Some people were asking for paren blinking a little while ago - here's
a quick attempt.  It uses bold instead of selection, so doesn't have the
annoying type-over danger of the previous changesets.

Avi


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'From Squeak3.2alpha of 1 November 2001 [latest update: #4599] on 7 January 2002 at 3:59:06 am'!
"Change Set:		ParenBlinking
Date:			7 January 2002
Author:			Avi Bryant

Adds simple paren blinking to ParagaphEditor - open parentheses are bolded when a close paren is typed, and stay bold until the next keystroke"!

ScrollController subclass: #ParagraphEditor
	instanceVariableNames: 'paragraph startBlock stopBlock beginTypeInBlock emphasisHere initialText selectionShowing otherInterval lastParenLocation '
	classVariableNames: 'ChangeText CmdActions FindText Keyboard ShiftCmdActions TextEditorYellowButtonMenu UndoInterval UndoMessage UndoParagraph UndoSelection Undone '
	poolDictionaries: 'TextConstants '
	category: 'Kernel-ST80 Remnants'!

!ParagraphEditor methodsFor: 'paren blinking' stamp: 'AB 1/7/2002 03:51'!
blinkParenAt: parenLocation 
	self text
		addAttribute: TextEmphasis bold
		from: parenLocation
		to: parenLocation.
	lastParenLocation _ parenLocation.! !

!ParagraphEditor methodsFor: 'paren blinking' stamp: 'AB 1/7/2002 03:51'!
blinkPrevParen
	| openDelimiter closeDelimiter level string here hereChar |
	string _ paragraph text string.
	here _ startBlock stringIndex.
	openDelimiter _ sensor keyboardPeek.
	closeDelimiter _ '([{' at: (')]}' indexOf: openDelimiter).
	level _ 1.
	[level > 0 and: [here > 2]]
		whileTrue:
			[hereChar _ string at: (here _ here - 1).
			hereChar = closeDelimiter
				ifTrue:
					[level _ level - 1.
					level = 0
						ifTrue: [^ self blinkParenAt: here]]
				ifFalse:
					[hereChar = openDelimiter
						ifTrue: [level _ level + 1]]].! !

!ParagraphEditor methodsFor: 'paren blinking' stamp: 'AB 1/7/2002 03:37'!
clearParens
	lastParenLocation ifNotNil:
		[self text
			removeAttribute: TextEmphasis bold
			from: lastParenLocation
			to: lastParenLocation].
! !

!ParagraphEditor methodsFor: 'paren blinking' stamp: 'AB 1/7/2002 03:50'!
dispatchOnCharacter: char with: typeAheadStream
	"Carry out the action associated with this character, if any.
	Type-ahead is passed so some routines can flush or use it."

	| honorCommandKeys |
	((honorCommandKeys _ Preferences cmdKeysInText) and: [char = Character enter])
		ifTrue: [^ self dispatchOnEnterWith: typeAheadStream].

	"Special keys overwrite crtl+key combinations - at least on Windows. To resolve this
	conflict, assume that keys other than cursor keys aren't used together with Crtl." 
	((self class specialShiftCmdKeys includes: char asciiValue) and: [char asciiValue < 27])
		ifTrue: [^ sensor controlKeyPressed
			ifTrue: [self perform: (ShiftCmdActions at: char asciiValue + 1) with: typeAheadStream]
			ifFalse: [self perform: (CmdActions at: char asciiValue + 1) with: typeAheadStream]].

	"backspace, and escape keys (ascii 8 and 27) are command keys"
	((honorCommandKeys and: [sensor commandKeyPressed]) or: [self class specialShiftCmdKeys includes: char asciiValue]) ifTrue:
		[^ sensor leftShiftDown
			ifTrue:
				[self perform: (ShiftCmdActions at: char asciiValue + 1) with: typeAheadStream]
			ifFalse:
				[self perform: (CmdActions at: char asciiValue + 1) with: typeAheadStream]].

	"the control key can be used to invoke shift-cmd shortcuts"
	(honorCommandKeys and: [sensor controlKeyPressed])
		ifTrue:
			[^ self perform: (ShiftCmdActions at: char asciiValue + 1) with: typeAheadStream].

	self clearParens.
	(')]}' includes: char)
		ifTrue: [self blinkPrevParen].

	^ self perform: #normalCharacter: with: typeAheadStream! !