refactor(vl53l1x): Migrate radar_screen example to steami_screen. (#391)

* refactor(vl53l1x): Migrate radar_screen example to steami_screen.

* refactor(vl53l1x): Clean up radar_screen.py by removing imports.

refactor(vl53l1x): Removed unused imports and sys.path modification.

* refactor(vl53l1x): Reorder micropython import statement.

* ci: Trigger checks rerun.

* fix(vl53l1x): Fix gauge/title draw order and subtitle label in radar_screen.

Address Copilot review comments on #391:

1. Call screen.gauge() before screen.title() so the title text layers on
   top of the arc, as documented in gauge()'s docstring.

2. Change subtitle from "Distance" to "Proximity" — the gauge shows
   proximity (inverted distance: arc grows as object gets closer), so
   labelling it "Distance" was misleading.

---------

Co-authored-by: Sébastien NEDJAR <sebastien@nedjar.com>

Author: MatteoCnda1

lib/vl53l1x/examples/radar_screen.py

@@ -2,77 +2,80 @@
 
 Displays a real-time distance bar on the screen. The closer the object,
 the longer and brighter the bar, similar to a car parking sensor.
-Adapted for a round display bezel.
+Adapted for a round display bezel using steami_screen widgets.
 """
 
 from time import sleep_ms
 
+import micropython
 import ssd1327
 from machine import I2C, SPI, Pin
+from steami_screen import DARK, GRAY, LIGHT, RED, Screen, SSD1327Display
 from vl53l1x import VL53L1X
 
+# === Constants ===
 MAX_DISTANCE_MM = 1000
 
-# Layout constants for the round screen
-BAR_X = 24
-BAR_Y = 70
-BAR_MAX_WIDTH = 80
-BAR_HEIGHT = 15
-TEXT_LBL_X = 28
-TEXT_LBL_Y = 35
-TEXT_VAL_X = 36
-TEXT_VAL_Y = 50
-TEXT_OUT_X = 16  # Shifted left to fit the longer "Out of range" text
-
-i2c = I2C(1)
-tof = VL53L1X(i2c)
-
+# === Display ===
 spi = SPI(1)
 dc = Pin("DATA_COMMAND_DISPLAY")
 res = Pin("RST_DISPLAY")
 cs = Pin("CS_DISPLAY")
+display = SSD1327Display(ssd1327.WS_OLED_128X128_SPI(spi, dc, res, cs))
+screen = Screen(display)
+
+# === Sensor ===
+i2c = I2C(1)
+tof = VL53L1X(i2c)
+
+
+@micropython.native
+def compute_display(distance):
+    """Compute proximity and color from distance value.
+
+    Returns (proximity, color) or (None, None) if out of range.
+    """
+    if distance > MAX_DISTANCE_MM:
+        return None, None
+    proximity = MAX_DISTANCE_MM - distance
+    if proximity > 700:
+        color = RED
+    elif proximity > 400:
+        color = LIGHT
+    else:
+        color = GRAY
+    return proximity, color
 
-display = ssd1327.WS_OLED_128X128_SPI(spi, dc, res, cs)
 
 try:
     while True:
         distance = tof.read()
 
-        # Clear the display frame buffer
-        display.fill(0)
-
-        # Clamp distance to maximum range and compute integer proximity
-        clamped_dist = max(0, min(distance, MAX_DISTANCE_MM))
-        proximity = MAX_DISTANCE_MM - clamped_dist
+        screen.clear()
 
-        # Map proximity to bar width (max 80px) and brightness (max 15)
-        bar_width = (80 * proximity) // MAX_DISTANCE_MM
-        brightness = (15 * proximity) // MAX_DISTANCE_MM
+        proximity, color = compute_display(distance)
 
-        # If the object is within the detection range, ensure minimum visibility
-        if distance <= MAX_DISTANCE_MM:
-            bar_width = max(1, bar_width)
-            brightness = max(1, brightness)
+        # Draw gauge first so that title/value text layers on top of the arc
+        if proximity is None:
+            screen.gauge(0, min_val=0, max_val=MAX_DISTANCE_MM, color=DARK)
+        else:
+            screen.gauge(proximity, min_val=0, max_val=MAX_DISTANCE_MM, color=color)
 
-        # Draw the outline box (1 pixel larger than the max bar size) at max brightness
-        display.framebuf.rect(BAR_X - 1, BAR_Y - 1, BAR_MAX_WIDTH + 2, BAR_HEIGHT + 2, 15)
-        # Draw the distance bar centered: x=24, y=70, max_width=80, height=15
-        display.framebuf.fill_rect(BAR_X, BAR_Y, bar_width, BAR_HEIGHT, brightness)
+        screen.title("RADAR")
 
-        # Display distance or "Out of range"
-        if distance > MAX_DISTANCE_MM:
-            display.text("Out of range", TEXT_OUT_X, TEXT_VAL_Y, 15)
+        if proximity is None:
+            screen.value("----", unit="mm")
+            screen.subtitle("Out of range")
         else:
-            display.text("{} mm".format(distance), TEXT_VAL_X, TEXT_VAL_Y, 15)
-
-        # Send the buffer to the physical screen
-        display.show()
+            screen.value(str(distance), unit="mm")
+            screen.subtitle("Proximity")
 
+        screen.show()
         sleep_ms(50)
 
 except KeyboardInterrupt:
     pass
+
 finally:
-    # Clear the screen on exit or error
-    display.fill(0)
-    display.show()
+    screen.clear()
+    screen.show()