Added basic theming engine.

This theming engine uses a bytestring (but supports anything indexable,
as long as the index results are a byte long),
stored as `wasp.system._theme`.
It has a default value, which should not change anything about the way this looks currently.

The theme can be set via `wasp.system.set_theme`,
but this should *ONLY* be used in `main.py`.
`wasp.system.set_theme` will return True if it was successful,
or False if the theme is of an old format.
Using an old format theme will *not* crash the watch,
but will use the default theme instead.

To theme this, one has to use tools/themer.py (use flag -h for complete explanation)
to generate a bytestring that's added in main.py (see diff).

The bytestring is then loaded into 'wasp.system._theme'.
Theme values can be looked up by apps by using `wasp.system.theme("theme-key")`.
Theme keys appear in the function body of `wasp.system.theme()`.

I've took the liberty of converting existing apps to use this method,
and it seems to work well.

A test theme is provided in `tools/test_theme.py`

Signed-off-by: kozova1 <mug66kk@gmail.com>

tools/test_theme.py

@@ -0,0 +1,15 @@
+from themer import DefaultTheme
+
+class Theme(DefaultTheme):
+    # These colors were chosen specifically because they're hard to miss.
+    # Using this theme on an actual device is not advised
+    # The default theme was generated by removing all the lines below and adding `pass` instead.
+    BLE_COLOR = 0xfb80
+    SCROLL_INDICATOR_COLOR = 0xf800
+    BATTERY_CHARGING_COLOR = 0x07ff
+    SMALL_CLOCK_COLOR = 0x599f
+    NOTIFICATION_COLOR = 0x8fe0
+    ACCENT_MID = 0xf800
+    ACCENT_LO = 0x001f
+    ACCENT_HI = 0x07e0
+    SLIDER_DEFAULT_COLOR = 0x7777

tools/themer.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Compiles themes for wasp-os"""
+
+from argparse import ArgumentParser, RawTextHelpFormatter
+from importlib import import_module
+from typing import Tuple
+
+class DefaultTheme():
+    """This represents the default theme.
+
+    Import this file and extend the Theme class, only changing the variables.
+    Export the resulting class as 'Theme'.
+    serialize() should NEVER be overriden!
+    """
+    BLE_COLOR = 0x7bef
+    SCROLL_INDICATOR_COLOR = 0x7bef
+    BATTERY_CHARGING_COLOR = 0x7bef
+    SMALL_CLOCK_COLOR = 0xe73c
+    NOTIFICATION_COLOR = 0x7bef
+    ACCENT_MID = 0xb5b6
+    ACCENT_LO = 0xbdb6
+    ACCENT_HI = 0xffff
+    SLIDER_DEFAULT_COLOR = 0x39ff
+
+    def serialize(self) -> bytes:
+        """Serializes the theme for use in wasp-os"""
+        def split_bytes(x: int) -> Tuple[int, int]:
+            return (x & 0xFF, (x >> 8) & 0xFF)
+        theme_bytes = bytes([
+            *split_bytes(self.BLE_COLOR),
+            *split_bytes(self.SCROLL_INDICATOR_COLOR),
+            *split_bytes(self.BATTERY_CHARGING_COLOR),
+            *split_bytes(self.SMALL_CLOCK_COLOR),
+            *split_bytes(self.NOTIFICATION_COLOR),
+            *split_bytes(self.ACCENT_MID),
+            *split_bytes(self.ACCENT_LO),
+            *split_bytes(self.ACCENT_HI),
+            *split_bytes(self.SLIDER_DEFAULT_COLOR),
+        ])
+        return theme_bytes
+
+
+if __name__ == '__main__':
+    parser = ArgumentParser(
+        description='''Compiles themes into a format understood by wasp-os.
+                       The resulting string should be put in main.py like this:
+
+                           theme_string = THEME_STRING_GOES_HERE
+
+                       for the theme to take effect.
+                    ''',
+        epilog=''' To create a theme,
+               import this file and extend the DefaultTheme class, only changing the variables.
+               Export the resulting class as 'Theme'.
+               Example:
+               --------
+               theme.py:
+                   from themer import DefaultTheme
+
+                   class Theme(DefaultTheme):
+                       BLE_ICON_COLOR = 0x041F
+
+               shell:
+                   $ ./themer.py theme # NOTE: do not include .py at end of file!
+                   > b'\xef{\xef{\xef{<\xe7\xef{\xb6\xb5\xb6\xbd\xff\xff\xff9'
+
+               main.py:
+                   ...
+                   wasp.system.set_theme(b'\xef{\xef{\xef{<\xe7\xef{\xb6\xb5\xb6\xbd\xff\xff\xff9')
+                   ...
+               ''',
+        formatter_class=RawTextHelpFormatter
+    )
+
+    parser.add_argument('input_file', type=str, nargs=1)
+    args = parser.parse_args()
+
+    theme = DefaultTheme()
+    theme = import_module(args.input_file[0]).Theme()
+    print(theme.serialize())
+

wasp/apps/clock.py

@@ -76,7 +76,8 @@ class ClockApp():
 
             # Clear the display and draw that static parts of the watch face
             draw.fill()
-            draw.rleblit(digits.clock_colon, pos=(2*48, 80), fg=0xb5b6)
+            draw.rleblit(digits.clock_colon, pos=(2*48, 80),
+                         fg=wasp.system.theme('accent-mid'))
 
             # Redraw the status bar
             wasp.system.bar.draw()
@@ -95,10 +96,14 @@ class ClockApp():
         month = MONTH[month*3:(month+1)*3]
 
         # Draw the changeable parts of the watch face
-        draw.rleblit(DIGITS[now[4]  % 10], pos=(4*48, 80))
+        draw.rleblit(DIGITS[now[4]  % 10], pos=(4*48, 80),
-        draw.rleblit(DIGITS[now[4] // 10], pos=(3*48, 80), fg=0xbdb6)
+                     fg=wasp.system.theme('accent-hi'))
-        draw.rleblit(DIGITS[now[3]  % 10], pos=(1*48, 80))
+        draw.rleblit(DIGITS[now[4] // 10], pos=(3*48, 80),
-        draw.rleblit(DIGITS[now[3] // 10], pos=(0*48, 80), fg=0xbdb6)
+                     fg=wasp.system.theme('accent-lo'))
+        draw.rleblit(DIGITS[now[3]  % 10], pos=(1*48, 80),
+                     fg=wasp.system.theme('accent-hi'))
+        draw.rleblit(DIGITS[now[3] // 10], pos=(0*48, 80),
+                     fg=wasp.system.theme('accent-lo'))
         draw.string('{} {} {}'.format(now[2], month, now[0]),
                 0, 180, width=240)
 

wasp/wasp.py

@@ -14,7 +14,6 @@
     wasp.watch is an import of :py:mod:`watch` and is simply provided as a
     shortcut (and to reduce memory by keeping it out of other namespaces).
 """
-
 import gc
 import machine
 import micropython
@@ -118,6 +117,8 @@ class Manager():
         self.musicstate = {}
         self.musicinfo = {}
 
+        self._theme = b'\xef{\xef{\xef{<\xe7\xef{\xb6\xb5\xb6\xbd\xff\xff\xff9'
+
         self.blank_after = 15
 
         self._alarms = []
@@ -514,4 +515,30 @@ class Manager():
 
         self._scheduling = enable
 
+    def set_theme(self, new_theme) -> bool:
+        """Sets the system theme.
+
+        Accepts anything that supports indexing,
+        and has a len() equivalent to the default theme."""
+        if len(self._theme) != len(new_theme):
+            return False
+        self._theme = new_theme
+        return True
+
+    def theme(self, theme_part: str) -> int:
+        """Returns the relevant part of theme. For more see ../tools/themer.py"""
+        theme_parts = ("ble",
+                       "scroll-indicator",
+                       "battery-charging",
+                       "status-clock",
+                       "notify-icon",
+                       "accent-mid",
+                       "accent-lo",
+                       "accent-hi",
+                       "slider-default")
+        if theme_part not in theme_parts:
+            raise IndexError('Theme part {} does not exist'.format(theme_part))
+        idx = theme_parts.index(theme_part) * 2
+        return self._theme[idx] | (self._theme[idx+1] << 8)
+
 system = Manager()

wasp/widgets.py

@@ -39,7 +39,8 @@ class BatteryMeter:
 
         if watch.battery.charging():
             if self.level != -1:
-                draw.rleblit(icon, pos=(239-icon[0], 0), fg=0x7bef)
+                draw.rleblit(icon, pos=(239-icon[0], 0),
+                             fg=wasp.system.theme('battery-charging'))
                 self.level = -1
         else:
             level = watch.battery.level()
@@ -108,7 +109,7 @@ class Clock:
 
             draw = wasp.watch.drawable
             draw.set_font(fonts.sans28)
-            draw.set_color(0xe73c)
+            draw.set_color(wasp.system.theme('status-clock'))
             draw.string(t1, 52, 12, 138)
 
         self.on_screen = now
@@ -137,13 +138,15 @@ class NotificationBar:
         (x, y) = self._pos
 
         if wasp.watch.connected():
-            draw.blit(icons.blestatus, x, y, fg=0x7bef)
+            draw.blit(icons.blestatus, x, y, fg=wasp.system.theme('ble'))
             if wasp.system.notifications:
-                draw.blit(icons.notification, x+22, y, fg=0x7bef)
+                draw.blit(icons.notification, x+22, y,
+                          fg=wasp.system.theme('notify-icon'))
             else:
                 draw.fill(0, x+22, y, 30, 32)
         elif wasp.system.notifications:
-            draw.blit(icons.notification, x, y, fg=0x7bef)
+            draw.blit(icons.notification, x, y,
+                      fg=wasp.system.theme('notify-icon'))
             draw.fill(0, x+30, y, 22, 32)
         else:
             draw.fill(0, x, y, 52, 32)
@@ -206,10 +209,13 @@ class ScrollIndicator:
     def update(self):
         """Update from scrolling indicator."""
         draw = watch.drawable
+        color = wasp.system.theme('scroll-indicator')
+
         if self.up:
-            draw.rleblit(icons.up_arrow, pos=self._pos, fg=0x7bef)
+            draw.rleblit(icons.up_arrow, pos=self._pos, fg=color)
         if self.down:
-            draw.rleblit(icons.down_arrow, pos=(self._pos[0], self._pos[1] + 13), fg=0x7bef)
+            draw.rleblit(icons.down_arrow, pos=(self._pos[0], self._pos[1] + 13),
+                         fg=color)
 
 _SLIDER_KNOB_DIAMETER = const(40)
 _SLIDER_KNOB_RADIUS = const(_SLIDER_KNOB_DIAMETER // 2)
@@ -221,14 +227,25 @@ _SLIDER_TRACK_Y2 = const(_SLIDER_TRACK_Y1 + _SLIDER_TRACK_HEIGHT)
 
 class Slider():
     """A slider to select values."""
-    def __init__(self, steps, x=10, y=90, color=0x39ff):
+    def __init__(self, steps, x=10, y=90, color=None):
         self.value = 0
         self._steps = steps
         self._stepsize = _SLIDER_TRACK / (steps-1)
         self._x = x
         self._y = y
         self._color = color
+        self._lowlight = None
 
+    def draw(self):
+        """Draw the slider."""
+        draw = watch.drawable
+        x = self._x
+        y = self._y
+        color = self._color
+        if self._color is None:
+            self._color = wasp.system.theme('slider-default')
+            color = self._color
+        if self._lowlight is None:
             # Automatically generate a lowlight color
             if color < 0b10110_000000_00000:
                 color = (color | 0b10110_000000_00000) & 0b10110_111111_11111
@@ -237,12 +254,6 @@ class Slider():
             if (color & 0b11111) < 0b10110:
                 color = (color | 0b11000) & 0b11111_111111_10110
             self._lowlight = color
-
-    def draw(self):
-        """Draw the slider."""
-        draw = watch.drawable
-        x = self._x
-        y = self._y
             color = self._color
         light = self._lowlight