Port the interval_face complication to Second Movement (#66)

* Port the interval_face complication to Second Movement

- Compile inside Second Movement
- Support custom display

* Refactor display buffer name, enlarge index buffer

Also removed now unused _blink_idx array

* Fix Clear setting not showing, and its formatting

* Rename work interval label to make it unique

* Skip empty interval timers while cycling through

watch-faces/complication/interval_face.h

@@ -0,0 +1,127 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2022 Andreas Nebinger
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef INTERVAL_FACE_H_
+#define INTERVAL_FACE_H_
+
+/*
+ * INTERVAL TIMER face
+ *
+ * This face brings 9 customizable interval timers to the sensor watch,
+ * to be used as hiit training device and/or for time management techniques.
+ *
+ * - There are 9 interval timer slots, you can cycle through these with the
+ *   alarm button (short press). For each timer slot, a short "slideshow"
+ *   displaying the relevant details (like length of each phase - see below)
+ *   is shown.
+ *
+ * - To start an interval timer, press and hold the alarm button.
+ *
+ * - To pause a running timer, press the alarm button (short press).
+ *
+ * - To completely abort a running timer, press and hold the alarm button.
+ *
+ * - Press and hold the light button to enter settings mode for each interval
+ *   timer slot.
+ *
+ * - Each interval timer has 1 to 4 phases of customizable length like so:
+ *   (1) prepare/warum up --> (2) work --> (3) break --> (4) cool down.
+ *   When setting up or running a timer, each of these phases is displayed by
+ *   the letters "PR" (prepare), "WO" (work), "BR" (break), "CD" (cool down).
+ *
+ * - Each of these phases is optional, you can set the corresponding
+ *   minutes and seconds to zero. But at least one phase needs to be set, if
+ *   you want to use the timer.
+ *
+ * - You can define the number of rounds either only for the work
+ *   phase and/or for the combination of work + break phase. Let's say you
+ *   want an interval timer that counts 3 rounds of 30 seconds work, 
+ *   followed by 20 seconds rest:
+ *         work 30s --> work 30s --> work 30s --> break 20s
+ *   You can do this by setting 30s for the "WO"rk phase and setting a 3
+ *   in the lower right hand corner of the work page. The "LAP" indicator
+ *   lights up at this position, to explain that we are setting laps here.
+ *   After that, set the "BR"eak phase to 20s and leave the rest as it is.
+ *
+ * - If you want to set up a certain number of "full rounds", consisting
+ *   of work phase(s) plus breaks, you can do so at the "BR"eak page. The
+ *   number in the lower right hand corner determines the number of full
+ *   rounds to be counted. A "-" means, that there is no limit and the 
+ *   timer keeps alternating between work and break phases.
+ *
+ * - This watch face comes with several pre-defined interval timers,
+ *   suitable for hiit training (timer slots 1 to 4) as well as doing
+ *   work according to the pomodoro principle (timer slots 5 to 6).
+ *   Feel free to adjust the timer slots to your own needs (or completely 
+ *   wipe them ;-)
+ */
+
+#include "movement.h"
+
+#define INTERVAL_TIMERS 9     // no of available customizable timers (be aware: only 4 bits reserved for this value in struct below)
+
+typedef struct {
+    uint8_t warmup_minutes;
+    uint8_t warmup_seconds;
+    uint8_t work_minutes;
+    uint8_t work_seconds;
+    uint8_t break_minutes;
+    uint8_t break_seconds;
+    uint8_t cooldown_minutes;
+    uint8_t cooldown_seconds;
+    uint8_t work_rounds;
+    uint8_t full_rounds;
+} interval_timer_setting_t;
+
+typedef enum {
+    interval_state_intro,
+    interval_state_waiting,
+    interval_state_setting,
+    interval_state_running,
+    interval_state_pausing
+} interval_timer_state_t;
+
+typedef struct {
+    bool is_active;
+    uint8_t face_idx;
+    uint8_t timer_idx;
+    uint8_t timer_running_idx;
+    interval_timer_state_t face_state;
+    interval_timer_setting_t timer[INTERVAL_TIMERS];
+} interval_face_state_t;
+
+void interval_face_setup(uint8_t watch_face_index, void ** context_ptr);
+void interval_face_activate(void *context);
+bool interval_face_loop(movement_event_t event, void *context);
+void interval_face_resign(void *context);
+
+#define interval_face ((const watch_face_t) { \
+    interval_face_setup, \
+    interval_face_activate, \
+    interval_face_loop, \
+    interval_face_resign, \
+    NULL \
+})
+
+#endif // INTERVAL_FACE_H_