ViewerPaintImpl.mesa; written by S. McGregor
Edited by McGregor on May 2, 1983 11:11 am
Edited by Maxwell, June 3, 1983 8:23 am
Russ Atkinson, September 1, 1983 11:47 am
Doug Wyatt, December 15, 1983 5:26 pm
DIRECTORY
Carets USING [ResumeCarets, SuspendCarets],
ColorWorld USING [NewContext],
Graphics
USING [black, ClipBox, Context, DrawBox, DrawRope,
FontRef, Mark, NewContext, nullMark, PaintMode, Restore, Save,
Scale, SetColor, SetCP, SetDefaultFont, SetPaintMode, Translate, white],
GraphicsOps USING [Disable],
IconManager USING [selectedIcon],
Icons USING [DrawIcon],
Menus USING [],
MenusPrivate USING [DrawMenu],
Process USING [Detach, GetCurrent, MsecToTicks, Pause, Ticks],
RefText USING [AppendRope, ObtainScratch, ReleaseScratch, TrustTextAsRope],
Rope USING [Length, ROPE, Run],
VFonts USING [defaultFont, defaultGFont, StringWidth],
ViewerOps,
ViewerClasses,
ViewerLocks USING [CallUnderReadLock, CallUnderWriteLock, ColumnWedged, Wedged],
ViewerSpecs,
ViewersStallNotifier,
ViewerTools USING [GetSelectedViewer];
ViewerPaintImpl: CEDAR MONITOR
IMPORTS Carets, ColorWorld, Graphics, GraphicsOps, IconManager, Icons, MenusPrivate, Process, RefText, Rope, VFonts, ViewerLocks, ViewerTools, ViewerOps, ViewerSpecs
EXPORTS ViewerOps, ViewersStallNotifier
SHARES Menus, ViewerClasses, ViewerLocks =
BEGIN OPEN Graphics, ViewerClasses, ViewerOps, ViewerSpecs;
ROPE: TYPE = Rope.ROPE;
InvisiblePaint: PUBLIC SIGNAL = CODE;
PaintDocumentHeader:
PROC [viewer: Viewer, context: Context, clear:
BOOL, hint: PaintHint, whatChanged:
REF
ANY] =
BEGIN OPEN viewer;
wbs: INTEGER = IF viewer.border THEN windowBorderSize ELSE 0;
ClipBox[context, [wx, wy, wx+ww, wy+wh]];
IF hint#menu
THEN
BEGIN
IF viewer.class.caption#
NIL
THEN
BEGIN
-- client-painted caption
mark: Mark ← Save[context];
ClipBox[context, [wx+wbs, wy+wh-captionHeight-wbs, wx+ww-(2*wbs),
wy+wh-wbs]];
viewer.class.caption[viewer, context];
Restore[context, mark];
END
ELSE
BEGIN
text: REF TEXT ~ RefText.ObtainScratch[100];
header: REF TEXT ← text;
headerW: INTEGER ← 0;
name: ROPE ~ viewer.name;
nameLen: INT ~ Rope.Length[name];
file: ROPE ~ viewer.file;
fileLen: INT ~ Rope.Length[file];
header ← RefText.AppendRope[to: header, from: name];
IF fileLen>nameLen
AND Rope.Run[s1: name, s2: file, case:
FALSE]=nameLen
THEN {
The intent of this crock is to show the file version for $Text viewers: if name is a prefix of file, show the remainder of file (presumably "!n") in parentheses
header ← RefText.AppendRope[to: header, from: " ("];
header ← RefText.AppendRope[to: header, from: file, start: nameLen];
header ← RefText.AppendRope[to: header, from: ")"];
};
IF viewer.saveInProgress
THEN
header ← RefText.AppendRope[to: header, from: " [Saving...]"]
ELSE
IF viewer.newFile
THEN
header ← RefText.AppendRope[to: header, from: " [New File]"]
ELSE
IF viewer.newVersion
THEN
header ← RefText.AppendRope[to: header, from: " [Edited]"];
IF viewer.link#
NIL
THEN
header ← RefText.AppendRope[to: header, from: " [Split]"];
headerW ← VFonts.StringWidth[RefText.TrustTextAsRope[header]];
headerW ← MIN[headerW, ww];
DrawBox[context, XYWH2Box[wx, wy+wh-captionHeight, ww, captionHeight]];
SetColor[context, white];
SetCP[context, wx+((ww-headerW)/2), wy+wh-captionHeight+4];
DrawRope[context, RefText.TrustTextAsRope[header]];
RefText.ReleaseScratch[text];
END;
END;
IF menu#
NIL
AND hint#caption
THEN
BEGIN
height: INTEGER ← menu.linesUsed*menuHeight;
IF whatChanged=
NIL
THEN
BEGIN
IF ~clear
THEN
BEGIN
SetColor[context, white];
DrawBox[context, XYWH2Box[wx+wbs, wy+wh-captionHeight-height,
ww-(2*wbs), height]];
END;
SetColor[context, black];
DrawBox[context, XYWH2Box[wx, wy+wh-captionHeight-height-windowBorderSize,
ww, menuBarHeight]];
END;
MenusPrivate.DrawMenu[viewer.menu, context, wx+wbs,
wy+wh-menuHeight-captionHeight, whatChanged];
END;
END;
PaintIcon:
PROC [viewer: Viewer, hint: PaintHint, whatChanged:
REF
ANY ←
NIL] =
BEGIN
context: Context;
label: Rope.ROPE;
IF viewer.parent#NIL THEN RETURN;
context ← AcquireContext[viewer, FALSE]; -- all icons on b&w display
IF flavor is private then client wants to draw the icon
IF viewer.icon=private THEN viewer.class.paint[viewer, context, whatChanged, hint=all]
ELSE
IF hint=all
OR hint=caption
THEN
BEGIN
mark: Mark ← Save[context]; -- since Icons.DrawIcon will set clipper
IF viewer.icon=document
AND (viewer.newVersion
OR viewer.newFile)
THEN
viewer.icon ← dirtyDocument
ELSE
IF viewer.icon=dirtyDocument
AND
NOT (viewer.newVersion
OR viewer.newFile)
THEN
viewer.icon ← document;
label ← NARROW[ViewerOps.FetchProp[viewer, $IconLabel]];
IF label = NIL THEN label ← viewer.name;
Icons.DrawIcon[flavor: viewer.icon, context: context, label: label];
Restore[context, mark];
IF IconManager.selectedIcon=viewer
THEN
BEGIN
[] ← SetPaintMode[context, invert];
DrawBox[context, [0, 0, iconWidth, iconHeight]];
END;
END;
ReleaseContext[context];
END;
SetIconLabel:
PUBLIC
PROC [viewer: Viewer, label: Rope.
ROPE] =
BEGIN
ViewerOps.AddProp[viewer, $IconLabel, label];
END;
RecursivelyPaintViewers:
PROC [viewer: Viewer, hint: PaintHint, clearClient:
BOOL,
clear: BOOL, rect: PaintRectangle, whatChanged: REF ANY] = BEGIN OPEN viewer;
vx, vy: INTEGER;
context: Context ← NIL;
bitmapY: INTEGER ← 0;
FOR v: Viewer ← viewer, v.parent
UNTIL v=
NIL
DO
-- visibility test
IF v.parent#
NIL
THEN
BEGIN
IF (v.wy+v.wh < 0) OR (v.wy > v.parent.ch) THEN RETURN;
IF (v.ww+v.ww < 0) OR (v.wx > v.parent.cw) THEN RETURN;
END
ENDLOOP;
IF hint#client
THEN
BEGIN
ENABLE UNWIND => IF context#NIL THEN ReleaseContext[context];
context ← AcquireContext[parent, viewer.column=color];
IF ~viewer.visible OR viewer.destroyed THEN SIGNAL InvisiblePaint;
IF clearClient
AND ~clear
AND hint=all
THEN
BEGIN
SetColor[context, white];
DrawBox[context, XYWH2Box[wx, wy, ww, wh]];
SetColor[context, black];
clear ← TRUE;
END;
IF border
AND hint=all
THEN
BEGIN
wbs: INTEGER ~ windowBorderSize;
DrawBox[context, XYWH2Box[wx, wy, ww, wbs]];
DrawBox[context, XYWH2Box[wx, wy, wbs, wh]];
DrawBox[context, XYWH2Box[wx+ww-wbs, wy, wbs, wh]];
DrawBox[context, XYWH2Box[wx, wy+wh-wbs, ww, wbs]];
END;
IF parent=
NIL
AND viewer.column#static
THEN PaintDocumentHeader[viewer, context, clear, hint, whatChanged];
ReleaseContext[context];
END;
IF hint=all
OR hint=client
THEN
BEGIN
ENABLE UNWIND => IF context#NIL THEN ReleaseContext[context];
context ← NIL; context ← AcquireContext[viewer, viewer.column=color];
IF ~viewer.visible OR viewer.destroyed THEN SIGNAL InvisiblePaint;
IF rect#NIL AND class.bltContents = none THEN clearClient ← TRUE;
IF clearClient
AND ~clear
THEN
BEGIN
SetColor[context, white];
DrawBox[context, [0, 0, cw, ch]];
SetColor[context, black];
IF rect # NIL THEN whatChanged ← NIL;
rect ← NIL;
clear ← TRUE;
END;
IF class.paint#NIL THEN class.paint[viewer, context, whatChanged, clear];
ReleaseContext[context];
END;
do we need to paint any of the children?
IF rect #
NIL
AND viewer.parent =
NIL
THEN {
IF viewer.cx >= rect.x
AND (viewer.cx + viewer.cw <= rect.x + rect.w)
AND
viewer.cy >= rect.y AND (viewer.cy + viewer.ch <= rect.y + rect.h) THEN RETURN};
recursively paint children
IF hint=all
OR hint=client
OR clear
THEN
these guys should be painted in reverse order for correct overlaps
FOR v: Viewer ← viewer.child, v.sibling
UNTIL v=
NIL
DO
IF rect #
NIL
THEN {
-- don't paint if it is completely within the blt
-- map to the coodinate system that rect uses
IF viewer.class.coordSys = top
THEN [vx, vy] ← ViewerOps.UserToScreenCoords[viewer, v.wx, v.wy+v.wh]
ELSE [vx, vy] ← ViewerOps.UserToScreenCoords[viewer, v.wx, v.wy];
IF vx >= rect.x
AND (vx + v.ww <= rect.x + rect.w)
AND
vy >= rect.y AND (vy + v.wh <= rect.y + rect.h) THEN LOOP};
RecursivelyPaintViewers[v, all, FALSE, clear, rect, whatChanged];
ENDLOOP;
END;
PaintViewer:
PUBLIC
PROC [viewer: Viewer, hint: PaintHint ← client, clearClient:
BOOL ←
TRUE,
whatChanged: REF ANY ← NIL] = BEGIN
LocalPaintViewer:
PROC = {
ENABLE ABORTED => {Carets.ResumeCarets[]; CONTINUE};
rect: PaintRectangle;
IF ~viewer.visible OR viewer.destroyed THEN RETURN;
IF viewer.iconic THEN {PaintIcon[viewer, hint, whatChanged]; RETURN};
Carets.SuspendCarets[];
IF ISTYPE[whatChanged, PaintRectangle] THEN rect ← NARROW[whatChanged];
RecursivelyPaintViewers[viewer, hint, clearClient
AND ~(hint=menu
OR hint=caption),
FALSE, rect, whatChanged ! InvisiblePaint => CONTINUE];
Carets.ResumeCarets[]};
ViewerLocks.CallUnderReadLock[LocalPaintViewer, viewer ! ViewerLocks.Wedged => CONTINUE];
END;
PaintVector: TYPE = REF PaintVectorRec;
PaintVectorRec:
TYPE =
RECORD [
next: PaintVector ← NIL,
viewer: Viewer ← NIL,
inUse: BOOL ← FALSE,
resetOnRelease: BOOL ← FALSE,
color: BOOL ← FALSE,
mark: Graphics.Mark ← nullMark,
process: UNSAFE PROCESS ← NIL,
context: Context ← NIL,
previous: PaintVector ← NIL];
nVectors: CARDINAL = 5;
usedVectors: CARDINAL ← 0;
PaintVectorAvailable: CONDITION;
paintingLock: CARDINAL ← 0;
vectorRoot: PaintVector ← NIL;
colorVector: PaintVector ← NIL;
Init:
ENTRY
PROC =
BEGIN
new: PaintVector;
FOR n:
CARDINAL
IN [0..nVectors)
DO
new ← NEW[PaintVectorRec];
new.context ← NewContext[];
SetDefaultFont[new.context, VFonts.defaultGFont];
new.next ← vectorRoot;
IF vectorRoot#NIL THEN vectorRoot.previous ← new;
vectorRoot ← new;
ENDLOOP;
newFW ← VFonts.StringWidth[newFT];
newVW ← VFonts.StringWidth[newVT];
linkW ← VFonts.StringWidth[linkT];
sipW ← VFonts.StringWidth[sipT];
expVW ← VFonts.StringWidth[expVT];
colorVector ← NEW[PaintVectorRec];
colorVector.color ← TRUE;
END;
colorInit: BOOL ← FALSE;
InitialiseColorPainting:
PUBLIC
PROC =
BEGIN
ColorCriticalInit:
ENTRY
PROC =
BEGIN
colorVector.context ← ColorWorld.NewContext[];
SetDefaultFont[colorVector.context, VFonts.defaultGFont];
colorInit ← TRUE;
END;
ColorCriticalInit[];
ViewerOps.GreyScreen[0, 0, 9999, 9999, TRUE, FALSE];
END;
ZapVector:
INTERNAL
PROC [p: PaintVector] =
BEGIN
oldContext: Context ← p.context;
p.context ← IF p.color THEN ColorWorld.NewContext[] ELSE NewContext[];
Graphics.SetDefaultFont[p.context, VFonts.defaultGFont];
p.viewer ← NIL;
p.inUse ← FALSE;
p.process ← NIL;
p.mark ← nullMark;
IF ~p.color THEN usedVectors ← usedVectors - 1;
GraphicsOps.Disable[oldContext]; -- smash old
BROADCAST PaintVectorAvailable;
END;
UnWedgePainter:
PUBLIC
ENTRY
PROC [process:
PROCESS, kind:
ATOM] =
BEGIN
ENABLE UNWIND => NULL;
IF colorVector.inUse AND colorVector.process=process THEN ZapVector[colorVector]
ELSE
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF p.inUse AND p.process=process THEN ZapVector[p];
ENDLOOP;
END;
UnWedge:
ENTRY
PROC [process:
PROCESS, kind:
ATOM] =
BEGIN
call from debugger
IF colorVector.inUse THEN ZapVector[colorVector]
ELSE
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF p.inUse THEN ZapVector[p];
ENDLOOP;
usedVectors ← 0; -- make sure
paintingLock ← 0; -- make sure
BROADCAST PaintVectorAvailable;
END;
DisablePainting:
PUBLIC
ENTRY
PROC [wait:
BOOL ←
TRUE] =
BEGIN
ENABLE UNWIND => NULL;
InternalDisablePainting[wait];
END;
InternalDisablePainting:
INTERNAL
PROC [wait:
BOOL ←
TRUE] =
INLINE
BEGIN
IF wait
THEN
WHILE usedVectors#0 OR colorVector.inUse DO WAIT PaintVectorAvailable;
ENDLOOP;
paintingLock ← paintingLock+1;
END;
EnablePainting:
PUBLIC
ENTRY
PROC =
BEGIN
ENABLE UNWIND => NULL;
InternalEnablePainting[];
END;
InternalEnablePainting:
INTERNAL
PROC =
INLINE
BEGIN
IF paintingLock#0 THEN paintingLock ← paintingLock-1;
broadcast since all are likely to be free
IF paintingLock=0 THEN BROADCAST PaintVectorAvailable;
END;
DisablePaintingUnWedged:
INTERNAL
PROC [wait:
BOOL ←
TRUE] =
INLINE
BEGIN
AllWedged:
INTERNAL
PROC
RETURNS[
BOOL] =
INLINE
BEGIN
IF colorVector.inUse
THEN
BEGIN
IF colorVector.viewer=NIL THEN RETURN[FALSE]; -- context = screen
IF ~ViewerLocks.ColumnWedged[color].wedged THEN RETURN[FALSE];
END;
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF ~p.inUse THEN LOOP;
IF p.viewer = NIL THEN RETURN[FALSE]; -- context = screen
IF ~ViewerLocks.ColumnWedged[ViewerColumn[p.viewer]].wedged THEN RETURN[FALSE];
ENDLOOP;
RETURN[TRUE];
END;
IF wait
THEN
WHILE usedVectors#0
OR colorVector.inUse
DO
IF AllWedged[] THEN EXIT ELSE WAIT PaintVectorAvailable;
ENDLOOP;
paintingLock ← paintingLock+1;
END;
WaitForPaintingToFinish:
PUBLIC
ENTRY
PROC =
BEGIN
assumes interesting paints already in progress
WHILE usedVectors#0 AND colorVector.inUse DO WAIT PaintVectorAvailable ENDLOOP;
END;
ResetPaintCache:
PUBLIC
ENTRY
PROC [viewer: Viewer ←
NIL, wait:
BOOL ←
TRUE] =
BEGIN
ENABLE UNWIND => NULL;
DisablePaintingUnWedged[wait];
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF p.inUse
THEN
BEGIN
IF p.viewer =
NIL
OR ~ViewerLocks.ColumnWedged[ViewerColumn[p.viewer]].wedged
THEN IF wait THEN RETURN WITH ERROR fatalViewersError;
p.resetOnRelease ← TRUE;
END
ELSE
IF p.viewer#
NIL
THEN
BEGIN
ResetContext[p.context];
p.viewer ← NIL;
END;
ENDLOOP;
IF colorVector.context#
NIL
THEN
BEGIN
IF colorVector.inUse
AND ~ViewerLocks.ColumnWedged[color].wedged
THEN
BEGIN
IF wait THEN RETURN WITH ERROR fatalViewersError;
colorVector.resetOnRelease ← TRUE;
END
ELSE
IF colorVector.viewer#
NIL
THEN
BEGIN
ResetContext[colorVector.context];
colorVector.viewer ← NIL;
END;
END;
InternalEnablePainting[];
END;
fatalViewersError: ERROR = CODE;
ReleaseContext:
PUBLIC
ENTRY
PROC [free: Context] =
BEGIN
ENABLE UNWIND => NULL;
CleanUp:
INTERNAL
PROC [p: PaintVector] =
BEGIN
Restore[free, p.mark]; -- throw away any client changes
p.inUse ← FALSE;
p.mark ← nullMark;
IF ~p.color
THEN {
IF usedVectors=0
THEN
RETURN
WITH
ERROR fatalViewersError
ELSE usedVectors ← usedVectors-1};
IF p.resetOnRelease
THEN
BEGIN
ResetContext[p.context];
p.viewer ← NIL;
p.resetOnRelease ← FALSE;
END;
p.process ← NIL;
BROADCAST PaintVectorAvailable;
END;
IF free=NIL THEN RETURN WITH ERROR fatalViewersError;
IF free=colorVector.context THEN CleanUp[colorVector]
ELSE
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF free=p.context THEN {CleanUp[p]; EXIT};
ENDLOOP;
END;
AcquireContext:
PUBLIC
ENTRY
PROC [viewer: Viewer, color:
BOOL ←
FALSE]
RETURNS [allocated: Context] = BEGIN
ENABLE UNWIND => NULL;
bestFit: PaintVector;
nil: BOOL ← FALSE;
MakeFirst:
INTERNAL
PROC [pv: PaintVector] =
INLINE
BEGIN
-- LRU caching scheme
IF pv=vectorRoot THEN RETURN;
pv.previous.next ← pv.next;
IF pv.next#NIL THEN pv.next.previous ← pv.previous;
pv.next ← vectorRoot;
vectorRoot.previous ← pv;
vectorRoot ← pv;
END;
IF color
THEN
BEGIN
IF ~colorInit THEN ERROR fatalViewersError;
WHILE colorVector.inUse OR paintingLock#0 DO WAIT PaintVectorAvailable; ENDLOOP;
IF viewer#
NIL
AND (~viewer.visible
OR viewer.destroyed)
THEN
SIGNAL InvisiblePaint; -- someone got changed while waiting in the loop above
bestFit ← colorVector;
END
ELSE
BEGIN
UNTIL usedVectors<nVectors AND paintingLock=0 DO WAIT PaintVectorAvailable; ENDLOOP;
IF viewer#
NIL
AND (~viewer.visible
OR viewer.destroyed)
THEN
SIGNAL InvisiblePaint; -- someone got changed while waiting in the loop above
FOR p: PaintVector ← vectorRoot, p.next
UNTIL p=
NIL
DO
IF p.inUse THEN LOOP;
IF viewer=p.viewer THEN {bestFit ← p; EXIT}
ELSE IF p.viewer=NIL THEN {bestFit ← p; nil ← TRUE}
ELSE IF ~nil THEN bestFit ← p;
ENDLOOP;
usedVectors ← usedVectors+1;
MakeFirst[bestFit];
END;
bestFit.inUse ← TRUE;
TRUSTED {bestFit.process ← Process.GetCurrent[]};
SetContext[viewer, bestFit];
bestFit.mark ← Save[allocated ← bestFit.context]; -- protect context
END;
SetContext:
INTERNAL
PROC [viewer: Viewer, paintVector: PaintVector] =
BEGIN
pViewer: Viewer = paintVector.viewer;
pContext: Context = paintVector.context;
RecursivelyPushParent:
INTERNAL
PROC [viewer: Viewer] =
BEGIN
IF viewer.parent#NIL THEN RecursivelyPushParent[viewer.parent];
PushContext[viewer, pContext]
END;
SELECT
TRUE
FROM
-- try to efficiently set up client context
pViewer=viewer => NULL;
viewer=NIL => ResetContext[pContext];
pViewer=viewer.parent => PushContext[viewer, pContext];
pViewer=NIL => RecursivelyPushParent[viewer];
pViewer.destroyed => {ResetContext[pContext]; RecursivelyPushParent[viewer]};
pViewer.parent=viewer => PopContext[pContext];
pViewer.parent=viewer.parent => {PopContext[pContext]; PushContext[viewer, pContext]};
ENDCASE => {ResetContext[pContext]; RecursivelyPushParent[viewer]};
paintVector.viewer ← viewer;
END;
PushContext:
INTERNAL
PROC [viewer: Viewer, context: Context] =
BEGIN
OPEN viewer;
invertCoords:
BOOL =
IF viewer.parent=
NIL
THEN viewer.class.coordSys=top
ELSE viewer.class.coordSys#viewer.parent.class.coordSys;
[] ← Save[context];
IF viewer.iconic
THEN
BEGIN
IF wy+wh > openBottomY THEN ClipIcon[context];
ClipBox[context, XYWH2Box[wx, wy, ww, wh]];
Translate[context, wx, wy];
END
ELSE
IF invertCoords
THEN
BEGIN
ClipBox[context, XYWH2Box[cx, cy, cw, ch]];
Translate[context, cx, cy+ch];
Scale[context, 1, -1];
END
ELSE
BEGIN
ClipBox[context, XYWH2Box[cx, cy, cw, ch]];
Translate[context, cx, cy];
END;
END;
PopContext:
INTERNAL
PROC [context: Context] =
INLINE
BEGIN
Restore[context];
END;
ResetContext:
INTERNAL
PROC [context: Context] =
INLINE
BEGIN
screen: Mark = LOOPHOLE[0];
Restore[context, screen];
END;
InvertForMenus:
PUBLIC
PROC [viewer: Viewer, x,y:
INTEGER, w,h:
INTEGER] =
BEGIN
context: Context;
context ← AcquireContext[viewer.parent, viewer.column=color];
[] ← SetPaintMode[context, invert];
DrawBox[context, ViewerOps.XYWH2Box[viewer.wx+x, y, MIN[w,viewer.ww-x], h]];
ReleaseContext[context];
END;
ClipIcon:
PROC [context: Context] =
BEGIN
clips for overlapping top level windows given valid Context and Viewer
ClipOpenViewer: ViewerOps.EnumProc =
BEGIN
IF ~v.iconic
AND (v.column=right
OR v.column=left)
THEN
Graphics.ClipBox[context, [v.wx, v.wy, v.wx+v.ww, v.wy+v.wh], TRUE];
END;
ViewerOps.EnumerateViewers[ClipOpenViewer];
END;
BlinkIcon:
PUBLIC PROC [viewer: Viewer, count, interval:
NAT] =
BEGIN
IF interval >= 1000 THEN interval ← interval/1000;
IF viewer.offDeskTop THEN ViewerOps.ChangeColumn[viewer, left];
IF count = 1 THEN BlinkProcess[viewer, count, interval]
ELSE TRUSTED {Process.Detach[FORK BlinkProcess[viewer, count, interval]]};
END;
BlinkProcess:
PROC [viewer: Viewer, count, n:
NAT] =
BEGIN
howOften: Process.Ticks = Process.MsecToTicks[500];
Blink:
PROC =
BEGIN OPEN viewer;
context: Context;
IF NOT visible OR destroyed THEN RETURN;
context ← AcquireContext[viewer, IF iconic THEN FALSE ELSE column=color];
[] ← SetPaintMode[context, invert];
DrawBox[context, ViewerOps.XYWH2Box[0, 0, viewer.ww, viewer.wh]];
Process.Pause[Process.MsecToTicks[400]];
DrawBox[context, ViewerOps.XYWH2Box[0, 0, viewer.ww, viewer.wh]];
ReleaseContext[context];
Process.Pause[Process.MsecToTicks[350]]; -- so can be called back-to-back
END;
DO
ViewerLocks.CallUnderWriteLock[Blink, viewer];
IF count = 1 THEN RETURN;
IF count > 0 THEN count ← count - 1;
FOR i:
NAT
IN [0..2*n)
DO
-- blink every n seconds, but wake up every half second.
Process.Pause[howOften];
IF viewer.destroyed
OR ~viewer.iconic
OR viewer = ViewerTools.GetSelectedViewer[] THEN RETURN;
ENDLOOP;
ENDLOOP;
END;
Init[];
ViewerOps.GreyScreen[0, 0, 9999, 9999, FALSE, FALSE];
END.