I have been experiencing slow performance when using Fl_Text_Editor in my application. I see a significant delay (some 7 seconds) when calling Fl_Text_Editor::buffer on a new Fl_Text_Buffer when my application starts. Is this normal behavior? I'm just so used to FLTK working almost instantly for every operation that this was surprising to me. I'm using FLTK 1.3.4 because I cannot right now move to a newer version of FLTK, because of system dependencies. Here's a snippet of the code I use, together with some debugging output so I could tell why it was being slow:

[...]

As you can see, the delay comes from the line where the editor is given the text buffer to use. Everything else is fast, as expected.

Any light that could be shed on this would be appreciated.

$ cat test/hello.cxx
#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_Text_Editor.H>
#include <stdio.h>

int w = 800;
Fl_Double_Window *window = nullptr;

void close_cb(void *p) {
  window->hide();
}

int main(int argc, char **argv) {
  window = new Fl_Double_Window(w, 615, "TEST");
  Fl_Text_Editor *caption_text = new Fl_Text_Editor(10, 10, w - 20, 125, "Caption Text: ");
  caption_text->align(FL_ALIGN_LEFT);
  caption_text->when(FL_WHEN_CHANGED);
  Fl_Text_Buffer *caption_buf = new Fl_Text_Buffer();
  caption_text->buffer(caption_buf);
  caption_text->wrap_mode(Fl_Text_Editor::WRAP_AT_BOUNDS, 5);
  window->end();
  window->show(argc, argv);
  printf("\nFL_API_VERSION = %d\n", FL_API_VERSION);
  Fl::add_timeout(0.001, close_cb, nullptr);
  return Fl::run();
}

$ fltk-config --compile test/hello.cxx && time ./hello
/usr/bin/c++ -I/usr/local/fltk/1.4-debug/include -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_THREAD_SAFE -D_REENTRANT -o hello test/hello.cxx /usr/local/fltk/1.4-debug/lib/libfltk.a -lm -lpthread -lXinerama -lXfixes -lXcursor -L/usr/lib/x86_64-linux-gnu -lpangocairo-1.0 -lpango-1.0 -lgobject-2.0 -lglib-2.0 -lharfbuzz -lcairo -L/usr/lib/x86_64-linux-gnu -lcairo -lgtk-3 -lgdk-3 -lgio-2.0 -lX11 -lXft -lXrender -lwayland-cursor -lwayland-client -lxkbcommon -ldbus-1 -lfontconfig -ldl

FL_API_VERSION = 10400

real	0m0.190s
user	0m0.153s
sys	0m0.032s

$ /git/fltk/branch-1.3/fltk-config --compile test/hello.cxx && time ./hello
g++ -I/git/fltk/branch-1.3 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_THREAD_SAFE -D_REENTRANT -o 'hello' 'test/hello.cxx' /git/fltk/branch-1.3/lib/libfltk.a -lXrender -lXcursor -lXfixes -lXext -lXinerama -lpthread -lm -lX11

FL_API_VERSION = 10304

real	0m0.075s
user	0m0.030s
sys	0m0.005s