RichMemo LineSpacing does not work in Linux?
lazarus / 8-Other

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paxnet_be · 2024-01-23 13:23

Hi,

I tested in RichMemo both procedures SetParaMetric and
SetRangeParaParams with LineSpacing.

Both procedures works well in Windows, but not in Linux. What did I
miss?

See here the code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
uLineSpacing; {$mode objfpc}{$H+} interface uses  Classes, SysUtils,
Forms, Controls, Graphics, Dialogs, StdCtrls, Menus,  RichMemo; type  
{ TForm1 }   TForm1 = class(TForm)    Button1: TButton;   
RatioSingle: TMenuItem;    RatioOneHalf: TMenuItem;    RatioDouble:
TMenuItem;    PMLineSpacing: TPopupMenu; // PM = PopMenu    RichMemo1:
TRichMemo;    procedure Button1Click(Sender: TObject);    procedure
RatioSingleClick(Sender: TObject);    procedure
RatioOneHalfClick(Sender: TObject);    procedure
RatioDoubleClick(Sender: TObject);  private    ParagraphMetric:
TParaMetric;  public   end; var  Form1: TForm1; implementation {$R
*.lfm} { TForm1 } procedure TForm1.Button1Click(Sender:
TObject);begin  {    PopUp menu with 3 items:    1.0: OnClick -->
RatioSingleClick    1.5: OnClick --> RatioOneHalfClick    2.0: OnClick
--> RatioDoubleClick  }  PMLineSpacing.PopUp;end; procedure
TForm1.RatioSingleClick(Sender: TObject);begin 
InitParaMetric(ParagraphMetric);  with RichMemo1 do begin   
GetParaMetric(SelStart, ParagraphMetric);   
ParagraphMetric.LineSpacing := DefLineSpacing;    ShowMessage('Line
Space:' + #13 +                'SelStart = ' + IntToStr(SelStart) +
#13 +                'SelLength = ' + IntToStr(SelLength) + #13 +    
          'LineSpacing = ' +
FloatToStr(ParagraphMetric.LineSpacing));    {      The use of
SetParaMetric or SetRangeParaParams works both well      in Windows,
but not in Linux.    }    SetParaMetric(SelStart, SelLength,
ParagraphMetric);    //SetRangeParaParams(SelStart, SelLength,
[pmm_LineSpacing], ParagraphMetric);  end;end; procedure
TForm1.RatioOneHalfClick(Sender: TObject);begin 
InitParaMetric(ParagraphMetric);  with RichMemo1 do begin   
GetParaMetric(SelStart, ParagraphMetric);   
ParagraphMetric.LineSpacing := DefLineSpacing * 1.5;   
ShowMessage('One Half Line Space:' + #13 +                'SelStart =
' + IntToStr(SelStart) + #13 +                'SelLength = ' +
IntToStr(SelLength) + #13 +                'LineSpacing = ' +
FloatToStr(ParagraphMetric.LineSpacing));    {      The use of
SetParaMetric or SetRangeParaParams works both well      in Windows,
but not in Linux.    }    SetParaMetric(SelStart, SelLength,
ParagraphMetric);    //SetRangeParaParams(SelStart, SelLength,
[pmm_LineSpacing], ParagraphMetric);  end;end; procedure
TForm1.RatioDoubleClick(Sender: TObject);begin 
InitParaMetric(ParagraphMetric);  with RichMemo1 do begin   
GetParaMetric(SelStart, ParagraphMetric);   
ParagraphMetric.LineSpacing := DefLineSpacing * 2;   
ShowMessage('Double Line Space:' + #13 +                'SelStart = '
+ IntToStr(SelStart) + #13 +                'SelLength = ' +
IntToStr(SelLength) + #13 +                'LineSpacing = ' +
FloatToStr(ParagraphMetric.LineSpacing));    {      The use of
SetParaMetric or SetRangeParaParams works both well      in Windows,
but not in Linux.    }    SetParaMetric(SelStart, SelLength,
ParagraphMetric);    //SetRangeParaParams(SelStart, SelLength,
[pmm_LineSpacing], ParagraphMetric);  end;end; end. 
Thanks in advance for your comments.
--------------------------
Lazarus 3.0 (rev lazarus_3_0) FPC 3.2.2 x86_64-linux-gtk2

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Thaddy · 2024-01-23 14:39

:'(Change #13 to LineSpacing,  or sLinebreak which is a default
constant per platform.  Under windows it is #13#10, under linux it is
just #10.

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paxnet_be · 2024-01-23 14:56

Sorry Thaddy, I was meaning the vertical line spacing, not the
horizontal. #13 is just for ShowMessage, but you are write about it.

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rvk · 2024-01-23 17:14

Quote from: Thaddy on January 23, 2024, 03:39:28 pm :'(Change #13 to
LineSpacing,  or sLinebreak which is a default constant per platform. 
Under windows it is #13#10, under linux it is just #10.
You are correct for the #13, but you might have missed that this is
only used for the ShowMessage, NOT for the RichMemo itself.

@paxnet_be
The linespacing is done correctly WITHIN the paragraph on
Linux/TRichMemo. But when using linebreak (enter) you begin a new
paragraph. If you, for example, type a very long line and let it wrap
a few times, then select that text/paragraph and press your button,
you'll see the linespacing change. So the TRichMemo interprets the
linespacing different for Windows vs Linux (because there it's for
every linebreak including inside a paragraph).

(You could try to play with ParagraphMetric.SpaceBefore but you'll
need to set that per paragraph, you can't do that for a selection and
have it be for every line.)

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paxnet_be · 2024-01-24 05:52

Thank you, RVK, I tried with word wrapping, and indeed it works that
way.
So the different interpretation in Windows and Linux is what I missed.
Case resolved. 
Now I have to figure out, how I could apply it with several
paragraphs.

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rvk · 2024-01-24 08:29

Quote from: paxnet_be on January 24, 2024, 06:52:42 amNow I have to
figure out, how I could apply it with several paragraphs. 
Actually, setting ParagraphMetric.SpaceBefore := 15 * DefLineSpacing
did apply to all paragraphs for me (selecting multiple
lines/paragraphs).

(I used 15 as an example for fontpixelsize which is used in setting
ParagraphMetric.LineSpacing)

But when setting it back to 0 it somehow switched the SpaceBefore to
SpaceAfter.
Not sure why, could be due to the GetParaMetric at SelStart.
(Doing it multiple times it did get back to 0   )

The relevant code for setting the paragraph in Linux is:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i   tag :=
gtk_text_buffer_create_tag (buffer, nil,      'pixels-above-lines',  
[ gint(round(AMetric.SpaceBefore*DPIFactor)),      'pixels-above-
lines-set', gboolean(gTRUE),      'pixels-below-lines',    
gint(round(AMetric.SpaceAfter*DPIFactor)),      'pixels-below-lines-
set', gboolean(gTRUE),      'left-margin',          
 gint(round(h*DPIFactor)),      'left-margin-set',      
 gboolean(gTRUE),      'right-margin',          
gint(round(AMetric.TailIndent*DPIFactor)),      'right-margin-set',  
   gboolean(gTRUE),      'indent',                
gint(round(fl*DPIFactor)),      'indent-set',            
gboolean(gTRUE),      'pixels-inside-wrap',    
gint((round(fp.Size*(AMetric.LineSpacing-
DefLineSpacing)*DPIFactor))),      'pixels-inside_wrap-set',
gboolean(gTRUE),      nil]);You can find documentation for gtktexttag
everywhere.
http://irtfweb.ifa.hawaii.edu/SoftwareDocs/gtk20/gtk/gtktexttag.html

See the fp.Size* in pixels-inside-wrap but not in pixels-above-lines.
So SpaceBefore and SpaceAfter are in pixels. You need to multiply them
with the DefLineSpacing * FontPixelHeight.

Further... for Linux you need to apply both the SpaceBefore (for the
paragraph) AND LineSpacing (for inside the paragraph) to get what you
want, where on Windows just LineSpacing would suffice (so you need to
work with {$IFDEF LINUX} for that).

Happy coding

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paxnet_be · 2024-02-14 16:10

Thanks to you RVK, for the GTK-tips.

Before I was able to apply them, I had to teach myself a little bit
about GTK. After searching for information, I found a GTK manual for
Free Pascal at:

  https://www.mimuw.edu.pl/~zbyszek/pgtk/html/contents.html

All examples works with the FP-IDE (some with minor changes), except
for the calendar, wich gives GTK-crtical errors, that I was not able
to fix with my knowledge as a novice.

Then I applied your tips in my Lazarus program, without success, until
... I copied the values of SelStart and SelLength into a local
variable and then passed these to the function SetParaMetric...

Finally, it turned out, that GTK calls are not required in Linux, only
(local) variables with the values of SelStart and SelLength are
needed. Why I don't know. 

Here the working code: 

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
uLineSpacing; {$mode objfpc}{$H+} interface uses  Classes, SysUtils,
Forms, Controls, Graphics, Dialogs, StdCtrls, Menus,  RichMemo; type  
{ TForm1 }   TForm1 = class(TForm)    Button1: TButton;   
RatioSingle: TMenuItem;    RatioOneHalf: TMenuItem;    RatioDouble:
TMenuItem;    PMLineSpacing: TPopupMenu; // PM = PopupMenu   
RichMemo1: TRichMemo;    procedure Button1Click(Sender: TObject);   
procedure RatioSingleClick(Sender: TObject);    procedure
RatioOneHalfClick(Sender: TObject);    procedure
RatioDoubleClick(Sender: TObject);  private    ParagraphMetric:
TParaMetric;  public   end; const  DPIFactor = 1.3333; // = 96 / 72
(Unit = Pixel / Point)var  Form1: TForm1;  //Tag: PGtkTextTag; 
//Buffer: PGtkTextBuffer; implementation {$R *.lfm} { TForm1
} procedure TForm1.Button1Click(Sender: TObject);begin  {    PopUp
menu with 3 items:    1.0: OnClick --> RatioSingleClick    1.5:
OnClick --> RatioOneHalfClick    2.0: OnClick --> RatioDoubleClick  } 
PMLineSpacing.PopUp;end; procedure TForm1.RatioSingleClick(Sender:
TObject);var  RMTextStart, RMTextLen: Integer;begin 
InitParaMetric(ParagraphMetric);  with RichMemo1 do begin   
GetParaMetric(SelStart, ParagraphMetric);    {      The function
SetParaMetric does not use the variables      SelStart and SelLength
properly in Linux (why?),      so we save their values in local
variables:    }    RMTextStart := SelStart;    RMTextLen :=
SelLength;    ParagraphMetric.LineSpacing := DefLineSpacing; // Single
ratio    ParagraphMetric.SpaceBefore := ParagraphMetric.LineSpacing; 
 SetParaMetric(RMTextStart, RMTextLen, ParagraphMetric); 
end;end; procedure TForm1.RatioOneHalfClick(Sender: TObject);var 
RMTextStart, RMTextLen: Integer;begin 
InitParaMetric(ParagraphMetric);  with RichMemo1 do begin   
GetParaMetric(SelStart, ParagraphMetric);    {      The function
SetParaMetric does not use the variables      SelStart and SelLength
properly in Linux (why?),      so we save their values in local
variables:    }    RMTextStart := SelStart;    RMTextLen :=
SelLength;    ParagraphMetric.LineSpacing := DefLineSpacing * 1.5; //
One half ratio    ParagraphMetric.SpaceBefore :=
ParagraphMetric.LineSpacing * 2;    SetParaMetric(RMTextStart,
RMTextLen, ParagraphMetric);  end;end; procedure
TForm1.RatioDoubleClick(Sender: TObject);var  RMTextStart, RMTextLen:
Integer;begin  InitParaMetric(ParagraphMetric);  with RichMemo1 do
begin    GetParaMetric(SelStart, ParagraphMetric);    {      The
function SetParaMetric does not use the variables      SelStart and
SelLength properly in Linux (why?),      so we save their values in
local variables:    }    RMTextStart := SelStart;    RMTextLen :=
SelLength;    ParagraphMetric.LineSpacing := DefLineSpacing * 2; //
Double ratio    ParagraphMetric.SpaceBefore :=
ParagraphMetric.LineSpacing * 4;    SetParaMetric(RMTextStart,
RMTextLen, ParagraphMetric);  end;end; end. 
Cheers!
Pax_Be