Advance text rendering on canvas

[stoffman]

Hi,

I'm familiar with TextOut. But I'm looking for something along the lines of Win32 DrawTextEx (That provides alignment, word wrapping and some other niceties) that is also cross platform. It would be great if it also supports different colors (TextOut/DrawTextEx uses the current pen color)   

Any suggestions ?

https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-drawtextexa

Thanks,

[wp]

AFAIK, DrawTextEx is not available in LCLIntf, in contrast to DrawText. The basic DrawText functionality is also available in the TCanvas.TextRect method which respects the TextStyle record of TCanvas.

Code: Pascal  [Select][+][-]

1. type
2.   TTextStyle = packed record
3.     Alignment : TAlignment;  // TextRect Only: horizontal alignment
4.  
5.     Layout    : TTextLayout; // TextRect Only: vertical alignment
6.  
7.     SingleLine: boolean;     // If WordBreak is false then process #13, #10 as
8.                              // standard chars and perform no Line breaking.
9.  
10.     Clipping  : boolean;     // TextRect Only: Clip Text to passed Rectangle
11.  
12.     ExpandTabs: boolean;     // Replace #9 by apropriate amount of spaces (default is usually 8)
13.  
14.     ShowPrefix: boolean;     // TextRect Only: Process first single '&' per
15.                              //    line as an underscore and draw '&&' as '&'
16.  
17.     Wordbreak : boolean;     // TextRect Only: If line of text is too long
18.                              //    too fit between left and right boundaries
19.                              //    try to break into multiple lines between
20.                              //    words
21.                              //    See also EndEllipsis.
22.  
23.     Opaque    : boolean;     // TextRect: Fills background with current Brush
24.                              // TextOut : Fills background with current
25.                              //            foreground color
26.  
27.     SystemFont: Boolean;     // Use the system font instead of Canvas Font
28.    
29.     RightToLeft: Boolean;    //For RightToLeft text reading (Text Direction)
30.  
31.     EndEllipsis: Boolean;    // TextRect Only: If line of text is too long
32.                              //    to fit between left and right boundaries
33.                              //    truncates the text and adds "..."
34.                              //    If Wordbreak is set as well, Workbreak will
35.                              //    dominate.
36.   end;
37.  
38.   TCanvas = class(TFPCustomCanvas)
39.   ...
40.     procedure TextRect(const ARect: TRect; X, Y: integer; const Text: string);
41.     procedure TextRect(ARect: TRect; X, Y: integer; const Text: string;
42.                        const Style: TTextStyle); virtual;
43.   end;

[jamie]

it's unfortunate the canvas.TextRect(… did not define the TRECT as a VAR because you can not use that function if all you want to do is simply calculate the rectangle without painting.


However, all is not lost..

 the LCLINTF unit which makes cross platform calls does have the DrawText which accepts the same parameters as the windows counter part..

 So all one needs to do is just include the unit.