move the caching of the filelist into the win32 implementation becaus…

…e only there the problem ever happens in the first place

dragdropgtk2.pas

@@ -94,17 +94,18 @@ procedure GtkDragDataGet(GtkW: PGtkWidget;
 
     FMT_FILELIST:
     begin
-      FileList := Src.CallOnDragGetFileList;
+      FileList := TStringList.Create;
+      Src.CallOnDragGetFileList(FileList);
       if FileList.Count > 0 then begin
         SetLength(A, FileList.Count);
         for I := 0 to FileList.Count - 1 do begin
-          if LeftStr(FileList.Strings[I], 7) <> 'file://' then
-            FileList.Strings[I] := 'file://' + FileList.Strings[i];
+          FileList.Strings[I] := 'file://' + FileList.Strings[i];
           A[i] := PChar(FileList.Strings[I]);
         end;
         A[FileList.Count] := nil;
         gtk_selection_data_set_uris(SelData, @A[0]);
       end;
+      FileList.Free;
     end;
   end;
 end;

dragdropqt4.pas

@@ -88,7 +88,8 @@ procedure StartDrag(Src: TNativeDragSource);
   end;
 
   if Assigned(Src.OnDragGetFileList) then begin
-    FileList := Src.CallOnDragGetFileList;
+    FileList := TStringList.Create;
+    Src.CallOnDragGetFileList(FileList);
     if FileList.Count > 0 then begin
       // we don't have QMimeData_setUrls() in libQt4Pas
       // unfortunately, so we must fiddle around with the
@@ -101,6 +102,7 @@ procedure StartDrag(Src: TNativeDragSource);
       MimeName := 'text/uri-list';
       QMimeData_setData(MimeObj, @MimeName, ByteArray);
     end;
+    FileList.Free;
   end;
 
   if Assigned(Mime) then begin

dragdropwin32.pas

@@ -102,6 +102,7 @@   TDropSource = class(TInterfacedObject, IDropSource)
   TDataObject = class(TInterfacedObject, IDataObject)
   public
     constructor Create(Src: TNativeDragSource);
+    destructor Destroy; override;
     function GetData(const formatetcIn: FORMATETC; out medium: STGMEDIUM): HRESULT; STDCALL;
     function GetDataHere(const pformatetc: FormatETC; out medium: STGMEDIUM): HRESULT; STDCALL;
     function QueryGetData(const pformatetc: FORMATETC): HRESULT; STDCALL;
@@ -113,9 +114,11 @@   TDataObject = class(TInterfacedObject, IDataObject)
     function EnumDAdvise(out enumAdvise: IEnumStatData): HResult; StdCall;
   private
     FSrc: TNativeDragSource;
+    FFileList: TStringList;
     FFmtList: array of FORMATETC;
     function HaveThisFormat(const AFmt: TFORMATETC): Boolean;
     procedure AddFormat(Fmt: FORMATETC);
+    function GetSrcFileList: TStringList;
   end;
 
 {$note SHCreateStdEnumFmtEtc() definition in shlobj is wrong, report this bug}
@@ -139,6 +142,7 @@ constructor TDataObject.Create(Src: TNativeDragSource);
 begin
   inherited Create;
   FSrc := Src;
+  FFileList := nil;
   if Assigned(Src.OnDragGetFileList) then begin
     AddFormat(TGT_FILELIST);
   end;
@@ -148,6 +152,13 @@ constructor TDataObject.Create(Src: TNativeDragSource);
   end;
 end;
 
+destructor TDataObject.Destroy;
+begin
+  if Assigned(FFileList) then
+    FreeAndNil(FFileList);
+  inherited Destroy;
+end;
+
 function TDataObject.GetData(const formatetcIn: FORMATETC; out medium: STGMEDIUM): HRESULT; STDCALL;
 var
   FileList: TStringList;       // Filenames must be UTF8 encoded
@@ -181,7 +192,7 @@ function TDataObject.GetData(const formatetcIn: FORMATETC; out medium: STGMEDIUM
     case formatetcIn.CfFormat of
       CF_HDROP:
       begin
-        FileList := FSrc.CallOnDragGetFileList;
+        FileList := GetSrcFileList;
 
         // First we need a widestring #0 sepatated and #0#0 at the end.
         WideStringData := '';
@@ -315,6 +326,15 @@ procedure TDataObject.AddFormat(Fmt: FORMATETC);
   FFmtList[I] := Fmt;
 end;
 
+function TDataObject.GetSrcFileList: TStringList;
+begin
+  if not Assigned(FFileList) then begin
+    FFileList := TStringList.Create;
+    FSrc.CallOnDragGetFileList(FFileList);
+  end;
+  Result := FFileList;
+end;
+
 { TDragSource }
 
 constructor TDropSource.Create(Src: TNativeDragSource);

nativednd.pas

@@ -83,7 +83,6 @@   TNativeDragSource = class(TComponent)
     FOldMouseMove: TMouseMoveEvent;
     FMouseDownPos: TPoint;
     FIsDragging: Boolean;
-    FFileListCache: TStringList;
     procedure UnsetControl;
     procedure SetControl(AControl: TWinControl);
     procedure MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
@@ -94,7 +93,7 @@   TNativeDragSource = class(TComponent)
     InternalData: TObject; // widgetset code may store internal stuff here
     procedure CallOnDragBegin;
     procedure CallOnDragEnd;
-    function CallOnDragGetFileList: TStringList;
+    procedure CallOnDragGetFileList(FileList: TStringList);
     procedure CallOnDragStringData(out StringData: UTF8String);
     property IsDragging: Boolean read FIsDragging;
   published
@@ -128,7 +127,6 @@ constructor TNativeDragSource.Create(AOwner: TComponent);
   FEndEvent := nil;
   FMouseDownPos := Point(-1, -1);
   FIsDragging := False;
-  FFileListCache := nil;
 end;
 
 procedure TNativeDragSource.UnsetControl;
@@ -204,14 +202,10 @@ procedure TNativeDragSource.CallOnDragBegin;
     OnDragBegin(Control, FMouseDownPos.X, FMouseDownPos.Y);
 end;
 
-function TNativeDragSource.CallOnDragGetFileList: TStringList;
+procedure TNativeDragSource.CallOnDragGetFileList(FileList: TStringList);
 begin
-  if not Assigned(FFileListCache) then begin
-    FFileListCache := TStringList.Create;
-    if Assigned(OnDragGetFileList) then
-      OnDragGetFileList(Control, FFileListCache);
-  end;
-  Result := FFileListCache;
+  if Assigned(OnDragGetFileList) then
+    OnDragGetFileList(Control, FileList);
 end;
 
 procedure TNativeDragSource.CallOnDragStringData(out StringData: UTF8String);
@@ -225,10 +219,6 @@ procedure TNativeDragSource.CallOnDragEnd;
   FIsDragging := False;
   if Assigned(OnDragEnd) then
     OnDragEnd(Control);
-  if Assigned(FFileListCache) then begin
-    FFileListCache.Free;
-    FFileListCache := nil;
-  end;
 end;
 
 procedure Register;