TEditDisplayImpl.mesa
Copyright (C) 1982, Xerox Corporation. All rights reserved.
Last edit by Paxton on January 27, 1983 3:31 pm
Last Edit by Maxwell, January 6, 1983 10:36 am
Last Edit by Plass, December 26, 1984 4:23:53 pm PST
DIRECTORY
Carets USING [pCaretViewer, sCaretViewer, StopCaret],
EditSpan USING [afterMoved1, afterMoved2],
Graphics USING [black, Box, Context, DrawBox, GetBounds, IsRectangular, SetColor, SetCP, white],
GraphicsOps USING [MoveDeviceRectangle],
NodeStyle USING [Alloc, ApplyAll, Free, GetBodyIndentI, GetBottomLeadingI, GetFirstIndentI, GetLeadingI, GetLeftIndentI, GetLineFormatting, GetRightIndentI, GetTopIndentI, GetTopLeadingI, Ref],
Process USING [Detach],
Real USING [RoundI],
RopeReader USING [Backwards, FreeRopeReader, Get, GetIndex, GetRopeReader, Ref, SetPosition],
Scaled USING [Float, FromInt, Round],
TEditCompile USING [minAvgLineLeading],
TEditDisplay USING [],
TEditDocument USING [LineBreak, LineTable, LineTableRec, maxClip, Selection, SelectionId, SelectionRec, SpinAndLock, TEditDocumentData, Unlock],
TEditFormat USING [Allocate, FormatLine, LineInfo, Paint, Release],
TEditImpl USING [],
TEditLocks USING [LockDocAndTdd, LockRef, UnlockDocAndTdd, WaitingForWrite],
TEditScrolling USING [AutoScroll],
TEditSelection USING [AdjustSelStates, FixUpAfterDisplay, fSel, InsertionPoint, InvalidateLineCache, pSel, SelectionRoot, ShowSelection, sSel, TakeDownForRedisplay, TakeSelectionDown],
TEditTouchup USING [fullUpdate, PreScrollDownRec, refresh, RefreshOver],
Terminal USING [Current],
TextEdit USING [Offset, Size],
TextNode USING [FirstChild, ForwardClipped, Level, Location, NarrowToTextNode, Offset, pZone, Ref, RefTextNode, Root, StepForward],
ViewerClasses USING [PaintProc, PaintRectangle, Viewer],
ViewerOps USING [UserToScreenCoords],
ViewerSpecs USING [screenH];
TEditDisplayImpl: CEDAR PROGRAM
IMPORTS Carets, Terminal, EditSpan, Graphics, GraphicsOps, NodeStyle, Process, Real, Scaled, TextEdit, TextNode, RopeReader, TEditDocument, TEditFormat, TEditLocks, TEditScrolling, TEditSelection, TEditTouchup, ViewerOps
EXPORTS TEditImpl = BEGIN
PaintTEditDocument: PUBLIC ViewerClasses.PaintProc =
BEGIN
tdd: TEditDocument.TEditDocumentData = NARROW[self.data];
lock: TEditLocks.LockRef;
moveDownLines, moveDownDistance: INTEGER ← 0; -- used with scrolling down
redisplay, refreshing: BOOLFALSE;
Cleanup: PROC = { TEditLocks.UnlockDocAndTdd[tdd]; TEditTouchup.RefreshOver[] };
IF tdd = NIL THEN RETURN;
BEGIN ENABLE UNWIND => Cleanup[];
interrupt: BOOL = clear OR whatChanged=TEditTouchup.fullUpdate OR whatChanged=NIL OR ISTYPE[whatChanged, ViewerClasses.PaintRectangle];
typescript: BOOL;
IF self.destroyed OR tdd=NIL THEN RETURN; -- the viewer changed while this was forked
tdd.invisible ← FALSE; -- or else we wouldn't have been called
lock ← TEditLocks.LockDocAndTdd[tdd, "PaintTEditDocument", read, interrupt, TRUE];
IF lock=NIL THEN { IF NOT interrupt THEN ERROR; RETURN }; -- someone else will do the display
IF Carets.pCaretViewer=self THEN Carets.StopCaret[primary];
IF Carets.sCaretViewer=self THEN Carets.StopCaret[secondary];
IF (self.ch/TEditCompile.minAvgLineLeading)+1 > tdd.lineTable.maxLines THEN BEGIN
make bigger line table
oldTable: TEditDocument.LineTable ← tdd.lineTable;
tdd.lineTable ← TextNode.pZone.NEW[TEditDocument.LineTableRec[(self.ch/TEditCompile.minAvgLineLeading)+1] ←
[lastLine: oldTable.lastLine, lastY: oldTable.lastY, lines: NULL]];
FOR n: INTEGER IN [0..oldTable.lastLine] DO-- copy old data
tdd.lineTable[n] ← oldTable[n];
ENDLOOP;
END;
typescript ← tdd.tsInfo # NIL;
refreshing ← whatChanged=TEditTouchup.refresh;
IF clear OR refreshing OR whatChanged=TEditTouchup.fullUpdate OR whatChanged=NIL THEN {
IF clear THEN TEditSelection.AdjustSelStates[self];
IF NOT refreshing THEN
FOR n: INTEGER IN [0..tdd.lineTable.lastLine] DO -- invalidate all lines
tdd.lineTable[n].valid ← FALSE;
ENDLOOP;
redisplay ← TRUE;
}
ELSE {
SELECT whatChanged FROM
$TakeDownPSel => TEditSelection.TakeSelectionDown[primary, self, context];
$ShowPSel => TEditSelection.ShowSelection[primary, self, context];
$TakeDownSSel => TEditSelection.TakeSelectionDown[secondary, self, context];
$ShowSSel => TEditSelection.ShowSelection[secondary, self, context];
$TakeDownFSel => TEditSelection.TakeSelectionDown[feedback, self, context];
$ShowFSel => TEditSelection.ShowSelection[feedback, self, context];
ENDCASE => WITH whatChanged SELECT FROM
x: REF TEditTouchup.PreScrollDownRec => {
move down to make room for new lines at top
IF clear THEN ERROR;
moveDownLines ← x.lines;
moveDownDistance ← x.distance;
refreshing ← redisplay ← TRUE
};
x: ViewerClasses.PaintRectangle => { -- fix up after Viewer blt
IF x.flavor # blt -- or if width has changed -- THEN {
Repaint all when width changes. Could try to be smart here, but probably better not to. Would have to worry about right indent and line formatting (e.g., centered lines).
FOR n: INTEGER IN [0..tdd.lineTable.lastLine] DO -- invalidate all lines
tdd.lineTable[n].valid ← FALSE;
ENDLOOP;
}
ELSE { -- height has changed
n: INTEGER ← 0;
h: INTEGER ← ViewerOps.UserToScreenCoords[self, 0, self.ch].sy-x.y; -- new height
UNTIL n > tdd.lineTable.lastLine OR tdd.lineTable[n].yOffset+tdd.lineTable[n].descent >= h DO
n ← n+1; ENDLOOP;
n ← MIN[n, tdd.lineTable.lastLine]; -- make sure invalidate at least one line
UNTIL n > tdd.lineTable.lastLine DO
tdd.lineTable[n].valid ← FALSE;
n ← n+1;
ENDLOOP
};
refreshing ← redisplay ← TRUE
};
ENDCASE => ERROR;
};
IF redisplay THEN {
TEditSelection.TakeDownForRedisplay[primary, self, context];
TEditSelection.TakeDownForRedisplay[secondary, self, context];
TEditSelection.TakeDownForRedisplay[feedback, self, context];
IF typescript AND self.ch < tdd.lineTable[tdd.lineTable.lastLine].yOffset THEN {
If a typescript viewer gets smaller such that bottom line is no longer visible, automatically scroll it up to keep bottom line on screen.
delta: INTEGER = tdd.lineTable[tdd.lineTable.lastLine].yOffset - self.ch;
n: INTEGER ← 0;
UNTIL n=tdd.lineTable.lastLine OR tdd.lineTable[n].yOffset > delta DO n ← n+1; ENDLOOP;
tdd.lineTable[0] ← tdd.lineTable[MIN[tdd.lineTable.lastLine, n+1]];
tdd.lineTable[0].valid ← FALSE };
IF NOT tdd.lineTable[0].valid THEN { -- check start location
startLoc: TextNode.Location;
node: TextNode.RefTextNode;
CheckLocNode: PROC [loc: TextNode.Location] RETURNS [BOOL] = {
startLoc ← loc;
RETURN [ loc.node # NIL AND TextNode.Root[loc.node] = tdd.text ]
};
IF CheckLocNode[tdd.lineTable[0].pos] THEN NULL
ELSE {
IF CheckLocNode[TEditSelection.InsertionPoint[]]
OR CheckLocNode[EditSpan.afterMoved1]
OR CheckLocNode[EditSpan.afterMoved2] THEN tdd.fixStart ← TRUE
ELSE startLoc ← [TextNode.FirstChild[tdd.text], 0]
};
IF (node ← TextNode.NarrowToTextNode[startLoc.node]) # NIL THEN {
size: TextEdit.Offset = TextEdit.Size[node];
IF startLoc.where NOT IN [0..size) THEN {
tdd.lineTable[0].valid ← FALSE;
tdd.fixStart ← TRUE;
startLoc.where ← MAX[MIN[size-1,startLoc.where],0]
}
};
IF tdd.fixStart AND node # NIL AND startLoc.where > 0 THEN {
Move startLoc to after CR or at start of node
rdr: RopeReader.Ref = RopeReader.GetRopeReader[];
cnt: INTEGER ← 0;
foundBreak: BOOLFALSE;
RopeReader.SetPosition[rdr,node.rope,startLoc.where];
FOR i:INT ← 0, i+1 DO
char: CHAR;
IF i=startLoc.where THEN { foundBreak ← TRUE; EXIT }; -- out of chars
IF cnt > 200 THEN EXIT; -- give up
char ← RopeReader.Backwards[rdr];
IF char = 15C THEN { foundBreak ← TRUE; [] ← RopeReader.Get[rdr]; EXIT };
cnt ← cnt+1;
ENDLOOP;
IF foundBreak THEN startLoc.where ← RopeReader.GetIndex[rdr];
RopeReader.FreeRopeReader[rdr];
};
tdd.fixStart ← FALSE;
tdd.lineTable[0].pos ← startLoc;
IF tdd.clipLevel < TEditDocument.maxClip THEN -- check level of startLoc
tdd.clipLevel ← MAX[tdd.clipLevel, TextNode.Level[startLoc.node]]; };
TEditSelection.InvalidateLineCache[]; -- since selection impl keeps accelerators
RefreshViewer[self, tdd, context, clear, (refreshing AND NOT typescript),
lock, moveDownLines, moveDownDistance];
};
IF whatChanged=$TakeDownPSel OR
whatChanged=$TakeDownSSel OR
whatChanged=$TakeDownFSel THEN NULL
ELSE IF refreshing AND NOT typescript AND
TEditLocks.WaitingForWrite[lock] THEN NULL
ELSE { --fix up the selections
TEditSelection.FixUpAfterDisplay[primary, self, context, NOT tdd.readOnly];
TEditSelection.FixUpAfterDisplay[secondary, self, context, TRUE];
TEditSelection.FixUpAfterDisplay[feedback, self, context, FALSE]
};
IF NOT tdd.dirty THEN SELECT tdd.scroll FROM
no => NULL;
endofdoc => {
TRUSTED {Process.Detach[FORK AutoScroll[self, tdd.scrollGlitch, TRUE, primary]]};
tdd.scroll ← no };
endofsel => {
sel: TEditDocument.Selection = SELECT tdd.scrollSelectionId FROM
primary => TEditSelection.pSel,
secondary => TEditSelection.sSel,
feedback => TEditSelection.fSel,
ENDCASE => ERROR;
IF TEditSelection.SelectionRoot[sel]=tdd.text THEN
TRUSTED {Process.Detach[FORK AutoScroll[self, tdd.scrollGlitch, FALSE, tdd.scrollSelectionId]]} };
ENDCASE => ERROR;
Cleanup[];
END; END; -- of unwind and PaintProc
AutoScroll: PROC [
self: ViewerClasses.Viewer, tryToGlitch, toEndOfDoc: BOOL, id: TEditDocument.SelectionId] = {
ENABLE ABORTED => GOTO Quit;
tdd: TEditDocument.TEditDocumentData ← NARROW[self.data];
IF tdd=NIL THEN RETURN;
TEditScrolling.AutoScroll[self, tryToGlitch, toEndOfDoc, id];
[] ← TEditDocument.SpinAndLock[tdd, "TEditDisplayImplAutoScroll"];
IF ~tdd.dirty THEN tdd.scroll ← no;
TEditDocument.Unlock[tdd];
TEditTouchup.RefreshOver[];
EXITS Quit => NULL
};
RefreshViewer: PROCEDURE [viewer: ViewerClasses.Viewer,
tdd: TEditDocument.TEditDocumentData, dc: Graphics.Context,
displayClear, refresh: BOOL, lock: TEditLocks.LockRef,
moveDownLines, moveDownDistance: INTEGER] = {
n: INTEGER ← 0;
start, end: INTEGER;
lines: TEditDocument.LineTable ← tdd.lineTable;
UNTIL n > lines.lastLine DO -- search for an invalid line
IF lines[n].valid THEN { n ← n+1; LOOP };
start ← n;
UNTIL n+1 > lines.lastLine DO
IF lines[n+1].valid THEN EXIT;
n ← n+1;
ENDLOOP;
end ← n;
IF start > 0 AND lines[start].pos.node # lines[start-1].pos.node THEN {
need to reinitialize the start pos; may have deleted start node
lines[start].pos.where ← 0;
IF (lines[start].pos.node ←
TextNode.ForwardClipped[lines[start-1].pos.node,tdd.clipLevel].nx) = NIL THEN
start ← start-1 --have deleted end of document-- };
n ← WhileInPosRange[viewer, tdd, dc, start, end, displayClear,
refresh, lock, moveDownLines, moveDownDistance];
moveDownLines ← moveDownDistance ← 0; -- only do this the first time
IF (refresh AND TEditLocks.WaitingForWrite[lock]) OR tdd.interrupt > 0 THEN {
tdd.dirty ← TRUE; RETURN };
ENDLOOP;
tdd.movedIn ← tdd.movedOut ← tdd.dirty ← FALSE;
};
The following procedure is passed two document line positions; the meaning is to paint all the lines marked as invalid and then continue painting within each node until the ripple has subsided. Returns line where stopped.
WhileInPosRange: PROCEDURE [
viewer: ViewerClasses.Viewer,
tdd: TEditDocument.TEditDocumentData,
dc: Graphics.Context,
start, end: INTEGER,
displayClear, refresh: BOOLEAN,
lock: TEditLocks.LockRef,
moveDownLines, moveDownDistance: INTEGER
] RETURNS [line: INTEGER] = {
lines: TEditDocument.LineTable ← tdd.lineTable;
oldBottomY: INTEGER ← ComputeInitialBottomY[];
ComputeInitialBottomY: PROC RETURNS [y: INTEGER] = {
Has to be done before node, pos, etc. are computed.
y ← MAX[0, lines[start].yOffset - lines[start].ascent];
WHILE start>0 AND lines[start-1].yOffset + lines[start-1].descent > y DO
start ← start-1;
lines[start].valid ← FALSE;
ENDLOOP;
};
node: TextNode.RefTextNode ← TextNode.NarrowToTextNode[lines[start].pos.node];
pos: TextEdit.Offset ← lines[start].pos.where;
leading, topLeading, bottomLeading, nodeLeading: INTEGER ← 0;
knowBottomLeading: BOOL ← start=0; -- otherwise need to get it
y: INTEGER ← 0;
nodeSize: TextEdit.Offset ← TextEdit.Size[node];
styleInit, yMatchRun: BOOLTRUE;
yMatch, eraseToEnd: BOOLFALSE;
lineInfo: TEditFormat.LineInfo ← TEditFormat.Allocate[];
nodeStyle: NodeStyle.Ref ← NodeStyle.Alloc[];
Cleanup: PROC = {lineInfo.Release[]; lineInfo ← NIL; nodeStyle.Free[]; nodeStyle ← NIL};
styleInfoNode: TextNode.Ref; -- node for which we were last called to get style info
This is used to avoid redoing GetStyleInfo after have peeked at next node style as part of trying to move lines down.
GetStyleInfo: PROC [node: TextNode.Ref] = {
IF node = styleInfoNode THEN RETURN; -- already have the style info
styleInfoNode ← node;
IF NOT knowBottomLeading AND pos=0 THEN { -- get it from previous node
NodeStyle.ApplyAll[nodeStyle, lines[line-1].pos.node];
bottomLeading ← NodeStyle.GetBottomLeadingI[nodeStyle]
};
NodeStyle.ApplyAll[nodeStyle, node];
leading ← NodeStyle.GetLeadingI[nodeStyle];
topLeading ← MAX[bottomLeading, NodeStyle.GetTopLeadingI[nodeStyle]];
use value of bottomLeading left from previous node
nodeLeading ← MAX[bottomLeading, topLeading]; -- use previous value of bottomLeading
bottomLeading ← NodeStyle.GetBottomLeadingI[nodeStyle];
knowBottomLeading ← TRUE;
};
FullyVisible: PROC RETURNS [BOOL] = {
box: Graphics.Box;
width, height: INTEGER;
checkedVisible ← TRUE;
IF NOT Graphics.IsRectangular[dc] THEN RETURN [FALSE];
box ← Graphics.GetBounds[dc];
width ← Real.RoundI[box.xmax-box.xmin];
IF width # viewer.cw THEN RETURN [FALSE];
height ← Real.RoundI[box.ymax-box.ymin];
IF height # viewer.ch THEN RETURN [FALSE];
RETURN [TRUE]
};
checkedVisible, fullyVisible: BOOLFALSE;
found: INTEGER ← 0; -- set by FindBelow
TryMoveUp: PROC RETURNS [ok: BOOL] = {
Returns true if found the desired line at a lower location on the screen. Blts the line and all following lines, clears out screen below them, then updates line table.
to, from, num, dist, bottom, diff: INTEGER;
dirtyScanlinesInFirstTextline: NAT ← 0;
FindBelow: PROC RETURNS [ok: BOOL] = INLINE { -- returns true if finds the desired line
Looks for valid line at or below current line with desired start location. Assumes oldBottomY has been set to bottom of previous line, so if found line starts below that it will be ok on the screen still. If finds such a line, stores its index in "found" and returns true.
FOR n: INTEGER IN [line..lines.lastLine] DO
IF lines[n].valid AND lines[n].pos=[node,pos] THEN {
found ← n;
RETURN [lines[n].yOffset-lines[n].ascent > oldBottomY]
};
ENDLOOP;
RETURN [FALSE]
};
IF NOT checkedVisible THEN fullyVisible ← FullyVisible[];
IF NOT fullyVisible OR NOT FindBelow[] THEN RETURN [FALSE];
IF found=lines.lastLine AND lines[found].yOffset+lines[found].descent >= viewer.ch
THEN RETURN [FALSE]; -- bottom is clipped
IF found>0 AND (
dirtyScanlinesInFirstTextline ←
MAX[0,
lines[found-1].yOffset+lines[found-1].descent - lines[found].yOffset-lines[found].ascent
]
) > 0 THEN lines[found].valid ← FALSE;
to ← y-lines[found].ascent + dirtyScanlinesInFirstTextline;
top of clean part of new line is destination for blt
from ← lines[found].yOffset-lines[found].ascent + dirtyScanlinesInFirstTextline;
uppermost source scan line
IF to < 0 THEN { -- top of line is clipped
from ← from-to; -- move source down by amount to be clipped
to ← 0 };
dist ← from-to; -- the distance to move
IF dist < 0 THEN RETURN [FALSE]; -- skip this bizarre case
bottom ← MIN[viewer.ch, lines.lastY];
num ← bottom-from; -- number of scan lines to move
IF num <= 0 THEN RETURN [FALSE];
ClearLine[oldBottomY, to]; -- clear gap above destination
MoveScanLines[to, from, num]; -- move the good scan lines up
ClearLine[bottom-dist, bottom]; -- clear the space at the bottom
oldBottomY ← bottom;
lines.lastY ← lines.lastY-dist; -- lastY tells last used scan line in viewer
diff ← found-line; -- number of lines skipped
IF diff # 0 THEN { -- update the line table info
FOR n: INTEGER IN [line..lines.lastLine-diff] DO
lines[n] ← lines[n+diff]; -- move all the info up to new location
ENDLOOP;
ClearEntries[lines.lastLine-diff+1, lines.lastLine]; -- these lines no longer in use
lines.lastLine ← lines.lastLine-diff;
end ← end-diff
};
FOR n: INTEGER IN [line..lines.lastLine] DO -- adjust the baselines
lines[n].yOffset ← lines[n].yOffset-dist; ENDLOOP;
lines[lines.lastLine].valid ← FALSE;
Set the last line invalid to force repaint to fill in gap at bottom of viewer.
RETURN [TRUE]
};
ClearEntries: PROC [from, to: INTEGER] = {
FOR n: INTEGER IN [from..to] DO
lines[n] ← [
pos: [NIL, 0],
valid: TRUE,
yOffset: 0,
xOffset: 0,
width: 0,
ascent: 0,
descent: 0];
ENDLOOP };
MoveScanLines: PROC [to, from, num: INTEGER] = BEGIN
dY, sY, vY, vX: INTEGER;
w: INTEGER ← viewer.cw;
IF num=0 THEN RETURN;
[vX, vY] ← ViewerOps.UserToScreenCoords[viewer, 0, viewer.ch];
screen coords for upper lefr
vY ← (IF viewer.column=color THEN Terminal.Current[].colorHeight ELSE ViewerSpecs.screenH)-vY;
dY ← vY+to; -- destination y coord
sY ← vY+from; -- source y coord
GraphicsOps.MoveDeviceRectangle[
self: dc,
width: w, -- full width of viewer
height: num, -- height of source is num
fromX: vX,
fromY: sY,
toX: vX,
toY: dY
];
END;
TryMoveDown: PROC [nchars: INTEGER, end: TEditDocument.LineBreak] = {
We are about to put [node, pos] in line. It will contain nchars with break specified by end. This procedure looks to see if we will overwrite what we will next want to put in line+1. If so, move it down now. This happens whenever we insert a single line.
This proc may need to call GetStyleInfo, so use all the style info you're interested in before you call it.
next: TextNode.Location;
from, lead, dist: INTEGER;
IF NOT checkedVisible THEN fullyVisible ← FullyVisible[];
IF NOT fullyVisible OR NOT lines[line].valid THEN RETURN;
from ← lines[line].yOffset-lines[line].ascent;
IF oldBottomY > from THEN RETURN; -- overwritten it already
next ← IF end=eon THEN [NextNode[],0] ELSE [node,pos+nchars];
IF lines[line].pos # next THEN RETURN;
IF end=eon THEN { -- need to get leading info for the next node
GetStyleInfo[next.node]; lead ← nodeLeading }
ELSE lead ← leading;
dist ← y+lead-lines[line].yOffset; -- how far down to move it
MoveLinesDown[line, 1, from, dist]
};
MoveLinesDown: PROC [startLine, numLines, from, dist: INTEGER] = {
to, num, bottom: INTEGER;
visible: BOOLFALSE;
dirtyScanlinesInFirstTextline: INTEGER;
IF dist <= 0 THEN RETURN; -- skip this weird case
to ← from+dist;
bottom ← MIN[viewer.ch, lines.lastY+dist]; -- new bottom after blt
num ← bottom-to; -- the number of scan lines to blt
IF num <= 0 THEN RETURN; -- stuff to move down won't be visible
MoveScanLines[from+dist, from, num];
IF startLine > 0 AND (
dirtyScanlinesInFirstTextline ←
lines[startLine-1].yOffset+lines[startLine-1].descent -
lines[startLine].yOffset-lines[startLine].ascent
) > 0 THEN {
Repaint the top line if it got dirtied by descenders.
lines[startLine].valid ← FALSE;
ClearLine[from, to + dirtyScanlinesInFirstTextline];
}
ELSE ClearLine[from, to]; -- clear the gap
FOR n: INTEGER DECREASING IN [startLine..lines.lastLine] DO
newOffset: INTEGER;
IF n+numLines >= lines.maxLines THEN LOOP; -- avoid bounds fault
newOffset ← lines[n].yOffset+dist; -- the new baseline
IF newOffset-lines[n].ascent > viewer.ch THEN LOOP; -- off the bottom of viewer
IF NOT visible AND newOffset+lines[n].descent <= viewer.ch THEN { -- first fully visible line
visible ← TRUE;
lines.lastLine ← n+numLines;
lines[n].valid ← FALSE; -- force repaint at bottom of viewer
lines.lastY ← newOffset+lines[n].descent;
ClearLine[lines.lastY, viewer.ch] };
lines[n+numLines] ← lines[n]; -- move all the info down by numLines
lines[n+numLines].yOffset ← newOffset; -- adjust the baseline
IF NOT visible THEN { -- line must be partly visible at bottom of screen
lines.lastLine ← n+numLines;
lines.lastY ← newOffset+lines[n].descent;
lines[n+numLines].valid ← FALSE };
ENDLOOP;
};
level: INTEGER ← 0; -- in case we are doing level clipping
maxLevel: INTEGER = tdd.clipLevel;
levelClipping: BOOL = maxLevel < TEditDocument.maxClip;
last, next: TextNode.Ref;
NextNode: PROC RETURNS [TextNode.Ref] = { -- returns next node to display
For future reference, TEditScrollingImpl.ScrollTEditDocument also has code to calculate next node for display to handle scrolling up in 1 line viewers.
IF node=last THEN RETURN [next]; -- 1 entry cache
last ← node;
IF levelClipping THEN [next,level] ← TextNode.ForwardClipped[node,maxLevel,level]
ELSE next ← TextNode.StepForward[node];
RETURN [next]
};
ClearLine: PROC [oldBottomY, newBottomY: INTEGER] = {
IF oldBottomY >= newBottomY THEN RETURN;
Graphics.SetColor[dc, Graphics.white];
Graphics.DrawBox[dc, [0, viewer.ch-newBottomY, viewer.cw, viewer.ch-oldBottomY]];
Graphics.SetColor[dc, Graphics.black];
};
IF (line ← start) > lines.lastLine OR end < 0 THEN
update not on screen
{Cleanup[]; RETURN};
IF moveDownLines > 0 AND (fullyVisible ← FullyVisible[]) THEN {
Move things down before start repainting. This accelerates scrolling down.
MoveLinesDown[0, moveDownLines, 0, moveDownDistance];
};
Paint lines until the line we would paint is:
(1) valid,
(2) past the range we were told to paint,
(3) matches the line table offsets (i.e. no ripple going forward), and
(4) matches in the Y coord.
An exit for end of text and off end of viewer are included below.
UNTIL line>=lines.maxLines
OR (
line>end
AND lines[line].valid
AND lines[line].pos=[node, pos]
AND yMatch
AND line<=lines.lastLine
) DO
IF (refresh AND TEditLocks.WaitingForWrite[lock])
OR tdd.interrupt > 0 THEN {
Either an edit is pending or a complete repaint is pending. In either case, we quit.
lines.lastLine ← MAX[line, lines.lastLine];
lines[line].pos ← [node, pos];
lines[line].valid ← FALSE;
Cleanup[]; RETURN
};
IF pos >= nodeSize THEN {
Nothing more to display in this node; pos is where this line should start, so we are done with the node.
DO -- stay in this loop until have a non-empty node or have reached end of document
IF (pos > 0 AND (line=0 OR lines[line-1].end=cr))
OR (nodeSize=0 AND node#tdd.text) THEN {
Show blank line
Line 0 starts at end of node, or CR at end of node on previous line, or empty node other than root node.
GetStyleInfo[node];
IF line=start THEN y ← IF line=0 THEN 0 ELSE lines[line-1].yOffset; -- initialize y
y ← y + (IF line=0 THEN NodeStyle.GetTopIndentI[nodeStyle] ELSE
IF pos=0 THEN nodeLeading ELSE leading);
IF y>=viewer.ch AND line>0 THEN {node ← NIL; EXIT};
If baseline would be off bottom of viewer and not the first line, don't show it.
IF NOT displayClear AND TryMoveUp[] THEN NULL
ELSE {
indent: INTEGERIF pos=0 THEN nodeStyle.GetFirstIndentI[] ELSE nodeStyle.GetBodyIndentI[];
lineStart: INTEGER ← nodeStyle.GetLeftIndentI[] + indent;
lineWidth: INTEGER ← viewer.cw - nodeStyle.GetRightIndentI[] - indent;
xoffset: INTEGERSELECT nodeStyle.GetLineFormatting[] FROM
FlushLeft, Justified => lineStart,
FlushRight => lineStart + lineWidth,
Centered => lineStart + lineWidth/2,
ENDCASE => ERROR;
IF NOT displayClear THEN TryMoveDown[0, eon];
Need to finish with style info before call this.
lines[line] ← [
valid: TRUE,
pos: [node, pos],
nChars: 0,
end: eon,
yOffset: y,
xOffset: xoffset,
width: 0,
ascent: 1,
descent: 0
];
};
line ← line+1;
};
pos ← 0;
step to the next node in the tree.
node ← TextNode.NarrowToTextNode[NextNode[]];
IF node=NIL OR (nodeSize←TextEdit.Size[node]) > 0 THEN EXIT;
ENDLOOP;
IF NOT displayClear THEN {ClearLine[oldBottomY, y]; oldBottomY ← y};
IF node#NIL THEN {styleInit ← TRUE; LOOP} -- reapply termination test
ELSE {eraseToEnd ← TRUE; EXIT}; -- off end of text
}
ELSE IF styleInit THEN {GetStyleInfo[node]; styleInit ← FALSE}; -- first time for this node
y --baseline--IF line=0 THEN NodeStyle.GetTopIndentI[nodeStyle]
ELSE (IF line#start THEN y ELSE lines[line-1].yOffset) -- baseline --
+ (IF pos=0 THEN nodeLeading ELSE leading) -- leading --;
IF y>=viewer.ch AND line>0 THEN {eraseToEnd ← TRUE; EXIT};
if baseline would be off bottom of viewer and not the first line, don't show it.
yMatch ← y=lines[line].yOffset;
true if the new line is baseline aligned with the previous bits on the screen
oldBottomY ← IF line=0 THEN 0 ELSE lines[line-1].yOffset+lines[line-1].descent;
bottom of the previous line
IF NOT displayClear AND TryMoveUp[] THEN NULL
ELSE {
TEditFormat.FormatLine[
self: lineInfo,
tdd: tdd,
node: node,
startOffset: pos,
nodeStyle: nodeStyle,
lineWidth: Scaled.FromInt[viewer.cw],
forPaint: TRUE
];
IF NOT displayClear THEN TryMoveDown[lineInfo.nChars, lineInfo.break];
Need to finish with style info before call this. May call GetStyleInfo for next node.
Graphics.SetCP[dc, lineInfo.xOffset.Float[], viewer.ch-y];
IF NOT displayClear THEN ClearLine[oldBottomY, y-lineInfo.ymin];
oldBottomY ← y-lineInfo.ymin;
TEditFormat.Paint[lineInfo, dc];
lines[line] ← [
valid: TRUE,
pos: [node, pos],
nChars: lineInfo.nChars,
end: lineInfo.break,
yOffset: y,
xOffset: lineInfo.xOffset.Round[],
width: lineInfo.xmax-lineInfo.xmin,
ascent: MIN[511, MAX[0, lineInfo.ymax]],
descent: MIN[127, MAX[0, -lineInfo.ymin]]
];
};
pos ← pos + lines[line].nChars;
line ← line + 1;
ENDLOOP;
Clear former bottom lines if we run off end of text or viewer (partial line must be clipped)
IF eraseToEnd OR line>=lines.maxLines THEN {
eraseToEnd starts false. set true if reach end of document or stop with line that would have baseline below bottom of viewer.
bottomOfNewLines: INTEGER
IF line=0 THEN 0 ELSE lines[line-1].yOffset+lines[line-1].descent;
lines.lastLine ← MAX[line,1]-1; -- set end mark
ClearEntries[lines.lastLine+1, lines.maxLines-1];
IF NOT displayClear AND bottomOfNewLines < lines.lastY THEN-- white out old lines
ClearLine[bottomOfNewLines, lines.lastY];
lines.lastY ← bottomOfNewLines;
}
ELSE {
Take this branch if got back in synch during repaint
IF y>viewer.ch OR displayClear THEN ERROR;
lines.lastLine ← MAX[lines.lastLine, MAX[line,1]-1];
lines.lastY ← MAX[lines.lastY, y+lines[lines.lastLine].descent];
};
Cleanup[];
};
END.