title: C++ Errror: "FL/Fl_xyz_Button.H: No such file or directory" in Fltk?
body: <p>I'm new to C++ and Fltk. Guys this code is working fine:</p>
  <pre class="lang-cpp prettyprint-override"><code>#include &lt;FL/Fl.H&gt;
  #include &lt;FL/Fl_Window.H&gt;
  #include &lt;FL/Fl_Box.H&gt;
  #include &lt;FL/Fl_Button.H&gt;
  
  int main(int argc, char **argv) {
      Fl_Window *window = new Fl_Window(800, 400);
      Fl_Box *box = new Fl_Box(20,40,300,100,&quot;Hello, World!&quot;);
      box-&gt;box(FL_NO_BOX);
      box-&gt;labeltype(FL_SHADOW_LABEL);
      Fl_Button *GG = new Fl_Button(150,90,40,30,&quot;GG&quot;);
      GG-&gt;type(FL_NORMAL_BUTTON);
  
      window-&gt;end();
      window-&gt;show(argc, argv);
      return Fl::run();
  }
  </code></pre>
  <p>but when I try this code (when using <code>Fl_xyz_Button.H</code>):</p>
  <pre class="lang-cpp prettyprint-override"><code>#include &lt;FL/Fl.H&gt;
  #include &lt;FL/Fl_Window.H&gt;
  #include &lt;FL/Fl_Box.H&gt;
  #include &lt;FL/Fl_xyz_Button.H&gt;
  
  int main(int argc, char **argv) {
      Fl_Window *window = new Fl_Window(800, 400);
      Fl_Box *box = new Fl_Box(20,40,300,100,&quot;Hello, World!&quot;);
      box-&gt;box(FL_NO_BOX);
      box-&gt;labelfont(FL_BOLD+FL_ITALIC);
      box-&gt;labelsize(36);
      box-&gt;labelcolor(FL_WHITE);
      box-&gt;labeltype(FL_SHADOW_LABEL);
      Fl_xyz_Button *GG = new Fl_xyz_Button(150,90,40,30,&quot;GG&quot;);
      GG-&gt;type(FL_NORMAL_BUTTON);
  
      window-&gt;end();
      window-&gt;show(argc, argv);
      return Fl::run();
  }
  </code></pre>
  <p>it's show me error:</p>
  <pre class="lang-cpp prettyprint-override"><code>&quot;FL/Fl_xyz_Button.H: No such file or directory&quot;
  </code></pre>
  <p>and I see in <code>/usr/local/include/FL</code> doesn't have <code>Fl_xyz_Button.H</code> ??
  How Can I fix it ? or download <code>Fl_xyz_Button.H</code> and put it inside <code>/usr/local/include/FL</code> folder?</p>
  <p>I searched in that and there is no resault?</p>
  <p>I use Xubutu(.deb) on Visual Studio Code.</p>