David T. Lewis uploaded a new version of Morphic to project The Trunk:
http://source.squeak.org/trunk/Morphic-dtl.366.mcz

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

Name: Morphic-dtl.366
Author: dtl
Time: 27 February 2010, 11:49:57.312 am
UUID: a1f4b02f-798f-46da-b8df-4a4167f1df36
Ancestors: Morphic-ar.365

Implement #resetDisplay, #setAsBackground: and #handledFatalDrawingError: to reduce use of #isMorphic.
Use Project>>handleFatalDrawingError: in PasteUpMorph and WorldState.

=============== Diff against Morphic-ar.365 ===============

Item was changed:
  ----- Method: WorldState>>handleFatalDrawingError: (in category 'update cycle') -----
  handleFatalDrawingError: errMsg
  	"Handle a fatal drawing error."
+ 	self flag: #toRemove. "Implementation moved to Project, but are there external packages with senders?"
+ 	Project current handleFatalDrawingError: errMsg
+ !
- 	Smalltalk isMorphic ifFalse:[^self error: errMsg]. "Can still handle it from MVC"
- 	Display deferUpdates: false. "Just in case"
- 	self primitiveError: errMsg.
- 
- 	"Hm... we should jump into a 'safe' worldState here, but how do we find it?!!"!

Item was changed:
  ----- Method: WorldState>>displayWorldSafely: (in category 'update cycle') -----
  displayWorldSafely: aWorld
  	"Update this world's display and keep track of errors during draw methods."
  
  	[aWorld displayWorld] ifError: [:err :rcvr |
  		"Handle a drawing error"
  		| errCtx errMorph |
  		errCtx := thisContext.
  		[
  			errCtx := errCtx sender.
  			"Search the sender chain to find the morph causing the problem"
  			[errCtx notNil and:[(errCtx receiver isMorph) not]] 
  				whileTrue:[errCtx := errCtx sender].
  			"If we're at the root of the context chain then we have a fatal drawing problem"
+ 			errCtx ifNil:[^Project current handleFatalDrawingError: err].
- 			errCtx ifNil:[^self handleFatalDrawingError: err].
  			errMorph := errCtx receiver.
  			"If the morph causing the problem has already the #drawError flag set,
  			then search for the next morph above in the caller chain."
  			errMorph hasProperty: #errorOnDraw
  		] whileTrue.
  		errMorph setProperty: #errorOnDraw toValue: true.
  		"Install the old error handler, so we can re-raise the error"
  		rcvr error: err.
  	].!

Item was added:
+ ----- Method: MorphicProject>>setAsBackground: (in category 'utilities') -----
+ setAsBackground: aForm
+ 	"Set  aForm as a background image."
+ 
+ 	| world newColor |
+ 	world := self currentWorld.
+ 	newColor := InfiniteForm with: aForm.
+ 	aForm rememberCommand:
+ 		(Command new cmdWording: 'set background to a picture' translated;
+ 			undoTarget: world selector: #color: argument: world color;
+ 			redoTarget: world selector: #color: argument: newColor).
+ 	world color: newColor
+ !

Item was added:
+ ----- Method: MorphicProject>>resetDisplay (in category 'display') -----
+ resetDisplay 
+ 	"Bring the display to a usable state after handling primitiveError."
+ 
+ 	World install "init hands and redisplay"!

Item was changed:
  ----- Method: PasteUpMorph>>handleFatalDrawingError: (in category 'world state') -----
  handleFatalDrawingError: errMsg
  	"Handle a fatal drawing error."
+ 	self flag: #toRemove. "Implementation moved to Project, but are there external packages with senders?"
+ 	Project current handleFatalDrawingError: errMsg
+ !
- 	Smalltalk isMorphic ifFalse:[^self error: errMsg]. "Can still handle it from MVC"
- 	Display deferUpdates: false. "Just in case"
- 	self primitiveError: errMsg.
- 
- 	"Hm... we should jump into a 'safe' worldState here, but how do we find it?!!"!

Item was added:
+ ----- Method: MorphicProject>>handleFatalDrawingError: (in category 'utilities') -----
+ handleFatalDrawingError: errMsg
+ 	"Handle a fatal drawing error."
+ 
+ 	Display deferUpdates: false. "Just in case"
+ 	self primitiveError: errMsg
+ 
+ 	"Hm... we should jump into a 'safe' worldState here, but how do we find it?!!"!