examples(micropython): add a few missing MP examples (#3672)

examples/widgets/checkbox/lv_example_checkbox_2.py

@@ -0,0 +1,83 @@
+import time
+
+class LV_Example_Checkbox_2:
+    def __init__(self):
+        #
+        # Checkboxes as radio buttons
+        #
+        # The idea is to enable `LV_OBJ_FLAG_EVENT_BUBBLE` on checkboxes and process the
+        #`LV.EVENT.CLICKED` on the container.
+        # Since user_data cannot be used to pass parameters in MicroPython I use an instance variable to
+        # keep the index of the active button
+        
+        self.active_index_1 = 0
+        self.active_index_2 = 0
+        self.style_radio = lv.style_t()
+        self.style_radio.init()
+        self.style_radio.set_radius(lv.RADIUS_CIRCLE)
+
+        self.style_radio_chk = lv.style_t()
+        self.style_radio_chk.init()
+        self.style_radio_chk.init()
+        self.style_radio_chk.set_bg_img_src(None)
+        
+        self.cont1 = lv.obj(lv.scr_act())
+        self.cont1.set_flex_flow(lv.FLEX_FLOW.COLUMN)
+        self.cont1.set_size(lv.pct(40), lv.pct(80))
+        self.cont1.add_event_cb(self.radio_event_handler, lv.EVENT.CLICKED, None)
+        
+        for i in range(5):
+            txt = "A {:d}".format(i+1)
+            self.radiobutton_create(self.cont1,txt)
+
+        # Make the first checkbox checked
+        #lv_obj_add_state(lv_obj_get_child(self.cont1, 0), LV_STATE_CHECKED);
+        self.cont1.get_child(0).add_state(lv.STATE.CHECKED)
+
+        self.cont2 = lv.obj(lv.scr_act())
+        self.cont2.set_flex_flow(lv.FLEX_FLOW.COLUMN)
+        self.cont2.set_size(lv.pct(40), lv.pct(80))
+        self.cont2.set_x(lv.pct(50))
+        self.cont2.add_event_cb(self.radio_event_handler, lv.EVENT.CLICKED, None)
+        
+        for i in range(3):
+            txt = "B {:d}".format(i+1)
+            self.radiobutton_create(self.cont2,txt)
+
+        # Make the first checkbox checked*/
+        self.cont2.get_child(0).add_state(lv.STATE.CHECKED)
+
+        
+    def radio_event_handler(self,e):
+        cont = e.get_current_target()
+        act_cb = e.get_target()
+        if cont == self.cont1:
+            active_id = self.active_index_1
+        else:
+            active_id = self.active_index_2
+        old_cb = cont.get_child(active_id)
+
+        # Do nothing if the container was clicked
+        if act_cb == cont:
+            return
+
+        old_cb.clear_state(lv.STATE.CHECKED)          # Uncheck the previous radio button
+        act_cb.add_state(lv.STATE.CHECKED)            # Uncheck the current radio button
+
+        if cont == self.cont1:
+            self.active_index_1 = act_cb.get_index()
+            # print("active index 1: ", self.active_index_1)
+        else:
+            self.active_index_2 = act_cb.get_index()
+            # print("active index 2: ", self.active_index_2)
+
+        print("Selected radio buttons: {:d}, {:d}".format(self.active_index_1, self.active_index_2))
+
+    def radiobutton_create(self,parent, txt):
+        obj = lv.checkbox(parent)
+        obj.set_text(txt)
+        obj.add_flag(lv.obj.FLAG.EVENT_BUBBLE)
+        obj.add_style(self.style_radio, lv.PART.INDICATOR)
+        obj.add_style(self.style_radio_chk, lv.PART.INDICATOR | lv.STATE.CHECKED)
+
+lv_example_checkbox_2 = LV_Example_Checkbox_2()