The Trunk: System-mt.1025.mcz

Marcel Taeumel uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-mt.1025.mcz

==================== Summary ====================

Name: System-mt.1025
Author: mt
Time: 9 May 2018, 9:23:01.362554 am
UUID: 061ddb0a-c159-884b-8964-3f3c2f74e7c7
Ancestors: System-mt.1024

Fixes typo.

=============== Diff against System-mt.1024 ===============

Item was changed:
  Object subclass: #UserInterfaceTheme
  instanceVariableNames: 'properties name next ignoreApply lastScaleFactor'
  classVariableNames: 'All Current Default'
  poolDictionaries: ''
  category: 'System-Support'!
 
+ !UserInterfaceTheme commentStamp: 'mt 5/9/2018 09:22' prior: 0!
- !UserInterfaceTheme commentStamp: 'rhi 5/5/2018 09:18' prior: 0!
  A UserInterfaceTheme is a dictionary of preferred visual properties; colors, borderStyles, borderWidths, fonts, forms, etc. used to color and style the IDE.
 
  Accessing the Theme
+ To access the proper UserInterfaceTheme instance for an object, send it #userInterfaceTheme.  The default implementation on Object returns an instance of UserInterfaceThemeRequest that provides a lightweight, clean proxy of the actual theme in use by the IDE at the current time. To do anything more sophisticated than basic querying and setting of properties, you must ask the proxy for the actual theme by sending #theme.
- To access the proper UserInterfaceTheme instance for an object, send it #userInterfaceTheme.  The default implementation on Object returns an instance of UserInterfaceThemeRequest that provides a lightweight, clean proxy of the actual theme in use by the IDE at the current time. To do anything more sophisticated than basic queryinh and setting of properties, you must ask the proxy for the actual theme by sending #theme.
 
  Customizing the Theme
  We can ask the #userInterfaceTheme for the value of any visual property by name:
 
  mySystemWindow userInterfaceTheme closeBoxImage
 
  Initially that would answer nil, which causes the legacy code to use whatever default it used so far. To override various visual properties of any kind of object, the #set:for:to: message can be used, for example:
 
  myUserInterfaceTheme
  set: #closeBoxImage
  for: SystemWindow
  to: MenuIcons smallCancelIcon
 
  Now the closeBoxImage message will answer the MenuIcons icon instead of nil.
 
  Alternatively, values may be derived based on other values in the theme, as in:
 
  myUserInterfaceTheme
  set: #color
  for: FillInTheBlankMorph
  to: { MenuMorph->#color. #twiceDarker }
 
  This makes FillInTheBlankMorph use the same color as a MenuMorph but #twiceDarker, providing a clean way to build coherent sets of colors within a theme. SystemWindow's code can be changed to use the expression above to access elements of the theme.
 
  Upgrading Legacy Code
  Following the introduction of this class, various client code all around the system must be modified to access it. This variety of legacy code uses a variety of methods to specify their visual properties:
 
  1) a hard-coded values.
  2) a values derived from some other value.
  3) providing local storage for a settable value which can be nil.
  4) providing local storage for a settable value which is expected to always have a particular valid value (never nil).
 
  The requirement, for each case, is to let the value be overridden.
 
  The solution for each of the above should be handled respectively to the above list, as follows:
 
  1) Check the #userInterfaceTheme, if that property returns nil, use the legacy hard-coded value. (see example: SystemWindow>>#createCloseBox).
  2) Nothing to do -- simply perform the same derivation on the result of (1).
  3) Check the local storage, if present, use it. If nil, then check the #userInterfaceTheme, if it has this property present, use it, else return nil.
  4) Check the #userInterfaceTheme, if the property is not nil, use it, otherwise use the local value.
 
  Tool Support
  If a new access to #userInterfaceTheme is added to the code, be sure to add the property and its description to the #themeSettings for that class. See implementors of #themeSettings for examples.!