Syntax10.Scn.Fnt
StampElems
Alloc
22 Apr 96
Syntax10b.Scn.Fnt
Syntax10i.Scn.Fnt
MarkElems
Alloc
MODULE LinkElems;  (** HM 
IMPORT
	Files, Fonts, Display, Input, Viewers, Texts, TextFrames, MenuViewers, TextPrinter, Oberon, PopupElems, MarkElems, FoldElems;
CONST
	left =2; middle = 1; right = 0;
	pixel = LONG(10000);
	stdMenu = "System.Close  System.Copy  System.Grow  Edit.Search  Edit.Replace  Edit.Store ";
	Elem* = POINTER TO ElemDesc;
	ElemDesc* = RECORD (Texts.ElemDesc)
		file*: ARRAY 32 OF CHAR;
		key*: LONGINT
	END ;
	FollowMsg* = RECORD (Texts.ElemMsg) f*: Display.Frame END ;
	Menu* = POINTER TO MenuDesc;
	MenuDesc* = RECORD (PopupElems.ElemDesc)
	END ;
	Frame = POINTER TO FrameDesc;
	FrameDesc = RECORD (TextFrames.FrameDesc)
		e: Elem
	END ;
	searchKey: LONGINT;	(*key of mark element searched in FollowLink; used in Check*)
	hint: TextFrames.Frame;	(*suggests frame to be used for links emanating from a link menu*)
	icon, invIcon: Display.Pattern; (* x = 0, y = 3, w = 9, h = 8 *)
	w: Texts.Writer;
PROCEDURE^ New* (file: ARRAY OF CHAR; key: LONGINT): Elem;
PROCEDURE 
GetSelection (VAR f: TextFrames.Frame);
	(* return frame f with the latest text selection*)
	VAR v: Viewers.Viewer; f0: Display.Frame; time: LONGINT; x: INTEGER;
BEGIN
	x := 0; time := -1; f := NIL;
	WHILE x < Display.Width DO
		v := Viewers.This(x, 0);
		WHILE v.state > 1 DO
			f0 := v.dsc;
			WHILE f0 # NIL DO
				WITH f0: TextFrames.Frame DO
					IF f0.hasSel & (f0.time > time) THEN f := f0; time := f.time END
				ELSE
				END ;
				f0 := f0.next
			END ;
			v := Viewers.Next(v)
		END ;
		x := x + v.W
END GetSelection;
PROCEDURE 
GetFileName (t: Texts.Text; VAR name: ARRAY OF CHAR);
	(* return the name of the viewer which contains text t*)
	VAR v, V: Viewers.Viewer; f: Display.Frame; s: Texts.Scanner; x: INTEGER;
BEGIN
	V := NIL; x := 0;
	WHILE x < Display.Width DO
		v := Viewers.This(x, 0);
		WHILE v.state > 1 DO
			f := v.dsc;
			WHILE f # NIL DO
				IF (f IS TextFrames.Frame) & (f(TextFrames.Frame).text = t) THEN V := v END ;
				f := f.next
			END ;
			v := Viewers.Next(v)
		END ;
		x := x + v.W
	END ;
	IF V # NIL THEN
		Texts.OpenScanner(s, V.dsc(TextFrames.Frame).text, 0); Texts.Scan(s);
		IF s.class IN {Texts.Name, Texts.String} THEN COPY(s.s, name) ELSE name[0] := 0X END
END GetFileName;
PROCEDURE 
GetFrame (name: ARRAY OF CHAR; VAR f: TextFrames.Frame);
	VAR x: INTEGER; v: Viewers.Viewer; s: Texts.Scanner;
BEGIN
	IF hint # NIL THEN f := hint
	ELSE
		x := 0; f := NIL;
		WHILE x < Display.Width DO
			v := Viewers.This(x, 0);
			WHILE v.state > 1 DO
				IF (v.dsc # NIL) & (v.dsc IS TextFrames.Frame) THEN
					Texts.OpenScanner(s, v.dsc(TextFrames.Frame).text, 0); Texts.Scan(s);
					IF s.s = name THEN f := v.dsc.next(TextFrames.Frame); RETURN END
				END ;
				v := Viewers.Next(v)
			END ;
			x := x + v.W
		END
END GetFrame;
PROCEDURE 
GetDsr (f: Display.Frame; pos: LONGINT; fnt: Fonts.Font; VAR dsr: INTEGER);
	VAR p: TextFrames.Parc; beg: LONGINT;
BEGIN
	IF f = NIL THEN
		IF fnt = NIL THEN dsr := 0 ELSE dsr := - fnt.minY END
	ELSE
		TextFrames.ParcBefore(f(TextFrames.Frame).text, pos, p, beg);
		dsr := SHORT(p.dsr DIV TextFrames.Unit)
END GetDsr;
PROCEDURE 
CollectMarks (pop: Menu; f0: Display.Frame);
	(* Fill popup menu with all mark elements in f0.next.text*)
	VAR r: Texts.Reader; s: Texts.Scanner; ch: CHAR; f: TextFrames.Frame; mark: MarkElems.Elem; link: Elem; n: INTEGER;
		file: ARRAY 32 OF CHAR;
BEGIN
	pop.menu := TextFrames.Text("");
	IF (f0.next = NIL) OR ~ (f0.next IS TextFrames.Frame) THEN
		Texts.WriteString(w, "link menu not in menu bar of a text viewer"); Texts.WriteLn(w); Texts.WriteLn(w)
	ELSE
		f := f0.next(TextFrames.Frame); hint := f; GetFileName(f.text, file); n := 0;
		Texts.OpenReader(r, f.text, 0); Texts.ReadElem(r);
		WHILE ~ r.eot DO
			IF r.elem IS MarkElems.Elem THEN
				mark := r.elem(MarkElems.Elem);
				link := New(file, mark.key);
				Texts.WriteElem(w, link); Texts.Write(w, " ");
				Texts.OpenScanner(s, f.text, Texts.Pos(r)); Texts.Scan(s);
				WHILE ~s.eot & (s.class # Texts.Name) DO Texts.Scan(s) END ;
				IF ~s.eot THEN Texts.WriteString(w, s.s); Texts.WriteLn(w); INC(n)
				END
			END ;
			Texts.ReadElem(r)
		END ;
		IF n = 0 THEN Texts.WriteString(w, "no marks"); Texts.WriteLn(w) END ;
		IF n <= 1 THEN Texts.WriteLn(w) END ;
	END ;
	Texts.Append(pop.menu, w.buf); PopupElems.MeasureMenu(pop)
END CollectMarks;
PROCEDURE 
ShowPos (f: TextFrames.Frame; pos: LONGINT);
	VAR beg, end, delta: LONGINT;
BEGIN delta := 200;
	LOOP beg := f.org; end := TextFrames.Pos(f, f.X + f.W, f.Y);
		IF (beg <= pos) & (pos < end) OR (delta = 0) THEN EXIT END ;
		TextFrames.Show(f, pos - delta); delta := delta DIV 2
	END ;
	TextFrames.SetSelection(f, pos, pos + 1)
END ShowPos;
PROCEDURE 
Check (e: Texts.Elem): BOOLEAN;
BEGIN RETURN (e IS MarkElems.Elem) & (e(MarkElems.Elem).key = searchKey)
END Check;
PROCEDURE 
FollowLink* (file: ARRAY OF CHAR; key: LONGINT; backF: Display.Frame; backE: Texts.Elem);
	VAR v: Viewers.Viewer; menu: TextFrames.Frame; x, y: INTEGER; t: Texts.Text; buf: Texts.Buffer;
		mark: Texts.Elem; f: TextFrames.Frame;
BEGIN
	GetFrame(file, f);
	IF f = NIL THEN
		f := TextFrames.NewText(TextFrames.Text(file), 0);
		Oberon.AllocateUserViewer(Oberon.Mouse.X, x, y);
		IF Files.Old("Edit.Menu.Text") = NIL THEN menu := TextFrames.NewMenu(file, stdMenu)
		ELSE menu := TextFrames.NewMenu(file, "");
			NEW(t); Texts.Open(t, "Edit.Menu.Text");
			NEW(buf); Texts.OpenBuf(buf); Texts.Save(t, 0, t.len, buf); Texts.Append(menu.text, buf)
		END ;
		v := MenuViewers.New(menu, f, TextFrames.menuH, x, y)
	END ;
	searchKey := key;
	FoldElems.FindElem(f.text, 0, Check, mark);
	IF mark # NIL THEN
		ShowPos(f, Texts.ElemPos(mark));
		IF backF # NIL THEN MarkElems.backF := backF(TextFrames.Frame) ELSE MarkElems.backF := NIL END ;
		MarkElems.backE := backE
END FollowLink;
PROCEDURE 
Edit (e: Elem);
	VAR t: Texts.Text; v: MenuViewers.Viewer; f: Frame; x, y: INTEGER;
BEGIN
	t := TextFrames.Text("");
	Texts.WriteString(w, e.file); Texts.Write(w, " "); Texts.WriteInt(w, e.key, 0);
	Texts.Append(t, w.buf);
	NEW(f); f.e := e; TextFrames.Open(f, t, 0);
	Oberon.AllocateSystemViewer(0, x, y);
	v := MenuViewers.New(
		TextFrames.NewMenu("LinkElem", "System.Close  LinkElems.Update "),
		f, TextFrames.menuH, x, y)
END Edit;
PROCEDURE 
Handle* (e: Texts.Elem; VAR m: Texts.ElemMsg);
	VAR e1: Elem; x, y, dsr, i: INTEGER; keys: SET; ch: CHAR; follow: FollowMsg;
BEGIN
	WITH e: Elem DO
		WITH m: Texts.FileMsg DO
			IF m.id = Texts.load THEN
				i := 0; REPEAT Files.Read(m.r, ch); e.file[i] := ch; INC(i) UNTIL ch = 0X;
				Files.ReadLInt(m.r, e.key)
			ELSE (*Texts.store*)
				i := 0; REPEAT ch := e.file[i]; Files.Write(m.r, ch); INC(i) UNTIL ch = 0X;
				Files.WriteLInt(m.r, e.key)
			END
		| m: Texts.CopyMsg DO
			IF m.e = NIL THEN NEW(e1); m.e := e1 ELSE e1 := m.e(Elem) END ;
			Texts.CopyElem(e, e1); COPY(e.file, e1.file); e1.key := e.key
		| m: Texts.IdentifyMsg DO
			m.mod := "LinkElems"; m.proc := "Alloc"
		| m: TextFrames.DisplayMsg DO
			IF ~m.prepare THEN
				GetDsr(m.frame, m.pos, m.fnt, dsr);
				Display.CopyPattern(Display.white, icon, m.X0, m.Y0+dsr, Display.paint)
			END
		| m: TextPrinter.PrintMsg DO
			IF m.prepare THEN e.W := 1 ELSE e.W := 10 * pixel END
		| m: TextFrames.TrackMsg DO
				IF middle IN m.keys THEN
					IF m.frame # NIL THEN
						GetDsr(m.frame, m.pos, m.fnt, dsr);
						Display.CopyPattern(Display.white, icon, m.X0, m.Y0+dsr, Display.invert);
						Display.CopyPattern(Display.white, invIcon, m.X0, m.Y0+dsr, Display.invert);
						REPEAT Input.Mouse(keys, x, y); m.keys := m.keys + keys;
							Oberon.DrawCursor(Oberon.Mouse, Oberon.Arrow, x, y)
						UNTIL keys = {};
						Display.CopyPattern(Display.white, invIcon, m.X0, m.Y0+dsr, Display.invert);
						Display.CopyPattern(Display.white, icon, m.X0, m.Y0+dsr, Display.invert)
					END ;
					IF m.keys = {middle} THEN follow.f := m.frame; e.handle(e, follow)
					ELSIF m.keys = {middle, right} THEN Edit(e)
					END
				END
		| m: FollowMsg DO
			FollowLink(e.file, e.key, m.f, e)
		ELSE
		END
END Handle;
PROCEDURE 
HandleMenu* (e: Texts.Elem; VAR m: Texts.ElemMsg);
	VAR e1: Menu;
BEGIN
	WITH e: Menu DO
		WITH
		  m: Texts.IdentifyMsg DO
			m.mod := "LinkElems"; m.proc := "AllocMenu"
		| m: Texts.CopyMsg DO
			NEW(e1); m.e := e1; PopupElems.Handle(e, m)
		| m: TextFrames.DisplayMsg DO
			IF m.prepare THEN
				e.W := 13 * pixel; e.H := LONG(TextFrames.menuH-1) * pixel;
			ELSE e.name := ""; PopupElems.Handle(e, m);
				Display.CopyPattern(Display.white, icon, m.X0+2, m.Y0+3, Display.paint)
			END
		| m: TextFrames.TrackMsg DO
			IF middle IN m.keys THEN
				CollectMarks(e, m.frame); PopupElems.Handle(e, m); hint := NIL
			END
		ELSE PopupElems.Handle(e, m)
		END
END HandleMenu;
PROCEDURE 
Alloc*;
	VAR e: Elem;
BEGIN
	NEW(e); e.handle := Handle; Texts.new := e
END Alloc;
PROCEDURE 
AllocMenu*;
	VAR e: Menu;
BEGIN
	NEW(e); e.handle := HandleMenu; Texts.new := e
END AllocMenu;
PROCEDURE 
New* (file: ARRAY OF CHAR; key: LONGINT): Elem;
	VAR e: Elem;
BEGIN
	NEW(e); e.W := 10 * pixel; e.H := 11 * pixel; e.handle := Handle; COPY(file, e.file); e.key := key;
	RETURN e
END New;
PROCEDURE 
Insert*;
	VAR link: Elem; mark: MarkElems.Elem; fromT, toT: Texts.Text; toPos, end, time: LONGINT;
		r: Texts.Reader; ch: CHAR; m: TextFrames.InsertElemMsg; f: TextFrames.Frame;
BEGIN
	f := Oberon.FocusViewer.dsc(TextFrames.Frame);
	IF f.hasCar THEN fromT := f.text ELSE fromT := f.next(TextFrames.Frame).text END ;
	Oberon.GetSelection(toT, toPos, end, time);
	IF time >= 0 THEN
		link := New("", 0); GetFileName(toT, link.file);
		Texts.OpenReader(r, toT, toPos); Texts.Read(r, ch);
		m.e := link; Viewers.Broadcast(m);
		IF (ch = Texts.ElemChar) & (r.elem IS MarkElems.Elem) THEN
			link.key := r.elem(MarkElems.Elem).key
		ELSE
			IF (fromT = toT) & (Texts.ElemPos(link) <= toPos) THEN INC(toPos) END ;
			mark := MarkElems.New(); link.key := mark.key;
			Texts.WriteElem(w, mark); Texts.Insert(toT, toPos, w.buf)
		END
END Insert;
PROCEDURE 
InsertMenu*;
	VAR e: Menu; insert: TextFrames.InsertElemMsg;
BEGIN
	NEW(e); e.handle := HandleMenu; e.name := ""; e.menu := TextFrames.Text(""); e.small := TRUE;
	PopupElems.MeasureMenu(e);
	insert.e := e; Viewers.Broadcast(insert)
END InsertMenu;
PROCEDURE 
Update*;
	VAR f: Frame; t: Texts.Text; s: Texts.Scanner; r: Texts.Reader; ch: CHAR;
BEGIN
	IF (Oberon.Par.frame = Oberon.Par.vwr.dsc) & (Oberon.Par.frame.next IS Frame) THEN
		f := Oberon.Par.frame.next(Frame);
		Texts.OpenScanner(s, f.text, 0); Texts.Scan(s);
		IF s.class = Texts.Name THEN
			COPY(s.s, f.e.file); Texts.Scan(s);
			IF s.class = Texts.Int THEN
				f.e.key := s.i;
				t := Oberon.Par.frame(TextFrames.Frame).text;
				Texts.OpenReader(r, t, t.len-1); Texts.Read(r, ch);
				IF ch = "!" THEN Texts.Delete(t, t.len-1, t.len) END
			END
		END
END Update;
PROCEDURE 
InitIcon;
	VAR line: ARRAY 9 OF SET;
BEGIN
	line[8] := {4};
	line[7] := {3, 5};
	line[6] := {2, 6};
	line[5] := {1..3, 5..7};
	line[4] := {3, 5};
	line[3] := {3, 5};
	line[2] := {3, 5};
	line[1] := {3..5};
	icon := Display.NewPattern(line, 9, 8);
	line[8] := {4};
	line[7] := {3..5};
	line[6] := {2..6};
	line[5] := {1..7};
	line[4] := {3..5};
	line[3] := {3..5};
	line[2] := {3..5};
	line[1] := {3..5};
	invIcon := Display.NewPattern(line, 9, 8)
END InitIcon;
BEGIN
	Texts.OpenWriter(w);
	InitIcon;
	hint := NIL
END LinkElems.