[Cyan]<Cedar6.0>Tioga>TextNode.mesa!3

TextNode.mesa

written by Bill Paxton. December 1980

last written by Paxton. December 21, 1982 9:46 am

Last Edited by: Maxwell, January 5, 1983 12:37 pm

Rick Beach, March 27, 1985 1:08:21 pm PST

Michael Plass, March 26, 1985 12:18:42 pm PST

Doug Wyatt, March 2, 1985 3:27:50 pm PST

DIRECTORY

Rope USING [ROPE],

TextLooks USING [Runs];

TextNode: CEDAR DEFINITIONS

= BEGIN

Offset: TYPE = INT ← 0;

MaxLen: INT = LAST[INT];

ROPE: TYPE = Rope.ROPE;

Ref: TYPE = REF Body;

RefTextNode: TYPE = Ref; -- a synonym for backwards compatibility.

Body: TYPE = RECORD [

next: Ref, -- points to next sibling, or if last=true, to parent

child: Ref, -- points to first child, if any, of this node

props: NodeProps, -- points to node property list

formatName: ATOM ← NIL, -- name of format for the node

last: BOOL ← FALSE, -- true if this is last sibling

hasstyledef: BOOL ← FALSE, -- true if node has StyleDef prop (accelerator)

hasprefix: BOOL ← FALSE, -- true if node has Prefix prop (accelerator)

haspostfix: BOOL ← FALSE, -- true if node has Postfix prop (accelerator)

hascharprops: BOOL ← FALSE, -- true if node has CharProps prop (accelerator)

hascharsets: BOOL ← FALSE, -- true if node has CharSets prop (accelerator)

hasartwork: BOOL ← FALSE, -- true if node has Artwork prop (accelerator)

deleted: BOOL ← FALSE, -- true if has been deleted or is root pending delete

dirty: BOOL ← FALSE, -- true if has been edited (contents, or children moved, inserted, ...)

new: BOOL ← FALSE, -- true if created during this editing session (i.e., not from file)

comment: BOOL ← FALSE, -- true if node is a comment

count: [0..countMax] ← 0, -- incremented by text edit routines

rope: ROPE,

runs: TextLooks.Runs

];

Location: TYPE = RECORD [node: Ref, where: INT];

where >= length of text means at end

where = loc in [0..length) means before that character

e.g., where = 0 means at start of text

where = NodeItself means location is the node itself rather than in its contents

NodeItself: INT = -1;

nullLocation: Location = [node: NIL, where: NodeItself];

MakeNodeLoc: PROC [n: Ref] RETURNS [Location];

Span: TYPE = RECORD [start, end: Location ← nullLocation];

start.node can equal end.node

in which case either both start.where and end.where = NodeItself, or

neither do and start.where <= end.where

otherwise, end.node should follow start.node in the tree

nodes need not be siblings

no restrictions on start.where or end.where

nullSpan: Span = [nullLocation,nullLocation];

MakeNodeSpan: PROC [first, last: Ref] RETURNS [Span];

countMax: NAT = 31; -- 5 bits for count

OfNode: TYPE = {text, other};

NodeList: TYPE = REF NodeListBody;

NodeListBody: TYPE = RECORD [node: Ref, next: NodeList];

NodeProps: TYPE = REF NodePropsBody;

NodePropsBody: TYPE; -- exported by NodePropsImpl

NewTextNode: PROC RETURNS [txt: RefTextNode];

NarrowToTextNode: PROC [n: Ref] RETURNS [txt: RefTextNode];

For backwards compatability.

Parent: PROC [n: Ref] RETURNS [Ref];

Root: PROC [n: Ref] RETURNS [Ref];

Next: PROC [n: Ref] RETURNS [Ref];

returns next sibling of n

returns NIL if n is last sibling

Previous: PROC [n: Ref, parent: Ref ← NIL] RETURNS [nx: Ref];

returns previous sibling of n

returns NIL if n is first sibling

runs faster if can supply parent

Forward: PROC [node: Ref] RETURNS [nx: Ref, levelDelta: INTEGER];

returns next node in standard tree walk order

levelDelta is level(node)-level(nx), where level is depth in tree

levelDelta = 0 if nx and node are siblings

levelDelta = 1 if nx is child of node

levelDelta < 0 if do Parent* and Next to reach nx from node

Backward: PROC [node: Ref, parent: Ref ← NIL]

RETURNS [back, backparent: Ref, levelDelta: INTEGER];

for backing through tree

runs faster if can supply parent

levelDelta same as for Forward

StepForward: PROC [node: Ref] RETURNS [Ref];

returns next node in standard tree walk order

StepBackward: PROC [node: Ref, parent: Ref ← NIL] RETURNS [Ref];

returns preceding node in standard tree walk order

Level: PROC [node: Ref] RETURNS [level: INTEGER];

Level[Root[x]] == 0; Level[FirstChild[n]]=Level[n]+1

ForwardClipped: PROC [node: Ref, maxLevel: INTEGER, nodeLevel: INTEGER ← 0] RETURNS [nx: Ref, nxLevel: INTEGER];

like Forward, but limits how deep will go in tree

if pass nodeLevel=0, correct value will be computed

nxLevel = Level[nx] <= MAX[maxLevel,Level[node]]

BackwardClipped: PROC [node: Ref, maxLevel: INTEGER, parent: Ref ← NIL,
nodeLevel: INTEGER ← 0] RETURNS [back, backparent: Ref, backLevel: INTEGER];

like Backward, but limits how deep will go in tree

backLevel = Level[back] <= MAX[maxLevel,Level[node]]

LocRelative: PROC [location: Location, count: INT,
break: NAT ← 1, skipCommentNodes: BOOL ← FALSE] RETURNS [Location];

count is interpreted as a character offset from given location

returns <node,offset> location corresponding to count

adds in break at the end of each text subnode

if skipCommentNodes is true, then ignores them in walking the tree

LocWithin: PROC [n: Ref, count: INT, break: NAT ← 1, skipCommentNodes: BOOL ← FALSE] RETURNS [Location];

LocOffset: PROC [loc1, loc2: Location, break: NAT ← 1, skipCommentNodes: BOOL ← FALSE] RETURNS [count: INT];

returns character offset of location2 relative to location1

loc1 and loc2 can be in same node

but loc2 must not be in node before loc1 or get ERROR BadArgs

if skipCommentNodes is true, then ignores them in walking the tree

BadArgs: ERROR;

LocNumber: PROC [at: Location, break: NAT ← 1, skipCommentNodes: BOOL ← FALSE] RETURNS [count: INT];

returns character offset of location relative to root

FirstSibling: PROC [n: Ref] RETURNS [Ref];

LastSibling: PROC [n: Ref] RETURNS [Ref];

LastWithin: PROC [n: Ref] RETURNS [Ref];

returns the last node within the branch

i.e., goes to last child of last child of last child ... until no child

LastLocWithin: PROC [n: Ref] RETURNS [Location];

returns the last location within the branch

FirstChild: PROC [n: Ref] RETURNS [Ref];

LastChild: PROC [n: Ref] RETURNS [Ref];

NthChild: PROC [n: Ref, location: INT ← 0] RETURNS [child: Ref];

NthSibling: PROC [n: Ref, cnt: INT ← 0] RETURNS [Ref];

CountChildren: PROC [n: Ref] RETURNS [count: INT];

CountFollowing: PROC [n: Ref] RETURNS [count: INT];

CountToParent: PROC [n: Ref] RETURNS [count: INT, parent: Ref];

CountToChild: PROC [parent, child: Ref] RETURNS [count: INT];

NodeRope: PROC [n: RefTextNode] RETURNS [ROPE];

NodeRuns: PROC [n: RefTextNode] RETURNS [TextLooks.Runs];

Props: PROC [n: Ref] RETURNS [NodeProps];

NodeFormat: PROC [n: Ref] RETURNS [ATOM];

IsLastSibling: PROC [n: Ref] RETURNS [BOOL];

EndPos: PROC [n: Ref] RETURNS [INT];

END.