Related Info: List Manager Quickdraw

Start Dragging My Lists Around

Here’s a way to drag items from one list to another

By Eric Rosé, Pittsburgh, Pennsylvania

About the author

Eric Rosé has a BS in Computer Science, is recently married, and is now trying to escape from a Masters program in Electrical and Computer Engineering so that he can get back to hacking Macintosh code.

A Question of Style

Anyone who has used the Font/DA Mover has probably experienced some degree of frustration in the clumsiness of having to select an item in the list, then click on a button to move or delete it. Trying to use this interface in a situation where you have more than two lists and could drag to and remove items from any one of them would quickly lead to a bewildering profusion of buttons which would leave even the hardiest user gasping for breath (besides being annoying to code up).

If you have seen the AppleShare Administrator you know that there is a more elegant and more intuitive way to handle this problem: simply allow the user to click on an object in a list and drag it into another list. For months I tried to find out if anyone had written up a TechNote on how to do this; failing to find one, I decided to roll my own solution. Here it is.

The Creeping Feature Creature

To do simple dragging between two lists, all you really need is a moderately complex LClikLoop routine (IM IV:266). In the pursuit of a more general and extendable solution to the problem, I decided to write a generic LClikLoop routine and package it in a unit which the programmer could customize. Among the features the unit provides are: 1) Letting the user drag from one list to any number of other lists; 2) Programmer-defined actions to be taken when a user drags items from one list to another list, to that same list, to a region outside of all the lists, and to a region outside the dialog (these actions could be unique for each source and destination list); 3) Different possible dragging options for each list (i.e., you can drag items between A and B, but not within A, but you can only drag items within list B). This third option is included for completeness - it could lead to a lot of confusion if not managed consistently.

Nuts & Bolts

As it stands, the LToLDragUnit provides three interface routines and whatever list variables and constants you want to include. If you want to use the dragging LClikLoop, you should define all of your ListHandle variables inside the file DragUnitUserDefs.i, and then include LtoLDragUnit in the USES clause for any unit that uses those list variables. I include a constant for each list (generally the dialog item number of the user item in which the list is placed) which I store in the list’s RefCon field so that I can tell the lists apart when I am handed a handle to one. If you have a different method, feel free to not include the constants; LtoLDragUnit does not directly reference any of these constants or variables, but you will most likely have to use them in the routines you define. Anyway, enough idle banter; on to a discussion of the interface routines!

InitLtoLDrag

This simple routine should be called once when your program first starts up. All it does is set initial values for the unit’s global variables.

SetDragEnvironment

Another simple routine; you should call this whenever you switch from one dialog which uses the LtoLDragUnit to another. For example, if you have two dialogs with draggable lists, whenever one is activated you should call this routine with its dialog pointer.

LtoLClickProc

This is the generic ClikLoop routine. A pointer to it should be stored in the LClikLoop field of any list you want to be ‘draggable’ (see TestDrag.p for examples of how to do this). When it is called, it stores the position where the mouse was clicked, then calls your SetSourceDestLists routine (described later) and promptly exits so that the item you clicked on can be hilighted. If the mouse button is still down, it promptly re-executes and continues with the main body of the routine which performs the following actions: 1) find the selected cell and get its rectangle; 2) Define a LimitRect and SlopRect for use with DragGrayRgn (IM I:294); if the list can only drag within itself, the LimitRect is the List’s view rectangle, otherwise it is the entire dialog; 3) Call DragGrayRgn to let the user drag the item around; 4) Call one of your four action routines depending on where the item was released and which drag options are available.

At this point, mention should be made of DragProc. This routine is responsible for hilighting the list items you pass over so that you know where the item will be inserted when it is released, and whether or not you can insert an item in a particular list. First it checks to see whether you can drag items within the source list. If so, it calls CheckList which hilights the cell in the source list which is underneath the cursor’s current position. Then it checks to see whether you can drag to any other list, and, if so, performs the same actions for each possible destination list.

So What Do You Have To Do?

I hear you cry? In order for the LtoLDragUnit to do anything useful, you must supply five routines - the routines which are declared as forward in the unit’s implementation section. These routines should be defined in the file DragUnitUserProcs.i. I will now discuss each of these routines in detail.

SetSourceDestLists

When the user first clicks in a lists (the source list), LtoLClickProc calls this routine so that you can 1) specify which other lists the source list’s items can be dragged into. 2) specify (using the kDragToOwnList, kDragOutside, and kDragToOtherList constants) what kinds of drags can be done with the source list’s items. To specify the destination lists, set gNumDestLists to the number of possible destination lists and store handles to each destination list in the first gNumDestLists entries in the gDestLists array. To specify the kind of drags to perform, set the gDragStyle variable to any combination of the three style constants (they can be added together to provide multiple effects).

DragToDestAction

This routine is called when kDragToOtherList is set and the user has dragged an item from the source list and released it over one of the destination lists. You are given a handle to the source and destination lists, along with the coordinates of the cell being dragged and the cell it was released over. What you do with that information is purely up to you.

DragToSourceAction

This routine is called when kDragToOwnList is set and the user has successfully dragged an item within the source list. You are given a handle to the source list, along with the coordinates of the cell being dragged and the cell it was released over. Again, what happens is for you to decide.

DragOutsideAction

This routine is called only if kDragOutside is set and 1) If kDragToOwnList is not set and the user drags an item from the source list back into itself; 2) If the item is released over a list which is not specified as a destination list in the SetSourceDestLists routine, or 3) If the item is not released over a list at all.

BadDragAction

This routine is called in two different cases: 1) If kDragToOwnList is set and the item is released outside of the source list, or 2) If kDragToOwnList is not set and the item is dragged outside of the dialog.

A Contrived Example

The source code in the file TestDrag.p presents an example of how to use the LtoLDragUnit routines (albeit in an extremely contrived way). It creates a modal dialog with three list variables. Items can be dragged from List1 to either List2 or List3, but not back into List1. Items from List2 can be dragged either into List2 or List3. Items from List3 can be dragged to either List1 or List2, but not back into List3. Items from all three of these lists can be dragged ‘outside’. For the purposes of this example, I have defined the meanings of the four action routines as follows: 1) DragToDestAction: insert the item from the source list into the destination list at the position where it was released, pushing the item already there down one row; 2) DragToSourceAction: swap the item being dragged with the item it was released over; 3) DragOutsideAction: delete the item being dragged from the source list; 4) BadDragAction: beep at the user to let them know they messed up, but don’t affect any of the lists.

Future Enhancements

Using your own LClikLoop means that the automatic scrolling provided by the default loop is deactivated; in other words, you can’t click in the list and then scroll it up or down by dragging inside the list with the mouse button held down. It might be nice to figure out how to add this feature, especially for a list with the kDragToOwnList feature set. Another interesting feature would be to be able to cause the destination lists to scroll up or down when you drag over them. A warning: LAutoScroll is rude enough to not save the penstate before it scrolls, so if you don’t manually save and restore the penstate before scrolling you get some very fascinating update problems with DragGrayRgn. Feel free to experiment, and please let me know if you find solutions to either of these problems. Good hacking to you all!

Listing:  LtoLDragUnit.p
{This unit lets you implement dragging items}
{between lists}
UNIT LToLDragUnit;

INTERFACE

USES
 MemTypes, QuickDraw, OSIntf, ToolIntf, PackIntf;

 PROCEDURE InitLtoLDrag;
 {Initialize the unit’s global variables}

 PROCEDURE SetDragEnvironment (DestDialog :
 DialogPtr);
 {Call this procedure when you switch dialogs}

 FUNCTION LtoLClickProc : BOOLEAN;
 {The ‘item dragging’ Clickproc}

{$i DragUnitUserDefs.i}

IMPLEMENTATION
 
VAR
 gSourceList: ListHandle;
 gDestLists : ARRAY [1..10] OF ListHandle;
 gNumDestLists : Integer;
 gTheDialog : DialogPtr;
 gDragStyle : Integer;
 AnchorDefined : BOOLEAN;
 AnchorPoint, 
 OldPoint,
 NextPoint  : Point;

CONST
 kDragToOwnList  = $01;
 kDragToOtherList= $02;
 kDragOutside    = $04;
 kInvalidDrag    = $8000;
 kMaxDestLists   = 10;

{The following routines should be defined by}
{the programmer in DragUnitUserProcs.i}
PROCEDURE DragToDestAction (SourceList : ListHandle;
 SourceCell : Point; DestList : 
 ListHandle; DestCell : Point);  FORWARD;
{action to take if the user drags an item from}
{the source list to the destination list}

PROCEDURE DragToSourceAction (SourceList :
 ListHandle; SourceCell, DestCell : Point);   FORWARD;
{action to be taken if the user drags an item}
{within the source list}

PROCEDURE BadDragAction (SourceList :
 ListHandle; SourceCell : Point);  FORWARD;
{action to be taken if the user drags an item}
{and releases it outside the draggable area}

PROCEDURE DragOutsideAction (SourceList :
 ListHandle; SourceCell : Point);  FORWARD;
{action to be taken if the user drags an item}
{and releases it within the draggable area, but}
{not inside of any of the lists}

PROCEDURE SetSourceDestLists (ClickPt : Point); FORWARD;
{For the selected list, define which lists its}
{items can be dragged to, and what kind of drags}
{can be performed}}

{------------------------}

PROCEDURE InitLtoLDrag;
VAR
 i : Integer;
BEGIN
 SetPt(AnchorPoint, 0, 0);
 AnchorDefined := FALSE;
 OldPoint := AnchorPoint;
 NextPoint := AnchorPoint;
 gSourceList := NIL;
 FOR i := 1 TO kMaxDestLists DO
 gDestLists[i] := NIL;
 gNumdestLists := 0;
END;

{------------------------}

PROCEDURE SetDragEnvironment (DestDialog :   DialogPtr);
BEGIN
 gTheDialog := DestDialog;
END;

{------------------------}
 
FUNCTION FindCell(VAR Selected_Cell :
 Point; TheList : ListHandle) : BOOLEAN;
{Return the currently selected cell in TheList}
BEGIN
 SetPt(Selected_Cell, 0, 0);
 FindCell:= LGetSelect(TRUE,
 Selected_Cell, TheList);
END;   

{------------------------}

FUNCTION CanDragToSelf : BOOLEAN;
BEGIN
 CanDragToSelf := BAND(kDragToOwnList,
 gDragStyle) > 0;
END;

{------------------------}

FUNCTION CanDragToOther : BOOLEAN;
BEGIN
 CanDragToOther := BAND(kDragToOtherList,
 gDragStyle) > 0 
END;

{------------------------}

FUNCTION CanDragOutside : BOOLEAN;
BEGIN
 CanDragOutside := BAND(kDragOutSide, gDragStyle) > 0;
END;

{------------------------}

PROCEDURE DragProc;
VAR
 MPos   : Point;
 WhichCell: Point;
 TempRect : Rect;
 i : Integer;

 PROCEDURE CheckOtherList(TheList:ListHandle);
 BEGIN
 IF TheList = NIL THEN
 EXIT(CheckotherList);
 TempRect := TheList^^.rView;
 IF PtInRect(MPos, TempRect) THEN
 BEGIN
 MPos.v := ((MPos.v - TempRect.Top) DIV 
 TheList^^.CellSize.v) +
 TheList^^.Visible.Top;
 MPos.h := 0;
 IF FindCell(WhichCell, TheList) THEN
 BEGIN
 IF NOT(EqualPt(WhichCell, MPos)) THEN
 BEGIN
 LSetSelect (FALSE, WhichCell, TheList);
 LSetSelect (TRUE, MPos, TheList);
 END; {equalpt}
 END  {FindCell}
 ELSE
 LSetSelect (TRUE, MPos, TheList);
 END; {PtInRect}
 END;

BEGIN
 GetMouse(MPos);
 IF CanDragToSelf THEN
 BEGIN
 TempRect := gSourceList^^.rView;
 IF PtInRect(MPos, TempRect) THEN
 BEGIN
 MPos.v := ((MPos.v - TempRect.Top) DIV
 gSourceList^^.CellSize.v) + 
 gSourceList^^.Visible.Top;
 MPos.h := 0;
 IF FindCell(WhichCell, gSourceList) THEN
 BEGIN
 IF NOT(EqualPt(WhichCell, MPos)) THEN
 BEGIN
 LSetSelect(FALSE,WhichCell,gSourceList);
 LSetSelect (TRUE, MPos, gSourceList);
 END; {equalpt}
 END  {FindCell}
 ELSE
 LSetSelect (TRUE, MPos, gSourceList);
 END; {PtInRect}
 END; {DragProc}

 IF CanDragToOther THEN
 FOR i := 1 TO gNumDestLists DO
 CheckOtherList(gDestLists[i]);
END;

FUNCTION  LtoLClickProc : BOOLEAN;
VAR
 R : RgnHandle;
 OldState : PenState;
 TT, L  : LongInt;
 B : BOOLEAN;
 DestCell, 
 SourceCell, 
 SelectedCell  : Point;
 CellRect : Rect;
 LimitRect, 
 SlopRect   : Rect;
 i : Integer;
 TempRect : Rect;
BEGIN
 LtoLClickProc := TRUE; 
 IF NOT(AnchorDefined) THEN
 BEGIN
 AnchorDefined := TRUE; {store the point where}
 GetMouse(AnchorPoint); {we initially clicked }
 {Call this to set the lists we can drag to}
 SetSourceDestLists (AnchorPoint);
 EXIT(LtoLClickProc);{exit here so that}
 END  {the cell will be hilighted}
 ELSE
   AnchorDefined := FALSE;
 
 IF FindCell(SourceCell, gSourceList) THEN
 BEGIN
 LRect(CellRect, SourceCell, gSourceList);
 IF CanDragToSelf & NOT(CanDragToOther) THEN
 BEGIN
 SetRect(LimitRect, gSourceList^^.rView.Left +
 (AnchorPoint.h - CellRect.Left),
 gSourceList^^.rView.Top +
 (AnchorPoint.v - CellRect.Top),
 gSourceList^^.rView.Right -
 (CellRect.Right - AnchorPoint.h),
 gSourceList^^.rView.Bottom -
 (CellRect.Bottom - AnchorPoint.v));
 SlopRect := gSourceList^^.rView;
 END
 ELSE
 BEGIN
 SetRect(LimitRect, gTheDialog^.PortRect.Left
 + (AnchorPoint.h - CellRect.Left),
 gTheDialog^.PortRect.Top + 
 (AnchorPoint.v - CellRect.Top),
 gTheDialog^.PortRect.Right - 
 (CellRect.Right - AnchorPoint.h),
 gTheDialog^.PortRect.Bottom - 
 (CellRect.Bottom - AnchorPoint.v));
 SlopRect := gTheDialog^.PortRect;
 END;
 {now that we have selected a cell, use}
 {DragGrayRgn to drag it around}
 InsetRect (SlopRect, -1, -1);
 R := NewRgn;
 RectRgn(R, CellRect);
 L := DragGrayRgn(R, AnchorPoint, LimitRect,
 SlopRect, noConstraint, @DragProc);
 IF HiWord(L) = kInvalidDrag THEN 
   BadDragAction (gSourceList, SourceCell)
 ELSE
 BEGIN
 DestCell.v := AnchorPoint.v + HiWord(L);
 DestCell.h := AnchorPoint.h + LoWord(L);
 IF PtInRect(DestCell, gSourceList^^.rView) &
 CanDragToSelf THEN
 BEGIN
 IF FindCell(DestCell, gSourceList) THEN
 DragToSourceAction (gSourceList,
 SourceCell, DestCell);
 END
 ELSE
 BEGIN
 IF CanDragToOther THEN
 BEGIN
 FOR i := 1 TO gNumDestLists DO
 BEGIN
 IF (gDestLists[i] <> NIL) &
 (PtInRect(DestCell,
 gDestLists[i]^^.rView)) &
 FindCell(DestCell, gDestLists[i])
 THEN
 BEGIN
 DragToDestAction (gSourceList,
 SourceCell, gDestLists[i],
 DestCell);
 EXIT(LtoLClickProc);
 END; {if FindCell}
 END; {for}
 END; {if CanDragToOther}
 
 IF CanDragOutSide THEN
 DragOutsideAction (gSourceList, SourceCell);
 END; {else}
 END; {if not kinvaliddrag}
 END; {FindCell}
END;  {LtoLClickProc}

{$i DragUnitUserProcs.i}
END.
-------------------------

listing:  DragActionProcs.i

{This include file contains the action procedures for each of the different 
kinds of drags you can do from one list to another or to itself}

PROCEDURE SetSourceDestLists (ClickPt : Point);
BEGIN
 IF PtInRect(AnchorPoint, gList1^^.RView) THEN
 BEGIN
 gSourceList := gList1;
 gDestLists[1] := gList2;
 gDestLists[2] := gList3;
 gNumDestLists := 2;
 gDragStyle := kDragToOtherList + kDragOutside;
 END
 ELSE
 IF PtInRect(ClickPt, gList2^^.RView) THEN
 BEGIN
 gSourceList := gList2;
 gDestLists[1] := gList3;
 gNumDestLists := 1;
 gDragStyle := kDragToOtherList +
 kDragToOwnList + kDragOutside;
 END
 ELSE
 IF PtInRect(ClickPt, gList3^^.RView) THEN
 BEGIN
 gSourceList := gList3;
 gDestLists[1] := gList1;
 gDestLists[2] := gList2;
 gNumDestLists := 2;
 gDragStyle := kDragToOtherList + kDragOutside;
 END;
END;

{------------------------}

PROCEDURE DragToDestAction (SourceList :
 ListHandle; SourceCell : Point; DestList :
 ListHandle; DestCell : Point);
VAR
 STemp : Str255;
 DLen  : Integer;
BEGIN
 DLen := SizeOF(STemp);
 LGetCell(@Stemp, DLen, SourceCell, SourceList);
 DestCell.v := LAddRow (1, DestCell.v, DestList);
 LSetCell (@Stemp, DLen, DestCell, DestList);
END;

{------------------------}

PROCEDURE DragToSourceAction (SourceList :
 ListHandle; SourceCell, DestCell : Point);
VAR
 STemp, DTemp : Str255;
 SLen, DLen   : Integer;
BEGIN
 DLen := SizeOF(STemp); SLen := SizeOF(STemp);
 LGetCell (@STemp, SLen, SourceCell, SourceList);
 LGetCell (@DTemp, DLen, DestCell, SourceList);
 LSetCell (@STemp, SLen, DestCell, SourceList);
 LSetCell (@DTemp, DLen, SourceCell, SourceList);
END;

{------------------------}

PROCEDURE BadDragAction (SourceList :
 ListHandle; SourceCell : Point);
BEGIN
 Sysbeep(1);
END;

{------------------------}

PROCEDURE DragOutsideAction (SourceList :
 ListHandle; SourceCell : Point);
BEGIN
 LDelRow (1, SourceCell.v, SourceList);
END;

-------------------------
File DragUnitUserDefs.p

VAR
 gList1, gList2, gList3 : ListHandle;

CONST
 U_List1= 3;
 U_List2= 2;
 U_List3= 5;

-------------------------

listing:  TestDrag.p

PROGRAM TestDrag;
USES
 MemTypes, QuickDraw, OSIntf, ToolIntf, PackIntf,
 LtoLDragUnit;

CONST
 kDialogID= 128;
 B_OK   = 1;
 kReturn= 13;
 kEnter = 3;
 kInvalidDrag =   $8000;
 
VAR
 gDragDialog: DialogPtr;
 ExitDialog : BOOLEAN;

{------------------------}

FUNCTION FindCell(VAR Selected_Cell : Point;
 TheList : ListHandle) : BOOLEAN; 
BEGIN
 SetPt(Selected_Cell, 0, 0);
 FindCell:= LGetSelect(TRUE, Selected_Cell, TheList);
END;   

{------------------------}

PROCEDURE AddListString(theString:Str255; VAR
 theList:ListHandle; AddWhere : Integer); 
{This is a routine used to add strings to an }
{existing list} 
VAR 
 cSize  : Point;
 Whichcell: Point;
BEGIN 
 IF (theList <> NIL) THEN 
 BEGIN 
 cSize.h := 0; 
 cSize.v := LAddRow(1, AddWhere, theList);
 LSetCell(@TheString[1], length(TheString),
 cSize, theList);
 LDraw(cSize, theList); {Draw the new string}
 END;
END; 
 
{------------------------}

PROCEDURE DrawList (TheWindow : WindowPtr;
 TheItem : Integer);
{Draw/Update the list which is connected to}
{the useritem TheItem} 
VAR
 TempRect : Rect;
 DType  : Integer;
 DItem  : Handle;
BEGIN
 IF gDragDialog = NIL THEN EXIT(DrawList);
 GetDItem(gDragDialog, TheItem, DType, DItem, tempRect);
 InsetRect(TempRect, -1, -1);
 FrameRect(TempRect);
 CASE TheItem OF
 U_List1:LUpdate(gDragDialog^.VisRgn, gList1);
 U_List2:LUpdate(gDragDialog^.VisRgn, gList2);
 U_List3:LUpdate(gDragDialog^.VisRgn, gList3);
 END;
END;

{------------------------}

PROCEDURE MakeList (WhichList : Integer; VAR
  ListVar : ListHandle);
VAR
 DType  : Integer;
 DItem  : Handle;
 RView, 
 DBounds: Rect;
 CSize  : Point;
BEGIN
 GetDItem (gDragDialog, WhichList, DType, DItem, RView);
 SetRect(DBounds, 0, 0, 1, 0);
 SetPt(CSize, RView.Right - RView.Left, 16);
 ListVar := LNew (RView, DBounds, CSize, 0,
 gDragDialog, TRUE, FALSE, FALSE, TRUE);
 ListVar^^.lClikLoop := ProcPtr(@LtoLClickProc);
 ListVar^^.RefCon := WhichList;
 SetDItem(gDragDialog, WhichList, DType,
 Handle(@DrawList), RView);
END;

{------------------------}

FUNCTION DetectListClick (VAR TheList :
 ListHandle; TheEvent : EventRecord) : BOOLEAN;
{Detect clicks in a list}
VAR
 MyPt : Point;
BEGIN
 DetectListClick := FALSE;
 IF TheList=NIL THEN EXIT(DetectListClick);
 MyPt := theEvent.where;
 GlobalToLocal(MyPt);
 DetectListClick := LClick(myPt,
 theEvent.modifiers, TheList);
END;  {procedure}

{------------------------}

FUNCTION MyFilter (theDialog : DialogPtr; VAR
 theEvent : EventRecord; VAR itemHit : integer) : BOOLEAN;
{catch clicks in the lists or ‘ok’ equivalents}
VAR
 chCode : Integer;
BEGIN
 MyFilter := FALSE;
 CASE theEvent.what OF
   KeyDown, AutoKey :
 WITH theEvent DO
 BEGIN
 chCode := BitAnd(message, CharCodeMask);
 IF (chCode = kEnter) | (chCode = kReturn)
 THEN
   ExitDialog := TRUE;
 END; {with}
 MouseDown :
 MyFilter:=DetectListClick(gList1,TheEvent) |
  DetectListClick(gList2,TheEvent) |
  DetectListClick(gList3,TheEvent);
 END; {case}
END;  {MyFilter}

{------------------------}

PROCEDURE DoDragDialog;
VAR
 TempRect : Rect;
 SavePort : GrafPtr;
 ItemHit: Integer;
 i : Integer;
 
 FUNCTION ToStr (tempint : LongInt) : Str255;
 VAR
 Tempstr : Str255;
 BEGIN
 NumToString(tempint, tempstr);
 ToStr := tempstr;
 END;
 
BEGIN
 ExitDialog := FALSE;
 SetRect (TempRect, 100, 100, 400, 400);
 gDragDialog := GetNewDialog (kDialogID, NIL, WindowPtr(-1));
 IF gDragDialog = NIL THEN EXIT (DoDragDialog);
 GetPort(SavePort);
 SetPort(gDragDialog);
 MakeList (U_List1, gList1);
 MakeList (U_List2, gList2);
 MakeList (U_List3, gList3);
 LDoDraw(FALSE, gList1);
 LDoDraw(FALSE, gList2);
 LDoDraw(FALSE, gList3);
 FOR i := 1 to 20 DO
 BEGIN
 AddListString(Concat(‘List 1, # ‘,ToStr(i)), gList1, i);
 AddListString(Concat(‘List 2, # ‘,ToStr(i)), gList2, i);
 AddListString(Concat(‘List 3, # ‘,ToStr(i)), gList3, i);
 END;
 LDoDraw(TRUE, gList1);
 LDoDraw(TRUE, gList2);
 LDoDraw(TRUE, gList3);
 SetDragEnvironment (gDragDialog);

 REPEAT
 ModalDialog(@MyFilter, itemHit);
 IF ItemHit = B_OK THEN ExitDialog := TRUE;
 UNTIL ExitDialog;
 
 LDispose(gList1);
 LDispose(gList2);
 LDispose(gList3);
 DisposDialog(gDragDialog);
 SetPort(SavePort);
END;

{------------------------}

PROCEDURE Initialize;
BEGIN
 InitGraf(@thePort);
 InitFonts;
 InitWindows;
 InitMenus;
 TEInit;
 InitDialogs(NIL);
 InitCursor;
 InitLtoLDrag;
 Flushevents(everyevent, 0);
 gDragDialog := NIL;
END;
 
BEGIN
 Initialize;
 DoDragDialog;
END.