[Solved] Saving Window position and High DPI
lazarus / 31-LCL

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lainz · 2018-05-02 17:29

Hi,

I'm with this problem, I can't solve.

I store the properties of the Form with JSONPropStorage. I store left,
top, width and height.

I'm using Lazarus trunk, and I set Use LCL Scaling (hi-dpi) to true in
the options.

The problem is that every time I open the window, it gets bigger.

As I understand the problem, it loads the stored values and then
scales it. The next time does the same, loads the stored values and
scales them.

How I can prevent this to happen?

I've set the properties to store (left, top, width, height) with the
object inspector (SessionProperties).

I don't know how I can solve it. The DPI can be changed also, I'm
running now at 120%, but when I switch to another mode for any reason,
It will stop working as well.

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balazsszekely · 2018-05-02 17:52

Did you try to scale with MulDiv from LCLType?
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 WidthX% :=
MulDiv(Width100%, Screen.PixelsPerInch, 96);Where Width100% is the
default value at 96 DPI. So one possible solution is to always store
the width in 96 DPI equivalent, then scale it whenever is needed.

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lainz · 2018-05-02 18:18

Thanks. Yes, I need to change the automatic saving and try with your
code.
The problem of the automatic saving / loading, is that I can't change
nothing.

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balazsszekely · 2018-05-02 18:27

Plese try something like this:

1. Save
Width96 := MulDiv(CurWidth, 96,  Screen.PixelsPerInch);
Save Width96 to json.

2. Load
Load Width96 from JSON:
CurWidth  := MulDiv(Width96,  Screen.PixelsPerInch, 96);

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lainz · 2018-05-02 19:42

Thanks GetMem, it works.

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 procedure
TfrmTimeEntry.JSONPropStorage1RestoreProperties(Sender:
TObject);begin  Width := MulDiv(Width, 96, Screen.PixelsPerInch); 
Height := MulDiv(Height, 96, Screen.PixelsPerInch);    end;
It's only needed on restore.