adding micropython examples (#2286)

* adding micropython examples

* adding micropython examples

examples/styles/lv_example_style_14.py

@@ -0,0 +1,53 @@
+# Will be called when the styles of the base theme are already added
+# to add new styles
+
+
+class NewTheme(lv.theme_t):
+    def __init__(self):
+        super().__init__()
+        # Initialize the styles
+        self.style_btn = lv.style_t()
+        self.style_btn.init()
+        self.style_btn.set_bg_color(lv.palette_main(lv.PALETTE.GREEN))
+        self.style_btn.set_border_color(lv.palette_darken(lv.PALETTE.GREEN, 3))
+        self.style_btn.set_border_width(3)
+
+        # This theme is based on active theme 
+        th_act = lv.theme_get_from_obj(lv.scr_act())
+        # This theme will be applied only after base theme is applied
+        self.set_parent(th_act)        
+        
+class ExampleStyle_14():
+    
+    def __init__(self):
+        # 
+        # Extending the current theme
+        #
+
+        btn = lv.btn(lv.scr_act())
+        btn.align(lv.ALIGN.TOP_MID, 0, 20)
+
+        label = lv.label(btn)
+        label.set_text("Original theme")
+        
+        self.new_theme_init_and_set()
+        
+        btn = lv.btn(lv.scr_act())
+        btn.align(lv.ALIGN.BOTTOM_MID, 0, -20)
+        
+        label = lv.label(btn)
+        label.set_text("New theme")
+        
+    def new_theme_apply_cb(self,th, obj):
+        print(th,obj)
+        if obj.get_class() == lv.btn_class:
+            obj.add_style(self.th_new.style_btn, 0)
+        
+    def new_theme_init_and_set(self):
+        print("new_theme_init_and_set")
+        # Initialize the new theme from the current theme        
+        self.th_new = NewTheme()
+        self.th_new.set_apply_cb(self.new_theme_apply_cb)
+        lv.disp_get_default().set_theme(self.th_new)
+        
+exampleStyle_14 = ExampleStyle_14()