Watermark: Positioning an image

rodrigomilha

Hello,
We're having troubles with positioning an watermark image in a specific X & Y coordenates. We're tryng to get the coordenates from the cursor position using the GetYPositionTw, GetXPositionTw and using this information to set the Canvas.StretchDraw to print the image, but is not working. The image is not at the exactly position, and there are some randomic results.
Please, help us! We need an example!

support

Please first check if the X,Y position you have is reasonable.

Then make sure that the X.Y positiion in your StretchDraw command use the correct resolution. THe resolution is passed as a parmeter to the event.

Julian Ziersch

rodrigomilha

Thank you, Julian, for your help, but i guess my explanation was not good. In fact, what we're trying to do is:

Based on a position of a word inside the text, we're positioning the cursor exactly at the first letter of this word and getting the X & Y coordenates based on the functions GetYPositionTw and GetXPositionTw. Then, we put the following code in the event OnPaintPage:

Code

procedure TWordPadForm.WPRichText1PaintPage(Sender: TObject;
  toCanvas: TCanvas; PageRect: TRect; XRes, YRes, PageNo: Integer;
  firstpar: PTParagraph; firstline: PTLine;
  BufferObj: TWPPageBackgroundBuffer);
var r : TRect;
    offx, offy : Integer;
    ScaleX, ScaleY: Integer;
    vLeft: integer;
    vTop: integer;
    vRight: integer;
    vBottom: integer;
    x, y: integer;
    leftMargin, topMargin: double;
begin
  r := PageRect;
  topMargin := WPTwipsToCentimeter(WPRichText1.Header.TopMargin);
  leftMargin := 7; // fixed left margin
  topMargin := topMargin + WPTwipsToCentimeter(WPRichText1.GetYPositionTw);
  if WPRichText1.PrintParameter.Printing then
  begin
        toCanvas.Pen.Color := clBlack; // on Printer !
        // Please note that if we print we need to respect the physical offset
        // This is calculated in the printer engine and provided as twips
       offx := MulDiv(WPRichText1.PrintParameter.PrintXOffset, XRes,    1440);
    offy := MulDiv(WPRichText1.PrintParameter.PrintYOffset, YRes, 1440);
    // Subtract the pysical offset since the printer is adding this anyway
    dec(r.Left, offx);
    dec(r.Top, offy);
    dec(r.Right, offx);
    dec(r.Bottom, offy);
    y := round(topMargin * 37.15) + round(WPTwipsToCentimeter  (WPRichText1.GetYPositionTw) * 0.5);
    x := round((leftMargin * 37.15));
    vLeft   := r.Left + round(x*6.25);
    vTop    := r.Top + round(y*6.25);
    // image : 250 width and 50 heigth
    vRight  := vLeft + round(250*6.25);
    vBottom := vTop + round(50*6.25);
    // Image2.Picture.Graphic - fixed image
    toCanvas.StretchDraw(Rect(vLeft, vTop, vRight, vBottom), Image2.Picture.Graphic);
  end
  else
  begin
    toCanvas.Pen.Color := clGray; // On screen
    r := PageRect;
    y := round(topMargin * 37.15) + round(WPTwipsToCentimeter(WPRichText1.GetYPositionTw) * 0.5);
    x := round((leftMargin * 37.15));
    vLeft   := r.Left + x;
    vTop    := r.Top + y;
    // image : 250 width and 50 heigth
    vRight  := vLeft + 250;
    vBottom := vTop + 50;
    // Image2.Picture.Graphic - fixed image
    toCanvas.StretchDraw(Rect(vLeft, vTop, vRight, vBottom), Image2.Picture.Graphic);
  end;
end;

Alles anzeigen

With this code, we're having troubles positioning the image. Sometimes the image is in the correct place, sometimes not. What we have to do to put the image always at the correct place?

support

Hi,

I see this code:

y := round(topMargin * 37.15) + round(WPTwipsToCentimeter (WPRichText1.GetYPositionTw) * 0.5);
x := round((leftMargin * 37.15));

This does not look right for two reasons.

a) You should keep the topMargin in twips and calculate the y like this:
y := MulDiv( topMargin + twipspos, yres, 1440)

b) WPRichText1.GetYPositionTw makes no sense here. The position of the cursor is absolutely random when this event is triggered.

If you need to place an image at a certain position you need to store that position with the image, use its position in place of 'twipspos' in the formula above. You will also need to store the page number and find the image for tbne correct page.

Better use WPTools 5 - it has a very stable support for images placed at a fixed position on a page and that can be also moved interactively - and flickerfree..

Julian

rodrigomilha

Thank you, Julian! It works very well! Now we got the correct result and our users are very thankful! We're using WPTools since 2K year and there's nothing better in the world to RTF edition. Your component is fantastic and we like to give you congratulations for this great work. Now, we are not using the Microsoft Word in our company 'cause we developed an entire editor based on WPTools, with almost every functions of the Microsoft product! We're showing your solution to many others companies, and we're always asked about a version of WPTools for JAVA. Are you thinking about that?

Thanks,
Rodrigo