example(micropython): updated MicroPython examples according to LVGL changes (#4031)

examples/widgets/label/lv_example_label_1.py

@@ -1,13 +1,18 @@
+#!/opt/bin/lv_micropython -i
+
+import lvgl as lv
+import display_driver
+
 #
 # Show line wrap, re-color, line align and text scrolling.
 #
 label1 = lv.label(lv.scr_act())
 label1.set_long_mode(lv.label.LONG.WRAP)      # Break the long lines*/
 label1.set_recolor(True)                      # Enable re-coloring by commands in the text
-label1.set_text("#0000ff Re-color# #ff00ff words# #ff0000 of a# label, align the lines to the center"
+label1.set_text("#0000ff Re-color# #ff00ff words# #ff0000 of a# label, align the lines to the center "
                               "and  wrap long text automatically.")
 label1.set_width(150)                         # Set smaller width to make the lines wrap
-label1.set_style_text_align(lv.ALIGN.CENTER, 0)
+label1.set_style_text_align(lv.TEXT_ALIGN.CENTER, 0)
 label1.align(lv.ALIGN.CENTER, 0, -40)
 
 

examples/widgets/label/lv_example_label_3.py

@@ -11,10 +11,24 @@ fs_drv = lv.fs_drv_t()
 fs_driver.fs_register(fs_drv, 'S')
 
 try:
-    ltr_label.set_style_text_font(ltr_label, lv.font_montserrat_16, 0)
+    ltr_label.set_style_text_font(ltr_label, lv.font_montserrat_16,0)
 except:
-    font_montserrat_16 = lv.font_load("S:../../assets/font/montserrat-16.fnt")
-    ltr_label.set_style_text_font(font_montserrat_16, 0)
+    fs_drv = lv.fs_drv_t()
+    fs_driver.fs_register(fs_drv, 'S')
+    print("montserrat-16 not enabled in lv_conf.h, dynamically loading the font")
+    
+    # get the directory in which the script is running
+    try:
+        script_path = __file__[:__file__.rfind('/')] if __file__.find('/') >= 0 else '.'
+    except NameError:
+        print("Could not find script path")
+        script_path = ''
+    if script_path != '':
+        try:
+            font_montserrat_16 = lv.font_load("S:" + script_path + "/../../assets/font/montserrat-16.fnt")
+            ltr_label.set_style_text_font(font_montserrat_16,0)            
+        except:
+            print("Cannot load font file montserrat-16.fnt")
 
 ltr_label.set_width(310)
 ltr_label.align(lv.ALIGN.TOP_LEFT, 5, 5)

examples/widgets/label/lv_example_label_4.py

@@ -0,0 +1,63 @@
+MASK_WIDTH = 100
+MASK_HEIGHT = 45
+
+def add_mask_event_cb(e,mask_map):
+
+    code = e.get_code()
+    obj = e.get_target_obj()
+    
+    if code == lv.EVENT.COVER_CHECK :
+        e.set_cover_res(lv.COVER_RES.MASKED)
+    
+    elif code == lv.EVENT.DRAW_MAIN_BEGIN:
+        m = lv.draw_mask_map_param_t()
+        obj_coords = lv.area_t()
+        obj.get_coords(obj_coords)
+        m.init(obj_coords, mask_map)
+        mask_id = lv.draw_mask_add(m,None)
+
+    elif code == lv.EVENT.DRAW_MAIN_END:
+        try:
+            m.free_param()
+            mask_id.remove_id()
+        except:
+            pass
+    
+#
+# Draw label with gradient color
+#
+# Create the mask of a text by drawing it to a canvas
+mask_map = bytearray(MASK_WIDTH * MASK_HEIGHT * 4)
+    
+#  Create a "8 bit alpha" canvas and clear it
+canvas = lv.canvas(lv.scr_act())
+canvas.set_buffer(mask_map, MASK_WIDTH, MASK_HEIGHT, lv.COLOR_FORMAT.NATIVE)
+canvas.fill_bg(lv.color_black(), lv.OPA.TRANSP)
+
+# Draw a label to the canvas. The result "image" will be used as mask
+label_dsc = lv.draw_label_dsc_t() 
+label_dsc.init()
+label_dsc.color = lv.color_white()
+label_dsc.align = lv.TEXT_ALIGN.CENTER
+canvas.draw_text(5, 5, MASK_WIDTH, label_dsc, "Text with gradient")
+
+# The mask is reads the canvas is not required anymore
+canvas.delete()
+
+# Convert the mask to A8
+# This is just a work around and will be changed later
+mask8 = bytearray(MASK_WIDTH * MASK_HEIGHT)
+for i in range(MASK_WIDTH * MASK_HEIGHT):
+    #mask8[i] = lv.color_brightness(mask_c[i]);
+    mask8[i] = mask_map[4*i]
+    
+# Create an object from where the text will be masked out.
+# Now it's a rectangle with a gradient but it could be an image too
+grad = lv.obj(lv.scr_act())
+grad.set_size( MASK_WIDTH, MASK_HEIGHT)
+grad.center()
+grad.set_style_bg_color(lv.color_hex(0xff0000), 0)
+grad.set_style_bg_grad_color(lv.color_hex(0x0000ff), 0)
+grad.set_style_bg_grad_dir(lv.GRAD_DIR.HOR, 0)
+grad.add_event(lambda e: add_mask_event_cb(e,mask8), lv.EVENT.ALL, None)
+