fix: improve Linux font handling

Author: jarczakpawel

source/apphelpers.pas

@@ -3617,13 +3617,22 @@ constructor TAppSettings.Create;
   InitSetting(asLogFileDdl,                       'LogFileDdl',                            0, False, '', True);
   InitSetting(asLogFileDml,                       'LogFileDml',                            0, False, '', True);
   InitSetting(asLogFilePath,                      'LogFilePath',                           0, False, DirnameUserAppData + 'Logs'+PathDelim+'%session'+PathDelim+'%db'+PathDelim+'%y%m%d.sql', True);
+  {$IFDEF LINUX}
+  // Use generic fontconfig families on Linux.
+  InitSetting(asFontName,                         'FontName',                              0, False, 'monospace');
+  {$ELSE}
   if Screen.Fonts.IndexOf('Consolas') > -1 then
     InitSetting(asFontName,                       'FontName',                              0, False, 'Consolas')
   else
     InitSetting(asFontName,                       'FontName',                              0, False, 'Courier New');
+  {$ENDIF}
   InitSetting(asFontSize,                         'FontSize',                              9);
   InitSetting(asTabWidth,                         'TabWidth',                              3);
+  {$IFDEF LINUX}
+  InitSetting(asDataFontName,                     'DataFontName',                          0, False, 'sans-serif');
+  {$ELSE}
   InitSetting(asDataFontName,                     'DataFontName',                          0, False, 'Tahoma');
+  {$ENDIF}
   InitSetting(asDataFontSize,                     'DataFontSize',                          8);
   InitSetting(asDataLocalNumberFormat,            'DataLocalNumberFormat',                 0, True);
   InitSetting(asLowercaseHex,                     'LowercaseHex',                          0, True);
@@ -4191,6 +4200,15 @@ function TAppSettings.ReadString(Index: TAppSettingIndex; FormatName: String='';
   B: Boolean;
 begin
   Read(Index, FormatName, adString, I, B, Result, 0, False, Default);
+  {$IFDEF LINUX}
+  // Keep imported font settings portable.
+  if FormatName.IsEmpty then begin
+    if (Index = asFontName) and (not SameText(Result, 'monospace')) and (Screen.Fonts.IndexOf(Result) < 0) then
+      Result := 'monospace'
+    else if (Index = asDataFontName) and (not SameText(Result, 'sans-serif')) and (Screen.Fonts.IndexOf(Result) < 0) then
+      Result := 'sans-serif';
+  end;
+  {$ENDIF}
 end;
 
 

source/preferences.pas

@@ -438,8 +438,34 @@ procedure TfrmPreferences.Apply(Sender: TObject);
 end;
 
 
+{$IFDEF LINUX}
+function EnumMonoFontFamilies(
+  var LogFont: TEnumLogFontEx;
+  var Metric: TNewTextMetricEx;
+  FontType: LongInt;
+  Data: LParam
+): LongInt; stdcall;
+var
+  FontList: TStringList;
+  FontName: String;
+begin
+  FontList := TStringList(PtrInt(Data));
+  FontName := LogFont.elfLogFont.lfFaceName;
+  if not FontName.IsEmpty then
+    FontList.Add(FontName);
+  Result := 1;
+end;
+{$ENDIF}
+
+
 // List monospace fonts
 procedure TfrmPreferences.GetMonoFonts(const AList: TStrings);
+{$IFDEF LINUX}
+var
+  DC: HDC;
+  LogFont: TLogFont;
+  FontList: TStringList;
+{$ELSE}
 const
   TestChars = 'ilMW 0';
 var
@@ -448,8 +474,29 @@ procedure TfrmPreferences.GetMonoFonts(const AList: TStrings);
   i: Integer;
   w0, w: Integer;
   IsMono: Boolean;
+{$ENDIF}
 begin
   AList.Clear;
+  {$IFDEF LINUX}
+  FillChar(LogFont, SizeOf(LogFont), 0);
+  LogFont.lfCharSet := DEFAULT_CHARSET;
+  LogFont.lfPitchAndFamily := FIXED_PITCH;
+
+  FontList := TStringList.Create;
+  FontList.Sorted := True;
+  FontList.Duplicates := dupIgnore;
+  DC := GetDC(0);
+  try
+    EnumFontFamiliesEx(DC, @LogFont, @EnumMonoFontFamilies, PtrInt(FontList), 0);
+    AList.Assign(FontList);
+  finally
+    ReleaseDC(0, DC);
+    FontList.Free;
+  end;
+
+  if AList.IndexOf('monospace') < 0 then
+    AList.Insert(0, 'monospace');
+  {$ELSE}
   Bmp := TBitmap.Create;
   try
     for FName in Screen.Fonts do begin
@@ -474,6 +521,7 @@ procedure TfrmPreferences.GetMonoFonts(const AList: TStrings);
   finally
     Bmp.Free;
   end;
+  {$ENDIF}
 end;
 
 
@@ -681,6 +729,10 @@ procedure TfrmPreferences.FormShow(Sender: TObject);
     if not Screen.Fonts[i].StartsWith('@') then
       comboDataFontName.Items.Add(Screen.Fonts[i]);
   end;
+  {$IFDEF LINUX}
+  if comboDataFontName.Items.IndexOf('sans-serif') < 0 then
+    comboDataFontName.Items.Insert(0, 'sans-serif');
+  {$ENDIF}
   comboDataFontName.ItemIndex := comboDataFontName.Items.IndexOf(AppSettings.ReadString(asDataFontName));
   spinDataFontSize.Value := AppSettings.ReadInt(asDataFontSize);
   spinMaxQueryResults.Value := AppSettings.ReadINt(asMaxQueryResults);