Oberon/A2/Oberon.Gadgets.Mod

(* ETH Oberon, Copyright 2001 ETH Zuerich Institut fuer Computersysteme, ETH Zentrum, CH-8092 Zuerich. Refer to the "General ETH Oberon System Source License" contract available at: http:&#47;/www.oberon.ethz.ch/ *) MODULE Gadgets IN Oberon;	(** portable *) (*, jm 18.1.95*) (**The Gadgets module forms the basis of the Gadgets system. It defines the most important types, provide default message handlers and often used utility procedures. In addition, a few gadget specific messages are defined. *) (* 	jm 9.2.93 - Attributes for abstract objects 		- object name belongs intrinsically to objects 		- support for non gadget frames removed 	jm 10.2.93 - support for empty object names 		- fixed attributes for abstract objects 	jm 11.2.93 - Display.ControlMsg 		- moved mask messages to Display3 	jm 15.3.93 - Better creation of default clip masks 	jm 16.3.93 - ReadRef bug 	jm 17.3.93 - Add context to executor dlink when executing a command 	jm 23.2.93 - Fixed semantics of Oberon.Par.obj & Oberon.Par.frame 	jm 24.2.93 - Warning thrown out 	jm 24.2.93 - Gadgets.Execute hack 	jm 2.3.93 - Notes removed 	jm 3.3.93 - ExecuteAttr corrected 	jm 10.3.93 - fix version message 	jm 11.3.93 - Call error correction 	7.4.93 - Introduced editing platform code 	8.4.93 - removed edit platform code 	23.7.93 - fixed copy object 	17.09.93 15:09:48 - Find message 	06.01.94 - improved handling of UpdateMsg slightly 29.3.94 - Broadcast removed - Fixed UpArrow macro 5.4.94 - fixed unnaming of objects in public libraries 19.4.94 - added aliasing support to Insert, removed aliasing from Attributes.Scanner 19.4.94 - Improved lookup macro 20.4.94 - added visible constant 27.5.94 - improved track highlight in track frame 29.6.94 - Added alias support to Change* 14.7.94 - added some more debug tests for invalid masks, most are deactivated now, search for debug 18.7.94 - changed object naming 3.11.94 - unchanged change of 18.7.94 7.11.94 - unchanged change of 18.7.94 8.11.94 - changed rules in IsLocked 29.11.94 		- removed optimization flags from Gadgets - removed nomove, noresize, nodelete, noselect flags from Gadgets - renamed lockchildren to locked 30.11.94 		- added lockedsize (same as noresize before) - renamed locked to lockedcontents 6.12.94 - added GetSelection 14.12.94 - CopyObject implemented 15.12.94 - removed col from Gadgets.Frame 16.12.94 - removed selection bug 21.12.94 - When no attribute exists on Objects.AttrMsg "get", nothing is returned. Previously an empty string was returned. 3.8.95 - load aliases from the Registry 6.12.95 - added ClipMask to Gadgets.ViewDesc (thanks ps) (changes the symbol file) 15.12.95 - CreateObject now uses Modules.resMsg 8.5.96 - fixed bug in Recursive 20.5.96 - CreateObject now understands aliases (ps - 20.5.96) 6.6.96 - changed Execute (light weight) 19.6.96 - fixed bug in new Execute 10.7.96 - added deep parameter to GetPublicObject (* ejz - 10.7.96 *) 4.8.96 - changed printer mask scaling to Printer.Frame 14.08.96 pjm - fix in UpArrowMacro for selected objects 18.2.97 - added ModifySize and Consume *) IMPORT 	Objects, Display, Display3, Effects, Oberon, Texts, Input, Files, Modules, 	Printer, Printer3, Attributes, Links, Viewers, Strings; CONST 	(** Priority message id's. *) 	top* = 0;		(** Move gadget to the front. *) 	bottom* = 1;		(** Move gadget to the back. *) 	visible* = 2;		(** Move gadget to the front if not completely visible. *) 	(** Gadget Frame states. *) 	selected* = 0;		(** Selected or not. *) 	lockedsize* = 2;		(** Gadget prefers a fixed W, H. *) 	transparent* = 4;		(** Transparent or not. *) 	lockedcontents* = 10;		(** All direct descendants are locked. *) 	left = 2; middle = 1; right = 0; TYPE 	(** Message broadcast in the display space to indicate that "obj" has changed. Normally used for updating model gadgets, although obj can be a list of gadget frames belonging to the same container. In this case all of the frames are to be displayed. This message is used by the Inspector to indicate that an attribute value has changed. *) 	UpdateMsg* = RECORD (Display.FrameMsg) 		obj*: Objects.Object; 	END; 	(** Message broadcast in the display space to indicate that the destination frame F wants to change its overlapping 	priority. *) 	PriorityMsg* = RECORD (Display.FrameMsg) 		id*: SIGNED16;	(** Top, bottom, visible. *) 		passon*: BOOLEAN;	(** Indication if a whole tree of containers should be changed in priority. *) 	END; 	CmdMsg* = RECORD (Objects.ObjMsg) 		cmd*: ARRAY 128 OF CHAR; (* Information to be passed, command to be executed; result returned. *) 		res*: SIGNED16; (* result code *) 	END; 	(** Base type of the Model gadgets *) 	Object* = POINTER TO ObjDesc; 	ObjDesc* = RECORD (Objects.ObjDesc) 		attr*: Attributes.Attr;	(** Attribute list. Private variable. *) 		link*: Links.Link (** Link list. Private variable. *) 	END; 	(** Base type of the visual gadgets *) 	Frame* = POINTER TO FrameDesc; 	FrameDesc* = RECORD (Display.FrameDesc) 		attr*: Attributes.Attr;	(** Attribute list. Private variable. *) 		link*: Links.Link; (** Link list. Private variable. *) 		state*: SET; 		mask*: Display3.Mask;	(** Cached display mask. Can be NIL to indicate no/invalid mask. *) 		obj*: Objects.Object	(** Model object, if any. *) 	END; 	(** Base type of the camera-view gadgets. *) 	View* = POINTER TO ViewDesc; 	ViewDesc* = RECORD (FrameDesc) 		absX*, absY*: SIGNED16;	(** Absolute screen position at last message forward to descendants. *) 		border*: SIGNED16;	(** Border width for clipping. *) 		(** Install own clipping to display/printer mask here if view has an irregular outline. Otherwise set to NIL. *) 		ClipMask*: PROCEDURE (v: View; M: Display3.Mask; ondisplay: BOOLEAN); 	END; 	(** Calculate a mask for gadget G positioned at X, Y in the context dlink. *) 	MakeMaskHandler* = PROCEDURE (G: Frame; X, Y: SIGNED16; dlink: Objects.Object; VAR M: Display3.Mask); 	RecursiveMsg = RECORD (Display.FrameMsg) END; 	Stack = RECORD 		Mdlink, Fdlink: Objects.Object; 		absX, absY: SIGNED16; 	END; CONST 	nameLen = 32; valueLen = 64; TYPE 	Alias = POINTER TO AliasDesc; 	AliasDesc = RECORD 		name: ARRAY nameLen OF CHAR; 		value: ARRAY valueLen OF CHAR; 		next: Alias; 	END; VAR 	framehandle*: Objects.Handler;	(** Default message handler for visual gadgets. *) 	objecthandle*: Objects.Handler;	(** Default message handler for Model gadgets. *) 	MakeMask*: MakeMaskHandler;	(** Calculates the current display mask of a visual gadget. *) 	MakePrinterMask*: MakeMaskHandler;	(** Calculates the current printer mask of a visual gadget. *) 	(** The following fields are used for parameter transfer during command execution. *) 	context*: Objects.Object;	(** Context/parent of a gadget executing the command *) 	executorObj*: Objects.Object;	(** Gadget executing the command. Same as Oberon.Par.obj. *) 	senderObj*: Objects.Object;	(** Initiator of a drag and drop operation i.e. the gadget being dropped. *) 	receiverObj*: Objects.Object;	(** Receiver of a dropped gadget. Often same as executorObj. *) 	aliases: Alias; 	par: Oberon.ParList; 	emptyText: Texts.Text; 	W, WW, mW: Texts.Writer; 	recurse, uparrowdone, verbose, enableMove: BOOLEAN; 	pMask: Display3.Mask; tmpX, tmpY: SIGNED16; (* Misc *) PROCEDURE Log; BEGIN Texts.Append(Oberon.Log, W.buf); END Log; PROCEDURE Push(VAR S: Stack; F: View; VAR M: Display.FrameMsg); BEGIN 	(* save old variables *) 	S.Fdlink := F.dlink; S.Mdlink := M.dlink; S.absX := F.absX; S.absY := F.absY; 	F.dlink := M.dlink; M.dlink := F END Push; PROCEDURE Pop(VAR S: Stack; F: View; VAR M: Display.FrameMsg); BEGIN 	M.dlink := S.Mdlink; F.dlink := S.Fdlink; F.absX := S.absX; F.absY := S.absY END Pop; (* general purpose *) (** Is the context/parent of the frame F locked ? *) PROCEDURE IsLocked*(F: Frame; dlink: Objects.Object): BOOLEAN; VAR A: Objects.AttrMsg; BEGIN 	IF dlink # NIL THEN 		IF dlink IS Frame THEN RETURN lockedcontents IN dlink(Frame).state 		ELSIF dlink.handle # NIL THEN (* not a frame *) 			A.id := Objects.get; A.name := "Locked"; A.res := -1; dlink.handle(dlink, A); 			RETURN (A.res >= 0) & (A.class = Objects.Bool) & A.b 		ELSE RETURN FALSE 		END 	ELSE RETURN FALSE 	END END IsLocked; (** Is the mouse located inside the work area of a gadget (i.e. excluding the control areas)? *) PROCEDURE InActiveArea*(F: Frame; VAR M: Oberon.InputMsg): BOOLEAN; VAR x, y, w, h: SIGNED16; BEGIN 	x := M.x + F.X; y := M.y + F.Y; w := F.W; h := F.H; 	IF Effects.Inside(M.X, M.Y, x, y, w, h) & ~(selected IN F.state) THEN 		IF IsLocked(F, M.dlink) THEN RETURN TRUE 		ELSIF Effects.InBorder(M.X, M.Y, x, y, w, h) THEN RETURN FALSE 		ELSE RETURN TRUE 		END 	ELSE RETURN FALSE 	END END InActiveArea; (** Returns the name of of obj. Sends an Objects.AttrMsg behind the scenes. *) PROCEDURE GetObjName*(obj: Objects.Object; VAR name: ARRAY OF CHAR); BEGIN 	Attributes.GetString(obj, "Name", name) END GetObjName; (** Name object obj. Sends an Objects.AttrMsg behind the scenes. *) PROCEDURE NameObj*(obj: Objects.Object; name: ARRAY OF CHAR); BEGIN 	Attributes.SetString(obj, "Name", name) END NameObj; (** Search for the object "O" in the public library "L.Lib" wherename is specified as "L.O". *) PROCEDURE FindPublicObj*(name: ARRAY OF CHAR): Objects.Object; (* Lib.obj format, assumes .Lib extension *) VAR obj: Objects.Object; libname, objname: ARRAY 64 OF CHAR; i, j, k, ref: SIGNED16; lib: Objects.Library; BEGIN 	obj := NIL; i := 0; j := 0; 	WHILE (name&#91;i] # ".") & (name&#91;i] # 0X) DO libname&#91;j] := name&#91;i]; INC(j); INC(i); END; 	IF name&#91;i] = 0X THEN RETURN NIL END; 	libname&#91;j] := 0X; k := j; INC(i); j := 0; 	WHILE (name&#91;i] # " ") & (name&#91;i] # 0X) DO objname&#91;j] := name&#91;i]; INC(j); INC(i); END; 	objname&#91;j] := 0X; 	libname&#91;k] := "."; libname&#91;k+1] := "L"; libname&#91;k+2] := "i"; libname&#91;k+3] := "b"; libname&#91;k+4] := 0X; 	lib := Objects.ThisLibrary(libname); 	IF lib # NIL THEN 		Objects.GetRef(lib.dict, objname, ref); 		IF ref # MIN(SIGNED16) THEN lib.GetObj(lib, ref, obj); END 	END; 	RETURN obj; END FindPublicObj; (** Search for object named name in context. *) PROCEDURE FindObj*(context: Objects.Object; name: ARRAY OF CHAR): Objects.Object; VAR obj: Objects.Object; M: Objects.FindMsg; BEGIN 	obj := NIL; 	IF context # NIL THEN (* search by find message *) 		M.obj := NIL; COPY(name, M.name); context.handle(context, M); 		obj := M.obj 	END; 	RETURN obj END FindObj; (** Sets new W and H to (offscreen) frame F. *) PROCEDURE ModifySize* (F: Display.Frame; W, H: SIGNED16); VAR M: Display.ModifyMsg; BEGIN 	IF (F # NIL) & ((F.W # W) OR (F.H # H)) THEN 		M.id := Display.extend; M.mode := Display.state; M.F := F; 		M.X := F.X; M.Y := F.Y + F.H - H; M.W := W; M.H := H; 		M.dW := W - F.W; M.dH := H - F.H; M.dX := 0; M.dY := -M.dH; 		M.dlink := NIL; M.x := 0; M.y := 0; M.res := -1; Objects.Stamp(M); 		F.handle(F, M) 	END END ModifySize; (** Inserts the frame f into container F at (u, v). (u, v) is relative to upper left corner of F. *) PROCEDURE Consume* (F, f: Frame; u, v: SIGNED16); VAR C: Display.ConsumeMsg; BEGIN 	IF (F # NIL) & (f # NIL) THEN 		f.slink := NIL; 		C.id := Display.drop; C.F := F; 		C.res := -1; C.dlink := NIL; C.x := 0; C.v := 0; 		C.u := u; C.v := v; C.obj := f; 		F.handle(F, C) 	END END Consume; (** Returns a deep or shallow copy of object obj, depending on parameter deep *) PROCEDURE Clone*(obj: Objects.Object; deep: BOOLEAN): Objects.Object; VAR C: Objects.CopyMsg; BEGIN 	C.obj := NIL; 	IF obj # NIL THEN 		IF deep THEN C.id := Objects.deep ELSE C.id := Objects.shallow END; 		Objects.Stamp(C); C.dlink := NIL; obj.handle(obj, C) 	END; 	RETURN C.obj END Clone; (* --- Recursion checking --- *) PROCEDURE RecursiveHandler(obj: Objects.Object; VAR M: Objects.ObjMsg); BEGIN IF ~(M IS Display3.UpdateMaskMsg) THEN recurse := TRUE END; END RecursiveHandler; (** Check if a message loop would be created should newchild be inserted in the container parent. Sends a dummy message behind the scenes. *) PROCEDURE Recursive*(parent, newchild: Objects.Object): BOOLEAN; VAR old: Objects.Handler; M: RecursiveMsg; BEGIN 	old := parent.handle; M.dlink := NIL; M.F := NIL; M.x := 0; M.y := 0; M.res:= -1; 	parent.handle := RecursiveHandler; recurse := FALSE; 	newchild.handle(newchild, M); 	parent.handle := old; 	RETURN recurse; END Recursive; (** Broadcasts an Gadgets.UpdateMsg should obj be a model gadget, or a Display.DisplayMsg if obj is a Display.Frame. *) PROCEDURE Update*(obj: Objects.Object); VAR M: UpdateMsg; D: Display.DisplayMsg; BEGIN 	IF obj IS Display.Frame THEN 		D.device := Display.screen; D.id := Display.full; D.F := obj(Display.Frame); Display.Broadcast(D) 	ELSE 		M.obj := obj; M.F := NIL; Display.Broadcast(M) 	END; END Update; (** Make a copy of a pointer to an object. A shallow copy returns a reference to obj. A deep copy results in M being forwarded to obj. *) PROCEDURE CopyPtr*(VAR M: Objects.CopyMsg; obj: Objects.Object): Objects.Object; BEGIN 	IF obj = NIL THEN RETURN NIL 	ELSE 		IF M.id = Objects.deep THEN 			M.obj := NIL; obj.handle(obj, M); RETURN M.obj 		ELSE (* shallow *) 			RETURN obj 		END; 	END; END CopyPtr; (** Copy the record fields belonging to the base gadget type. Copies handle, X, Y, W, H, state, attr and obj.*) PROCEDURE CopyFrame*(VAR M: Objects.CopyMsg; F, F0: Frame); BEGIN 	(* F0.slink := NIL; F0.lib := NIL; F0.ref := -1; F0.next := NIL; F0.dsc := NIL; *) 	F0.handle := F.handle; F0.X := F.X; F0.Y := F.Y; F0.W := F.W; F0.H := F.H; 	F0.state := F.state; 	Attributes.CopyAttributes(F.attr, F0.attr); 	Links.CopyLinks(M, F.link, F0.link); 	F0.obj := CopyPtr(M, F.obj); END CopyFrame; (** Copy the record fields belonging to the base Model gadget type. Copies handle and attr. *) PROCEDURE CopyObject*(VAR M: Objects.CopyMsg; obj, obj0: Object); BEGIN 	obj0.handle := obj.handle; 	Attributes.CopyAttributes(obj.attr, obj0.attr); 	Links.CopyLinks(M, obj.link, obj0.link) END CopyObject; PROCEDURE EmptyHandler(obj: Objects.Object; VAR M: Objects.ObjMsg); END EmptyHandler; (** Default handling of Display.ModifyMsg for visual gadgets. F.mask is invalidated when the frame changes its location or size. Sends behind the scenes to F an Display.OverlapMsg message to invalidate F.mask. Finally, a Display.DisplayMsg is broadcast to update F on the display.*) PROCEDURE Adjust*(F: Display.Frame; VAR M: Display.ModifyMsg); VAR D: Display.DisplayMsg; O: Display3.OverlapMsg; BEGIN 	IF (F.X # M.X) OR (F.Y # M.Y) OR (F.W # M.W) OR (F.H # M.H) THEN (* first adjust *) 		F.X := M.X; F.Y := M.Y; F.W := M.W; F.H := M.H; 		IF F IS Frame THEN O.F := F; O.M := NIL; O.x := 0; O.y := 0; O.res := -1; O.dlink := M.dlink; F.handle(F, O); 		END 	END; 	IF (M.mode = Display.display) & (F.H > 0) & (F.W >0) THEN 		D.x := M.x; D.y := M.y; D.F := F; D.device := Display.screen; D.id := Display.full; 		D.dlink := M.dlink; D.res := -1; Objects.Stamp(D); 		F.handle(F, D) 	END END Adjust; (** Returns the frame that is located at X, Y on the display. U, v return the relative coordinates of X, Y inside F. Behind the scenes a Display.LocateMsg is broadcast. *) PROCEDURE ThisFrame*(X, Y: SIGNED16; VAR F: Display.Frame; VAR u, v: SIGNED16); VAR M: Display.LocateMsg; BEGIN M.X := X; M.Y := Y; M.F := NIL; M.loc := NIL; Display.Broadcast(M); F := M.loc; u := M.u; v := M.v END ThisFrame; (** Implements standard resize handling for frames. Rubber-bands the gadget size and broadcasts a Display.ModifyMsg. *) PROCEDURE SizeFrame*(F: Display.Frame; VAR M: Oberon.InputMsg); VAR x, y, w, h, X, Y: SIGNED16; keys: SET; A: Display.ModifyMsg; BEGIN 	x := M.x + F.X; y := M.y + F.Y; w := F.W; h := F.H; 	Input.Mouse(keys, X, Y); 	Effects.SizeRect(NIL, keys, X, Y, x, y, w, h, NIL); 	IF keys # {0, 1, 2} THEN 		A.id := Display.extend; A.mode := Display.display; A.X := x - M.x; A.Y := y - M.y; A.W := w; A.H := h; 		A.F := F; A.dX := A.X - F.X; A.dY := A.Y - F.Y; A.dW := A.W - F.W; A.dH := A.H - F.H; 		Display.Broadcast(A); 		M.res := 0 	ELSE M.res := 1 	END END SizeFrame; (** Implements standard move behaviour for frames. Tracks the gadget outline, broadcasts a ConsumeMsg on a copy-over or consume interclick, or broadcast a Display.ModifyMsg for a simple move operation. *) PROCEDURE MoveFrame*(F: Display.Frame; VAR M: Oberon.InputMsg); VAR x, y, w, h, X, Y, u0, v0: SIGNED16; keys: SET; A: Display.ModifyMsg; f: Display.Frame; 	C: Display.ConsumeMsg; old: Objects.Handler; CM: Objects.CopyMsg; BEGIN 	x := M.x + F.X; y := M.y + F.Y; w := F.W; h := F.H; 	Input.Mouse(keys, X, Y); 	Effects.MoveRect(NIL, keys, X, Y, x, y, w, h); 	old := F.handle; F.handle := EmptyHandler; 	ThisFrame(X, Y, f, u0, v0); 	F.handle := old; 	IF keys = {middle, right} THEN (* copy frame *) 		IF f # NIL THEN 			CM.id := Objects.shallow; Objects.Stamp(CM); F.handle(F, CM); CM.obj.slink := NIL; (* copy the object *) 			C.id := Display.drop; C.obj := CM.obj; C.F := f; C.u := u0 + (x - X); C.v := v0 + (y - Y); 			Display.Broadcast(C); 		END; 		M.res := 2; (* copied *) 	ELSIF keys = {middle, left} THEN (* consume frame *) 		IF f # NIL THEN 			(* do a consume *) 			C.id := Display.drop; C.obj := F; F.slink := NIL; C.F := f; C.u := u0 + (x - X); C.v := v0 + (y - Y); Display.Broadcast(C) END; M.res := 0 (* moved *) ELSIF (keys = {middle}) OR (keys = {left}) THEN (* move frame, left key is a special hack, see docframes *) A.id := Display.move; A.mode := Display.display; A.X := x - M.x; A.Y := y - M.y; 		A.W := w; A.H := h; 		A.F := F; A.dX := A.X - F.X; A.dY := A.Y - F.Y; A.dW := A.W - F.W; A.dH := A.H - F.H; 		Display.Broadcast(A); M.res := 0 (* moved *) ELSE M.res := 1 (* cancel *) END; (* Kernel.GC *) END MoveFrame; (** Integrate obj at the caret position. A Display.ConsumeMsg is broadcast behind the scenes. *) PROCEDURE Integrate*(obj: Objects.Object); VAR C: Display.ConsumeMsg; BEGIN IF obj # NIL THEN C.id := Display.integrate; C.obj := obj; C.F := NIL; Display.Broadcast(C); END; END Integrate; PROCEDURE Atom(lib: Objects.Library; name: ARRAY OF CHAR): SIGNED16; VAR ref: SIGNED16; BEGIN Objects.GetKey(lib.dict, name, ref); RETURN ref; END Atom; (** Write an object POINTER to a file. Lib is the library of the object that contains the pointer.*) PROCEDURE WriteRef*(VAR r: Files.Rider; lib: Objects.Library; obj: Objects.Object); BEGIN IF obj = NIL THEN Files.WriteInt(r, -1); ELSE IF obj.lib # NIL THEN IF obj.lib # lib THEN IF obj.lib.name = "" THEN (* private library *) Files.WriteInt(r, -1); Texts.WriteString(W, "Warning: Object belonging to private library referenced in "); IF lib.name = "" THEN Texts.WriteString(W, "(private)") ELSE Texts.WriteString(W, lib.name) END; Texts.WriteLn(W); Log; ELSE Files.WriteInt(r, obj.ref); Files.WriteInt(r, Atom(lib, obj.lib.name)); END; ELSE Files.WriteInt(r, obj.ref); Files.WriteInt(r, Atom(lib, "")); (* belongs to this library *) END; IF obj.lib.name # lib.name THEN IF verbose THEN Texts.WriteString(W, "Note: "); IF lib.name = "" THEN Texts.WriteString(W, "(private)") ELSE Texts.WriteString(W, lib.name) END; Texts.WriteString(W, " imports "); Texts.WriteString(W, obj.lib.name); Texts.WriteLn(W); Log END END ELSE Files.WriteInt(r, -1); IF verbose THEN Texts.WriteString(W, "Warning: Object without library referenced in "); IF lib.name = "" THEN Texts.WriteString(W, "(private)") ELSE Texts.WriteString(W, lib.name) END; Texts.WriteLn(W); Log END END END END WriteRef; (** Read an object POINTER from a file. Lib is the library of the object that contains the pointer. Obj might be of type Objects.Dummy if a loading failure occured. *) PROCEDURE ReadRef*(VAR r: Files.Rider; lib: Objects.Library; VAR obj: Objects.Object); VAR i, l: SIGNED16; F: Objects.Library; name: ARRAY 32 OF CHAR; BEGIN Files.ReadInt(r, i); IF i = -1 THEN obj := NIL; ELSE Files.ReadInt(r, l); Objects.GetName(lib.dict, l, name); IF name&#91;0] = 0X THEN F := lib; COPY(lib.name, name); ELSE F := Objects.ThisLibrary(name); END; IF F # NIL THEN F.GetObj(F, i, obj); IF (name # lib.name) & (obj # NIL) THEN IF verbose THEN Texts.WriteString(W, "Note: "); IF lib.name = "" THEN Texts.WriteString(W, "(private)") ELSE Texts.WriteString(W, lib.name) END; Texts.WriteString(W, " imports "); Texts.WriteString(W, obj.lib.name); Texts.WriteLn(W); Log END END; IF obj = NIL THEN Texts.WriteString(W, "Warning: "); Texts.WriteString(W, "Object imported from "); Texts.WriteString(W, name); Texts.WriteString(W, " does not exist (NIL pointer)"); Texts.WriteLn(W); Log; END; ELSE Texts.WriteString(W, "Warning: "); Texts.WriteString(W, name); Texts.WriteString(W, " not found"); Texts.WriteLn(W); Log; obj := NIL; END; END; END ReadRef; PROCEDURE MakeMaskFor(G: Frame); VAR MM: Display3.UpdateMaskMsg; O: Display3.OverlapMsg; M: Display3.Mask; BEGIN MM.F := G; Display.Broadcast(MM); IF G.mask = NIL THEN (* good debug test 		IF ~(dlink IS View) & (dlink IS Frame) THEN HALT(99) END; 		*) (* constructing a dummy mask *) NEW(M); Display3.Open(M); Display3.Add(M, 0, -G.H+1, G.W, G.H); M.x := 0; M.y := 0; O.F := G; O.M := M; O.dlink := NIL; O.res := -1; O.x := 0; O.y := 0; G.handle(G, O); IF G.mask = NIL THEN G.mask := M END; (* frame is still misbehaving *) END END MakeMaskFor; PROCEDURE MakeMask0(G: Frame; X, Y: SIGNED16; dlink: Objects.Object; VAR M: Display3.Mask); VAR ox, oy, x, y, w, h, b, b2: SIGNED16; R: Display3.Mask; v: Objects.Object; BEGIN IF G.mask = NIL THEN (* mask has been invalidated *) MakeMaskFor(G) END; M := G.mask; M.x := X; M.y := Y + G.H - 1; (* clear the clipping port *) M.X := X; M.Y := Y; M.W := G.W; M.H := G.H; 	(* go through the view stack and modify the mask *) IF dlink # NIL THEN v := dlink; WHILE v # NIL DO 			IF v IS View THEN WITH v: View DO 					IF v.mask = NIL THEN (* very bad *) MakeMaskFor(v) END; ox := v.mask.x; oy := v.mask.y; 					v.mask.x := v.absX; v.mask.y := v.absY + v.H - 1; (* place mask at absolute position *) IF Display3.Rectangular(v.mask, x, y, w, h) THEN Display3.AdjustMask(M, x, y, w, h); ELSIF Display3.Visible(v.mask, X, Y, G.W, G.H) THEN (* frame completely visible *) Display3.AdjustMask(M, X, Y, G.W, G.H); ELSE (* waste memory because of overlapping *) Display3.IntersectMasks(M, v.mask, R); R.X := M.X; R.Y := M.Y; R.W := M.W; R.H := M.H; (* set new port to old port *) M := R; 					END; IF v.ClipMask # NIL THEN v.ClipMask(v, M, TRUE) ELSE b := v.border; b2 := b * 2; Display3.AdjustMask(M, v.absX+b, v.absY+b, v.W-b2, v.H-b2) END; v.mask.x := ox; v.mask.y := oy 				END (* 			ELSIF (v IS Frame) & (31 IN v(Frame).state) THEN (* from definition these should be position absolutely *) 				WITH v: Display.Frame DO 					Display3.AdjustMask(M, v.X, v.Y, v.W, v.H) 				END 			*) ELSIF (v IS Viewers.Viewer) THEN ELSIF ~(v IS Frame) & (v IS Display.Frame) THEN (* from definition these should be position absolutely *) WITH v: Display.Frame DO 					Display3.AdjustMask(M, v.X, v.Y, v.W, v.H) 				END END; v := v.dlink END END END MakeMask0; PROCEDURE P(x : SIGNED16) : SIGNED16; BEGIN RETURN SHORT(x * Display.Unit DIV Printer.Unit) END P; PROCEDURE EnumMakePrinterMask(X,Y,W,H: SIGNED16); VAR R, T, L, B: SIGNED16; BEGIN L := P(X-tmpX) + tmpX; B := P(Y - tmpY) + tmpY; R := P(X-tmpX + W) + tmpX; T := P(Y - tmpY +H) + tmpY; Display3.Add(pMask, L, B, R-L, T-B); END EnumMakePrinterMask; PROCEDURE MakePMask0(G: Frame; X, Y: SIGNED16; VAR M: Display3.Mask); VAR MM: Display3.UpdateMaskMsg; BEGIN IF G.mask = NIL THEN (* mask has been invalidated *) MM.F := G; Display.Broadcast(MM); IF G.mask = NIL THEN (* constructing a dummy mask *) NEW(M); Display3.Open(M); Display3.Add(M, 0, -G.H+1, G.W, G.H); M.x := X; M.y := Y + G.H - 1; IF verbose THEN Texts.WriteString(W, "Warning Gadgets.MakeMask: creating a default mask"); Texts.WriteLn(W); Log END ELSE M := G.mask; M.x := X; M.y := Y + G.H - 1 END; ELSE M := G.mask; M.x := X; M.y := Y + G.H - 1 END; (* clear the clipping port *) M.X := X; M.Y := Y; M.W := G.W; M.H := G.H; END MakePMask0; PROCEDURE ScaleMask(px, py: SIGNED16; in: Display3.Mask; VAR out: Display3.Mask); BEGIN NEW(pMask); Display3.Open(pMask); tmpX := px; tmpY := py; Display3.EnumRect(in, in.X, in.Y, in.W, in.H, EnumMakePrinterMask); pMask.X := Printer.FrameX; pMask.Y := Printer.FrameY; pMask.W := Printer.FrameW; pMask.H := Printer.FrameH; out := pMask; END ScaleMask; PROCEDURE MakePrinterMask0(G: Frame; X, Y: SIGNED16; dlink: Objects.Object; VAR M: Display3.Mask); VAR ox, oy, x, y, w, h, b, b2: SIGNED16; R, R0: Display3.Mask; v: Objects.Object; BEGIN (* make the basic mask *) MakePMask0(G, X, Y, M); (* scale it *) ScaleMask(X, Y, M, M); (* add views clipping *) v := dlink; WHILE v # NIL DO 		IF (v IS View) & (v(View).mask # NIL) THEN WITH v: View DO 				ox := v.mask.x; oy := v.mask.y; 				v.mask.x := v.absX; v.mask.y := v.absY + v.H - 1; (* place mask at absolute position *) ScaleMask(v.absX, v.absY, v.mask, R); IF Display3.Rectangular(R, x, y, w, h) THEN Display3.AdjustMask(M, x, y, w, h); ELSIF Display3.Visible(R, X, Y, P(G.W), P(G.H)) THEN (* frame completely visible *) Display3.AdjustMask(M, X, Y, P(G.W), P(G.H)); ELSE (* waste memory because of overlapping *) Display3.IntersectMasks(M, R, R0); R0.X := M.X; R0.Y := M.Y; R0.W := M.W; R0.H := M.H; (* set new port to old port *) M := R0; END; IF v.ClipMask # NIL THEN v.ClipMask(v, M, FALSE) ELSE b := v.border; b2 := b * 2; Display3.AdjustMask(M, v.absX+P(b), v.absY+P(b), P(v.W-b2), P(v.H-b2)) END; v.mask.x := ox; v.mask.y := oy 			END END; v := v.dlink; END END MakePrinterMask0; (** Execute a string as an Oberon command. The parameters executor, dlink, sender, receiver are copied to the global variables executorObj, context, senderObj, receiverObj respectively. Dlink must be the parent of executor. If a '%' is leading the command, no Oberon.Par is set up. *) PROCEDURE Execute*(cmd: ARRAY OF CHAR; executor, dlink, sender, receiver: Objects.Object); VAR T: Texts.Text; S: Attributes.Scanner; ch: CHAR; res, cx, cy, cw, chl, i, j: SIGNED16; oldcontext, obj: Objects.Object; str: BOOLEAN; BEGIN IF cmd&#91;0] = 0X THEN RETURN END; ch := 0X; T := NIL; Display.GetClip(cx, cy, cw, chl); Display.ResetClip; executorObj := executor; context := dlink; senderObj := sender; receiverObj := receiver; NEW(par); par.obj := executor; (* calculate outermost frame in the menuviewer*) IF context = NIL THEN context := executor END; (* may be the outside most frame *) obj := context; LOOP IF (obj = NIL) OR (obj.dlink = NIL) OR (obj.dlink IS Viewers.Viewer) THEN EXIT END; obj := obj.dlink END; IF (obj # NIL) & (obj IS Display.Frame) THEN par.frame := obj(Display.Frame) ELSE par.frame := Oberon.Par.frame (* hack, otherwise Oberon.Call traps *) END; (* modified ps - 6.6.96 *) IF cmd&#91;0] = "%" THEN par.text := emptyText; par.pos := 0; i := 1; WHILE cmd&#91;i] > " " DO cmd&#91;i-1] := cmd&#91;i]; INC(i) END; cmd&#91;i-1] := 0X ELSIF cmd&#91;0] = "$" THEN NEW(par.text); Texts.Open(par.text, ""); i := 1; WHILE cmd&#91;i] > " " DO 			Texts.Write(W, cmd&#91;i]); cmd&#91;i-1] := cmd&#91;i]; INC(i) END; cmd&#91;i-1] := 0X; par.pos := i-1; WHILE cmd&#91;i] # 0X DO 			Texts.Write(W, cmd&#91;i]); INC(i) END; Texts.Append(par.text, W.buf) ELSE IF ("A" &#60;= CAP(cmd&#91;0])) & (CAP(cmd&#91;0]) &#60;= "Z") THEN (* direct command *) i := 0; WHILE (cmd&#91;i] # 0X) & (cmd&#91;i] > " ") DO INC(i) END; j := i; 			WHILE (cmd&#91;j] # 0X) & (cmd&#91;j] &#60;= " ") DO INC(j) END; IF cmd&#91;j] # 0X THEN Attributes.StrToTxt(cmd, T); Attributes.OpenScanner(S, T, 0); Attributes.Scan(S); Attributes.Read(S.R, ch) END ELSE	(* command has to be retrieved by macro handler *) Attributes.StrToTxt(cmd, T); Attributes.OpenScanner(S, T, 0); Attributes.Scan(S); i := 0; j:= 0; WHILE S.s&#91;i] # 0X DO cmd&#91;i] := S.s&#91;i]; INC(i) END; Attributes.Read(S.R, ch); WHILE ~S.R.eot & (ch &#60;= " ") DO Attributes.Read(S.R, ch) END; IF S.R.eot THEN cmd&#91;i] := 0X; j := i END END; (* set up parameter block *) IF cmd&#91;j] # 0X THEN str := FALSE; WHILE ~S.R.eot & (str OR (ch # "~")) DO 				IF (ch = 22X) THEN S.R.substitute := ~S.R.substitute; str := ~str END; Texts.Write(W, ch); Attributes.Read(S.R, ch); END; par.pos := T.len; par.text := T; 			Texts.Append(T, W.buf) ELSE par.text := emptyText; par.pos := 0 END; cmd&#91;i] := 0X END; IF executor # NIL THEN oldcontext := executor.dlink; executor.dlink := context END; Oberon.Call(cmd, par, FALSE, res); IF res # 0 THEN Texts.WriteString(W, "Call error: "); Texts.WriteString(W, Modules.resMsg); Texts.WriteLn(W); Texts.Append(Oberon.Log, W.buf) END; IF par # NIL THEN par.obj := NIL END; IF executor # NIL THEN executor.dlink := oldcontext END; Display.SetClip(cx, cy, cw, chl); executorObj := NIL; context := NIL; senderObj := NIL; receiverObj := NIL; par := NIL END Execute; (* Macros *) PROCEDURE ReadName(VAR T: Attributes.Reader; VAR name: ARRAY OF CHAR); VAR ch: CHAR; i: SIGNED16; old: BOOLEAN; PROCEDURE Ok(ch: CHAR): BOOLEAN; BEGIN RETURN (ch = ".") OR ((ch >= "0") & (ch &#60;= "9")) OR ((CAP(ch) >= "A") & (CAP(ch) &#60;= "Z")); END Ok; BEGIN i := 0; old := T.substitute; T.substitute := FALSE; LOOP Attributes.Read(T, ch); IF T.eot THEN EXIT; END; IF ~Ok(ch) THEN EXIT END; name&#91;i] := ch; INC(i); END; name&#91;i] := 0X; T.substitute := old; END ReadName; (* special code for the & macro. && for next higher context etc. *) PROCEDURE Lookup0(VAR T: Attributes.Reader; VAR name: ARRAY OF CHAR; VAR context: Objects.Object); VAR ch: CHAR; i: SIGNED16; old: BOOLEAN; PROCEDURE Ok(ch: CHAR): BOOLEAN; BEGIN RETURN (ch = ".") OR ((ch >= "0") & (ch &#60;= "9")) OR ((CAP(ch) >= "A") & (CAP(ch) &#60;= "Z")); END Ok; BEGIN i := 0; old := T.substitute; T.substitute := FALSE; Attributes.Read(T, ch); WHILE ~T.eot & (ch = "&") DO 		IF (context # NIL) & (context.dlink # NIL) THEN context := context.dlink END; Attributes.Read(T, ch) END; LOOP IF T.eot THEN EXIT; END; IF ~Ok(ch) THEN EXIT END; name&#91;i] := ch; INC(i); Attributes.Read(T, ch); END; name&#91;i] := 0X; T.substitute := old; END Lookup0; PROCEDURE ObjAttr(name: ARRAY OF CHAR; context: Objects.Object; VAR W: Texts.Writer); VAR i, j: SIGNED16; attr: ARRAY 32 OF CHAR; obj: Objects.Object; BEGIN IF name # "" THEN i := 0; WHILE name&#91;i] # 0X DO INC(i); END; WHILE (i > 0) & (name&#91;i] # ".") DO DEC(i); END; IF name&#91;i] = "." THEN name&#91;i] := 0X; INC(i); j := 0; WHILE name&#91;i] # 0X DO attr&#91;j] := name&#91;i]; INC(i); INC(j); END; attr&#91;j] := 0X; obj := FindObj(context, name); IF obj # NIL THEN Attributes.WriteAttr(obj, attr, W); ELSE Texts.WriteLn(WW); Texts.WriteString(WW, "Object not found: "); Texts.WriteString(WW, name); Texts.WriteLn(WW); Texts.Append(Oberon.Log, WW.buf) END ELSE Texts.WriteLn(WW); Texts.WriteString(WW, "Syntax error: "); Texts.WriteString(WW, name); Texts.WriteLn(WW); Texts.Append(Oberon.Log, WW.buf) END END END ObjAttr; PROCEDURE StandardMacros(ch: CHAR; VAR T: Attributes.Reader; VAR res: Texts.Text; VAR beg: SIGNED32); VAR name: ARRAY 64 OF CHAR; f, context0: Objects.Object; BEGIN IF ch # 0X THEN NEW(res); Texts.Open(res, ""); beg := 0; IF ch = "&" THEN context0 := context; Lookup0(T, name, context0); ObjAttr(name, context0, mW); Texts.Append(res, mW.buf) ELSIF ch = "#" THEN ReadName(T, name); Attributes.WriteAttr(executorObj, name, mW); Texts.Append(res, mW.buf); ELSIF ch = "!" THEN (* more than one sender *) IF senderObj # NIL THEN ReadName(T, name); f := senderObj; WHILE f # NIL DO 					Attributes.WriteAttr(f, name, mW); Texts.Write(mW, " "); f := f.slink END; Texts.Write(mW, " "); Texts.Append(res, mW.buf); END ELSIF ch = "'" THEN Texts.Write(mW, 22X); Texts.Append(res, mW.buf); ELSIF ch = "?" THEN (* only one recipient *) ReadName(T, name); Attributes.WriteAttr(receiverObj, name, mW); Texts.Append(res, mW.buf); END END END StandardMacros; PROCEDURE UpArrowMacro(ch: CHAR; VAR T: Attributes.Reader; VAR res: Texts.Text; VAR beg: SIGNED32); VAR text, text0: Texts.Text; bg, end, ttime: SIGNED32; obj: Objects.Object; S: Display.SelectMsg; i: SIGNED16; name: ARRAY 32 OF CHAR; R: Attributes.Reader; ch0: CHAR; old: Objects.Library; string: BOOLEAN; BEGIN IF ch = 0X THEN (* Reset *) uparrowdone := FALSE; ELSIF (ch = "^") THEN (* getselection *) IF ~uparrowdone THEN uparrowdone := TRUE; Attributes.Read(T, ch); IF (CAP(ch) >= "A") & (CAP(ch) &#60;= "Z") THEN (* skip word *) i := 0; LOOP name&#91;i] := ch; INC(i); Attributes.Read(T, ch); IF T.eot THEN EXIT; END; IF (ch # ".") & ((ch &#60;= " ") OR ((CAP(ch) &#60; "A") OR (CAP(ch) > "Z"))) THEN EXIT END END; name&#91;i] := 0X END; Oberon.GetSelection(text, bg, end, ttime); S.id := Display.get; S.F := NIL; S.sel := NIL; S.obj := NIL; S.time := -1; Display.Broadcast(S); IF (S.time # -1) & ((ttime-S.time) &#60; 0) & (S.obj # NIL) & (name # "") THEN NEW(text); Texts.Open(text, ""); beg := 0; obj := S.obj; WHILE obj # NIL DO 					IF obj IS Frame THEN Attributes.WriteAttr(obj, name, W); Texts.Write(W, " ") END; obj := obj.slink END; Texts.Append(text, W.buf); res := text ELSIF ttime # -1 THEN (* res := text; beg := bg; *) Attributes.OpenReader(R, text, bg); uparrowdone := TRUE; beg := bg; NEW(text0); Texts.Open(text0, ""); string := FALSE; Attributes.Read(R, ch0); WHILE ~R.eot & (beg &#60; end) DO 					IF ch0 = 22X THEN R.substitute := ~R.substitute; string := ~string END; old := W.lib; W.lib := R.lib; Texts.Write(W, ch0); W.lib := old; IF beg + 1 = end THEN (* reached the end, ch0 is the last character read *) IF (ch0 # " ") & (ch0 # 0DX) & (ch0 # 9X) THEN Attributes.Read(R, ch0) ELSE ch0 := " " (* ended on a termination char *) END ELSE Attributes.Read(R, ch0) END; INC(beg) END; WHILE ~R.eot & (string OR ((ch0 # " ") & (ch0 # 0DX) & (ch0 # 9X))) DO 					IF ch0 = 22X THEN R.substitute := ~R.substitute; string := ~string END; old := W.lib; W.lib := R.lib; Texts.Write(W, ch0); W.lib := old; Attributes.Read(R, ch0); INC(beg) END; Texts.Write(W, " "); Texts.Append(text0, W.buf); beg := 0; end := text0.len; res := text0 ELSE res := NIL END ELSE res := NIL; beg := 0 END END END UpArrowMacro; (** Forwards a message from a camera-view to its contents, inserting the camera-view in the message thread. X, Y is the absolute screen coordinates of the bottom-left corner of the camera-view. This is important for calculating the correct display mask for the contents of the view. *) PROCEDURE Send*(from: View; X, Y: SIGNED16; to: Display.Frame; VAR M: Display.FrameMsg); VAR S: Stack; BEGIN Push(S, from, M); from.absX := X; from.absY := Y; to.handle(to, M); Pop(S, from, M); END Send; (* -- leaf handler -- *) PROCEDURE HandleFrameAttributes(F: Frame; VAR M: Objects.AttrMsg); VAR b: Attributes.BoolAttr; c: Attributes.CharAttr; i: Attributes.IntAttr; r: Attributes.RealAttr; s: Attributes.StringAttr; a, f: Attributes.Attr; BEGIN IF M.id = Objects.get THEN a := F.attr; WHILE (a # NIL) & (a.name # M.name) DO a := a.next END; IF a # NIL THEN IF a IS Attributes.BoolAttr THEN M.class := Objects.Bool; M.b := a(Attributes.BoolAttr).b; 			ELSIF a IS Attributes.CharAttr THEN M.class := Objects.Char; M.c := a(Attributes.CharAttr).c; 			ELSIF a IS Attributes.IntAttr THEN M.class := Objects.Int; M.i := a(Attributes.IntAttr).i; 			ELSIF a IS Attributes.RealAttr THEN M.class := Objects.LongReal; M.y := a(Attributes.RealAttr).r; 			ELSIF a IS Attributes.StringAttr THEN M.class := Objects.String; COPY(a(Attributes.StringAttr).s, M.s); ELSE HALT(42) END; M.res := 0; ELSIF M.name = "Gen" THEN HALT(99) ELSIF (M.name = "Name") & (F.lib # NIL) & (F.lib.name # "") THEN M.s&#91;0] := 0X; Objects.GetName(F.lib.dict, F.ref, M.s); M.class := Objects.String; M.res := 0 ELSIF M.name = "Transparent" THEN (* hidden attributes: special hack/rs wish *) M.b := transparent IN F.state; M.class := Objects.Bool; M.res := 0 (* should return nothing 		ELSE M.class := Objects.String; M.s&#91;0] := 0X; M.res := 0 (* must be. some gadgets advertize Cmd *) 		*) END; ELSIF M.id = Objects.set THEN IF M.name = "Gen" THEN HALT(99) ELSIF (M.name = "Name") (*& (M.s # "")*) THEN f := Attributes.FindAttr(M.name, F.attr); (* Search attribute *) IF M.s&#91;0] # 0X THEN (* Insert name *) IF (f = NIL) OR ~(f IS Attributes.StringAttr) THEN (* Does not exist, insert *) NEW(s); COPY(M.s, s.s); Attributes.InsertAttr(F.attr, M.name, s) 				ELSE (* Does exist, overwrite *) COPY(M.s, f(Attributes.StringAttr).s) 				END; ELSE (* Delete name *) IF f # NIL THEN (* Name in list, has to be deleted *) Attributes.DeleteAttr(F.attr, "Name") END END; M.res := 0; ELSE a := NIL; f := Attributes.FindAttr(M.name, F.attr); IF M.class = Objects.Bool THEN IF (f = NIL) OR ~(f IS Attributes.BoolAttr) THEN NEW(b); b.b := M.b; a := b ELSE f(Attributes.BoolAttr).b := M.b 				END; ELSIF M.class = Objects.Char THEN IF (f = NIL) OR ~(f IS Attributes.CharAttr) THEN NEW(c); c.c := M.c; a := c ELSE f(Attributes.CharAttr).c := M.c END; ELSIF M.class = Objects.Int THEN IF (f = NIL) OR ~(f IS Attributes.IntAttr) THEN NEW(i); i.i := M.i; a := i ELSE f(Attributes.IntAttr).i := M.i END; ELSIF M.class = Objects.Real THEN IF (f = NIL) OR ~(f IS Attributes.RealAttr) THEN NEW(r); r.r := M.x; a := r ELSE f(Attributes.RealAttr).r := M.x END; ELSIF M.class = Objects.LongReal THEN IF (f = NIL) OR ~(f IS Attributes.RealAttr) THEN NEW(r); r.r := M.y; a := r ELSE f(Attributes.RealAttr).r := M.y END; ELSIF (M.class = Objects.String) THEN IF (f = NIL) OR ~(f IS Attributes.StringAttr) THEN NEW(s); COPY(M.s, s.s); a:= s ELSE COPY(M.s, f(Attributes.StringAttr).s) 				END; ELSE RETURN END; IF a # NIL THEN Attributes.InsertAttr(F.attr, M.name, a); END; M.res := 0; END; ELSIF M.id = Objects.enum THEN M.Enum("Name"); a := F.attr; WHILE a # NIL DO M.Enum(a.name); a := a.next END; M.res := 0; END END HandleFrameAttributes; PROCEDURE HandleObjectAttributes(obj: Object; VAR M: Objects.AttrMsg); VAR b: Attributes.BoolAttr; c: Attributes.CharAttr; i: Attributes.IntAttr; r: Attributes.RealAttr; s: Attributes.StringAttr; a, f: Attributes.Attr; BEGIN IF M.id = Objects.get THEN a := obj.attr; WHILE (a # NIL) & (a.name # M.name) DO a := a.next END; IF a # NIL THEN IF a IS Attributes.BoolAttr THEN M.class := Objects.Bool; M.b := a(Attributes.BoolAttr).b; 			ELSIF a IS Attributes.CharAttr THEN M.class := Objects.Char; M.c := a(Attributes.CharAttr).c; 			ELSIF a IS Attributes.IntAttr THEN M.class := Objects.Int; M.i := a(Attributes.IntAttr).i; 			ELSIF a IS Attributes.RealAttr THEN M.class := Objects.LongReal; M.y := a(Attributes.RealAttr).r; 			ELSIF a IS Attributes.StringAttr THEN M.class := Objects.String; COPY(a(Attributes.StringAttr).s, M.s); ELSE HALT(42) END; M.res := 0; ELSIF M.name = "Gen" THEN HALT(99) ELSIF (M.name = "Name") & (obj.lib # NIL) & (obj.lib.name # "") THEN M.s&#91;0] := 0X; Objects.GetName(obj.lib.dict, obj.ref, M.s); M.class := Objects.String; M.res := 0 ELSE M.class := Objects.String; M.s&#91;0] := 0X; M.res := 0 END; ELSIF M.id = Objects.set THEN IF M.name = "Gen" THEN HALT(99) ELSIF M.name = "Name" THEN (* 			IF (obj.lib # NIL) & (obj.lib.name # "") THEN (* &#60;&#60; only insert names in public libraries *) 				Objects.GetRef(obj.lib.dict, M.s, ref); 				IF (ref # MIN(SIGNED16)) & (ref # obj.ref) THEN 					Texts.WriteString(W, " overwriting name "); Texts.WriteString(W, M.s); Texts.WriteLn(W); Log 				END; 				Objects.PutName(obj.lib.dict, obj.ref, M.s) 			END; 			*) f := Attributes.FindAttr(M.name, obj.attr); (* Search attribute *) IF M.s&#91;0] # 0X THEN (* Insert name *) IF (f = NIL) OR ~(f IS Attributes.StringAttr) THEN (* Does not exist, insert *) NEW(s); COPY(M.s, s.s); Attributes.InsertAttr(obj.attr, M.name, s) 				ELSE (* Does exist, overwrite *) COPY(M.s, f(Attributes.StringAttr).s) 				END; ELSE (* Delete name *) IF f # NIL THEN (* Name in list, has to be deleted *) Attributes.DeleteAttr(obj.attr, "Name") END END; M.res := 0 ELSE a := NIL; f := Attributes.FindAttr(M.name, obj.attr); IF M.class = Objects.Bool THEN IF (f = NIL) OR ~(f IS Attributes.BoolAttr) THEN NEW(b); b.b := M.b; a := b ELSE f(Attributes.BoolAttr).b := M.b 				END; ELSIF M.class = Objects.Char THEN IF (f = NIL) OR ~(f IS Attributes.CharAttr) THEN NEW(c); c.c := M.c; a := c ELSE f(Attributes.CharAttr).c := M.c END; ELSIF M.class = Objects.Int THEN IF (f = NIL) OR ~(f IS Attributes.IntAttr) THEN NEW(i); i.i := M.i; a := i ELSE f(Attributes.IntAttr).i := M.i END; ELSIF M.class = Objects.Real THEN IF (f = NIL) OR ~(f IS Attributes.RealAttr) THEN NEW(r); r.r := M.x; a := r ELSE f(Attributes.RealAttr).r := M.x END; ELSIF M.class = Objects.LongReal THEN IF (f = NIL) OR ~(f IS Attributes.RealAttr) THEN NEW(r); r.r := M.y; a := r ELSE f(Attributes.RealAttr).r := M.y END; ELSIF (M.class = Objects.String) THEN IF (f = NIL) OR ~(f IS Attributes.StringAttr) THEN NEW(s); COPY(M.s, s.s); a:= s ELSE COPY(M.s, f(Attributes.StringAttr).s) 				END; ELSE RETURN END; IF a # NIL THEN Attributes.InsertAttr(obj.attr, M.name, a); END; M.res := 0 END ELSIF M.id = Objects.enum THEN M.Enum("Name"); a := obj.attr; WHILE a # NIL DO M.Enum(a.name); a := a.next END; M.res := 0; END END HandleObjectAttributes; (** Bind an object to a library. Nothing happens if obj is already bound to a public library, or is already bound to lib. This is the default behavior when an object received the Objects.BindMsg. *) PROCEDURE BindObj*(obj: Objects.Object; lib: Objects.Library); VAR ref: SIGNED16; BEGIN IF lib # NIL THEN IF (obj.lib = NIL) OR (obj.lib.name&#91;0] = 0X) & (obj.lib # lib) THEN lib.GenRef(lib, ref); IF ref >= 0 THEN lib.PutObj(lib, ref, obj) END END END END BindObj; PROCEDURE findobj(obj: Objects.Object; link: Links.Link; VAR M: Objects.FindMsg); VAR name: Objects.Name; BEGIN GetObjName(obj, name); IF name = M.name THEN M.obj := obj END; WHILE (link # NIL) & (M.obj = NIL) DO 		IF link.obj # NIL THEN GetObjName(link.obj, name); IF name = M.name THEN M.obj := link.obj END END; link := link.next END END findobj; PROCEDURE ObjectHandler(obj: Objects.Object; VAR M: Objects.ObjMsg); VAR obj0: Object; ch: CHAR; BEGIN WITH obj: Object DO 		IF M IS Objects.FileMsg THEN WITH M: Objects.FileMsg DO 				IF M.id = Objects.load THEN Files.Read(M.R, ch); IF (ch = 43X) OR (ch = 42X) THEN Files.Set(M.R, Files.Base(M.R), Files.Pos(M.R) - 1); (* rewind *) Attributes.LoadAttributes(M.R, obj.attr) ELSIF ch = 80X THEN Attributes.LoadAttributes(M.R, obj.attr); Links.LoadLinks(M.R, obj.lib, obj.link) ELSE HALT(99) END ELSIF M.id = Objects.store THEN IF obj.link = NIL THEN (* no links, use old format for compatibility *) Attributes.StoreAttributes(M.R, obj.attr) ELSE Files.Write(M.R, 80X); (* version number *) Attributes.StoreAttributes(M.R, obj.attr); Links.StoreLinks(M.R, obj.lib, obj.link); END END END ELSIF M IS Objects.AttrMsg THEN WITH M: Objects.AttrMsg DO HandleObjectAttributes(obj, M) END ELSIF M IS Objects.BindMsg THEN WITH M: Objects.BindMsg DO BindObj(obj, M.lib); Links.BindLinks(obj.link, M) END ELSIF M IS Objects.CopyMsg THEN WITH M: Objects.CopyMsg DO 				IF M.stamp = obj.stamp THEN M.obj := obj.dlink ELSE NEW(obj0); obj.stamp := M.stamp; obj.dlink := obj0; CopyObject(M, obj, obj0); M.obj := obj0 END END ELSIF M IS Objects.LinkMsg THEN WITH M: Objects.LinkMsg DO 				Links.HandleLinkMsg(obj.link, M) 			END ELSIF M IS Objects.FindMsg THEN WITH M: Objects.FindMsg DO 				findobj(obj, obj.link, M) 			END END END END ObjectHandler; PROCEDURE HasCmdAttr(F: Frame; attr: ARRAY OF CHAR): BOOLEAN; VAR A: Objects.AttrMsg; BEGIN A.id := Objects.get; COPY(attr, A.name); A.class := Objects.Inval; A.res := -1; A.dlink := NIL; Objects.Stamp(A); F.handle(F, A); RETURN (A.res >= 0) & (A.class = Objects.String) & (A.s # "") END HasCmdAttr; (** Execute the attribute with name attr of F as an Oberon command. Sends a Objects.AttrMsg to retrieve the attribute attr of F. The attributed must be of the string class. *) PROCEDURE ExecuteAttr*(F: Frame; attr: ARRAY OF CHAR; dlink, sender, receiver: Objects.Object); VAR A: Objects.AttrMsg; BEGIN A.id := Objects.get; COPY(attr, A.name); A.class := Objects.Inval; A.res := -1; A.dlink := NIL; Objects.Stamp(A); F.handle(F, A); IF (A.res >= 0) & (A.class = Objects.String) & (A.s # "") THEN Execute(A.s, F, dlink, sender, receiver) END END ExecuteAttr; PROCEDURE EnableMove*; VAR S: Attributes.Scanner; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); enableMove := ~(((S.class = Attributes.Name) OR (S.class = Attributes.String)) & (S.s = "No")) END EnableMove; (** Standard mouse tracking behavior of visual gadgets. Calls ExecuteAttr for the "Cmd" attribute, calls MoveFrame and SizeFrame.*) PROCEDURE TrackFrame*(F: Display.Frame; VAR M: Oberon.InputMsg); VAR keys: SET; x, y, w, h: SIGNED16; R: Display3.Mask; BEGIN WITH F: Frame DO 		IF ~(selected IN F.state) & ((middle IN M.keys) OR (Oberon.New & (left IN M.keys))) THEN (* only when not selected and middle key *) x := M.x + F.X; y := M.y + F.Y; w := F.W; h := F.H; 			IF InActiveArea(F, M) THEN (* usable areas, corner, sides may be part, TRUE if locked *) IF HasCmdAttr(F, "Cmd") THEN MakeMask(F, x, y, M.dlink, R); Effects.TrackHighlight(R, keys, M.X, M.Y, x, y, w, h); IF InActiveArea(F, M) & ((keys = {1}) OR (Oberon.New & (keys = {2}))) THEN ExecuteAttr(F(Frame), "Cmd", M.dlink, NIL, NIL) END; M.res := 0 ELSIF ~IsLocked(F, M.dlink) THEN MoveFrame(F, M) 				END ELSIF enableMove & Effects.InCorner(M.X, M.Y, x, y, w, h) & ~(lockedsize IN F.state) THEN SizeFrame(F, M) 			ELSIF enableMove & (Effects.InBorder(M.X, M.Y, x, y, w, h) OR Effects.InCorner(M.X, M.Y, x, y, w, h)) THEN MoveFrame(F, M) 			END END END END TrackFrame; PROCEDURE FrameHandler(F: Objects.Object; VAR M: Objects.ObjMsg); VAR F0: Frame; x, y, w, h, u, v: SIGNED16; D: Display.DisplayMsg; R: Display3.Mask; obj: Objects.Object; name: ARRAY 64 OF CHAR; BEGIN WITH F: Frame DO 		IF M IS Objects.FileMsg THEN WITH M: Objects.FileMsg DO 				IF M.id = Objects.load THEN Files.ReadInt(M.R, F.X); Files.ReadInt(M.R, F.Y); Files.ReadInt(M.R, F.W); Files.ReadInt(M.R, F.H); ReadRef(M.R, F.lib, obj); (* dummy next pointer *) Files.ReadSet(M.R, F.state); Files.ReadInt(M.R, x); (* dummy *) IF x # 8367 THEN (* old version *) ELSE (* x = 2 version with links *) Links.LoadLinks(M.R, F.lib, F.link) END; ReadRef(M.R, F.lib, F.obj); Attributes.LoadAttributes(M.R, F.attr); (* hack *) Objects.GetName(F.lib.dict, F.ref, name); IF name&#91;0] # 0X THEN NameObj(F, name) END ELSIF M.id = Objects.store THEN Files.WriteInt(M.R, F.X); Files.WriteInt(M.R, F.Y); Files.WriteInt(M.R, F.W); Files.WriteInt(M.R, F.H); WriteRef(M.R, F.lib, NIL); (* not really needed *) Files.WriteSet(M.R, F.state); IF F.link = NIL THEN Files.WriteInt(M.R, 1); (* write old version *) ELSE Files.WriteInt(M.R, 8367); Links.StoreLinks(M.R, F.lib, F.link) END; WriteRef(M.R, F.lib, F.obj); Attributes.StoreAttributes(M.R, F.attr) END END ELSIF M IS Objects.CopyMsg THEN WITH M: Objects.CopyMsg DO 				IF M.stamp = F.stamp THEN M.obj := F.dlink ELSE NEW(F0); F.stamp := M.stamp; F.dlink := F0; CopyFrame(M, F, F0); M.obj := F0 				END END ELSIF M IS Objects.BindMsg THEN WITH M: Objects.BindMsg DO 				BindObj(F, M.lib); IF F.obj # NIL THEN F.obj.handle(F.obj, M) END; Links.BindLinks(F.link, M) 			END ELSIF M IS Objects.AttrMsg THEN WITH M: Objects.AttrMsg DO HandleFrameAttributes(F, M) END ELSIF M IS Objects.LinkMsg THEN WITH M:Objects.LinkMsg DO 				IF (M.id = Objects.get) & (M.name = "Model") THEN M.obj := F.obj; M.res := 0 ELSIF (M.id = Objects.set) & (M.name = "Model") THEN F.obj := M.obj; M.res := 0 ELSIF M.id = Objects.enum THEN M.Enum("Model"); Links.HandleLinkMsg(F.link, M) 				ELSE Links.HandleLinkMsg(F.link, M) 				END END ELSIF M IS Objects.FindMsg THEN WITH M: Objects.FindMsg DO 				IF F.obj # NIL THEN GetObjName(F.obj, name); IF name = M.name THEN M.obj := F.obj END END; findobj(F, F.link, M) 			END ELSIF M IS Display.FrameMsg THEN WITH M: Display.FrameMsg DO 				IF (M.res >= 0) THEN (* another debug test 					IF M IS Display3.OverlapMsg THEN HALT(100) END; 					*) RETURN END; x := M.x + F.X; y := M.y + F.Y; w := F.W; h := F.H; u := M.x; v := M.y; 				(* debug tests *) IF (M.F # NIL) & (M.F IS Frame) THEN (* check if M.F is initialized. Should trap if not *) END; IF (ABS(x) > 20000) OR (ABS(y) > 20000) THEN HALT(99) END; (* end of debug tests *) IF M IS Display.DisplayMsg THEN WITH M: Display.DisplayMsg DO 						IF M.device = Display.screen THEN IF (M.F = NIL) OR ((M.id = Display.full) & (M.F = F)) THEN MakeMask(F, x, y, M.dlink, R); Display3.ReplConst(R, 1, x, y, w, h, Display.replace); ELSIF (M.id = Display.area) & (M.F = F) THEN MakeMask(F, x, y, M.dlink, R); Display3.AdjustMask(R, x + M.u, y + h - 1 + M.v, M.w, M.h); Display3.ReplConst(R, 1, x, y, w, h, Display.replace); END ELSIF M.device = Display.printer THEN MakePrinterMask(F(Frame), M.x, M.y, M.dlink, R); Printer3.Rect(R, 15, Display.solid, M.x, M.y, P(w), P(h), 1, Display.replace) END END ELSIF M IS UpdateMsg THEN WITH M: UpdateMsg DO 						IF ~(transparent IN F.state) & (M.obj IS Frame) THEN (* causes a trap if message not initialised correctly *) obj := M.obj; WHILE obj # NIL DO 								IF obj = F THEN D.device := Display.screen; D.id := Display.full; D.F := F; D.x := M.x; D.y := M.y; 									D.dlink := M.dlink; D.res := -1; F.handle(F, D) 								END; obj := obj.slink END END END ELSIF M IS Display3.OverlapMsg THEN WITH M: Display3.OverlapMsg DO IF (M.F = F) OR (M.F = NIL) THEN F.mask := M.M; M.res := 0 END END ELSIF M IS Display.ModifyMsg THEN WITH M: Display.ModifyMsg DO 						IF (M.F = F) THEN (*Copying*)Adjust(F, M) END END ELSIF M IS Display.LocateMsg THEN WITH M: Display.LocateMsg DO 						IF (M.loc = NIL) & Effects.Inside(M.X, M.Y, x, y, w, h) THEN M.loc := F; M.u := M.X - x; M.v := M.Y - (y+h-1); M.res := 0 END END ELSIF M IS Display.SelectMsg THEN WITH M: Display.SelectMsg DO 						IF (M.id = Display.set) & (M.F = F) THEN INCL(F.state, selected); M.res := 0 ELSIF (M.id = Display.reset) & (M.F = F) THEN EXCL(F.state, selected); M.res := 0 ELSIF M.id = Display.get THEN END END ELSIF M IS Display.ConsumeMsg THEN WITH M: Display.ConsumeMsg DO 						IF (M.id = Display.drop) & (M.F = F) & (F IS Frame) THEN IF HasCmdAttr(F, "ConsumeCmd") THEN ExecuteAttr(F(Frame), "ConsumeCmd", M.dlink, M.obj, F); M.res := 0 END END END ELSIF M IS Display.ControlMsg THEN IF F.obj # NIL THEN F.obj.handle(F.obj, M) END ELSIF M IS Oberon.InputMsg THEN WITH M: Oberon.InputMsg DO 						IF M.id = Oberon.track THEN TrackFrame(F, M) END END END; M.x := u; M.y := v 			END END END END FrameHandler; (* --- Additional commands *) (** Look up value of the name alias. Empty string is returned if name is not aliased. *) PROCEDURE GetAlias*(name: ARRAY OF CHAR; VAR value: ARRAY OF CHAR); VAR a: Alias; BEGIN a := aliases; value&#91;0] := 0X; WHILE (a # NIL) & (a.name # name) DO a := a.next END; IF a # NIL THEN COPY(a.value, value); END; END GetAlias; (** Create an object from the generator procedure or alias objname. *) PROCEDURE CreateObject*(objname: ARRAY OF CHAR): Objects.Object; VAR genproc: ARRAY 64 OF CHAR; res: SIGNED16; BEGIN Objects.NewObj := NIL; GetAlias(objname, genproc);	(* ps 20.5.96 *) IF genproc = "" THEN COPY(objname, genproc) END; Oberon.Call(genproc, Oberon.Par, FALSE, res); IF res # 0 THEN Texts.WriteString(W, "Call error: "); Texts.WriteString(W, Modules.resMsg); Texts.WriteLn(W); Texts.Append(Oberon.Log, W.buf); RETURN NIL END; IF Objects.NewObj = NIL THEN Texts.WriteString(W, objname); Texts.WriteString(W, " is not a generator procedure or alias"); Texts.WriteLn(W); Log; END; RETURN Objects.NewObj END CreateObject; (** Create a View/Model pair from the generator procedures viewnewproc and modelnewproc. Aliasing is supported. *) PROCEDURE CreateViewModel*(viewnewproc, modelnewproc: ARRAY OF CHAR): Display.Frame; VAR F: Display.Frame; obj: Objects.Object; L: Objects.LinkMsg; BEGIN obj := CreateObject(viewnewproc); IF obj # NIL THEN IF ~(obj IS Display.Frame) THEN Texts.WriteString(W, viewnewproc); Texts.WriteString(W, " is not a Display.Frame generator procedure"); Texts.WriteLn(W); Log; RETURN NIL; END; F := obj(Display.Frame); IF modelnewproc # "" THEN obj := CreateObject(modelnewproc); IF (F IS Frame) THEN L.id := Objects.set; L.obj := obj; L.name := "Model"; L.res := -1; F.handle(F, L); IF L.res &#60; 0 THEN Texts.WriteString(W, " Model could not be set"); Texts.WriteLn(W); Log END; RETURN F; 			ELSE Texts.WriteString(W, viewnewproc); Texts.WriteString(W, " is not a Gadget"); Texts.WriteLn(W); Log; RETURN F; 			END; ELSE RETURN F; 		END; END; RETURN NIL; END CreateViewModel; (** Adds a generator alias. *) PROCEDURE AddAlias*(name, value: ARRAY OF CHAR); VAR a, b: Alias; BEGIN IF aliases = NIL THEN NEW(a); aliases := a; COPY(name, a.name); ELSE a := aliases; b := NIL; WHILE (a # NIL) & (a.name # name) DO b := a; a := a.next END; IF a = NIL THEN NEW(a); b.next := a; COPY(name, a.name) END; END; COPY(value, a.value); END AddAlias; (** Command to insert a newly allocated gadget at the caret. Used in the form: 	Gadgets.Insert &#60;generatorproc> ~		for a single object 		or 	Gadgets.Insert &#60;viewgeneratorproc> &#60;modelgeneratorproc> ~	for a model-view pair 	Aliasing is supported. *) PROCEDURE Insert*; (* ^ is "Frame.New Thing.New" *) VAR S: Attributes.Scanner; fname, tname: ARRAY 32 OF CHAR; F: Display.Frame; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); IF S.class = Attributes.Name THEN COPY(S.s, fname); Attributes.Scan(S); IF S.class = Attributes.Name THEN COPY(S.s, tname); F := CreateViewModel(fname, tname); IF F # NIL THEN Integrate(F); IF (F IS Frame) & (F(Frame).obj # NIL) THEN Update(F(Frame).obj) END; END; ELSE Integrate(CreateViewModel(fname, "")); END END; Objects.NewObj := NIL; END Insert; (** Returns the latest object selection. Time &#60; 0 indicates no selection. *) PROCEDURE GetSelection*(VAR objs: Objects.Object; VAR time: SIGNED32); VAR SM: Display.SelectMsg; BEGIN time := -1; objs := NIL; SM.id := Display.get; SM.F := NIL; SM.sel := NIL; SM.obj := NIL; SM.time := -1; Display.Broadcast(SM); IF (SM.time # -1) & (SM.obj # NIL) THEN time := SM.time; objs := SM.obj END END GetSelection; (** Search for the object "O" in the public library "L.Lib" where the name is specified as "L.O" and return a deep copy or shallow copy. *) PROCEDURE CopyPublicObject*(name: ARRAY OF CHAR; deep: BOOLEAN): Objects.Object; VAR C: Objects.CopyMsg; obj: Objects.Object; BEGIN obj := FindPublicObj(name); IF obj # NIL THEN Objects.Stamp(C); C.obj := NIL; (* ejz 10.7.96 *) IF deep THEN C.id := Objects.deep ELSE C.id := Objects.shallow END; obj.handle(obj, C); RETURN C.obj ELSE RETURN NIL END END CopyPublicObject; (** Changes the selected frame into a new frame type. Used in the form 	Gadgets.Change &#60;generatorproc> 	Aliasing is supported. *) PROCEDURE Change*; (* ^ Frame.New *) VAR S: Attributes.Scanner; C: Display.ConsumeMsg; fname: ARRAY 32 OF CHAR; oF, nF: Display.Frame; CM: Display.ControlMsg; SM: Display.SelectMsg; obj: Objects.Object; BEGIN SM.id := Display.get; SM.F := NIL; SM.sel := NIL; SM.obj := NIL; SM.time := -1; Display.Broadcast(SM); IF SM.time # -1 THEN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); IF S.class = Attributes.Name THEN COPY(S.s, fname); nF := CreateViewModel(fname, ""); IF (nF # NIL) & (SM.obj IS Display.Frame) THEN obj := SM.obj; WHILE obj # NIL DO 					oF := obj(Display.Frame); nF.X := oF.X; nF.Y := oF.Y; 					IF (nF IS Frame) & (oF IS Frame) THEN nF(Frame).obj := oF(Frame).obj; IF ~(lockedsize IN nF(Frame).state) THEN nF.W := oF.W; nF.H := oF.H; 					END; END; obj := obj.slink; CM.id := Display.remove; CM.F := oF; Display.Broadcast(CM); (* &#60;&#60;&#60; remove *) C.id := Display.drop; C.F := SM.sel; C.u := nF.X; C.v := nF.Y; C.obj := nF; Display.Broadcast(C); IF (nF IS Frame) & (nF(Frame).obj # NIL) THEN Update(nF(Frame).obj) END; IF obj # NIL THEN nF := CreateViewModel(fname, ""); END; END; END; END; END; END Change; (** Make a deep copy of the object selection and insert the result at the caret. *) PROCEDURE Copy*; VAR M: Display.SelectMsg; p, nl: Objects.Object; C: Objects.CopyMsg; CM: Display.ConsumeMsg; BEGIN M.id := Display.get; M.F := NIL; M.time := -1; M.sel := NIL; M.obj := NIL; Display.Broadcast(M); IF M.time # -1 THEN p := M.obj; nl := NIL; Objects.Stamp(C); WHILE p # NIL DO 			C.id := Objects.deep; p.handle(p, C); C.obj.slink := nl; nl := C.obj; p := p.slink END; CM.id := Display.integrate; CM.obj := nl; CM.F := NIL; Display.Broadcast(CM); END; END Copy; (** Change the value(s) of (an) attribute(s) in the object selection. Used in the form: 		Gadgets.ChangeAttr &#60;AttributeName> &#60;AttributeValue> ~ 	AttributeValue can take several forms, depending on the type of the attribute: 	names		For string attributes 	Yes/No     For boolean attributes 	1234	  	For number attributes 	"strings"	For string attributes *) PROCEDURE ChangeAttr*; VAR S: Attributes.Scanner; U: UpdateMsg; M: Display.SelectMsg; obj: Objects.Object; A: Objects.AttrMsg; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); IF (S.class = Attributes.Name) OR (S.class = Attributes.String) THEN A.id := Objects.set; COPY(S.s, A.name); Attributes.Scan(S); A.class := Objects.Inval; A.s := ""; IF S.class = Attributes.Int THEN A.class := Objects.Int; A.i := S.i 		ELSIF S.class = Attributes.Name THEN A.class := Objects.String; COPY(S.s, A.s) 		ELSIF S.class = Attributes.String THEN A.class := Objects.String; COPY(S.s, A.s) 		END; IF (A.s = "Yes") OR (A.s = "No") THEN Strings.StrToBool(A.s, A.b); A.class := Objects.Bool END; IF A.class # Objects.Inval THEN M.id := Display.get; M.F := NIL; M.sel := NIL; M.obj := NIL; M.time := -1; Display.Broadcast(M); IF M.time # -1 THEN obj := M.obj; WHILE obj # NIL DO 					A.res := -1; obj.handle(obj, A); IF A.res = -1 THEN Texts.WriteString(W, "Attribute not set"); Texts.WriteLn(W); Log END; obj := obj.slink END; U.F := NIL; U.obj := M.obj; Display.Broadcast(U) ELSE Texts.WriteString(W, "No selection"); Texts.WriteLn(W); Log END END END END ChangeAttr; (** Set an attribute value of a named object. Used in the form: 	Gadgets.Set O.A &#60;AttributeValue> ~		for attribute A of named object O in the current context *) PROCEDURE Set*; (* O.A value *) VAR S: Attributes.Scanner; name: ARRAY 64 OF CHAR; i, j: SIGNED16; attr: ARRAY 32 OF CHAR; obj: Objects.Object; A: Objects.AttrMsg; B: Objects.AttrMsg;  (*fof*) PROCEDURE Convert(VAR A,to: Objects.AttrMsg); (*fof*) BEGIN IF to.class = Objects.LongReal THEN IF A.class = Objects.Real THEN A.y := A.x; 			ELSIF A.class = Objects.Int THEN A.y := A.i; 			ELSE RETURN END; ELSIF to.class = Objects.Real THEN IF A.class = Objects.Int THEN A.x := A.i; 			ELSE RETURN END; ELSIF to.class= Objects.String THEN IF A.class = Objects.LongReal THEN Strings.RealToStr(A.y,A.s); ELSIF A.class = Objects.Real THEN Strings.RealToStr(A.x,A.s); ELSIF A.class = Objects.Int THEN Strings.IntToStr(A.i,A.s); ELSIF A.class = Objects.Bool THEN Strings.BoolToStr(A.b,A.s); ELSE RETURN END; ELSE RETURN END; A.class := to.class; END Convert; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); name := ""; IF S.class = Attributes.String THEN COPY(S.s, name) ELSIF S.class = Attributes.Name THEN COPY(S.s, name) END; WHILE name&#91;0] = "." DO 		i := 0; REPEAT name&#91;i] := name&#91;i+1]; INC(i) UNTIL name&#91;i] = 0X; IF context # NIL THEN context := context.dlink END END; Attributes.Scan(S); A.class := Objects.Inval; A.s := ""; A.id := Objects.set; IF S.class = Attributes.Int THEN A.class := Objects.Int; A.i := S.i; 	ELSIF S.class = Attributes.Real THEN A.class := Objects.Real; A.x := S.x; 	ELSIF S.class = Attributes.LongReal THEN A.class := Objects.LongReal; A.y := S.x; 	ELSIF S.class = Attributes.Name THEN A.class := Objects.String; COPY(S.s, A.s); ELSIF S.class = Attributes.String THEN A.class := Objects.String; COPY(S.s, A.s); END; IF (A.s = "Yes") OR (A.s = "No") THEN Strings.StrToBool(A.s, A.b); A.class := Objects.Bool END; IF (A.class # Objects.Inval) & (name # "") THEN i := 0; WHILE name&#91;i] # 0X DO INC(i); END; WHILE (i > 0) & (name&#91;i] # ".") DO DEC(i); END; IF name&#91;i] = "." THEN name&#91;i] := 0X; INC(i); j := 0; WHILE name&#91;i] # 0X DO attr&#91;j] := name&#91;i]; INC(i); INC(j); END; attr&#91;j] := 0X; COPY(attr, A.name); obj := FindObj(context, name); IF obj # NIL THEN B.id := Objects.get; (*fof*) COPY(A.name,B.name); B.class := -1;B.res := -1; obj.handle(obj,B); IF (B.res #-1) & (B.class #-1) & (B.class # A.class) THEN Convert(A,B) END; A.res := -1; obj.handle(obj, A); IF A.res = -1 THEN Texts.WriteString(W, "Attribute not set"); Texts.WriteLn(W); Log; ELSE Update(obj) END END END END END Set; (** Create a new Model gadget and link it to all the visual objects in the current selection. Used in the form: 	Gadgets.Link &#60;modelgenerator> 	Aliasing is supported. An Objects.LinkMsg is sent behind the scenes. *) PROCEDURE Link*; VAR S: Attributes.Scanner; M: Display.SelectMsg; obj, o: Objects.Object; B: Objects.BindMsg; L: Objects.LinkMsg; oname: ARRAY 64 OF CHAR; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); IF (S.class = Attributes.Name) OR (S.class = Attributes.String) THEN M.id := Display.get; M.F := NIL; M.sel := NIL; M.obj := NIL; M.time := -1; Display.Broadcast(M); COPY(S.s, oname); obj := CreateObject(oname); IF (obj # NIL) & (M.time # -1) THEN o := M.obj; IF o # NIL THEN IF o.lib # NIL THEN B.lib := o.lib; obj.handle(obj, B) END (* bind *) END; WHILE o # NIL DO 				IF o IS Frame THEN L.id := Objects.set; L.name := "Model"; L.obj := obj; L.res := -1; o.handle(o, L); IF L.res &#60; 0 THEN Texts.WriteString(W, " Model could not be set"); Texts.WriteLn(W); Log END (* old way 					o(Frame).obj := obj 					*) END; o := o.slink END; Update(obj) END END END Link; PROCEDURE LoadAliases; VAR S: Texts.Scanner; alias: Objects.Name; err: BOOLEAN; BEGIN Oberon.OpenScanner(S, "Gadgets.Aliases"); IF S.class = Texts.Inval THEN Texts.WriteString(W, "Oberon.Text - Gadgets.Aliases not found"); Texts.WriteLn(W); Log ELSE err := FALSE; WHILE (S.class IN {Texts.Name, Texts.String}) & ~err DO 			COPY(S.s, alias); Texts.Scan(S); IF (S.class = Texts.Char) & (S.c = "=") THEN Texts.Scan(S); IF S.class IN {Texts.Name, Texts.String} THEN AddAlias(alias, S.s); Texts.Scan(S) ELSE err := TRUE END ELSE err := TRUE END END; IF err OR (S.class # Texts.Char) OR (S.c # "}") THEN Texts.WriteString(W, "Error in Gadgets.Aliases"); Texts.WriteLn(W); Log END END; Oberon.OpenScanner(S, "Gadgets.Verbose"); verbose := ((S.class = Texts.Name) OR (S.class = Texts.String)) & (CAP(S.s&#91;0]) = "Y") END LoadAliases; BEGIN enableMove := TRUE; Texts.OpenWriter(W); Texts.OpenWriter(WW); Texts.OpenWriter(mW); NEW(emptyText); Texts.Open(emptyText, ""); LoadAliases; (* 	IF Display.Width &#60; 800 THEN 		Texts.WriteString(W, "Higher resolution recommended for Gadgets"); 		Texts.WriteLn(W); Log 	END; *) Attributes.AddMacro("&", StandardMacros); (* lookup *) Attributes.AddMacro("#", StandardMacros); (* executor *) Attributes.AddMacro("!", StandardMacros); (* sender *) Attributes.AddMacro("'", StandardMacros); (* substitute *) Attributes.AddMacro("^", UpArrowMacro); framehandle := FrameHandler; objecthandle := ObjectHandler; MakeMask := MakeMask0; MakePrinterMask := MakePrinterMask0; Oberon.Collect END Gadgets. (** Remarks: 1. Objects The type Gadgets.Object forms the base class of all model gadgets. Examples of these are the Integer, Boolean, Real, String and Complex gadgets. 2. Frames The Frame definition is the base type of all displayable gadgets (sometimes called views when discussed in relation to the MVC model). The state variable (a SET) plays an important role in controlling the gadget frame. It remembers state information and controls editing abilities by setting flags. A flag is represented by a small integer value (a flag is set if that number is a member of the state set). The selected flag indicates if the gadget is selected or not. The lockedsize flag prevents resizing of the gadget. The transparent flag indicates that a gadget is transparent. It is possible to "see through" parts of a transparent gadget to gadgets lying behind it. The lockchildren flag locks the direct children of a container gadget. A locked gadget cannot be moved or resized. The lockchildren flag is inspected by the IsLocked function and also used by the InActiveArea function to determine if a gadget can be moved or resized. This flag is normally visible to the outside world through a "Locked" attribute. The obj field points to the model of the gadget (if it has one). The mask field contains the gadget cached mask. This mask is calculated by the parent of a gadget, and transfered from parent to child through the Display3.OverlapMsg. During editing operations in the display space, the mask might become invalid due to new gadgets overlapping the gadget. In this case, a parent will invalidate the mask by setting no (i.e. NIL) mask. This results in the cached mask to be set to NIL. However, as soon as a gadget wants to display itself, the MakeMask procedure will notice the invalidated mask and request its parent to inform it of the correct mask (using Display3.UpdateMaskMsg). The mask is located in the fourth quadrant, with the top left corner of the gadget positioned at the origin (0, 0) of the mask. Before displaying a visual gadget, the cached mask is translated to the correct position on the display. This is done by a call to Gadgets.MakeMask. 3. Views The View type forms the base of a special class of gadgets called camera-views. A camera-view displays other displayable gadgets. Different camera views may display the same gadget, where each camera view may display a different part of it. The View base type is used to calculate the actual visible area of the object being viewed. This operation is hidden behind the secens in Gadgets.MakeMask. The absX, absY pair indicate the absolute position of the camera view on the display. This is set by the camera view itself when it forwards a message down to its model (i.e. the thing it is displaying). The border field indicates how wide the border of the camera view is (the border clips away parts of the model). The display mask generation of Gadgets.MakeMask is intimitely coupled with the structure of the display space. The remainder of this paragraph is for those curious about how mask calculation is done. The display space is organized in a DAG-like structure. Messages travel through the DAG, possibly passing to the same frame through different messages paths Conceptually, we take the DAG and partition it into separate display groups. This is done by removing all the edges in the DAG that connect a camera view with its model, and eliminating all the non-visual gadgets and their corresponding edges. As no multiple views of the same visual gadget through camera views are involved, the mask of each gadget in a display group only takes into account the overlapping between gadgets in the same display group. These masks remain static, and can be cached for each gadget. This is under the assumption that the root object of a display-group is completely visible. In practice, display groups corresponds to panels and their contents. The display groups are used to determine the visibility of a gadget when it calls Gadgets.MakeMask. Using the message thread, all camera-views from the root of the display space to the displayed frame are visited. For each of these, the camera-view can influence the visibility of its descendants. By intersecting the cached mask of a gadget with all of the masks of the camera-views located in the message path, we can determine exactly what area of a gadget is visible. 4. UpdateMsg The Smalltalk MVC framework is supported with the UpdateMsg. This message must always be broadcast to inform everybody of a change of a model gadget. It contains a pointer to the object that has changed. All gadgets that have this object as a model, has to update themselves. The object that changes need not always be a model gadget; it can also be a frame (this indicates that the frame's parent should redraw the frame). In the latter case, a whole list of frames may be updated (the frames are linked through the slink field). By convention, all the frames updated should belong to one single parent. 5. PriorityMsg The Priority message allows the changing of the overlapping order of gadgets. Each container gadget contains a list of children gadgets, where the position in the dsc-next list specifies the overlapping priority (from back to front). Changing the position of a child in the list has the affect of moving it to the front or the back in the container. When the PriorityMsg is broadcast the destination F indicates the child that wants to change its display priority. The top, bottom and visible flags are used to move the child to the front, to the back or to make it visible when not. The visible flag has the affect of moving the child to the front only when it is overlapped by a sibling. Otherwise, no action is undertaken. The passon flag indicates if the priority change should be recursive, meaning that the parent of F and onwards should also change priority, and thus bring a whole hierarchy to the front or back. 6. Default message handlers To simplify programming, default handlers for model and visual gadgets are provided. These may be called to handle messages a default way. The default frame handler (framehandle) responds to the Objects.FileMsg (storing/loading X, Y, W, H, state, obj and attr), Objects.CopyMsg (calls CopyFrame), BindMsg (calls BindObj), Objects.AttrMsg, Objects.FindMsg (returning itself or the model), Display.DisplayMsg (simply draws rectangle), Display3.OverlapMsg, Display.LocateMsg, Display.ModifyMsg (calls Adjust), Display.SelectMsg (only flips the selected flag), Display.ConsumeMsg (executes the ConsumeCmd attribute if the gadget has one), Display.ControlMsg (forwards it to the gadgets model), and Oberon.InputMsg (calling TrackFrame on a mouse track event). The default model gadget handler (objecthandle) respond to the Objects.FileMsg (storing/loading attr), Objects.AttrMsg, Objects.BindMsg (calls BindObj), Objects.CopyMsg (calling CopyObject), and Objects.FindMsg (returning the model if the names match). 7. The Imaging Model Two important relationships exist between gadgets: the view relationship and parent-child relationship. A panel may display several gadgets contained inside of it. This is the parent-child relationship, where the children are displayed and managed by the parent. The parent does not assume anything about the type of its children, and the children do not assume to be contained in an object of a specified type. This allows a gadget to be integrated in all environments, and for parents to manage children that are unknown to it. This is the principle of complete integration and plays a central role in the gadgets system. The view relationship allows one gadget to display or view another gadget. The first (the viewer) may either visualize the state of the viewed gadget (for example, a slider representing an integer value), or display the viewed gadget. In the first case, a model is viewed, while in the latter, a displayable object is viewed (a camera-view). Models form the interface to the application, and displayable models allow the same gadget to be displayed many times on the display. Many different views of the same object (model or displayable) may be possible, where each view can visualize the viewed object in a different manner. Views may be nested to an arbitrary depth, as long as no recursive views are created. Messages travel through the system informing views that a model has changed. These Update messages indicate the model involved, which the views may check to find out if it needs to redisplay or recalculate itself. The model-view framework is open; it is also possible for one model gadget to be dependent on another model gadget.You may have different representations of the same data, allow objects to depend on others, and allow data or objects to be shared between different documents. It is this flexible model-view framework combined with the ability to have gadgets overlapping each other and edited-in-place, that complicates the imaging model. A displayable gadget may be partially visible through one camera-view, and partially visible through another. The same object, can be seen and edited two or more times on different areas of the display. Also, some of these camera-views may be partially overlapped by other displayable gadgets. The problem is compounded when camera-views are nested inside camera-views, increasing the number of display instances. Thus a gadget may potentially have to display itself in many different ways. Clearly, with a single displayable gadget having so many different display instances (one for each view, in the simplest case), the gadget cannot have one unique display coordinate. The gadgets system uses relative coordinates, where the coordinate of a gadget is always relative to its parent. All displayable frame are connected to a data structure called the display root. Broadcasting a message through the display space causes all displayable objects in the structure to be reached. If we assume that views relay the message to the objects they display, the display space forms a directed a-cyclic graph (DAG). There are certain objects where two or more message paths converges. Such a convergence point can occur when two or more camera-views display the same object. Thus during a single message broadcast, the message may arrive twice or more times at the same object. If this object is displayable, it receives the message exactly once for each of its display instances. For each of these message arrivals, the gadget should have different coordinates on the display. In practice, the coordinates of a gadget is determined by the path the message follows to reach that gadget. Each message relay operation may change the coordinate system. This is reflected in the origin stored in the message. The display coordinates of a display instance of a gadget is thus the combination of the current origin (in the message) and the relative coordinates of the gadget itself. A gadget can be prompted into displaying itself on many different locations on the display by varying the origin of the message. This is called the multiple view model of the gadgets system. The main disadvantage of the multiple view model is that potentially each display instance of a frame may have a different visible area. Theoretically, the visible area of a display instance is a function of the message path to that instance. A data structure is used to indicate what part of a gadget is visible. Such a data structure is called a display mask. The mask can be constructed as the message travels through the display space, continually being reduced and expanded as the message travels. It consists of a set of non-overlapping rectangles which indicate which areas of the gadget are visible. Drawing primitives are issued through this mask, which has the effect of clipping them only to the visible areas in the mask. Operations on masks are also provided. You can, for example, calculate the intersection or union between masks, or enumerate all the visible areas in a mask. Implementing the sketched procedure is inefficient. Masks may be calculated that are not used at all (not all broadcasts are display related). Also, masks should be cached for each display instance, rather being recalculated each time. In practice, a imaging model is used that is based on these observations. The following remarks give an idea of how things have actually been implemented. 8. Masks Each gadget has a mask that shows which areas of it are visible. The mask field can be set to NIL, to indicates that no mask exists. A gadget can only be displayed once it becomes a mask. Should no mask exist, the Display3.UpdateMaskMsg is broadcast, with F set the maskless gadget. The parent of F is responsible for creating a new mask for F. The Display3.OverlapMsg is used to inform the gadget of its new mask. It is sent directly from the parent to the gadget (the above protocol is explained in the section about the Display3 module). The mask generation is hidden from gadget programmers. When displaying a gadget, the mask's relative coordinates have to be converted into absolute screen coordinates, or possibly even a new mask created (as described above). The whole process is hidden behind the procedures MakeMask and MakePrinterMask. G is the frame for which a mask is needed, X and Y indicate the absolute screen position of the left-bottom corner of G, and dlink is the context of G. The context of G can be found in the dlink field of the received frame message. The MakePrinterMask procedure variable functions in the same way, except that a mask for the printer is created. For the latter X, Y should be the absolute printer coordinates of the gadget. The resulting masks are return in variable parameter M, and can immediately be used for displaying or printing the gadget. 9. Mask Calculations Masks are calculated from the intersection of the cached mask of a gadget and all the camera-views through which a message travels. We need a backward traversal from the gadget through all the display groups. On receiving a frame message, the dlink field in the message points to the first frame in the message thread. The list can be traversed further backwards with the dlink field of the frame. The backward traversal can continue by following the dlink fields through all frames in the thread. Thus when masks are generated one should distinguish between normal frames and camera-views, as we are only interested in camera-views when generating masks. Broadcast messages travel from one display group to another (through views) to reach a gadget. Thus the actual visible area of a gadget is the intersection of its static/cached mask plus all the masks of views through which the message travelled. This calculation only need to be made on demand. For example, when a gadget decides to display itself, it calls MakeMask to build it's visibility mask. MakeMask has to find out the path the message traveled to reach the gadget, extract all the camera-views, and build the intersection of the static mask plus all the masks of the views. This can be done by following the message path back from the receiver gadget to the root of the display. Typically we don't want to modify the static mask of a gadget. However, this mask will be changed by the intersection process during mask calculation. Observations shows that the masks of views are mostly rectangular, i.e they are seldomly partially overlapped. If we assume that this is always the case, the mask calculation is nothing more than reducing the static mask by rectangular areas (clipping windows or ports). For this situation, the mask is provided with a rectangular clipping port, to which all output primitives are clipped after they have been clipped by the mask itself. The simple structure of the clipping port means that it can easily be saved, modified and restored, without affecting the static portion of the mask. Of course, the latter condition fails when the views are also partially obscured. In this case, the mask calculation has to be done in the less efficient way. 10. Command Execution Gadgets may execute Oberon commands (procedures Execute and ExecuteAttr) specified by their command attributes. Commands can take their parameters from the user interface. For this purpose, several global variables are exported from the gadgets module. The variable context identifies the context, normally the parent, of the gadget executing the command. The context of a gadget is found in the dlink field of a Display.FrameMsg the gadget receives. The variable executorObj identifies the gadget executing the command, which is always the same as Oberon.Par.obj. The senderObj and receiverObj identifies the objects involved in consume operations, and may be NIL. 11. Aliasing The Gadgets module implements a simple aliasing feature. This allows the user to give more meaningful abbreviations or names to the not so easy to remember object generator procedures. The principle client of aliasing are the Gadgets.Insert and Gadgets.Link commands. The aliases are found in the Oberon.Text/Registry section called Aliases. The aliases are read into an internal lookup table when the Gadgets module is loaded for the first time. The format of each line of the Aliases section is: Alias=GeneratorProc

*) Diff.Do Oberon.Gadgets.Mod a.Mod