instance protocol
  • dummy event flushing
  • event processing
  • event processing-private
  • event simulation
  • initialization
  • specials

Inheritance:

   Object
   |
   +--WindowSensor
      |
      +--SynchronousWindowSensor

Package:

stx:libview

Category:

Interface-Support-UI

Version:

rev: 1.39 date: 2018/05/11 07:24:25

user: cg

file: SynchronousWindowSensor.st directory: libview

module: stx stc-classLibrary: libview

Author:

Claus Gittinger

Description:

These sensors are not used with regular views.

In contrast to a regular windowSensor, instances of SynchronousWindowSensor
do NOT put events into a queue and do NOT wakeup any windowGroup process.
Instead, the underlying view is notified synchronously (via a message send)
immediately about the event.

SynchronousWindowSensor are used for only one single situation: 
    when a super-modal debugger is open
(i.e. one that is debugging the scheduler or event-dispatcher).

This debugger's windowGroup is augmented with a synchronous Sensor, in order
to prevent the event handling code from suspending any process 
(you cannot suspend the scheduler; you should not suspend the event dispatcher).

This is pretty tricky and magic - and you don't have to understand this.
(consider this system internal code)

Instance protocol:

 compressKeyPressEventsWithKey: aKey

 flushEventsFor: aViewOrNil inQueue: anEventQueue where: aCondition

 addDamage: aRectangle view: aView wakeup: doWakeup

forward as an expose for some view

 exposeX: x y: y width: w height: h view: aView

forward an expose for some view

 graphicsExposeX: x y: y width: w height: h final: final view: aView

forward a graphic expose for some view

 noExposeView: aView

forward a noExpose event for some view

 saveAndTerminateView: aView

forward a saveAndTerminate event for some view

 terminateView: aView

forward a terminate event for some view

 basicPushEvent: anEvent

dispach the event immediately

 pushDamageEvent: anEvent

disptach the event immediately

 pushUserEvent: selector for: anyObject withArguments: argList

disptach the event immediately

 enqueueMessage: selector for: someone arguments: argList

do it synchronously

 initialize

(comment from inherited method)
initialize the event queues to empty

 catchExposeFor: aView

start catching noExpose events (must be done BEFORE a bitblt).

 waitForExposeFor: aView

wait until a graphicsExpose or a noExpose arrives (after a bitblt).