Class new title: ListPane
	subclassof: Textframe
	fields: 'list firstShown lastShown selection scrollBar'
	declare: ''

close 
	[selection _ 0.
	scrollBar close]

compselection 
	[selection  0  [self selectionRect comp]]

deselected

dirty 
	[false]

displayall 
	[self displaylines: firstShown to: lastShown]

dummy 
	['']

eachtime 
	[[window has: user mp 
		[user kbck  [self kbd]
		[user anybug 
			[user redbug  [self redbug]
			user yellowbug  [self yellowbug]
			user bluebug  [false]]].
		user anykeys  [self keyset]]].
	self outside]

enter 
	[scrollBar show]

fill 
	[[firstShown  nil  [self makeParagraph]
	lastShown _ self lineofy: window maxY - (style lineheight - 1)].
	[self locked or selection > 0 
		[selection < firstShown  [frame origin y_ window minY - (selection * style lineheight) + style lineheight]
		selection > lastShown  [frame origin y_ window minY - (selection * style lineheight + style lineheight) + (window maxY - window minY | style lineheight) min: window minY]]].
	firstShown _ self lineofy: window minY + (style lineheight - 1).
	lastShown _ self lineofy: window maxY - (style lineheight - 1)]

firstShown: t1 | t2 t3 
	[t2 _ t1 - firstShown.
	t3 _ 0  (0 - t2 * style lineheight).
	firstShown _ t1.
	lastShown _ lastShown + t2.
	frame moveby: t3.
	(window origin - t3 rect: window corner) blt: window origin mode: storing.
	self displaylines: (firstShown max: lastShown - t2 + 1) to: lastShown]

firsttime 
	[window has: user mp  [self enter]
	false]

frame_ t1 
	[window _ t1.
	frame _ window inset: 2  0 and: 0  0.
	frame width_ 999.
	self fill.
	scrollBar _ [scrollBar  nil  [ScrollBar new]
			scrollBar] on: window from: self]

grayselection 
	[selection  0  [self selectionRect color: ltgray mode: oring]]

init 
	[self para: nil frame: nil]

kbd 
	[window flash.
	user kbd]

keyset | t1 t2 
	[t1 _ user currentCursor.
	self scrollControl 
		[t2 _ user keyset.
		[t2 = 6  [2]
		t2 = 12  [2]
		t2 = 2  [1]
		t2 = 8  [1]
		0]].
	t1 show]

lastShown: t1 | t2 t3 
	[t2 _ t1 - lastShown.
	t3 _ 0  (0 - t2 * style lineheight).
	lastShown _ t1.
	firstShown _ firstShown + t2.
	frame moveby: t3.
	(Rectangle new origin: window origin extent: window width  (window height - t3 y | style lineheight)) blt: window origin + t3 mode: storing.
	self displaylines: firstShown to: (firstShown - t2 - 1 min: lastShown)]

lasttime 
	[self leave]

leave 
	[scrollBar hide]

locked 
	[[selection = 0  [false]
	self dirty]]

makeParagraph | t1 t2 t3  
	[[firstShown  nil 
		[firstShown _ 1.
		selection _ 0]].
	t3 _ (String new: 200) asStream.
	t3 append: self dummy.
	t3 cr.
	[list  nil  []
	for t1 to: list length do
		[list  t1 printon: t3.
		t3 cr]].
	t3 append: self dummy.
	t3 cr.
	para _ t3 contents asParagraph.
	self measureall.
	lastShown _ self lineofy: window maxY - (style lineheight - 1).
	frame corner y_ (self yofline: lastline) + style lineheight.
	selection > lastShown  [selection _ 0]]

of: t1 
	[list _ t1.
	selection _ 0.
	self makeParagraph.
	self frame_ window.
	self outline.
	self displayall.
	self deselected]

outline 
	[window outline: 1]

outside 
	[scrollBar startup]

picked 
	[window has: user mp]

redbug | t1 t2 
	[t2 _ self locked.
	[t2  []
	self compselection.
	t1 _ ((self lineofy: user mp y) max: 1) - 1.
	XeqCursor showwhile [self select: [t1 = selection  [0]
		t1]]].
	while (user anybug and (window has: user mp)) do
		[t2 
			[t2 flash.
			self compselection.
			self compselection]]]

revise: t1 with: t2 | t3 
	[t3 _ list  t1.
	[t3 
		[list _ t1.
		self makeParagraph.
		self fill.
		self displayall]
	selection > 0 
		[t3 _ list  selection  t2.
		t3  [self compselection]]
	t3 _ true].
	t3 
		[selection _ 1.
		self select: (list find: t2)]]

scrollPos 
	[(firstShown  nil or list  nil) or list length = 0  [0.0]
	(firstShown - 1) asFloat / list length]

scrollTo: t1 | t2 t3 
	[self scrollUp: (t1 * lastline) asInteger - firstShown + 1 * style lineheight]

scrollUp: t1 | t2 
	[self compselection.
	t1 _ t1 | style lineheight.
	t2 _ (self lineofy: window minY + t1) max: 1.
	[t1 > 0 
		[lastline = lastShown  []
		self locked 
			[selection + 1 = firstShown  [window flash]
			self firstShown: (t2 min: selection + 1)]
		self firstShown: (t2 min: lastline - (window height / style lineheight) + 1)]
	firstShown = 1  []
	self locked 
		[selection + 1 = lastShown  [window flash]
		self lastShown: (lastShown - (firstShown - t2) max: selection + 1)]
	self lastShown: (lastShown - (firstShown - t2) max: (lastline min: window height / style lineheight))].
	(window origin x  ((self yofline: lastline) + style lineheight) rect: window corner) clear: white.
	self select: selection]

select: t1 | t2 
	[t2 _ selection.
	(1 max: firstShown - 1) 
 t1 and t1 
 (list length min: lastShown - 1) 
		[selection _ t1.
		self compselection.
		t2  selection  [self selected]]
	selection _ 0.
	t2  selection  [self deselected]]

selected

selectionRect | t1 
	[t1 _ selection * style lineheight + frame minY.
	(Rectangle new origin: frame minX  t1 corner: frame maxX  (t1 + style lineheight)) intersect: window]

windowenter 
	[self outline.
	self displayall.
	self compselection]

windowleave 
	[self compselection.
	self grayselection]

yellowbug 
	[window flash]