Lazarus Detect DPI Scalling Level of Windows [SOLVED]

[AlphaInc.]

Hello everybody,

I recently opened a thread asking how you could scale the tool's window proportional to the resolution of the client (windows). I was pointed to an external component TFormResizer (EasySize) with which I could resize the image based on the resolution. All the components on my form (Buttons) did also resize.

Now I wanted to expand on that a little by also detecting the zoom (don't know if it's called DPI Scalling, in windows settings it's called "change the size of text apps and other items") and setting a secreen resolution based on that.

My code so far:

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormCreate(Sender: TObject);
2. begin
3.    Sizer := TFormResizer.Create(self);
4.    Sizer.EnforceMinSize := false;
5.    Sizer.ResizeFonts := true;
6.    Sizer.MinFontSize := 6;
7.    Sizer.MaxFontSize := 30;
8.    Sizer.InitializeForm;
9.  
10.    Width := round(Screen.Width/2.4);
11.    Height := round(Screen.Height/2.4);
12.  
13.    Position := poScreenCenter;
14. end;

I want to change the code to something like this.

Code: Pascal  [Select][+][-]

1.    if Zoom=100% then
2.       begin
3.          Width := round(Screen.Width/2.4);
4.          Height := round(Screen.Height/2.4);
5.       end;
6.    else if Zoom=125% then
7.       begin
8.          Width := round(Screen.Width/2.8);
9.          Height := round(Screen.Height/2.8);
10.       end;
11.    ...

The only problem I have is that I don't know how to detect the Zoom-factor.

[sstvmaster]

Maybe like so?

Code: Pascal  [Select][+][-]

1. Screen.PixelsPerInch

[wp]

LCL does not support zooming. So your zoom factor is fully under your own control. I'd say that your design machine defines what is 100%.

[AlphaInc.]

Maybe like so?

Code: Pascal  [Select][+][-]

1. Screen.PixelsPerInch

So how to check for DPI Scaling 100%?

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 100

or

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 1

or how do you set 100%

[AlphaInc.]

LCL does not support zooming. So your zoom factor is fully under your own control. I'd say that your design machine defines what is 100%.

Not sure if we are talking about the same (if yes and I didn't understand you correctly, excuse me) but I don't want to zoom the software I just want to read (or better import the value as an integer) the defined zoom in windows settings to use it in my tool.

[dseligo]

Maybe like so?

Code: Pascal  [Select][+][-]

1. Screen.PixelsPerInch

So how to check for DPI Scaling 100%?

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 100

or

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 1

or how do you set 100%

Put you Windows DPI to 100% and then check result:

Code: Pascal  [Select][+][-]

1. ShowMessage(IntToStr(Screen.PixelsPerInch));

[AlphaInc.]

Maybe like so?

Code: Pascal  [Select][+][-]

1. Screen.PixelsPerInch

So how to check for DPI Scaling 100%?

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 100

or

Code: Pascal  [Select][+][-]

1. If Screen.PixelsPerInch := 1

or how do you set 100%

Put you Windows DPI to 100% and then check result:

Code: Pascal  [Select][+][-]

1. ShowMessage(IntToStr(Screen.PixelsPerInch));

Ahh Thank you. It got it. 

[sstvmaster]

You are welcome.