paweld/lazarus
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/lazarus/lazarus.git synced 2025-06-04 10:18:18 +02:00
Code Issues Packages Projects Releases Wiki Activity

LCL, DbImage implements loading stream directly if it doesn't have a known header, WriteHeader property to make writing img header optional

Browse Source 
git-svn-id: trunk@43779 -
This commit is contained in:
jesus 2014-01-22 08:12:23 +00:00
parent db5590d263
commit 7ee5132796
2 changed files with 57 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lcl/dbctrls.pp
View File

@ -974,6 +974,7 @@ Type
FQuickDraw: Boolean;
FPictureLoaded: boolean;
FUpdatingRecord: boolean;
FWriteHeader: Boolean;
function GetDataField: string;
function GetDataSource: TDataSource;
function GetField: TField;
@ -1025,6 +1026,7 @@ Type
property Stretch;
property Transparent;
property Visible;
property WriteHeader: Boolean read FWriteHeader write FWriteHeader default True;
end;
{ TDBCalendar }

68
lcl/include/dbimage.inc
View File

@ -104,7 +104,10 @@ begin
if assigned(FOnDBImageWrite) then
OnDBImageWrite(self,s,fe) //Call extermal method to save type of image
else
s.WriteAnsiString(fe); //otherwise write file extension to stream
begin
if FWriteHeader then
s.WriteAnsiString(fe); //otherwise write file extension to stream
end;
Picture.Graphic.SaveToStream(s);
finally
s.Free;
@ -125,7 +128,21 @@ var s : Tstream;
GraphExt : string;
gc : TGraphicClass;
AGraphic : TGraphic;
CurPos : Int64;
function LoadImageFromStream: boolean;
begin
result := (s<>nil);
if result then
try
curPos := s.Position;
Picture.LoadFromStream(s);
except
s.Position := Curpos;
result := false;
end;
end;
begin
if not FPictureLoaded then
begin
@ -136,35 +153,59 @@ begin
begin
if FDatalink.field is TBlobField then
begin
if FDatalink.Field.IsNull then
begin
Picture.Clear;
exit;
end;
s := FDataLink.DataSet.CreateBlobStream(FDataLink.Field,bmRead);
if (S=Nil) or (s.Size = 0) then
begin
Picture.Clear;
exit;
end;
AGraphic := nil;
try
AGraphic := nil;
GraphExt := '';
//External method to identify graphic type
//returns file extension for graphic type (e.g. jpg)
if assigned(FOnDBImageRead) then
OnDBImageRead(self,s,GraphExt) //External method to identify graphic type
//returns file extension for graphic type (e.g. jpg)
OnDBImageRead(self,s,GraphExt)
else
GraphExt := s.ReadAnsiString; //Read file extension Graphic type from stream
gc := GetGraphicClassForFileExtension(GraphExt);
if assigned(gc) then
begin
AGraphic := gc.Create;
AGraphic.LoadFromStream(s);
Picture.Assign(AGraphic);
CurPos := s.Position;
try
GraphExt := s.ReadAnsiString;
except
s.Position := CurPos;
GraphExt := '';
end;
end;
if GraphExt <> '' then
begin
gc := GetGraphicClassForFileExtension(GraphExt);
if gc<>nil then
begin
AGraphic := gc.Create;
AGraphic.LoadFromStream(s);
Picture.Assign(AGraphic);
end
else
GraphExt := ''; // try next loading direct stream
end;
if GraphExt = '' then
begin
if not LoadImageFromStream then
Picture.Clear;
end;
finally
if assigned(AGraphic) then AGraphic.Free;
AGraphic.Free;
s.Free;
end {try}
@ -194,6 +235,7 @@ begin
ControlStyle:=ControlStyle+[csReplicatable];
FAutoDisplay:=True;
FQuickDraw:=true;
FWriteHeader:=True;
FDataLink:=TFieldDataLink.Create;
FDataLink.Control:=Self;
FDataLink.OnDataChange:=@DataChange;