add dial simpletest example

Author: kmatch98

adafruit_displayio_layout/widgets/dial.py

@@ -104,12 +104,12 @@ def __init__(
         start_angle=None,
         clip_needle=False,
         # trims off the needle outside of the dial region, used for sweep_angles < 180
-        needle_width=3,
+        needle_width=7,
         # triangle with this base width, best if this is odd
         needle_color=0x880000,
         value=None,
         value_font=None,
-        display_value=True,
+        display_value=False,
         value_color=0xFF0000,
         value_format_string=":0.0f",
         min_value=0.0,
@@ -436,6 +436,8 @@ def _create_needle(self):
             self._needle_width = round(
                 self._needle_width_requested * self._dial_radius / needle_length_showing
             )
+        else:
+            self._needle_width = self._needle_width_requested
 
     def _update_value(self):
 
@@ -493,8 +495,8 @@ def _draw_position(self, position):
         # Get the position offset from the motion function
         angle_offset = self._get_offset_position(position)
 
-        d_x = self._needle_width / 2 * math.cos(angle_offset)
-        d_y = self._needle_width / 2 * math.sin(angle_offset)
+        d_x = (self._needle_width / 2) * math.cos(angle_offset)
+        d_y = (self._needle_width / 2) * math.sin(angle_offset)
 
         x_0 = round(self._dial_center[0] - d_x)
         y_0 = round(self._dial_center[1] - d_y)
@@ -593,7 +595,8 @@ def draw_ticks(
     sweep_angle,
     tick_color_index=1,
 ):
-    """Helper function for drawing ticks on the dial widget.
+    """Helper function for drawing ticks on the dial widget.  Can be used to
+    customize the dial face.
 
     :param displayio.Bitmap target_bitmap: Bitmap where ticks will be drawn into
     :param (int,int) dial_center: the (x,y) pixel location in the bitmap of
@@ -662,7 +665,8 @@ def draw_labels(
     rotate_labels=True,
     tick_label_scale=1.0,
 ):
-    """Helper function for drawing text labels on the dial widget.
+    """Helper function for drawing text labels on the dial widget.  Can be used
+    to customize the dial face.
 
     :param displayio.Bitmap target_bitmap: Bitmap where ticks will be drawn into
     :param Font font: the font to be used to draw the tick mark text labels

examples/displayio_layout_dial_simpletest.py

@@ -0,0 +1,64 @@
+# SPDX-FileCopyrightText: 2021 Kevin Matocha
+#
+# SPDX-License-Identifier: MIT
+#############################
+# This is a trial of the Dial using Adafruit_DisplayIO_Layout
+#
+
+import time
+import board
+import displayio
+from adafruit_displayio_layout.widgets.dial import Dial
+
+from adafruit_bitmap_font import bitmap_font
+
+glyphs = "0123456789"
+
+# Fonts used for the Dial tick labels
+tick_font_file = "fonts/BitstreamVeraSans-Bold-16.pcf"
+tick_font = bitmap_font.load_font(tick_font_file)
+tick_font.load_glyphs(glyphs)
+
+display = board.DISPLAY  # create the display on the PyPortal or Clue (for example)
+# otherwise change this to setup the display
+# for display chip driver and pinout you have (e.g. ILI9341)
+
+
+# Define the minimum and maximum values for the dial
+minimum_value = 0
+maximum_value = 100
+
+# Create a Dial widget
+my_dial = Dial(
+    x=20,  # set x-position of the dial inside of my_group
+    y=20,  # set y-position of the dial inside of my_group
+    width=180,  # requested width of the di
+    height=180,
+    padding=25,  # add 25 pixels around the dial to make room for labels
+    start_angle=-120,  # left angle position at -120 degrees
+    sweep_angle=240,  # total sweep angle of 240 degrees
+    min_value=minimum_value,  # set the minimum value shown on the dial
+    max_value=maximum_value,  # set the maximum value shown on the dial
+    tick_label_font=tick_font,  #
+)
+
+my_group = displayio.Group(max_size=1)
+my_group.append(my_dial)
+
+display.show(my_group)  # add high level Group to the display
+
+step_size = 1
+
+while True:
+
+    # run the dial from minimum to maximum
+    for this_value in range(minimum_value, maximum_value + 1, step_size):
+        my_dial.value = this_value
+        display.refresh()  # force the display to refresh
+    time.sleep(0.5)
+
+    # run the dial from maximum to minimum
+    for this_value in range(maximum_value, minimum_value - 1, -step_size):
+        my_dial.value = this_value
+        display.refresh()  # force the display to refresh
+    time.sleep(0.5)