"

COPYRIGHT (c) 1993 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.

"

HostGraphicsDevice subclass:#DeviceWorkstation

	instanceVariableNames:'visualType monitorType depth ncells bitsPerRGB bitsRed bitsGreen

		bitsBlue redMask greenMask blueMask redShift greenShift blueShift

		hasColors hasGreyscales width height widthMM heightMM

		resolutionHor resolutionVer idToTableIndexMapping knownViews

		knownIds knownBitmaps knownBitmapIds dispatching dispatchProcess

		ctrlDown shiftDown metaDown altDown motionEventCompression lastId

		lastView keyboardMap rootView isSlow activeKeyboardGrab

		activePointerGrab buttonTranslation multiClickTimeDelta

		altModifiers metaModifiers ctrlModifiers shiftModifiers

		supportsDeepIcons preferredIconSize ditherColors fixColors

		numFixRed numFixGreen numFixBlue copyBuffer lastCopyBuffer

		blackColor whiteColor'

	classVariableNames:'ButtonTranslation MultiClickTimeDelta DeviceErrorSignal

	poolDictionaries:''

	category:'Interface-Graphics'

!

!DeviceWorkstation class methodsFor:'documentation'!

copyright

"

COPYRIGHT (c) 1993 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.

"

!

documentation

"

    this abstract class defines common protocol to all Display types.

    For compatibility with ST-80, this class (actually a concrete subclass) 

    is also bound to the global variable Screen.

    DeviceWorkstation (and its concrete subclasses) are the central classes

    around windowManagement and event processing.

    See the documentation in #events and #workstationDevices for more detailed

    info.

    [instance variables:]

      displayId       <Number>          the device id of the display

      visualType      <Symbol>          one of #StaticGray, #PseudoColor, ... #TrueColor

      monitorType     <Symbol>          one of #monochrome, #color, #unknown

      depth           <SmallInteger>    bits per color

      ncells          <SmallInteger>    number of colors (i.e. colormap size; not always == 2^depth)

      bitsPerRGB      <SmallInteger>    number of valid bits per rgb component

					(actual number taken in A/D converter; not all devices report the true value)

      bitsRed         <SmallInteger>    number of red bits (only valid for TrueColor displays)

      bitsGreen       <SmallInteger>    number of green bits (only valid for TrueColor displays)

      bitsBlue        <SmallInteger>    number of blue bits (only valid for TrueColor displays)

      redMask         <SmallInteger>    shifted red mask (only useful for TrueColor displays)

      greenMask       <SmallInteger>    shifted green mask (only useful for TrueColor displays)

      blueMask        <SmallInteger>    shifted blue mask (only useful for TrueColor displays)

      shiftRed        <SmallInteger>    number of bits to shift red bits (only valid for TrueColor displays)

      shiftGreen      <SmallInteger>    number of bits to shift green bits (only valid for TrueColor displays)

      shiftBlue       <SmallInteger>    number of bits to shift blue bits (only valid for TrueColor displays)

      hasColors       <Boolean>         true, if display supports colors

      hasGreyscales   <Boolean>         true, if display supports grey-scales (i.e is not b/w display)

      width           <SmallInteger>    number of horizontal pixels

      height          <SmallInteger>    number of vertical pixels 

      heightMM        <Number>          screen height in millimeter

      widthMM         <Number>          screen width in millimeter

      resolutionHor   <Number>          pixels per horizontal millimeter

      resolutionVer   <Number>          pixels per vertical millimeter

      idToTableIndexMapping <Dictionary>      maps view-ids to views

      knownViews      <WeakArray>       all of my known views

      knownIds        <Collection>      corresponding device-view ids

      knownBitmaps    <Collection>      all known device bitmaps

      knownBitmapIds  <Collection>      corresponding device-bitmap ids

      dispatching     <Boolean>         true, if currently in dispatch loop

      ctrlDown        <Boolean>         true, if control key currently pressed

      shiftDown       <Boolean>         true, if shift key currently pressed

      metaDown        <Boolean>         true, if meta key (cmd-key) is currently pressed

      altDown         <Boolean>         true, if alt key is currently pressed

      motionEventCompression

		      <Boolean>         if true motion events are compressed

					(obsolete: now done in sensor)

      lastId          <Number>          the id of the last events view (internal)

      lastView        <View>            the last events view (internal, for faster id->view mapping)

      keyboardMap     <KeyBdMap>        mapping for keys

      rootView        <DisplayRootView> this displays root window

      isSlow          <Boolean>         set/cleared from startup - used to turn off

					things like popup-shadows etc.

    [class variables:]

      MultiClickTimeDelta               in ms; controls how long of a delay is

					required between two clicks, to NOT take

					it as a multi-click.

      ErrorPrinting                     controls low-level (X-) error message printing

      AllScreens                        a collectin of known screens

      ExitOnLastClose                   if true, the dispatch process terminates when the

					last view is closed. (for stand alone apps)

					Should be set to false, if a standAlone app

					closes all views and still needs an event dispatcher

					later (i.e. is temporary view-less)

    [see also:]

	GraphicsContext DeviceDrawable

	WindowSensor WindowGroup WindowEvent

	ProcessorScheduler

	PSMedium

    [author:]

	Claus Gittinger

"

!

events

"

    All events are processed in a workstations dispatchEvent method.

    There, incoming events are first sent to itself, for a first (view independent)

    preprocessing. For example, the devices state of the shift-, alt-, control and

    meta keys are updated there. After that, the event is forwarded either to

    the views sensor or to the view directly (if it has no sensor).

    (Sensorless views are a leftover from ancient times and will sooner or

     later vanish - simplifying things a bit. Do not depend on views without

     sensors to work correctly in future versions.)

    This event processing is done by the event dispatcher process, which is

    launched in ST/X's startup sequence (see Smalltalk>>start).

    Event processing is done at a high priority, to allow keyboad processing

    and CTRL-C handling to be performed even while other processes are running.

    The code executed by the event process is found in startDispatch.

    Individual events can be enabled or disabled. The ones that are enabled

    by default are:

	keypress / keyRelease

	buttonPress / buttonRelease / buttonMotion (i.e. motion with button pressed)

	pointerEnter / pointerLeave

    other events have to be enabled by sending a corresponding #enableXXXEvent

    message to the view which shall receive those events.

    For example, pointerMotion events (i.e. motion without button being pressed)

    are enabled by: 'aView enableMotionEvent'

    The above is only of interest, if you write your own widget classes,

    existing widgets set things as required in their #initEvents method.

"

!

workstationDevices

"

    In ST/X, all interaction with the graphics device is done through

    an instance of (a subclass) of DeviceWorkstation.

    Every view has a reference to the device it has been created on in

    its 'device' instance variable. 

    One particular device instance is bound to the global variable Display:

    this is the default graphics display, on which new views are created

    (however, provisions exist for multi-display operation)

    the following are coming soon:

    An experimental version for a NeXTStep interface exists, but is currently

    no longer maintained and not released.

    DeviceWorkstation itself is an abstract class; the methods as defined

    here perform things which are common to all graphic devices or block

    methods and raise a subclassResponsibilty error condition.

    have to be reimplemented in a concrete subclass.

    For example, in X, it is possible to create another instance of XWorkstation, 

    start a dispatch process for it, and to create and open views on this display. 

    If you want to experiment with multi-display applications,

    you have to:

    However, as mentioned above, there may be a few places, where the default

    display 'Display' is still hard-coded - especially, in contributed and

    Public domain code, you may find those.

    Beside this (little bug ;-), remote display operation works pretty well. 

    If you write your application to work around those, multi-display applications are

    To make your application ready for multi-display operation, replace all

    references to 'Display' by: 'Screen current', which evaluates to the currently

    active display. I.e. each view gets its actual display via this expression.

    Since ST/X views already use this, new views opened by remote views should

    come up on the remote display.

    There is no easy solution for things like Notifiers, WarnBoxes or

    Debuggers when opened from some background or non-view process.

    These will come up one the default Display, as returned by 'Screen default'.

    There may still some problems to be expected,

    if the screens have different display capabilities (b&w vs. greyscale vs.

    color display). The current styleSheet approach keeps default values

"

! !

!DeviceWorkstation class methodsFor:'initialization'!

initialize

    "create local error signals; enable errorPrinting"

    DeviceErrorSignal isNil ifTrue:[

	DeviceErrorSignal := (Signal new) mayProceed:true.

	DeviceErrorSignal notifierString:'device error'.

	DeviceIOErrorSignal := (Signal new) mayProceed:false.

	DeviceIOErrorSignal notifierString:'device IO error'.

	CurrentScreenQuerySignal := QuerySignal new.

	CurrentScreenQuerySignal nameClass:self message:#currentScreenQuerySignal.

	CurrentScreenQuerySignal notifierString:'asking for current screen'.

    ].

    ErrorPrinting := true.

    ExitOnLastClose := false.

    self initializeConstants.

    "Modified: 15.2.1997 / 15:08:40 / cg"

!

initializeConstants

    "initialize some (soft) constants"

    MultiClickTimeDelta := 300.       "a click within 300ms is considered a double one"

    ButtonTranslation := #(1 2 3)     "identity translation"

! !

!DeviceWorkstation class methodsFor:'Signal constants'!

currentScreenQuerySignal

    "return the signal which can be used to provide a current

     screen (if background processes ask for one)"

    ^ CurrentScreenQuerySignal

    "Created: 15.2.1997 / 15:07:20 / cg"

!

deviceErrorSignal

    "return the signal used for device error reporting.

     In multi-display configurations, this is the parent of

     all per-instance deviceErrorSignals."

    ^ DeviceErrorSignal

!

deviceIOErrorSignal

    "return the signal used for device I/O error reporting.

     In multi-display configurations, this is the parent of

     all per-instance deviceIOErrorSignals."

    ^ DeviceIOErrorSignal

! !

!DeviceWorkstation class methodsFor:'accessing'!

buttonTranslation:anArray

    "set the button translation, #(1 2 3) is no-translation,

     #(3 2 1) is ok for left-handers"

    ButtonTranslation := anArray.

    Display notNil ifTrue:[

	Display buttonTranslation:anArray

    ].

! !

!DeviceWorkstation class methodsFor:'error handling'!

errorInterrupt:errID with:aParameter

    "{ Pragma: +optSpace }"

    "an error in the devices low level code (typically Xlib or XtLib)

     This is invoked via 

	XError->errorInterrupt:#DisplayError->registeredErrorInterruptHandlers

     or

	XError->errorInterrupt:#DisplayIOError->registeredErrorInterruptHandlers

     looks if a signal handler for DeviceErrorSignal is present,

     and - if so raises the signal. 

     If the signal not handled, simply output a message and continue.

     This allows for non disrupted error reporting OR to catch and

     investigate errors as required.

     However, io-errors are always delivered as a signal raise."

    |badId badResource msg theDevice theSignal p|

    errID notNil ifTrue:[

	AllScreens do:[:aDisplayDevice |

	    aDisplayDevice id = aParameter ifTrue:[

		theDevice := aDisplayDevice.

	    ]

	]

    ].

    "/ now, we have the bad guy at hand ...

    "/ get a per-instance signal.

    theDevice isNil ifTrue:[

	errID == #DisplayIOError ifTrue:[

	    theSignal := self deviceIOErrorSignal.

	] ifFalse:[

	    theSignal := self deviceErrorSignal

	]

    ] ifFalse:[

	errID == #DisplayIOError ifTrue:[

	    theSignal := theDevice deviceIOErrorSignal.

	] ifFalse:[

	    theSignal := theDevice deviceErrorSignal

	]

    ].

    errID == #DisplayIOError ifTrue:[

	"/ always raises an exception

	msg := 'Display I/O Error'.

	badResource := theDevice.

    ] ifFalse:[

	"/ only raises an exception if handled

	"/ that will become instance-specific information in

	"/ the near future ...

	badId := self resourceIdOfLastError.

	badId ~~ 0 ifTrue:[

	    badResource := self resourceOfId:badId.

	].

	msg := 'Display error: ' , (self lastErrorString).

	theSignal isHandled ifFalse:[

	    ErrorPrinting ifTrue:[

		('DeviceWorkstation [error]: ' , msg) errorPrintCR

	    ].

	    ^ self

	]

    ].

    "/ interrupt that dispatcher

    theDevice notNil ifTrue:[

	p := theDevice dispatchProcess.

	p ~~ Processor activeProcess ifTrue:[

'interrupting: ' print. p displayString printCR.

	    p interruptWith:[

		theDevice brokenConnection.

		theSignal 

		    raiseRequestWith:badResource

		    errorString:msg.

		p terminateWithAllSubprocesses.

		p terminateNoSignal.   "/ just in case

	    ].

	    Processor reschedule.

	    AbortSignal raise.

	].

    ].

    theDevice brokenConnection.

    theSignal

	raiseRequestWith:badResource 

	errorString:msg.

    AbortSignal raise.

    "Modified: 11.4.1997 / 11:28:27 / cg"

!

errorPrinting

    "return the `errorPrinting-is-on' flag"

    ErrorPrinting isNil ifTrue:[^ false].

    ^ ErrorPrinting

    "Modified: 24.4.1996 / 19:35:55 / cg"

!