How to access the Linux clipboard without unit Clipbrd?
lazarus / 32-Linux

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Hartmut · 2019-08-06 15:27

I want to access the Linux clipboard (only for plain text) from a
small console program. I cannot use unit Clipbrd, because it does not
work in a console program, because of using the LCL (on Windows this
works perfectly). More see
https://forum.lazarus.freepascal.org/index.php/topic,46259.0.html

So my idea is (inspired by reply #4 of the above link) the following
program:

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 {$mode
objfpc}{$H+} uses gtk2,gdk2; var c: PGtkClipboard;    s:
string; beginwriteln('AAA'); 
 c:=gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);writeln('BBB'); 
 s:='Hello world';   gtk_clipboard_set_text(c, PChar(s),
Length(s));writeln('CCC'); 
 gtk_clipboard_store(c);writeln('DDD');end.
It compiles but gives the following runtime errors:

Code: [Select]AAA
(process:2761): Gtk-CRITICAL **: 17:09:15.766:
IA__gtk_clipboard_get_for_display: assertion 'display != NULL' failed
BBB
(process:2761): Gtk-CRITICAL **: 17:09:15.767:
IA__gtk_clipboard_set_text: assertion 'clipboard != NULL' failed
CCC
(process:2761): Gtk-CRITICAL **: 17:09:15.767:
IA__gtk_clipboard_store: assertion 'GTK_IS_CLIPBOARD (clipboard)'
failed
DDD
Probably some initialization is missing. I tried to look into the code
but failed to understand it.

Does anyone know, how to modify this code that it works? I use Lazarus
1.8.4 with FPC 3.0.4 on Ubuntu 18.04 (64 bit). Thanks in advance.

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bytebites · 2019-08-06 16:56

Error disappeared when I added
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
gtk_init(@argc, @argv);

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Hartmut · 2019-08-06 17:26

Hello bytebites, yes, the errors disappeared now. Thanks a lot. But I
expected, after running my program, that the clipboard contains "Hello
world". But it still contains that, what was in the clipboard, before
I started my program. Is there some kind of "finalization" missing?

Do you or somebody else know, how my code must be modified to work? I
want to write something into the clipboard.

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bytebites · 2019-08-06 17:42

Add readln at the end of the code and see what happens.
When the program terminates, pasted text disappears.

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Hartmut · 2019-08-06 18:04

I placed a readln() at the end of my program. While the program is
waiting for the readln(), the clipboard is empty, does not contain
"Hello world". After I press ENTER, the clipboard again contains that
text, what was in the clipboard, before I started my program.