Class: AbstractBackground

• Inheritance
• Description
• Class protocol
  • queries
• Instance protocol
  • drawing
  • ignored conversion
  • testing
• Examples

Inheritance:

   Object
   |
   +--AbstractBackground
      |
      +--DiffTextView::DiffTextScrollerBackground
      |
      +--GradientBackground
      |
      +--ImageBackground
      |
      +--NoBackground
      |
      +--SolidBackground
      |
      +--Tools::CodeView2::AnnotationShowingScrollerBackground

Package:

stx:libview

Category:

Graphics-Support

Version:

rev: 1.10 date: 2021/01/20 15:45:02

user: cg

file: AbstractBackground.st directory: libview

module: stx stc-classLibrary: libview

Description:

This will replace the viewBackground color.
Instances of me (and subclasses) can be set as a widget's
viewBackground, and will get 
    fillRectangleX:x y:y width:w height:h in:aView
messages whenever the widget wants to redraw (parts of) its background.

See the example in GradientBackground.

copyright
COPYRIGHT (c) 2009 by Claus Gittinger / eXept Software AG
             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:

 fillRectangleX: x y: y width: w height: h in: aView

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

 asFormOn: aDevice

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

 onDevice: aDevice

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

 isViewBackground

(comment from inherited method)
return false here; to be redefined in subclass(es)

 needsFullRedrawOnChangeOfHeight

 needsFullRedrawOnChangeOfWidth

Examples:

|v|

v := View new.
v viewBackground:(SolidBackground new color:Color red).
v open.