[SOLVED] How to detect touchscreen?
lazarus / 31-LCL

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dsiders · 2019-01-10 12:36

I am wondering how to detect if a touch-enabled device is attached
during form creation/display. It is needed to adjust font and control
sizes and alignment for UI controls that are just too small for touch
usage.

Any ideas? Neither Google nor Forum Search were very helpful on this
topic.

Thanks in advance.

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tr_escape · 2019-01-10 13:25

Maybe this can be help for windows:

https://stackoverflow.com/questions/20923853/why-i-cant-detect-touch-
screen

and related:

https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-
winuser-getsystemmetrics

Note : I never used yet

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Josh · 2019-01-10 13:27

Hi

Windows getsystemmetrics maybe the route to go.

I have not tested; but should be ok.

Code: [Select]VAR Touch_Screen_Enabled:Boolean=True;
begin
  Touch_Screen_Enabled:=GetSystemMetrics(SM_MAXIMUMTOUCHES)>0;       
                         
note need to add windows to uses

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dsiders · 2019-01-10 13:49

Quote from: josh on January 10, 2019, 02:27:17 pmWindows
getsystemmetrics maybe the route to go.

I have not tested; but should be ok.

Code: [Select]VAR Touch_Screen_Enabled:Boolean=True;
begin
  Touch_Screen_Enabled:=GetSystemMetrics(SM_MAXIMUMTOUCHES)>0;       
                         
note need to add windows to uses

Thanks Josh. This does in fact work for Windows. Looks like lcltype.pp
needs a refresh though... it doesn't have some the SM_* values from
the MSDN docs.

Now I need to poke around and see how Linux handles this.

Thanks again.

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dsiders · 2019-01-10 14:47

Quote from: dsiders on January 10, 2019, 02:49:17 pmNow I need to poke
around and see how Linux handles this.

So far, all I have found that seems remotely distro-independent is
capturing output from udevadm info. The search continues...