Alternative implementation of world clock (#216)

* Implementation of alternative world clock.

* Fixed two minor bugs
- Only start in settings mode on first activation
- Fixed typo in time zone names

---------

Co-authored-by: joeycastillo <joeycastillo@utexas.edu>

4 files changed, 515 insertions, 0 deletions

diff --git a/movement/make/Makefile b/movement/make/Makefile
index dec3ffab..b930585e 100644
--- a/movement/make/Makefile
+++ b/movement/make/Makefile
@@ -105,6 +105,7 @@ SRCS += \
   ../watch_faces/clock/repetition_minute_face.c \
   ../watch_faces/complication/timer_face.c \
   ../watch_faces/complication/invaders_face.c \
+  ../watch_faces/clock/world_clock2_face.c \
 # New watch faces go above this line.
 
 # Leave this line at the bottom of the file; it has all the targets for making your project.
diff --git a/movement/movement_faces.h b/movement/movement_faces.h
index 50b084d3..278e6616 100644
--- a/movement/movement_faces.h
+++ b/movement/movement_faces.h
@@ -81,6 +81,7 @@
 #include "repetition_minute_face.h"
 #include "timer_face.h"
 #include "invaders_face.h"
+#include "world_clock2_face.h"
 // New includes go above this line.
 
 #endif // MOVEMENT_FACES_H_
diff --git a/movement/watch_faces/clock/world_clock2_face.c b/movement/watch_faces/clock/world_clock2_face.c
new file mode 100644
index 00000000..0077f639
--- /dev/null
+++ b/movement/watch_faces/clock/world_clock2_face.c
@@ -0,0 +1,450 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Konrad Rieck
+ * Copyright (c) 2022 Joey Castillo
+ *
+ * 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.
+ */
+
+/*
+ * World Clock 2
+ * =============
+ *
+ * This is an alternative world clock face that allows the user to cycle
+ * through a list of selected time zones. It extends the original
+ * implementation by Joey Castillo. The face has two modes *display mode*
+ * and *settings mode*.
+ *
+ * ### Settings mode
+ *
+ * When the clock face is activated for the first time, it enters
+ * *settings mode*. Here, the user can select the time zones they want to
+ * display. The face shows a summary of the current time zone:
+ *
+ * - The top of the face displays the first two letters of the time zone
+ *   abbreviation, such as "PS" for Pacific Standard Time or CE for
+ * "Central European Time".
+ *
+ * - The upper-right corner shows the index number of the time zone. This
+ *   helps avoid confusion when multiple time zones have the same
+ *   two-letter abbreviation.
+ *
+ * - The main display shows the offset from UTC, with a "+" indicating a
+ *   positive offset and a "-" indicating a negative offset. For example,
+ *   the offset for Japanese Standard Time is displayed as "+9:00".
+ *
+ * The user can navigate through the time zones and select them using the
+ * following buttons:
+ *
+ * - The *alarm button* moves forward to the next time zone, while the
+ *   *light button* moves backward to the previous zone. This way, the
+ *   user can cycle through all 41 supported time zones.
+ *
+ * - A *long press* on the *light button* selects the current time zone,
+ *   and the signal indicator appears at the top left. Another *long
+ *   press* of the *light button* deselects the time zone.
+ *
+ * - A *long press* on the *alarm button* exits settings mode and returns
+ *   to display mode.
+ *
+ * ### Display mode
+ *
+ * In the display mode, the face shows the time of the currently selected
+ * time zone. The face includes the following components:
+ *
+ * - The top of the face displays the first two letters of the time zone
+ *   abbreviation, such as "PS" for Pacific Standard Time or "CE" for
+ *   Central European Time.
+ *
+ * - The upper-right corner shows the current day of the month, which
+ *   helps indicate time zones that cross the international date line
+ *   with respect to the local time.
+ *
+ * - The main display shows the time in the selected time zone in either
+ *   12-hour or 24-hour form. There is no timeout, allowing users to keep
+ *   the chosen time zone displayed for as long as they wish.
+ *
+ * The user can navigate through the selected time zones using the
+ * following buttons:
+ *
+ * - The *alarm button* moves to the next selected time zone, while the
+ *   light button moves to the *previous zone*. If no time zone is
+ *   selected, the face simply shows UTC.
+ *
+ * - A *long press* on the *alarm button* enters settings mode and
+ *   enables the user to re-configure the selected time zones.
+ *
+ * - A *long press* on the *light button* activates the LED illumination
+ *   of the watch.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "world_clock2_face.h"
+#include "watch.h"
+#include "watch_utility.h"
+#include "watch_utility.h"
+
+static bool refresh_face;
+
+/* Simple macros for navigation */
+#define FORWARD             +1
+#define BACKWARD            -1
+
+/* Activate refresh of time */
+#define REFRESH_TIME        0xffffffff
+
+/* List of all time zone names */
+const char *zone_names[] = {
+    "UTC",	//  0 :   0:00:00 (UTC)
+    "CET",	//  1 :   1:00:00 (Central European Time)
+    "SAST",	//  2 :   2:00:00 (South African Standard Time)
+    "ARST",	//  3 :   3:00:00 (Arabia Standard Time)
+    "IRST",	//  4 :   3:30:00 (Iran Standard Time)
+    "GET",	//  5 :   4:00:00 (Georgia Standard Time)
+    "AFT",	//  6 :   4:30:00 (Afghanistan Time)
+    "PKT",	//  7 :   5:00:00 (Pakistan Standard Time)
+    "IST",	//  8 :   5:30:00 (Indian Standard Time)
+    "NPT",	//  9 :   5:45:00 (Nepal Time)
+    "KGT",	// 10 :   6:00:00 (Kyrgyzstan time)
+    "MYST",	// 11 :   6:30:00 (Myanmar Time)
+    "THA",	// 12 :   7:00:00 (Thailand Standard Time)
+    "CST",	// 13 :   8:00:00 (China Standard Time, Australian Western Standard Time)
+    "ACWS",	// 14 :   8:45:00 (Australian Central Western Standard Time)
+    "JST",	// 15 :   9:00:00 (Japan Standard Time, Korea Standard Time)
+    "ACST",	// 16 :   9:30:00 (Australian Central Standard Time)
+    "AEST",	// 17 :  10:00:00 (Australian Eastern Standard Time)
+    "LHST",	// 18 :  10:30:00 (Lord Howe Standard Time)
+    "SBT",	// 19 :  11:00:00 (Solomon Islands Time)
+    "NZST",	// 20 :  12:00:00 (New Zealand Standard Time)
+    "CHAS",	// 21 :  12:45:00 (Chatham Standard Time)
+    "TOT",	// 22 :  13:00:00 (Tonga Time)
+    "CHAD",	// 23 :  13:45:00 (Chatham Daylight Time)
+    "LINT",	// 24 :  14:00:00 (Line Islands Time)
+    "BIT",	// 25 : -12:00:00 (Baker Island Time)
+    "NUT",	// 26 : -11:00:00 (Niue Time)
+    "HST",	// 27 : -10:00:00 (Hawaii-Aleutian Standard Time)
+    "MART",	// 28 :  -9:30:00 (Marquesas Islands Time)
+    "AKST",	// 29 :  -9:00:00 (Alaska Standard Time)
+    "PST",	// 30 :  -8:00:00 (Pacific Standard Time)
+    "MST",	// 31 :  -7:00:00 (Mountain Standard Time)
+    "CST",	// 32 :  -6:00:00 (Central Standard Time)
+    "EST",	// 33 :  -5:00:00 (Eastern Standard Time)
+    "VET",	// 34 :  -4:30:00 (Venezuelan Standard Time)
+    "AST",	// 35 :  -4:00:00 (Atlantic Standard Time)
+    "NST",	// 36 :  -3:30:00 (Newfoundland Standard Time)
+    "BRT",	// 37 :  -3:00:00 (Brasilia Time)
+    "NDT",	// 38 :  -2:30:00 (Newfoundland Daylight Time)
+    "FNT",	// 39 :  -2:00:00 (Fernando de Noronha Time)
+    "AZOT",	// 40 :  -1:00:00 (Azores Standard Time)
+};
+
+/* Modulo function */
+static inline unsigned int mod(int a, int b)
+{
+    int r = a % b;
+    return r < 0 ? r + b : r;
+}
+
+/* Find the next selected time zone */
+static inline uint8_t find_selected_zone(world_clock2_state_t *state, int direction)
+{
+    uint8_t i = state->current_zone;
+
+    do {
+	i = mod(i + direction, NUM_TIME_ZONES);
+	/* Could not find a selected zone. Return UTC */
+	if (i == state->current_zone) {
+	    return 0;
+	}
+    } while (!state->zones[i].selected);
+
+    return i;
+}
+
+/* Beep when zone is enabled. An octave up */
+static void beep_enable() {
+    watch_buzzer_play_note(BUZZER_NOTE_G7, 50);
+    watch_buzzer_play_note(BUZZER_NOTE_REST, 75);
+    watch_buzzer_play_note(BUZZER_NOTE_C8, 75);
+}
+
+/* Beep when zone id disable. An octave down */
+static void beep_disable() {
+    watch_buzzer_play_note(BUZZER_NOTE_C8, 50);
+    watch_buzzer_play_note(BUZZER_NOTE_REST, 75);
+    watch_buzzer_play_note(BUZZER_NOTE_G7, 75);
+}
+
+void world_clock2_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void **context_ptr)
+{
+    (void) settings;
+    (void) watch_face_index;
+
+    if (*context_ptr == NULL) {
+        *context_ptr = malloc(sizeof(world_clock2_state_t));
+        memset(*context_ptr, 0, sizeof(world_clock2_state_t));
+
+        /* Start in settings mode */
+        world_clock2_state_t *state = (world_clock2_state_t *) * context_ptr;
+        state->current_mode = WORLD_CLOCK2_MODE_SETTINGS;
+    }
+}
+
+void world_clock2_face_activate(movement_settings_t *settings, void *context)
+{
+    (void) settings;
+    world_clock2_state_t *state = (world_clock2_state_t *) context;
+
+    if (watch_tick_animation_is_running())
+        watch_stop_tick_animation();
+
+    switch (state->current_mode) {
+        case WORLD_CLOCK2_MODE_DISPLAY:
+            /* Normal tick frequency */
+            movement_request_tick_frequency(1);
+            break;
+        case WORLD_CLOCK2_MODE_SETTINGS:
+            /* Faster frequency for blinking effect */
+            movement_request_tick_frequency(4);
+            break;
+    }
+    refresh_face = true;
+}
+
+static bool mode_display(movement_event_t event, movement_settings_t *settings, world_clock2_state_t *state)
+{
+    char buf[11];
+    uint8_t pos;
+
+    uint32_t timestamp;
+    uint32_t previous_date_time;
+    watch_date_time date_time;
+
+    switch (event.event_type) {
+	case EVENT_ACTIVATE:
+	case EVENT_TICK:
+	case EVENT_LOW_ENERGY_UPDATE:
+	    /* Update indicators and colon on refresh */
+	    if (refresh_face) {
+		watch_clear_indicator(WATCH_INDICATOR_SIGNAL);
+		watch_set_colon();
+                if (settings->bit.clock_mode_24h)
+                    watch_set_indicator(WATCH_INDICATOR_24H);
+
+                state->previous_date_time = REFRESH_TIME;
+                refresh_face = false;
+            }
+
+            /* Determine current time at time zone and store date/time */
+	    date_time = watch_rtc_get_date_time();
+	    timestamp = watch_utility_date_time_to_unix_time(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
+	    date_time = watch_utility_date_time_from_unix_time(timestamp, movement_timezone_offsets[state->current_zone] * 60);
+	    previous_date_time = state->previous_date_time;
+	    state->previous_date_time = date_time.reg;
+
+	    if ((date_time.reg >> 6) == (previous_date_time >> 6) && event.event_type != EVENT_LOW_ENERGY_UPDATE) {
+                /* Everything before seconds is the same, don't waste cycles setting those segments. */
+		pos = 8;
+		sprintf(buf, "%02d", date_time.unit.second);
+	    } else if ((date_time.reg >> 12) == (previous_date_time >> 12) && event.event_type != EVENT_LOW_ENERGY_UPDATE) {
+		/* Everything before minutes is the same. */
+		pos = 6;
+		sprintf(buf, "%02d%02d", date_time.unit.minute, date_time.unit.second);
+	    } else {
+		/* Other stuff changed; Let's do it all. */
+		if (!settings->bit.clock_mode_24h) {
+		    /* If we are in 12 hour mode, do some cleanup. */
+		    if (date_time.unit.hour < 12) {
+			watch_clear_indicator(WATCH_INDICATOR_PM);
+		    } else {
+			watch_set_indicator(WATCH_INDICATOR_PM);
+		    }
+		    date_time.unit.hour %= 12;
+		    if (date_time.unit.hour == 0)
+			date_time.unit.hour = 12;
+		}
+
+		pos = 0;
+		if (event.event_type == EVENT_LOW_ENERGY_UPDATE) {
+		    if (!watch_tick_animation_is_running())
+			watch_start_tick_animation(500);
+
+		    sprintf(buf, "%.2s%2d%2d%02d  ",
+                            zone_names[state->current_zone],
+                            date_time.unit.day,
+                            date_time.unit.hour,
+                            date_time.unit.minute);
+		} else {
+		    sprintf(buf, "%.2s%2d%2d%02d%02d",
+			    zone_names[state->current_zone],
+                            date_time.unit.day,
+                            date_time.unit.hour,
+                            date_time.unit.minute,
+                            date_time.unit.second);
+		}
+	    }
+	    watch_display_string(buf, pos);
+	    break;
+	case EVENT_ALARM_BUTTON_UP:
+	    state->current_zone = find_selected_zone(state, FORWARD);
+            state->previous_date_time = REFRESH_TIME;
+	    break;
+	case EVENT_LIGHT_BUTTON_DOWN:
+	    /* Do nothing. */
+	    break;
+	case EVENT_LIGHT_BUTTON_UP:
+	    state->current_zone = find_selected_zone(state, BACKWARD);
+            state->previous_date_time = REFRESH_TIME;
+	    break;
+	case EVENT_LIGHT_LONG_PRESS:
+	    movement_illuminate_led();
+	    break;
+	case EVENT_ALARM_LONG_PRESS:
+	    /* Switch to settings mode */
+	    state->current_mode = WORLD_CLOCK2_MODE_SETTINGS;
+	    refresh_face = true;
+            movement_request_tick_frequency(1);
+
+            if (settings->bit.button_should_sound)
+                watch_buzzer_play_note(BUZZER_NOTE_C8, 50);
+	    break;
+        case EVENT_MODE_BUTTON_UP:
+            /* Reset frequency and move to next face */
+            movement_request_tick_frequency(1);
+            movement_move_to_next_face();
+            break;
+	default:
+	    return movement_default_loop_handler(event, settings);
+    }
+
+    return true;
+}
+
+static bool mode_settings(movement_event_t event, movement_settings_t *settings, world_clock2_state_t *state)
+{
+    char buf[11];
+    int8_t hours, minutes;
+    uint8_t zone;
+    div_t result;
+
+    switch (event.event_type) {
+	case EVENT_ACTIVATE:
+	case EVENT_TICK:
+	case EVENT_LOW_ENERGY_UPDATE:
+            /* Update indicator and colon on refresh */
+            if (refresh_face) {
+                watch_clear_colon();
+                watch_clear_indicator(WATCH_INDICATOR_24H);
+                watch_clear_indicator(WATCH_INDICATOR_PM);
+                refresh_face = false;
+            }
+	    result = div(movement_timezone_offsets[state->current_zone], 60);
+	    hours = result.quot;
+	    minutes = result.rem;
+
+	    /*
+	     * Display time zone. The range of the parameters is reduced
+	     * to avoid accidentally overflowing the buffer and to suppress
+	     * corresponding compiler warnings.
+	     */
+	    sprintf(buf, "%.2s%2d %c%02d%02d",
+                    zone_names[state->current_zone],
+                    state->current_zone % 100,
+                    hours < 0 ? '-' : '+',
+                    abs(hours) % 24,
+		    abs(minutes) % 60);
+
+            /* Let the zone number blink */
+            if (event.subsecond % 2)
+                buf[2] = buf[3] = ' ';
+
+	    if (state->zones[state->current_zone].selected)
+		watch_set_indicator(WATCH_INDICATOR_SIGNAL);
+	    else
+		watch_clear_indicator(WATCH_INDICATOR_SIGNAL);
+
+	    watch_display_string(buf, 0);
+	    break;
+	case EVENT_ALARM_BUTTON_UP:
+	    state->current_zone = mod(state->current_zone + FORWARD, NUM_TIME_ZONES);
+	    break;
+	case EVENT_LIGHT_BUTTON_UP:
+	    state->current_zone = mod(state->current_zone + BACKWARD, NUM_TIME_ZONES);
+	    break;
+	case EVENT_LIGHT_BUTTON_DOWN:
+	    /* Do nothing */
+	    break;
+	case EVENT_ALARM_LONG_PRESS:
+	    /* Find next selected zone */
+	    if (!state->zones[state->current_zone].selected)
+		state->current_zone = find_selected_zone(state, FORWARD);
+
+	    /* Switch to display mode */
+	    state->current_mode = WORLD_CLOCK2_MODE_DISPLAY;
+	    refresh_face = true;
+            movement_request_tick_frequency(1);
+
+            if (settings->bit.button_should_sound)
+                watch_buzzer_play_note(BUZZER_NOTE_C8, 50);
+	    break;
+	case EVENT_LIGHT_LONG_PRESS:
+	    /* Toggle selection of current zone */
+	    zone = state->current_zone;
+	    state->zones[zone].selected = !state->zones[zone].selected;
+
+            if (settings->bit.button_should_sound) {
+                if (state->zones[zone].selected) {
+                    beep_enable();
+                } else {
+                    beep_disable();
+                }
+            }
+            break;
+        case EVENT_MODE_BUTTON_UP:
+            /* Reset frequency and move to next face */
+            movement_request_tick_frequency(1);
+            movement_move_to_next_face();
+            break;
+        default:
+            return movement_default_loop_handler(event, settings);
+    }
+
+    return true;
+}
+
+bool world_clock2_face_loop(movement_event_t event, movement_settings_t *settings, void *context)
+{
+    world_clock2_state_t *state = (world_clock2_state_t *) context;
+    switch (state->current_mode) {
+	case WORLD_CLOCK2_MODE_DISPLAY:
+	    return mode_display(event, settings, state);
+	case WORLD_CLOCK2_MODE_SETTINGS:
+	    return mode_settings(event, settings, state);
+    }
+    return false;
+}
+
+void world_clock2_face_resign(movement_settings_t *settings, void *context)
+{
+    (void) settings;
+    (void) context;
+}
diff --git a/movement/watch_faces/clock/world_clock2_face.h b/movement/watch_faces/clock/world_clock2_face.h
new file mode 100644
index 00000000..f70dca1f
--- /dev/null
+++ b/movement/watch_faces/clock/world_clock2_face.h
@@ -0,0 +1,63 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Konrad Rieck
+ * Copyright (c) 2022 Joey Castillo
+ *
+ * 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 WORLD_CLOCK2_FACE_H_
+#define WORLD_CLOCK2_FACE_H_
+
+/* Number of zones. See movement_timezone_offsets. */
+#define NUM_TIME_ZONES  41
+
+#include "movement.h"
+
+typedef enum {
+    WORLD_CLOCK2_MODE_DISPLAY,
+    WORLD_CLOCK2_MODE_SETTINGS
+} world_clock2_mode_t;
+
+typedef struct {
+    bool selected;
+} world_clock2_zone_t;
+
+typedef struct {
+    world_clock2_zone_t zones[NUM_TIME_ZONES];
+    world_clock2_mode_t current_mode;
+    uint8_t current_zone;
+    uint32_t previous_date_time;
+} world_clock2_state_t;
+
+void world_clock2_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void **context_ptr);
+void world_clock2_face_activate(movement_settings_t *settings, void *context);
+bool world_clock2_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void world_clock2_face_resign(movement_settings_t *settings, void *context);
+
+#define world_clock2_face ((const watch_face_t){ \
+    world_clock2_face_setup, \
+    world_clock2_face_activate, \
+    world_clock2_face_loop, \
+    world_clock2_face_resign, \
+    NULL, \
+})
+
+#endif /* WORLD_CLOCK2_FACE_H_ */