Newline in canvas.Textout
lazarus / 39-Graphics

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cov · 2013-06-07 09:21

Hi,

I have a string 'A long sentence which is split'+#13+#10+'over
multiple lines'.

I'm using Canvas.Textout to write it to the Canvas.

Is there a way of doing this neatly?

Or must I split it into a TStringList and TextOut each entry?

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Zoran · 2013-06-07 09:42

Canvas has TextOut and TextRect methods which does the same - write
text to canvas, but TextRect seems to be more adjustible.
Instead of Canvas.TextOut, use Canvas.TextRect, but first adjust
Canvas.TextStyle as in the following example:
Code: [Select]procedure TForm1.FormPaint(Sender: TObject);
var
  TextStyle: TTextStyle;
begin
  TextStyle := Canvas.TextStyle;
  TextStyle.SingleLine := False;
  TextStyle.Wordbreak := True;
  TextStyle.Opaque := False;
  Canvas.TextStyle := TextStyle;
  Canvas.TextOut(5, 5, 'trt' + LineEnding + 'mrt'); // line breaking
does not work
  Canvas.TextRect(Self.ClientRect, 45, 45, 'trt' + LineEnding +
'mrt'); // line breaking works!
end;

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exdatis · 2013-06-07 10:10

Thank you very much Zoran.

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cov · 2013-06-07 10:41

Yes, indeed, thanks, Zoran.

A question, though: TextRect requires 4 arguments: a TRect, an X
position, a Y position and the string.

How do you define the TRect?

if TextExtent:=Image1.Canvas.TextExtent('A long sentence which is
split'+#13+#10+'over multiple lines');

I would have thought that giving Rect(0,0,TextExtent.cx,TextExtent.cy)
would have been okay.

But it seems that the following is needed:

Image1.Canvas.TextRect(Rect(x,y,TextExtent.cx+x,TextExtent.cy+y),x,y,'
A long sentence which is split'+#13+#10+'over multiple lines');

Is this correct?

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Zoran · 2013-06-07 12:09

Quote from: exdatis on June 07, 2013, 12:10:43 pmThank you very much
Zoran.


Quote from: cov on June 07, 2013, 12:41:56 pmYes, indeed, thanks,
Zoran.

You are welcome

Quote from: cov on June 07, 2013, 12:41:56 pmA question, though:
TextRect requires 4 arguments: a TRect, an X position, a Y position
and the string.

How do you define the TRect?

if TextExtent:=Image1.Canvas.TextExtent('A long sentence which is
split'+#13+#10+'over multiple lines');

I would have thought that giving Rect(0,0,TextExtent.cx,TextExtent.cy)
would have been okay.

But it seems that the following is needed:

Image1.Canvas.TextRect(Rect(x,y,TextExtent.cx+x,TextExtent.cy+y),x,y,'
A long sentence which is split'+#13+#10+'over multiple lines');

Is this correct?

It seems to be correct. I know nothing more about it than what I
learned by trying. Try for yourself.
When TextStyle.Opaque is set to True, you can see the rectangle.
I suggest you to play with TextStyle values and see what you get.

See here about TextStyle values: http://lazarus-
ccr.sourceforge.net/docs/lcl/graphics/ttextstyle.html

Something about TextRect method: http://lazarus-
ccr.sourceforge.net/docs/lcl/graphics/tcanvas.textrect.html. You can
see there that you can also use TextStyle directly as a TextRect
parameter, in longer version of this method (instead of setting the
Canvas.TextStyle property).