Add class NexSlider and example.

Signed-off-by: shennongmin <wupangfee@gmail.com>

examples/CompSlider/CompSlider.ino

@@ -0,0 +1,53 @@
+/**
+ * @example CompSlider.ino
+ *
+ * @par Show how to use API of class NexSlider.  
+ *
+ * @author  Wu Pengfei (email:<pengfei.wu@itead.cc>)
+ * @date    2015/8/11
+ * @copyright 
+ * Copyright (C) 2014-2015 ITEAD Intelligent Systems Co., Ltd. \n
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+ 
+#include "NexText.h"
+#include "NexSlider.h"
+
+
+NexText t0 = NexText(0, 2, "t0");
+NexSlider h0 = NexSlider(0, 1, "h0");
+
+NexTouch *nex_listen_list[] = 
+{
+    &h0,
+    NULL
+};
+
+void h0PopCallback(void *ptr)
+{
+    uint32_t number = 0;
+    char temp[10] = {0};
+    
+    dbSerialPrintln("h0PopCallback");
+
+    h0.getValue(&number);
+    utoa(number, temp, 10);
+    t0.setText(temp);
+}
+
+
+void setup(void)
+{
+    nexInit();
+    h0.attachPop(h0PopCallback);
+    dbSerialPrintln("setup done");
+}
+
+void loop(void)
+{
+    nexLoop(nex_listen_list);
+}
+