adding micropython examples (#2286)

* adding micropython examples

* adding micropython examples

examples/widgets/arc/lv_example_arc_2.py

@@ -1,43 +1,37 @@
-# Create an arc which acts as a loader.
-class loader_arc(lv.arc):
-
-    def __init__(self, parent, color=lv.color_hex(0x000080), 
-                       width=8, style=lv.style_plain, rate=20):
-        super().__init__(parent)
+#
+# An `lv_timer` to call periodically to set the angles of the arc
+#
+class ArcLoader():
+    def __init__(self):
+        self.a = 270
         
-        self.a = 0
-        self.rate = rate
+    def arc_loader_cb(self,tim,arc):
+        # print(tim,arc)
+        self.a += 5
 
-        # Create style for the Arcs
-        self.style = lv.style_t()
-        lv.style_copy(self.style, style)
-        self.style.line.color = color
-        self.style.line.width = width
+        arc.set_end_angle(self.a)
 
-        # Create an Arc
-        self.set_angles(180, 180);
-        self.set_style(self.STYLE.MAIN, self.style);
+        if self.a >= 270 + 360:
+            tim._del()
 
-        # Spin the Arc
-        self.spin()
 
-    def spin(self):
-        # Create an `lv_task` to update the arc.
-        lv.task_create(self.task_cb, self.rate, lv.TASK_PRIO.LOWEST, {})
+#
+# Create an arc which acts as a loader.
+#
 
-    
-    # An `lv_task` to call periodically to set the angles of the arc
-    def task_cb(self, task):
-        self.a+=5;
-        if self.a >= 359: self.a = 359
+# Create an Arc
+arc = lv.arc(lv.scr_act())
+arc.set_bg_angles(0, 360)
+arc.set_angles(270, 270)
+arc.center()
 
-        if self.a < 180: self.set_angles(180-self.a, 180)
-        else: self.set_angles(540-self.a, 180)
+# create the loader
+arc_loader = ArcLoader()
 
-        if self.a == 359:
-            self.a = 0
-            lv.task_del(task)
+# Create an `lv_timer` to update the arc.
+
+timer = lv.timer_create_basic()
+timer.set_period(20)
+timer.set_cb(lambda src: arc_loader.arc_loader_cb(timer,arc))
+  
 
-# Create a loader arc
-loader_arc = loader_arc(lv.scr_act())
-loader_arc.align(None, lv.ALIGN.CENTER, 0, 0)