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: 1.51 date: 2023/11/24 12:53:12

user: cg

file: SynchronousWindowSensor.st directory: libview

module: stx stc-classLibrary: libview

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)

copyright
COPYRIGHT (c) 1995 by Claus Gittinger
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Instance protocol:

 compressKeyPressEventsWithKey: aKey

 flushEventsFor: aViewOrNil inQueue: anEventQueue where: aCondition

 addDamage: aRectangle view: aView wakeup: doWakeup

forward as an expose for some view

 dispatchEvent: event to: aView

because this may be called directly from the event dispatcher,

 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

dispatch the event immediately

 pushUserEvent: selector for: anyObject withArguments: argList

dispatch 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).