Class: DeviceHandle

• Inheritance
• Description
• Class protocol
  • queries
• Instance protocol
  • accessing
  • finalization
  • private-accessing

Inheritance:

   Object
   |
   +--DeviceHandle
      |
      +--DeviceGraphicsContext::DevicePixmapGCHandle
      |
      +--DeviceGraphicsContext::DeviceWindowGCHandle

Package:

stx:libview

Category:

Graphics-Support

Version:

rev: 1.19 date: 2021/01/20 14:35:39

user: cg

file: DeviceHandle.st directory: libview

module: stx stc-classLibrary: libview

Description:

This is an abstract class for device handles which are responsible
for finalization i.e. to destroy underlying system resources, when the GC
frees an object which has created some system object.
Currently, these are forms and views (streams, cursors, colors and
fonts could also make use of this class - however, for historical reasons,
they continue to use their own private finalization machanisms. This may
change in future versions).

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.

Class protocol:

 isAbstract

Return if this class is an abstract class.
True is returned here for myself only; false for subclasses.
Abstract subclasses must redefine this again.

Instance protocol:

 device

 id

return the id of the dravable

 finalize

I am abstract

** This method must be redefined in concrete classes (subclassResponsibility) **

 setDevice: aDevice id: aDrawableId gcId: aGCId

set the handles contents