[Cyan]<PreISLCedar>Tioga>TextEditImpl.mesa!1

-- TextEditImpl.mesa

-- written by Bill Paxton, March 1981

-- last edit by Bill Paxton, December 28, 1982 11:43 am

Last Edited by: Maxwell, January 5, 1983 3:31 pm

DIRECTORY

TextEdit,

EditNotify,

UndoEvent,

NodeProps,

RopeEdit,

RopeFrom,

RopeReader,

TextLooks,

TextNode,

NodeAddrs,

Atom,

Rope,

CheckNode;

TextEditImpl: CEDAR MONITOR

IMPORTS npI:NodeProps, RopeEdit, TextLooks, EditNotify, UndoEvent, NodeAddrs,

TextNode, RopeFrom, RopeReader, Rope, Atom, CheckNode

EXPORTS TextEdit =

BEGIN

OPEN TextEdit, EditNotify;

Runs: TYPE = TextLooks.Runs;

-- **** Cache of notify records ****

scratch1, scratch2, scratch3: REF ChangingText Change;

Create: PROC RETURNS [REF ChangingText Change] = {

RETURN [TextNode.pZone.NEW[ChangingText Change]] };

Alloc: ENTRY PROC RETURNS [scratch: REF ChangingText Change] = {

ENABLE UNWIND => NULL;

IF scratch3 # NIL THEN { scratch ← scratch3; scratch3 ← NIL }

ELSE IF scratch2 # NIL THEN { scratch ← scratch2; scratch2 ← NIL }

ELSE IF scratch1 # NIL THEN { scratch ← scratch1; scratch1 ← NIL }

ELSE scratch ← Create[] };

Free: ENTRY PROC [scratch: REF ChangingText Change] = {

ENABLE UNWIND => NULL;

IF scratch3 = scratch OR scratch2 = scratch OR scratch1 = scratch THEN ERROR;

IF scratch3 = NIL THEN scratch3 ← scratch

ELSE IF scratch2 = NIL THEN scratch2 ← scratch

ELSE IF scratch1 = NIL THEN scratch1 ← scratch };

-- **** Text Editing Operations ****

DoReplace: PROC [root: Ref,

dest: RefTextNode, destStart, destLen, destSize: Offset,

sourceRope: ROPE, sourceRuns: Runs,

sourceStart, sourceLen: Offset, event: Event]

RETURNS [resultStart, resultLen: Offset] = {

destRope, replaceRope, newRope: ROPE;

size: Offset;

notify: REF ChangingText Change;

alreadysaved: BOOLEAN;

destRuns, replaceRuns, newRuns: Runs;

special: BOOLEAN;

size ← destSize-destLen+sourceLen;

destRuns ← dest.runs; destRope ← dest.rope;

notify ← IF (alreadysaved ← AlreadySaved[dest,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,dest,destStart,sourceLen,destLen,destRope,destRuns]];

Notify[notify,before];

IF sourceLen > 0 THEN {

replaceRope ← RopeEdit.Substr[sourceRope,sourceStart,sourceLen];

replaceRuns ← TextLooks.Substr[sourceRuns,sourceStart,sourceLen]};

special ← FALSE;

IF destLen=0 THEN { -- doing an insert

IF destStart=0 THEN { -- insert at start

newRope ← RopeEdit.Concat[replaceRope,destRope,sourceLen,destSize];

newRuns ← TextLooks.Concat[replaceRuns,destRuns,sourceLen,destSize];

special ← TRUE }

ELSE IF destStart=destSize THEN { -- insert at end

newRope ← RopeEdit.Concat[destRope,replaceRope,destSize,sourceLen];

newRuns ← TextLooks.Concat[destRuns,replaceRuns,destSize,sourceLen];

special ← TRUE }}

ELSE IF sourceLen=0 THEN { -- doing a delete

IF destStart=0 THEN { -- delete from start

newRope ← RopeEdit.Substr[destRope,destLen,size];

newRuns ← TextLooks.Substr[destRuns,destLen,size];

special ← TRUE }

ELSE IF (destStart+destLen)=destSize THEN { -- delete from end

newRope ← RopeEdit.Substr[destRope,0,size];

newRuns ← TextLooks.Substr[destRuns,0,size];

special ← TRUE }};

IF ~special THEN {

newRope ← RopeEdit.Replace[destRope,destStart,destLen,

replaceRope,destSize,sourceLen];

newRuns ← TextLooks.Replace[destRuns,destStart,destLen,

replaceRuns,destSize,sourceLen] };

dest.rope ← newRope; dest.runs ← newRuns;

NodeAddrs.Replace[dest,destStart,destLen,sourceLen];

BumpCount[dest];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify];

RETURN [destStart,sourceLen] };

MoveText: PUBLIC PROC [

destRoot, sourceRoot: Ref,

dest: RefTextNode, destLoc: Offset ← 0,

source: RefTextNode, start: Offset ← 0, len: Offset ← MaxLen,

event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

MoveAddrs: PROC [addr: REF, location: Offset] RETURNS [quit: BOOLEAN] = {

IF location NOT IN [start..start+len) THEN RETURN [FALSE];

IF dest=source THEN { -- pin addr at new location

new: Offset ← destLoc+location-start;

IF destLoc > start THEN new ← new-len; -- moving toward end of node

NodeAddrs.PutTextAddr[dest, addr, new];

NodeAddrs.PinTextAddr[dest, addr] -- so it won't be changed by Replace -- }

ELSE NodeAddrs.MoveTextAddr[ -- move the addr to the new node

from: source, to: dest, addr: addr, location: destLoc+location-start];

RETURN [FALSE] };

destSize, sourceSize: Offset;

sourceSize ← RopeEdit.Size[source.rope];

start ← MIN[MAX[0,start],sourceSize];

len ← MIN[MAX[0,len],sourceSize-start];

destSize ← IF dest=source THEN sourceSize ELSE RopeEdit.Size[dest.rope];

destLoc ← MIN[MAX[0,destLoc],destSize];

IF source=dest AND destLoc IN [start..start+len] THEN RETURN [start,len];

IF len=0 THEN RETURN [destLoc,0];

[] ← NodeAddrs.MapTextAddrs[source, MoveAddrs];

[resultStart, resultLen] ← CopyText[destRoot, sourceRoot, dest, destLoc, source, start, len, event];

IF dest=source THEN { -- need to adjust locations

IF destLoc > start THEN resultStart ← destLoc-len -- moving toward end of node

ELSE start ← start+len -- moving toward start of node-- };

DeleteText[sourceRoot, source, start, len, event];

IF dest=source THEN NodeAddrs.UnpinAll[source] };

TransposeText: PUBLIC PROC [

alphaRoot, betaRoot: Ref,

alpha: RefTextNode, alphaStart: Offset ← 0, alphaLen: Offset ← MaxLen,

beta: RefTextNode, betaStart: Offset ← 0, betaLen: Offset ← MaxLen, event: Event ← NIL]

RETURNS [alphaResultStart, alphaResultLen, betaResultStart, betaResultLen: Offset] = {

SwitchResults: PROC = {

start, len: Offset;

start ← betaResultStart; len ← betaResultLen;

betaResultStart ← alphaResultStart; betaResultLen ← alphaResultLen;

alphaResultStart ← start; alphaResultLen ← len };

alphaSize, betaSize: Offset;

switched: BOOLEAN ← FALSE;

alphaSize ← RopeEdit.Size[alpha.rope];

alphaStart ← MIN[MAX[0,alphaStart],alphaSize];

alphaResultLen ← alphaLen ← MIN[MAX[0,alphaLen], alphaSize-alphaStart];

betaSize ← IF beta=alpha THEN alphaSize ELSE RopeEdit.Size[beta.rope];

betaStart ← MIN[MAX[0,betaStart],betaSize];

betaResultLen ← betaLen ← MIN[MAX[0,betaLen],betaSize-betaStart];

IF alpha=beta THEN {

alphaEnd: Offset;

IF alphaStart > betaStart THEN { -- switch them

start: Offset ← alphaStart;

len: Offset ← alphaLen;

root: Ref ← alphaRoot;

alphaStart ← betaStart; betaStart ← start;

alphaResultLen ← alphaLen ← betaLen;

alphaRoot ← betaRoot; betaRoot ← root;

betaResultLen ← betaLen ← len;

switched ← TRUE };

alphaEnd ← alphaStart+alphaLen;

IF alphaEnd = betaStart THEN { -- turn into a move instead

[] ← MoveText[alphaRoot,betaRoot,alpha,alphaStart,alpha,betaStart,betaLen,event];

betaResultStart ← alphaStart;

alphaResultStart ← alphaStart+betaLen;

IF switched THEN SwitchResults;

RETURN };

IF alphaEnd > betaStart THEN { -- overlapping

overlap, alphaHeadLen, betaTailLen: Offset;

alphaHeadLen ← betaStart-alphaStart;

betaTailLen ← betaStart+betaLen-alphaEnd;

IF alphaHeadLen < 0 OR betaTailLen < 0 THEN

RETURN [alphaStart,alphaLen,betaStart,betaLen];

overlap ← alphaEnd-betaStart;

[alphaResultStart,alphaResultLen,betaResultStart,betaResultLen] ←

TransposeText[alphaRoot,betaRoot,alpha,alphaStart,alphaHeadLen,

alpha,alphaEnd,betaTailLen,event];

betaResultLen ← betaResultLen+overlap;

alphaResultStart ← alphaResultStart-overlap;

alphaResultLen ← alphaResultLen+overlap;

IF switched THEN SwitchResults;

RETURN }};

[alphaResultStart, alphaResultLen] ← MoveText[ -- move alpha after beta

destRoot: betaRoot, sourceRoot: alphaRoot,

dest: beta, destLoc: betaStart+betaLen,

source: alpha, start: alphaStart, len: alphaLen, event: event];

IF alpha=beta THEN betaStart ← betaStart-alphaLen

ELSE alphaResultStart ← alphaResultStart-betaLen;

[betaResultStart, betaResultLen] ← MoveText[ -- move beta to old alpha location

destRoot: alphaRoot, sourceRoot: betaRoot,

dest: alpha, destLoc: alphaStart,

source: beta, start: betaStart, len: betaLen, event: event];

IF switched THEN SwitchResults };

ReplaceByChar: PUBLIC PROC [

root: Ref, dest: RefTextNode, char: CHAR,

start: Offset ← 0, len: Offset ← MaxLen,

inherit: BOOLEAN ← TRUE, looks: Looks ← noLooks, event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

-- if inherit is false, char gets specifed looks

-- if inherit is true, char gets looks in following manner:

-- if dest length is 0, then gets looks from argument list, else

-- if start > 0, then looks and list of previous char,

-- else looks of char following replacement

notify: REF ChangingText Change;

destRope, newRope: ROPE;

destSize: Offset;

alreadysaved: BOOLEAN;

IF dest=NIL THEN RETURN [0,0];

destSize ← RopeEdit.Size[destRope ← dest.rope];

start ← MIN[MAX[0,start],destSize];

len ← MIN[MAX[0,len],destSize-start];

notify ← IF (alreadysaved ← AlreadySaved[dest,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,dest,start,1,len,destRope,dest.runs]];

Notify[notify,before];

newRope ← RopeEdit.ReplaceByChar[destRope,char,start,len,destSize];

dest.runs ← TextLooks.ReplaceByRun[dest.runs,start,len,1,destSize,inherit,looks];

dest.rope ← newRope;

NodeAddrs.Replace[dest,start,len,1];

BumpCount[dest];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify];

RETURN [start,1] };

ReplaceByString: PUBLIC PROC [

root: Ref, dest: RefTextNode, string: REF READONLY TEXT,

stringStart: NAT ← 0, stringNum: NAT ← MaxNat,

start: Offset ← 0, len: Offset ← MaxLen,

inherit: BOOLEAN ← TRUE, looks: Looks ← noLooks, event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

notify: REF ChangingText Change;

destRope, newRope: ROPE;

alreadysaved: BOOLEAN;

destSize: Offset;

IF dest=NIL THEN RETURN [0,0];

stringNum ← IF string=NIL OR stringStart >= string.length THEN 0 ELSE

MIN[stringNum, string.length-stringStart];

destSize ← RopeEdit.Size[destRope ← dest.rope];

start ← MIN[MAX[0,start],destSize];

len ← MIN[MAX[0,len],destSize-start];

notify ← IF (alreadysaved ← AlreadySaved[dest,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,dest,start,stringNum,len,destRope,dest.runs]];

Notify[notify,before];

newRope ← RopeEdit.ReplaceByString[destRope,string,stringStart,stringNum,

start,len,destSize];

dest.runs ← TextLooks.ReplaceByRun[dest.runs,start,len,stringNum,

destSize,inherit,looks];

dest.rope ← newRope;

NodeAddrs.Replace[dest,start,len,stringNum];

BumpCount[dest];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify];

RETURN [start,stringNum] };

UndoChangeText: PROC [undoRef: REF, currentEvent: Event] = TRUSTED {

saved: REF Change ← NARROW[undoRef];

WITH x:saved SELECT FROM

ChangingText => [] ← ReplaceByText[x.root,x.text,0,MaxLen,

x.oldRope,x.oldRuns,0,MaxLen,currentEvent];

-- must replace all of text since only save first change per event

ENDCASE => ERROR };

ReplaceByText: PUBLIC PROC [

root: Ref, dest: RefTextNode, destStart: Offset ← 0, destLen: Offset ← MaxLen,

sourceRope: ROPE, sourceRuns: Runs,

sourceStart: Offset ← 0, sourceLen: Offset ← MaxLen, event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

sourceSize, destSize: Offset;

IF dest=NIL THEN RETURN [0,0];

sourceSize ← RopeEdit.Size[sourceRope];

sourceStart ← MIN[MAX[0,sourceStart],sourceSize];

IF sourceLen # 0 THEN {

IF sourceStart >= sourceSize THEN sourceStart ← sourceSize;

sourceLen ← MIN[MAX[0,sourceLen], sourceSize-sourceStart]};

destSize ← RopeEdit.Size[dest.rope];

destStart ← MIN[MAX[0,destStart],destSize];

destLen ← MIN[MAX[0,destLen],destSize-destStart];

IF destLen=0 AND sourceLen=0 THEN RETURN [destStart,0];

[resultStart,resultLen] ← DoReplace[root,dest,destStart,destLen,destSize,

sourceRope,sourceRuns,sourceStart,sourceLen,event] };

ReplaceText: PUBLIC PROC [

destRoot, sourceRoot: Ref,

dest: RefTextNode, destStart: Offset ← 0, destLen: Offset ← MaxLen,

source: RefTextNode, sourceStart: Offset ← 0, sourceLen: Offset ← MaxLen,

event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

-- replace the dest text by a copy of the source text

-- names that are in the replaced text move to destStart

-- names that are after the replaced text are adjusted

sourceRope: ROPE;

sourceSize, destSize: Offset;

sourceRuns: Runs;

IF dest=NIL THEN RETURN [0,0];

IF source # NIL THEN { sourceRope ← source.rope; sourceRuns ← source.runs };

sourceSize ← RopeEdit.Size[sourceRope];

sourceStart ← MIN[MAX[0,sourceStart],sourceSize];

IF sourceLen # 0 THEN {

IF sourceStart >= sourceSize THEN sourceStart ← sourceSize;

sourceLen ← MIN[MAX[0,sourceLen], sourceSize-sourceStart]};

destSize ← RopeEdit.Size[dest.rope];

destStart ← MIN[MAX[0,destStart],destSize];

destLen ← MIN[MAX[0,destLen],destSize-destStart];

IF destLen=0 AND sourceLen=0 THEN RETURN [destStart,0];

[resultStart,resultLen] ← DoReplace[destRoot,dest,destStart,destLen,destSize,

sourceRope,sourceRuns,sourceStart,sourceLen,event] };

DeleteText: PUBLIC OneSpanProc = {

[] ← ReplaceText[root, NIL, text, start, len, NIL, 0, MaxLen, event] };

CopyText: PUBLIC DestSpanProc = { -- copy the specified text

[resultStart,resultLen] ← ReplaceText[destRoot, sourceRoot, dest, destLoc, 0,

source, start, len, event] };

MoveTextOnto: PUBLIC PROC [

destRoot, sourceRoot: Ref,

dest: RefTextNode, destStart: Offset ← 0, destLen: Offset ← MaxLen,

source: RefTextNode, sourceStart: Offset ← 0, sourceLen: Offset ← MaxLen,

event: Event ← NIL]

RETURNS [resultStart, resultLen: Offset] = {

sourceSize, destSize, start, len, end, destEnd: Offset;

start ← sourceStart; len ← sourceLen;

sourceSize ← Size[source];

start ← MIN[MAX[0,start],sourceSize];

len ← MIN[MAX[0,len],sourceSize-start];

end ← start+len;

destSize ← IF dest=source THEN sourceSize ELSE Size[dest];

destStart ← MIN[MAX[0,destStart],destSize];

destLen ← MIN[MAX[0,destLen],destSize-destStart];

destEnd ← destStart+destLen;

IF source=dest THEN { -- check for overlapping or adjacent

IF start IN [destStart..destEnd) THEN {

IF end < destEnd THEN

[] ← DeleteText[sourceRoot,source,end,destEnd-end,event];

IF start > destStart THEN

[] ← DeleteText[sourceRoot,source,destStart,start-destStart,event];

RETURN [destStart,len] };

IF end IN (destStart..destEnd) THEN {

[] ← DeleteText[sourceRoot,source,end,destEnd-end,event];

RETURN [start,len] };

IF start <= destStart AND end >= destEnd THEN RETURN [start,len];

IF end=destStart THEN {

[] ← DeleteText[sourceRoot,source,destStart,destLen,event];

RETURN [start,len] };

IF start=destEnd THEN {

[] ← DeleteText[sourceRoot,source,destStart,destLen,event];

RETURN [destStart,len] }};

[] ← DeleteText[destRoot,dest,destStart,destLen,event];

IF source=dest AND start > destStart THEN start ← start-destLen;

[resultStart,resultLen] ←

MoveText[destRoot,sourceRoot,dest,destStart,source,start,len,event] };

ReplaceByRope: PUBLIC PROC [

root: Ref, dest: RefTextNode, rope: ROPE,

start: Offset ← 0, len: Offset ← MaxLen,

inherit: BOOLEAN ← TRUE, looks: Looks ← noLooks, event: Event]

RETURNS [resultStart, resultLen: Offset] = {

notify: REF ChangingText Change;

destRope, newRope: ROPE;

alreadysaved: BOOLEAN;

destSize, ropeSize: Offset;

IF dest=NIL THEN RETURN [0,0];

ropeSize ← RopeEdit.Size[rope];

destSize ← RopeEdit.Size[destRope ← dest.rope];

start ← MIN[MAX[0,start],destSize];

len ← MIN[MAX[0,len],destSize-start];

notify ← IF (alreadysaved ← AlreadySaved[dest,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,dest,start,ropeSize,len,destRope,dest.runs]];

Notify[notify,before];

newRope ← RopeEdit.Replace[destRope,start,len,rope,destSize,ropeSize];

dest.runs ← TextLooks.ReplaceByRun[dest.runs,start,len,ropeSize,destSize,inherit,looks];

dest.rope ← newRope;

NodeAddrs.Replace[dest,start,len,ropeSize];

BumpCount[dest];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify];

RETURN [start,ropeSize] };

-- **** Operation to add or delete looks ****

ChangeLooks: PUBLIC PROC [

root: Ref, text: RefTextNode, remove, add: Looks,

start: Offset ← 0, len: Offset ← MaxOffset, event: Event ← NIL] = {

-- first remove then add in the given range

size: Offset;

newRuns: Runs;

IF text=NIL THEN RETURN;

size ← RopeEdit.Size[text.rope];

start ← MIN[MAX[0,start],size];

len ← MIN[MAX[0,len],size-start];

IF len=0 THEN RETURN;

newRuns ← TextLooks.ChangeLooks[text.runs,size,remove,add,start,len];

IF newRuns=text.runs THEN RETURN; -- no change

DoChangeLooks[root,text,newRuns,start,len,event] };

DoChangeLooks: PROC [root: Ref, text: RefTextNode,

newRuns: Runs, start, len: Offset, event: Event] = {

oldRuns: Runs ← text.runs;

notify: REF ChangingText Change;

alreadysaved: BOOLEAN;

notify ← IF (alreadysaved ← AlreadySaved[text,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,text,start,len,len,text.rope,oldRuns]];

Notify[notify,before];

text.runs ← newRuns;

BumpCount[text];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify] };

-- **** Changing Style / Type of node ****

ChangeType: PUBLIC PROC [node: Ref, typeName: TextNode.TypeName, event: Event ← NIL, root: Ref ← NIL] = {

notify: REF ChangingType Change;

oldTypeName: TextNode.TypeName ← node.typename;

IF node=NIL THEN RETURN;

IF root=NIL THEN root ← TextNode.Root[node];

IF oldTypeName = typeName THEN RETURN; -- no change

notify ← TextNode.pZone.NEW[ChangingType Change ←

[ChangingType[root,node,typeName,oldTypeName]]];

Notify[notify,before];

node.typename ← typeName;

Notify[notify,after];

IF event#NIL THEN UndoEvent.Note[event,UndoChangeType,notify] };

UndoChangeType: PROC [undoRef: REF, currentEvent: Event] = TRUSTED {

saved: REF Change ← NARROW[undoRef];

WITH x:saved SELECT FROM

ChangingType => ChangeType[x.node,x.oldTypeName,currentEvent,x.root];

ENDCASE => ERROR };

prefixAtom: ATOM = npI.PrefixAtom[];

prefixName: ROPE = npI.PrefixName[];

ChangeStyle: PUBLIC PROC [node: Ref, name: ROPE, event: Event ← NIL, root: Ref ← NIL] = {

newprefix: ROPE;

IF node=NIL THEN RETURN;

IF RopeEdit.Size[name] > 0 THEN

newprefix ← RopeEdit.Concat["\"",RopeEdit.Concat[name,"\" style"]];

PutProp[node,prefixName,newprefix,event,root] };

PutProp: PUBLIC PROC [node: Ref, name: ROPE, value: REF, event: Event ← NIL, root: Ref ← NIL] = {

notify: REF ChangingProp Change;

key: ATOM;

oldval: REF;

IF node=NIL THEN RETURN;

IF root=NIL THEN root ← TextNode.Root[node];

key ← Atom.MakeAtom[name];

IF (oldval ← npI.GetProp[node,key]) = value THEN RETURN;

notify ← TextNode.pZone.NEW[ChangingProp Change ←

[ChangingProp[root,node,name,key,value,oldval]]];

Notify[notify,before];

npI.PutProp[node,key,value];

Notify[notify,after];

IF event#NIL THEN UndoEvent.Note[event,UndoPutProp,notify] };

UndoPutProp: PROC [undoRef: REF, currentEvent: Event] = TRUSTED {

saved: REF Change ← NARROW[undoRef];

WITH x:saved SELECT FROM

ChangingProp => PutProp[x.node,x.propName,x.oldval,currentEvent,x.root];

ENDCASE => ERROR };

GetProp: PUBLIC PROC [node: Ref, name: ROPE] RETURNS [value: REF] = {

key: ATOM;

IF node=NIL THEN RETURN;

key ← Atom.MakeAtom[name];

RETURN [npI.GetProp[node,key]] };

-- **** Fetch info operations ****

Fetch: PUBLIC PROC [text: RefTextNode, index: Offset] RETURNS [CHAR, Looks] = {

-- fetches the indexed information

-- use readers if want info from contiquous locations

RETURN [RopeEdit.Fetch[text.rope,index],

TextLooks.FetchLooks[text.runs,index]] };

FetchChar: PUBLIC PROC [text: RefTextNode, index: Offset] RETURNS [CHAR] = {

-- fetches the indexed information

-- use readers if want info from contiquous locations

RETURN [RopeEdit.Fetch[text.rope,index]] };

FetchLooks: PUBLIC PROC

[text: RefTextNode, index: Offset] RETURNS [Looks] = {

-- returns the looks for the character at the given location

-- use reader's if getting looks for sequence of locations

RETURN [TextLooks.FetchLooks[text.runs,index]] };

GetRope: PUBLIC PROC [text: RefTextNode] RETURNS [ROPE] =

{ RETURN [IF text=NIL THEN NIL ELSE text.rope] };

GetRuns: PUBLIC PROC [text: RefTextNode] RETURNS [Runs] =

{ RETURN [IF text=NIL THEN NIL ELSE text.runs] };

Size: PUBLIC PROC [text: RefTextNode] RETURNS [Offset] =

{ RETURN [IF text=NIL THEN 0 ELSE RopeEdit.Size[text.rope]] };

-- **** Operations to create a text node ****

FromRope: PUBLIC PROC [rope: ROPE] RETURNS [new: RefTextNode] = {

-- create a text node with looks from a normal rope

new ← TextNode.NewTextNode[];

new.rope ← rope; new.last ← TRUE;

new.runs ← TextLooks.CreateRun[RopeEdit.Size[rope]] };

FromString: PUBLIC PROC [string: REF READONLY TEXT]

RETURNS [new: RefTextNode] = {

-- copies the contents of the string

new ← TextNode.NewTextNode[]; new.last ← TRUE;

new.rope ← RopeFrom.String[string];

new.runs ← TextLooks.CreateRun[RopeEdit.Size[new.rope]] };

DocFromNode: PUBLIC PROC [child: Ref] RETURNS [new: Ref] = {

new ← TextNode.NewTextNode[];

new.child ← child; new.last ← TRUE;

child.next ← new; child.last ← TRUE };

-- ***** Cap's and Lowercase

ChangeCaps: PUBLIC PROC [

root: Ref,

dest: RefTextNode, start: Offset ← 0, len: Offset ← MaxLen,

how: CapChange ← allCaps, event: Event ← NIL] = {

notify: REF ChangingText Change;

oldRope, destRope: ROPE;

rdr: RopeReader.Ref;

initCap: BOOLEAN ← TRUE;

destSize: Offset;

alreadysaved: BOOLEAN;

IF dest=NIL THEN RETURN;

destSize ← RopeEdit.Size[oldRope ← destRope ← dest.rope];

start ← MIN[MAX[0,start],destSize];

IF (len ← MIN[MAX[0,len],destSize-start])=0 THEN RETURN;

notify ← IF (alreadysaved ← AlreadySaved[dest,event]) THEN Alloc[]

ELSE TextNode.pZone.NEW[ChangingText Change];

notify^ ← [ChangingText[root,dest,start,len,len,destRope,dest.runs]];

Notify[notify,before];

rdr ← RopeReader.GetRopeReader[];

UNTIL len=0 DO

c: CHAR;

maxText: NAT = 1000;

num: NAT ← MIN[len, maxText];

new: REF TEXT ← TextNode.pZone.NEW[TEXT[num]];

RopeReader.SetPosition[rdr,destRope,start];

SELECT how FROM

firstCap => IF num > 0 THEN {

new[0] ← RopeEdit.UpperCase[RopeReader.Get[rdr]];

FOR i:NAT IN [1..num) DO

new[i] ← RopeEdit.LowerCase[RopeReader.Get[rdr]];

ENDLOOP };

allCaps => FOR i:NAT IN [0..num) DO

new[i] ← RopeEdit.UpperCase[RopeReader.Get[rdr]];

ENDLOOP;

allLower => FOR i:NAT IN [0..num) DO

new[i] ← RopeEdit.LowerCase[RopeReader.Get[rdr]];

ENDLOOP;

initCaps => {

init: BOOLEAN ← TRUE;

FOR i:NAT IN [0..num) DO

SELECT c ← RopeReader.Get[rdr] FROM

IN ['a..'z] => {

new[i] ← IF init THEN c-40B ELSE c; -- force first upper

init ← FALSE };

IN ['A..'Z] => {

new[i] ← IF init THEN c ELSE c+40B; -- force others lower

init ← FALSE };

ENDCASE => {

new[i] ← c;

init ← c # '\' AND ~RopeEdit.AlphaNumericChar[c] };

ENDLOOP };

ENDCASE => ERROR;

new.length ← num;

destRope ← RopeEdit.ReplaceByString[destRope,new,0,num,start,num,destSize];

IF RopeEdit.Size[destRope] # destSize THEN ERROR;

len ← len-num; start ← start+num;

ENDLOOP;

dest.rope ← destRope;

RopeReader.FreeRopeReader[rdr];

Notify[notify,after];

IF alreadysaved THEN Free[notify]

ELSE UndoEvent.Note[event,UndoChangeText,notify] };

-- ***** Miscellaneous

BumpCount: PROC [text: RefTextNode] = {

countLimit: Offset ← 20;

count: [0..TextNode.countMax];

IF text=NIL THEN RETURN;

IF(count←text.count) = TextNode.countMax OR (text.count ← count+1) >= countLimit THEN

-- see if need to flatten

IF Flatten[text] THEN text.count ← 0

ELSE text.count ← text.count/2 };

maxRopeDepth: Offset;

debug: BOOL ← FALSE;

Flatten: PUBLIC PROC [text: RefTextNode] RETURNS [BOOLEAN] = {

ropeSize, ropePieces, ropeDepth: Offset;

looksSize, looksPieces, looksDepth: Offset;

ropeFlag, looksFlag: BOOLEAN;

rope: ROPE ← text.rope;

runs: Runs ← text.runs;

[ropeSize,ropePieces,ropeDepth] ← RopeEdit.RopeStats[rope];

[looksSize,looksPieces,looksDepth] ← TextLooks.LooksStats[runs];

-- size = # of characters

-- pieces = # terminal nodes in tree

-- depth = max depth of tree

IF ropeSize=0 AND looksSize=0 THEN RETURN [FALSE];

IF ropeDepth > maxRopeDepth THEN maxRopeDepth ← ropeDepth; -- for debugging

ropeFlag ← (ropePieces > 20 AND ropeSize < 5*ropePieces) OR ropeDepth > 100 OR

(SELECT ropePieces/8 FROM

< 2 => ropeDepth/4 > ropePieces,

< 6 => ropeDepth/2 > ropePieces,

< 12 => ropeDepth > ropePieces,

ENDCASE => ropeDepth > ropePieces/2);

looksFlag ← (looksPieces > 20 AND looksSize < 5*looksPieces) OR looksDepth > 100 OR

(SELECT looksPieces/8 FROM

< 2 => looksDepth/4 > looksPieces,

< 6 => looksDepth/2 > looksPieces,

< 12 => looksDepth > looksPieces,

ENDCASE => looksDepth > looksPieces/2);

IF ropeFlag OR looksFlag THEN {

IF debug THEN {

CheckNode.CheckRope[rope];

CheckNode.CheckRuns[runs] };

text.rope ←

IF ropeSize > 256 THEN RopeEdit.SemiFlatten[rope]

ELSE RopeEdit.Flatten[rope];

text.runs ← TextLooks.Flatten[runs];

IF debug THEN {

CheckNode.CheckRope[text.rope];

CheckNode.CheckRuns[text.runs] };

RETURN [TRUE] };

RETURN [FALSE] };

AlreadySaved: PUBLIC PROC [text: RefTextNode, event: Event] RETURNS [BOOLEAN] = TRUSTED {

-- returns TRUE if there is already a ChangingText record for given node in the event

IF event = NIL THEN RETURN [TRUE];

FOR l: UndoEvent.SubEvent ← event.subevents, l.next UNTIL l=NIL DO

IF l.undoRef # NIL THEN

WITH x: l.undoRef SELECT FROM

ChangingText => IF x.text = text THEN RETURN[TRUE];

ENDCASE;

ENDLOOP;

RETURN [FALSE] };

-- ***** Initialization

Start: PUBLIC PROC = {

};

END.