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Writing on a bitmap with RichText format

I need to write some richtext formated data(text) to a bitmap. The text is contained in a richtext memo object. I need to get a single line with it's SelAttributes. Onto the bitmap. The attributes would be Ttextattributes only.

EM_GETCHARFORMAT Doesn't seem to work or exists in the messages.unit?

here's a start:

with richtext1 do
begin
// set the line start character index
selstart := perform( em_lineindex, LineNumer, 0 );
// set the length of the line
SelLength := Length( richtext1.Lines[LineNumer]);
// get the line into a tmp string
tmpstr :=SelText;
// get the attributes for this line
tmpatrib:=richtext1.SelAttributes;
end;

I guess my problem is trying to assign the "tmpatrib" properties to the bitmaps's canvas's font (or something) before writing on the bitmap's canvas.

Maybe I'm looking at the problem wrong,don't know.
Thanks for any help!
steve

simonet

My approach would be:

Copy the contents of the RicheEdit's canvas to a temp bitmap (this will be the "image" of the text, not the text itself). Now set the transparent color of the temp bitmap to the background color of the richedit control (let's say clWhite). All you have to do now is place the transparent temp bitmap on top of the first bitmap.

Yours,

Alex
Athena's Place: http://www.bhnet.com.br/~simonet

sz3905

ASKER

Thank You Alex, I'll check the concept out.
Would this still work if:
1) The richtext object's canvas is very large (say 5-32k?)
I may need many lines processed, only one line at a time however?
2) The richtext object's canvas is not visible while we're doing this "canvas copy"?
thx!

sz3905

ASKER

Alex,
Is the richedit object's canvas exposed?
/steve

sz3905

ASKER

Edited text of question.

sz3905

ASKER

Edited text of question.

philipleighs

Have a look at TRichEdit.Print in the VCL.
It uses FormatRange (I think) which writes rich text to a DC.

ASKER CERTIFIED SOLUTION

kretzschmar

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kotik

Hi, sz3905
Here is another example of drawing rich text on a bitmap's canvas.
By the way, EM_GETCHARFORMAT is defined in RichEdit.pas

procedure ShowBMP(ABMP : TBitmap);
begin
Form1.Image1.Canvas.Draw(0, 0, ABMP);
Form1.ShowModal;
end;

procedure DrawRichText;
var Bmp : TBitmap;
begin
Bmp := TBitmap.Create;
Bmp.Width := 100;
Bmp.Height := 100;
Bmp.Canvas.Brush.Color := clWhite;
Bmp.Canvas.Brush.Style := bsSolid;
Bmp.Canvas.FillRect(Rect(0, 0, Bmp.Width, Bmp.Height));
{Here set the selection in the RichEdit}
Bmp.Canvas.Font.Name := Editor.SelAttributes.Name;
Bmp.Canvas.Font.Size := Editor.SelAttributes.Size;
Bmp.Canvas.Font.Color := Editor.SelAttributes.Color;
Bmp.Canvas.Font.Style := Editor.SelAttributes.Style;
Bmp.Canvas.TextOut(10, 10, Editor.SelText);
ShowBMP(Bmp);
end;

kretzschmar

hi kotik,

this idea i had also

this part

Bmp.Canvas.Font.Name := Editor.SelAttributes.Name;
Bmp.Canvas.Font.Size := Editor.SelAttributes.Size;
Bmp.Canvas.Font.Color := Editor.SelAttributes.Color;
Bmp.Canvas.Font.Style := Editor.SelAttributes.Style;

can replaced with

Bmp.Canvas.Font.Assign(Editor.SelAttributes);

the problem by this line is that the text has a white background

Bmp.Canvas.TextOut(10, 10, Editor.SelText)

well, it doesnt matter, if the destination-Bitmap is white
i'm working about to write the text to a bmp with a picture

meikl ;-)

kretzschmar

hi sz3905,

thats better, writes the Richtext line on the Bitmap and
leave the Background of the Bitmap as it was,
works now also with colored text.

Procedure CopyLineFromRichEditToBitmap(R : TRichEdit;
Line : Integer;
B : TBitMap;
AtPos : TPoint);
var
I, C, MH, H, W : Integer; //Counter, CharPos, MaxHeight, CharHeight, CharWidth
TB, TB2 : TBitmap; //Temporary Bitmaps
begin
TB := TBitmap.Create; //Create Temporary
TB2 := TBitmap.Create;
MH := 0; //Initialize
H := 0;
TB.Height := 100;
TB.Width := 5;
C := R.Perform(EM_LINEINDEX,Line,0);
for I := 0 to Length(R.Lines[Line]) do //Paint Line
begin
R.Selstart := C+I;
R.SelLength := 1;
TB.Canvas.Font.Assign(R.SelAttributes); //Assign CharAttributes
W := TB.Canvas.TextWidth(R.SelText);
TB.Width := TB.Width + W; //Expand Bitmap
H := TB.Canvas.TextHeight(R.SelText);
if MH < H then // MaxHeight
MH := H;
TB.Canvas.TextOut(TB.Width-W,50-h,R.SelText); //Paint a Char
end;
TB2.Width := TB.Width - 5; //adjust Painting Rect
Tb2.Height := MH;
TB2.Canvas.CopyRect(Rect(0,0,TB2.Width,TB2.Height),TB.Canvas,Rect(5,50-mh,tb.width,50));
TB2.Transparent := True; //Prepare
TB2.TransparentMode := tmFixed;
TB2.TransparentColor := clWhite;
B.Canvas.Draw(AtPos.x,AtPos.Y,TB2); //Paint to Original
TB2.Free; //Free Memory
TB.Free;
end;

meikl

kretzschmar

appendix,
by this sample
a line can contain multiple styles, fonts, colors

meikl ;-)

sz3905

ASKER

Thanks kotik for your insight.
------------------------------

Thanks Meikl!
I will run your idea. It's being used in a display system so I need to make it faster. Thanks for the Jump Start!
/steve