| author | Claus Gittinger <cg@exept.de> |
| Sat, 27 Apr 1996 16:19:26 +0200 | |
| changeset 228 | 8f73cdf66b60 |
| parent 226 | c5a265ceddd1 |
| child 232 | b898f5762952 |
| permissions | -rw-r--r-- |
| 88 | 1 |
" |
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COPYRIGHT (c) 1995 by Claus Gittinger |
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e577a2f332d0
uff - version methods changed to return stings
Claus Gittinger <cg@exept.de>
parents:
96
diff
changeset
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All Rights Reserved |
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This software is furnished under a license and may be used |
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only in accordance with the terms of that license and with the |
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inclusion of the above copyright notice. This software may not |
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be provided or otherwise made available to, or used by, any |
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other person. No title to or ownership of the software is |
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hereby transferred. |
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" |
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Model subclass:#Plug |
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instanceVariableNames:'simulatedProtocol' |
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classVariableNames:'' |
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poolDictionaries:'' |
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category:'Kernel-Objects' |
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! |
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!Plug class methodsFor:'documentation'! |
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copyright |
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" |
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COPYRIGHT (c) 1995 by Claus Gittinger |
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114
e577a2f332d0
uff - version methods changed to return stings
Claus Gittinger <cg@exept.de>
parents:
96
diff
changeset
|
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All Rights Reserved |
| 88 | 26 |
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This software is furnished under a license and may be used |
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only in accordance with the terms of that license and with the |
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inclusion of the above copyright notice. This software may not |
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be provided or otherwise made available to, or used by, any |
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other person. No title to or ownership of the software is |
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hereby transferred. |
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" |
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! |
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||
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documentation |
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" |
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A Plug is an object which simulates a protocol and evaluates |
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a corresponding block when receiving messages. |
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A plugs interface can be changed dynamically. |
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Its main use is for the demo doIts, to play the role of a model, |
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when no actual modelClass is available for the demonstration. |
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However, it can be used wherever some object is needed which responds to |
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some protocol AND you do not want to add a class for it |
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(lightWeight objects). |
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There is a slight performance penalty - compared to `normal' objects, |
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getting `normal' messages, though. |
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[author:] |
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Claus Gittinger |
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[see also:] |
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Model |
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" |
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! |
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examples |
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" |
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[exBegin] |
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|plug| |
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plug := Plug new. |
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plug respondTo:#foo with:[Transcript showCr:'received foo']. |
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plug respondTo:#foo: with:[:arg | Transcript showCr:'received foo: ', arg printString]. |
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plug foo. |
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plug foo:'some argument' |
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[exEnd] |
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simulating ``instance variables'': |
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(actually, this is somewhat expensive - the contexts locals are used for them ...) |
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be careful with unintended variable sharing (if plugs are created in a loop ..) |
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[exBegin] |
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|plug1 plug2 local1 local2| |
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plug1 := Plug new. |
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plug1 respondTo:#get with:[local1]. |
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plug1 respondTo:#set: with:[:arg | local1 := arg]. |
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plug2 := Plug new. |
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plug2 respondTo:#get with:[local2]. |
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plug2 respondTo:#set: with:[:arg | local2 := arg]. |
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Transcript show:'plug1''s value: '; showCr:plug1 get. |
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Transcript show:'plug2''s value: '; showCr:plug2 get. |
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plug1 set:5. |
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plug2 set:17. |
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Transcript show:'plug1''s value: '; showCr:plug1 get. |
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Transcript show:'plug2''s value: '; showCr:plug2 get. |
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[exEnd] |
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" |
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! ! |
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!Plug class methodsFor:'instance creation'! |
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new |
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^ super basicNew __privateInitialize__ |
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"Modified: 27.4.1996 / 16:16:59 / cg" |
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! ! |
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!Plug methodsFor:'initialization'! |
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__privateInitialize__ |
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"this method is NOT called `#initialize' to allow plugging that |
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selector ..." |
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simulatedProtocol := IdentityDictionary new. |
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"Modified: 27.4.1996 / 16:15:45 / cg" |
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"Created: 27.4.1996 / 16:17:07 / cg" |
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! ! |
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!Plug methodsFor:'message sending'! |
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doesNotUnderstand:aMessage |
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"catch unhandled messages by looking in my simulated protocol |
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definition; if there is some block for it, return its value. |
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Otherwise, fall into the real doesNotUnderstand error." |
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|block| |
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block := simulatedProtocol at:aMessage selector ifAbsent:[]. |
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block isNil ifTrue:[ |
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^ super doesNotUnderstand:aMessage |
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]. |
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^ block valueWithArguments:(aMessage arguments) |
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"Modified: 27.4.1996 / 16:15:34 / cg" |
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! ! |
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!Plug methodsFor:'protocol definition'! |
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forgetAbout:aSelector |
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"tell the receiver to forget about how to respond to the given by selector" |
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simulatedProtocol removeKey:aSelector ifAbsent:nil |
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" |
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|p| |
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p := Plug new. |
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p respondTo:#foo with:[Transcript showCr:'foo']. |
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p respondTo:#foo: with:[:arg | Transcript show:'foo:'; showCr:arg]. |
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p foo. |
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p foo:'hello'. |
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p forgetAbout:#foo. |
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p foo. |
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" |
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"Modified: 27.4.1996 / 16:14:19 / cg" |
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"Created: 27.4.1996 / 16:19:08 / cg" |
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! |
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respondTo:aSelector with:aBlock |
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"tell the receiver to respond to a message given by selector, |
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with evaluating aBlock. The number of arguments as defined by the |
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selector must match the number of blockArsg expected by the block. |
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The value returned from aBlock will be the value returned from the |
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message." |
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simulatedProtocol at:aSelector put:aBlock |
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" |
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|p| |
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p := Plug new. |
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p respondTo:#foo with:[Transcript showCr:'foo']. |
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p respondTo:#foo: with:[:arg | Transcript show:'foo:'; showCr:arg]. |
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p foo. |
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p foo:'hello' |
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" |
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"Modified: 27.4.1996 / 16:14:19 / cg" |
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! ! |
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!Plug methodsFor:'queries'! |
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respondsTo:aSelector |
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"return true, if the receiver responds to a message" |
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(simulatedProtocol includesKey:aSelector) ifTrue:[^ true]. |
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^ super respondsTo:aSelector |
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"Modified: 27.4.1996 / 16:14:41 / cg" |
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! ! |
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!Plug class methodsFor:'documentation'! |
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version |
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^ '$Header: /cvs/stx/stx/libview2/Plug.st,v 1.11 1996-04-27 14:19:26 cg Exp $' |
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! ! |