1 files changed, 49 insertions, 0 deletions
diff --git a/test/minimum.cxx b/test/minimum.cxx
new file mode 100644
index 000000000..f946639a6
--- /dev/null
+++ b/test/minimum.cxx
@@ -0,0 +1,49 @@
+// This is a test of the minimal update code.  The right slider has a
+// label that extends outside it's border, and the minimal update
+// assummes this does not happen.  Thus there is *supposed* to be
+// display errors when you move the right-most or any other slider.
+// If you *don't* see these errors, then the minimal update is
+// broken!!!
+
+// I cannot emphasize how important it is to test this and make sure
+// any changes have not broken the minimal update.  These sort of bugs
+// are extremely hard to fix and must be detected right away!
+
+// The reason it is important to fix this is that otherwise you will
+// swiftly end up with a toolkit that thinks it has to draw the window
+// 20 times each time the display changes.  I don't care how fast the
+// machine is, this is an insane waste of resources, and should be
+// stopped!
+
+#include <stdlib.h>
+#include <FL/Fl.H>
+#include <FL/Fl_Window.H>
+#include <FL/Fl_Slider.H>
+#include <FL/Fl_Box.H>
+#include <FL/Fl_Return_Button.H>
+
+int main(int argc, char **argv) {
+  Fl_Window *window = new Fl_Window(400,320,argv[0]);
+  window->resizable(*(new Fl_Box(FL_ENGRAVED_FRAME,10,10,300,300,
+"MINIMUM UPDATE TEST\n"
+"\n"
+"The slider on the right purposely\n"
+"draws outside it's boundaries.\n"
+"Moving it should leave old copies\n"
+"of the label.  These copies should\n"
+"*not* be erased by any actions\n"
+"other than hiding and showing\n"
+"of that portion of the window\n"
+"or changing the button that\n"
+"intesects them.")));
+
+  Fl_Slider *s;
+  s = new Fl_Slider(320,10,20,300,"Too_Big_Label");
+  s->align(0);
+
+  new Fl_Button(20,270,100,30,"Button");
+  new Fl_Return_Button(200,270,100,30,"Button");
+
+  window->show(argc, argv);
+  return Fl::run();
+}