Added simple "draw an 'X'" example.

examples/Makefile

@@ -12,6 +12,7 @@ ALL = browser-simple$(EXEEXT) \
       howto-add_fd-and-popen$(EXEEXT) \
       howto-browser-with-icons$(EXEEXT) \
       howto-drag-and-drop$(EXEEXT) \
+      howto-draw-an-x$(EXEEXT) \
       howto-menu-with-images$(EXEEXT) \
       howto-parse-args$(EXEEXT) \
       howto-remap-numpad-keyboard-keys$(EXEEXT) \

examples/howto-draw-an-x.cxx

@@ -0,0 +1,54 @@
+//
+// "$Id$"
+//
+// Demonstrate how to draw an 'X' in fltk
+//
+//     Create a custom widget that draws an 'X' to the corners of the window,
+//     even when window is resized. Here we subclass Fl_Widget, the lowest level
+//     FLTK widget object. Origin: http://seriss.com/people/erco/fltk/#FltkX
+//
+// Copyright 2005 by Greg Ercolano.
+// Copyright 1998-2017 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     http://www.fltk.org/COPYING.php
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+
+#include <FL/Fl.H>
+#include <FL/fl_draw.H>
+#include <FL/Fl_Double_Window.H>
+
+class DrawX : public Fl_Widget {
+public:
+    DrawX(int X, int Y, int W, int H, const char*L=0) : Fl_Widget(X,Y,W,H,L) {
+    }
+    void draw() {
+        // Draw background - a white filled rectangle
+	fl_color(FL_WHITE); fl_rectf(x(),y(),w(),h());
+        // Draw black 'X' over base widget's background
+        fl_color(FL_BLACK);
+        int x1 = x(),       y1 = y();
+        int x2 = x()+w()-1, y2 = y()+h()-1;
+        fl_line(x1, y1, x2, y2);
+        fl_line(x1, y2, x2, y1);
+    }
+};
+int main() {
+    Fl_Double_Window win(200,200,"Draw X");
+    DrawX draw_x(10, 10, win.w()-20, win.h()-20);	// put our widget 10 pixels within window edges
+    draw_x.color(FL_WHITE);				// make widget's background white
+    win.resizable(draw_x);
+    win.show();
+    return(Fl::run());
+}
+
+//
+// End of "$Id$".
+//