version 6.3 - vcl font scaling review

CompInstall.ini

@@ -3,7 +3,7 @@ IniVersion=2
 
 [General]
 Name=Digao Dalpiaz - DzHTMLText component
-Version=6.2
+Version=6.3
 DelphiVersions=XE3;XE4;XE5;XE6;XE7;XE8;10;10.1;10.2;10.3;10.4;11;12
 Packages=DzHTMLText_VCL;DzHTMLText_FMX;DzHTMLTextDesign_VCL;DzHTMLTextDesign_FMX
 AddLibrary=1

README.md

@@ -36,14 +36,18 @@
 
 ## What's New
 
-- 03/24/2024 (Version 6.2)
+- 03/25/2024 (Version 6.3)
 
-   - Better FMX design-time border (using the Delphi pattern).
-   - Keep Canvas properties state in FMX (font changes and other Canvas properties were retained and could affect the painting of other controls on the form)
+   - VCL font scaling review (Height is calculated by default screen PPI)
 
 <details>
   <summary>Click here to view the entire changelog</summary>
 
+- 03/24/2024 (Version 6.2)
+
+   - Better FMX design-time border (using the Delphi pattern).
+   - Keep Canvas properties state in FMX (font changes and other Canvas properties were retained and could affect the painting of other controls on the form)
+
 - 02/26/2024 (Version 6.1)
 
    - Opacity supporting in FMX environment.

Source/Vcl.DzHTMLText.pas

@@ -29,7 +29,7 @@ interface
   {$ENDIF}
 {$ENDIF};
 
-const DZHTMLTEXT_INTERNAL_VERSION = 712; //Synchronizes TDam component
+const DZHTMLTEXT_INTERNAL_VERSION = 713; //Synchronizes TDam component
 
 const _DEF_LISTLEVELPADDING = 20;
 
@@ -487,7 +487,7 @@   TDzHTMLText = class(
     property SyntaxErrors: TDHSyntaxErrorList read LError;
 
     {$IFDEF VCL}
-    function CalcMulDiv(Size, DesignPPI: Integer; IsFont: Boolean): Integer;
+    function CalcMulDiv(Size: Integer): Integer;
     function CalcFontHeight(Size: Integer): Integer;
     {$ENDIF}
     function CalcScale(Size: TPixels): TPixels;
@@ -679,7 +679,7 @@ implementation
   {$ENDIF}
 {$ENDIF};
 
-const STR_VERSION = '6.2';
+const STR_VERSION = '6.3';
 
 const DEFAULT_PPI = 96;
 
@@ -1651,35 +1651,40 @@ procedure TDzHTMLText.CMMouseleave(var Message: TMessage);
 
 {$IFDEF VCL}
 type THackForm = class(TCustomForm); //older Delphi version - Scaled is a protected property
-function TDzHTMLText.CalcMulDiv(Size, DesignPPI: Integer; IsFont: Boolean): Integer;
+function TDzHTMLText.CalcMulDiv(Size: Integer): Integer;
 var
-  MonitorPPI: Integer;
+  MonitorPPI, DesignPPI: Integer;
 begin
-  MonitorPPI := DEFAULT_PPI;
   {$IF (Defined(DCC) and (CompilerVersion >= 30)) or Defined(FPC)} //D10 Seattle or Lazarus
-  if {$IFDEF DCC}not (csDesigning in ComponentState) and{$ENDIF} //design always based on Default PPI in Delphi
-    (ParentForm<>nil) and THackForm(ParentForm).Scaled then
+  if (ParentForm<>nil) and THackForm(ParentForm).Scaled
+    {$IFDEF DCC}and not (csDesigning in ComponentState){$ENDIF} //design always based on Default PPI in Delphi
+  then
+  begin
     MonitorPPI := ParentForm.Monitor.PixelsPerInch;
-  {$ENDIF}
+    DesignPPI := {$IFDEF FPC}ParentForm.PixelsPerInch{$ELSE}DEFAULT_PPI{$ENDIF};
+    //in Delphi, form PixelsPerInch changes by current monitor
+    //in Lazarus, form PixelsPerInch stay fixed by designer (default screen)
 
-  {$IFDEF FPC}
-  if not IsFont and (ParentForm<>nil) then DesignPPI := ParentForm.DesignTimePPI;
+    Result := Round(Size * MonitorPPI / DesignPPI); //MulDiv equivalent
+  end else
   {$ENDIF}
-
-  Result := Round(Size * MonitorPPI / DesignPPI); //MulDiv equivalent
+    Result := Size;
 end;
 
 function TDzHTMLText.CalcFontHeight(Size: Integer): Integer;
+var
+  H: Integer;
 begin
-  Result := -CalcMulDiv(Size, 72, True);
+  H := -Round(Size * Screen.PixelsPerInch / 72);
+  Result := CalcMulDiv(H);
 end;
 {$ENDIF}
 
 function TDzHTMLText.CalcScale(Size: TPixels): TPixels;
 begin
   Result :=
   {$IFDEF VCL}
-    CalcMulDiv(Size, DEFAULT_PPI, False)
+    CalcMulDiv(Size)
   {$ELSE}
     Size
   {$ENDIF};