apps: FacesApp: Add a watch face chooser

This app is enabled by default and allows users to select a watch face
based on a fullscreen preview of how the app will draw the screen.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

1 files changed, 69 insertions, 0 deletions

diff --git a/wasp/apps/faces.py b/wasp/apps/faces.py
new file mode 100644
index 0000000..7e3ed3e
--- /dev/null
+++ b/wasp/apps/faces.py
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: LGPL-3.0-or-later
+# Copyright (C) 2020 Daniel Thompson
+"""Watch Face Chooser
+~~~~~~~~~~~~~~~~~~~~~
+
+A tool to select a suitable watch face.
+
+.. figure:: res/FacesApp.png
+    :width: 179
+
+The app is intended to be enabled by default and has, therefore, been carefully
+structured to minimize memory usage when the app is not active.
+"""
+
+import wasp
+import icons
+
+class FacesApp():
+    """Choose a default watch face."""
+    NAME = 'Faces'
+    ICON = icons.clock
+
+    def foreground(self):
+        """Activate the application."""
+        choices = []
+        choices.append(('clock', 'Clock'))
+        choices.append(('chrono', 'Chrono'))
+        choices.append(('dual_clock', 'DualClock'))
+        choices.append(('fibonacci_clock', 'FibonacciClock'))
+        choices.append(('word_clock', 'WordClock'))
+
+        self.choices = choices
+        self.choice = 0
+        self.si = wasp.widgets.ScrollIndicator()
+
+        self._update()
+        wasp.system.request_event(wasp.EventMask.SWIPE_UPDOWN)
+
+    def background(self):
+        del self.choices
+        del self.choice
+        del self.si
+
+        # When the watch face redraws then the change to the scrolling indicator
+        # is a little subtle. Let's provide some haptic feedback too so the user
+        # knows something has happened.
+        wasp.watch.vibrator.pulse()
+
+    def swipe(self, event):
+        """Notify the application of a touchscreen swipe event."""
+        choice = self.choice
+        if event[0] == wasp.EventType.DOWN:
+            choice = choice - 1 if choice > 0 else len(self.choices)-1
+        if event[0] == wasp.EventType.UP:
+            choice = choice + 1 if choice < len(self.choices)-1 else 0
+        self.choice = choice
+
+        mute = wasp.watch.display.mute
+        mute(True)
+        self._update()
+        mute(False)
+
+    def _update(self):
+        """Draw the display from scratch."""
+        wasp.watch.drawable.fill()
+        (module, label) = self.choices[self.choice]
+        wasp.system.register('apps.{}.{}App'.format(module, label), watch_face=True)
+        wasp.system.quick_ring[0].preview()
+        self.si.draw()