Help: preview of Svg image in Open-Dialog works only with VCLStyle active.

[Carlo Barazzetta 116]

I have a question about a problem developing SVGIconImageList components:

At design-time, the component editor cannot show the svg icon preview into the OpenDialog when loading files from "Add..." button.
Compiling the demo, *and* and activating any VCLStyle, the icon is visibile:

Disabling the VCL style, the preview is not visible also at run-time (I'm using Windows in dark mode):

Could it be possible to have the same functionality at design time? It is very important to see the preview, during selection of svg files using the editor!
Do I need some OpenDialog "hook" to have the preview also in "normal" style?

Thansk for any suggestions.

Carlo

Edited September 3, 2020 by Carlo Barazzetta

[pyscripter 689]

It should be mentioned that one of the package units registers the new file format:

initialization
  TPicture.RegisterFileFormat('SVG', 'Scalable Vector Graphics', TSVGGraphic);

 

Use PowerToys to get SVG preview at run time when you disable Vcl styles. (Also in File Explorer)

Edited September 3, 2020 by pyscripter

[Carlo Barazzetta 116]

1 hour ago, pyscripter said:

It should be mentioned that one of the package units registers the new file format:

initialization
  TPicture.RegisterFileFormat('SVG', 'Scalable Vector Graphics', TSVGGraphic);

 

Yes! I've notice now that the two Dialog are quite different... but the call is always the same: OpenDialog.Execute.
The TOpenDialog properties:
  object OpenDialog: TOpenPictureDialog
    Filter = 'Scalable Vector Graphics (*.svg)|*.svg'
    Options = [ofHideReadOnly, ofAllowMultiSelect, ofPathMustExist, ofFileMustExist, ofEnableSizing]
    Left = 328
    Top = 96
  end
 

[Carlo Barazzetta 116]

Ok, I've resolved, with this solution:

I'm using a new class, implementing Execute without call the "inherited" metod, because the "magic" OpenDialog with the preview is activated by :  Template := 'DLGTEMPLATE' but it's used only when TStyleManager.IsCustomStyleActive

Using Template 'DLGTEMPLATE' also without CustomStyleActive shows always the dialog with the preview:
 

TOpenPictureDialogSvg = class(TOpenPictureDialog)

function TOpenPictureDialogSvg.Execute(ParentWnd: HWND): Boolean;
begin
  Template := 'DLGTEMPLATE';
  Result := DoExecute(@GetOpenFileName, ParentWnd);
end;

Not very elegant, but it works...

Edited September 3, 2020 by Carlo Barazzetta

[Sashka 0]

On 9/3/2020 at 1:49 PM, Carlo Barazzetta said:

 

Could it be possible to have the same functionality at design time? It is very important to see the preview, during selection of svg files using the editor!
Do I need some OpenDialog "hook" to have the preview also in "normal" style?

Thansk for any suggestions.

Carlo

You need an interface IPreviewHandler implementation in COM DLL that supports displaying SVG-graphics

After that you can use   classic new TOpenDialog

[Carlo Barazzetta 116]

Now with SVGShellExtensions (https://github.com/EtheaDev/SVGShellExtensions) the icons are visibile also into Internet Explorer as Thumbnails and Preview 😉