Implement home menu

Buttons are now detected and reported to the current running application
(demoed in main_clock and home_menu with `oledWriteString(oled, 0,0,2,
&data[0], FONT_6x8, 0, 1);`). I start to see the limitations with
APP_DATA. It will be dropped in a futur commit after moving each app
into its own namespace. Variables will be allocated dynamically on app
init.

7 files changed, 159 insertions, 15 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e9e2c8b..0b9aa59 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,8 @@ add_executable(pico-watch
         init.h
         buttons.c
         buttons.h
+        apps/home_menu.c
+        apps/home_menu.h
         apps/main_clock.c
         apps/main_clock.h
 	)
diff --git a/apps/home_menu.c b/apps/home_menu.c
new file mode 100644
index 0000000..b7c15b0
--- /dev/null
+++ b/apps/home_menu.c
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/rtc.h"
+#include "pico/util/datetime.h"
+#include "../oled/ss_oled.h"
+
+#include "home_menu.h"
+#include "../buttons.h"
+
+extern void app_switch(int old_appid, int new_appid);
+
+#define NUMBER_OF_APPS 2
+
+char* APPS_NAME[NUMBER_OF_APPS][12] = {"Home", "Clock"};
+
+void title_str(char *buf, uint buf_size, const datetime_t *t) {
+    snprintf(buf,
+             buf_size,
+             "%d:%02d Home Menu",
+             t->hour,
+             t->min,
+             t->sec);
+};
+
+void show_title(SSOLED *oled) {
+    char datetime_buf[256];
+    char *datetime_str = &datetime_buf[0];
+    datetime_t t;
+    rtc_get_datetime(&t);
+
+    // title with time
+    title_str(datetime_str, sizeof(datetime_buf), &t);
+    oledWriteString(oled, 0,0,0, datetime_str, FONT_8x8, 0, 1);
+}
+
+// Rendering of app
+int home_menu_render(SSOLED *oled, char *data, uint data_size) {
+    show_title(oled);
+    oledWriteString(oled, 0,0,2, &data[0], FONT_6x8, 0, 1);
+    oledWriteString(oled, 0,5,3, APPS_NAME[data[1]][0], FONT_12x16, 0, 1); // FIXME: The name does not update, it seems that the second string is empty… but data[1]'s content is correct, as BUTTON_SELECT switches to the correct app.
+    return 0;
+}
+
+// Interpret button inputs
+int home_menu_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio) {
+    switch (gpio) {
+        case BUTTON_HOME:
+            data[0] = 'H'; break;
+        case BUTTON_SELECT:
+            data[0] = 'S';
+            app_switch(0, data[1]);
+            break;
+        case BUTTON_MODE:
+            data[0] = 'M'; break;
+        case BUTTON_DOWN:
+            data[0] = 'D';
+            data[1]--;
+            break;
+        case BUTTON_UP:
+            data[0] = 'U';
+            data[1]++;
+            break;
+        default:
+            data[0] = '?';
+    }
+    if (data[1] > NUMBER_OF_APPS-1) {
+        data[1] = NUMBER_OF_APPS-1; data[0] = '>';
+    } else if (data[1] < NUMBER_OF_APPS-1) {
+        data[1] = 0; data[0] = '<';
+    }
+    return 0;
+}
+
+// Initlisation of the app.
+int home_menu_init(SSOLED *oled, char *data, uint data_size) {
+    data[1] = 0;
+    return 0; // return 1 when function not implemented
+}
+
+// Processor intensive operations and functions related to drawing to the screen should only be done when the app is in_foreground(=1). This function is only called when the app is init.
+int home_menu_bgrefresh(SSOLED *oled, char *data, uint data_size, char in_foreground) {
+    return 1;
+}
+
+// Destruction of app, deinitlisation should be done here. This is only called if the app's APPS_DESTROY_ON_EXIT is set to 1. When it is not a "service" app.
+int home_menu_destroy(SSOLED *oled, char *data, uint data_size) {
+    return 1;
+}
diff --git a/apps/home_menu.h b/apps/home_menu.h
new file mode 100644
index 0000000..507e818
--- /dev/null
+++ b/apps/home_menu.h
@@ -0,0 +1,15 @@
+#ifndef __HOME_MENU_H__
+#define __HOME_MENU_H__
+
+#include "pico/util/datetime.h"
+#include "../oled/ss_oled.h"
+
+void show_title(SSOLED *oled);
+
+int home_menu_init(SSOLED *oled, char *data, uint data_size);
+int home_menu_render(SSOLED *oled, char *data, uint data_size);
+int home_menu_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio);
+int home_menu_bgrefresh(SSOLED *oled, char *data, uint data_size, char in_foreground);
+int home_menu_destroy(SSOLED *oled, char *data, uint data_size);
+
+#endif
\ No newline at end of file
diff --git a/apps/main_clock.c b/apps/main_clock.c
index 496c696..547057e 100644
--- a/apps/main_clock.c
+++ b/apps/main_clock.c
@@ -51,6 +51,7 @@ void show_datetime(SSOLED *oled) {
     oledWriteString(oled, 0,0,7, datetime_str, FONT_8x8, 0, 1);
 }
 
+// Rendering of the app
 int main_clock_render(SSOLED *oled, char *data, uint data_size) {
     oledWriteString(oled, 0,15,0, (char *)"Test clock", FONT_8x8, 0, 1);
     show_datetime(oled);
@@ -78,14 +79,17 @@ int main_clock_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio) {
     return 0;
 }
 
+// Initlisation of the app.
 int main_clock_init(SSOLED *oled, char *data, uint data_size) {
     return 1; // return 1 when function not implemented
 }
 
-int main_clock_bgrefresh(SSOLED *oled, char *data, uint data_size) {
+// Processor intensive operations and functions related to drawing to the screen should only be done when the app is in_foreground(=1). This function is only called when the app is init.
+int main_clock_bgrefresh(SSOLED *oled, char *data, uint data_size, char in_foreground) {
     return 1;
 }
 
+// Destruction of app, deinitlisation should be done here. This is only called if the app's APPS_DESTROY_ON_EXIT is set to 1. When it is not a "service" app.
 int main_clock_destroy(SSOLED *oled, char *data, uint data_size) {
     return 1;
 }
diff --git a/apps/main_clock.h b/apps/main_clock.h
index a7acdfe..70d9755 100644
--- a/apps/main_clock.h
+++ b/apps/main_clock.h
@@ -11,7 +11,7 @@ void show_datetime(SSOLED *oled);
 int main_clock_init(SSOLED *oled, char *data, uint data_size);
 int main_clock_render(SSOLED *oled, char *data, uint data_size);
 int main_clock_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio);
-int main_clock_bgrefresh(SSOLED *oled, char *data, uint data_size);
+int main_clock_bgrefresh(SSOLED *oled, char *data, uint data_size, char in_foreground);
 int main_clock_destroy(SSOLED *oled, char *data, uint data_size);
 
 #endif
\ No newline at end of file
diff --git a/buttons.c b/buttons.c
index 2e9996b..3a71d9c 100644
--- a/buttons.c
+++ b/buttons.c
@@ -2,7 +2,9 @@
 #include "pico/stdlib.h"
 
 #include "buttons.h"
+// From pico-watch.c:
 extern int app_btnpressed(int app_id, uint gpio);
+extern void app_switch(int old_appid, int new_appid);
 extern int current_app;
 
 // Debounce control
@@ -15,7 +17,11 @@ const int button_delayTime = 50; // 50ms worked fine for me .... change it to yo
 
 void gpio_interrupt_cb(uint gpio, uint32_t events) {
     if ((to_ms_since_boot(get_absolute_time())-button_time)>button_delayTime) {
-        app_btnpressed(current_app, gpio);
+        if (gpio == BUTTON_HOME && (current_app != 0)) // Home app
+            app_switch(current_app, 0);
+        else
+            app_btnpressed(current_app, gpio);
+        
         button_time = to_ms_since_boot(get_absolute_time());
     }
 }
@@ -38,7 +44,7 @@ void init_buttons() {
     gpio_set_irq_enabled_with_callback(BUTTON_UP, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
 
     /* For some reason for loop does not work… TODO
-    for (int i=0; i == NUMBER_OF_BUTTONS; i++) {
+    for (int i=0; i < NUMBER_OF_BUTTONS; i++) {
         uint button = BUTTON_PINS[i];
         gpio_init(button);
         gpio_pull_up(button);
diff --git a/pico-watch.c b/pico-watch.c
index eb5f7cc..37dcd35 100644
--- a/pico-watch.c
+++ b/pico-watch.c
@@ -8,23 +8,27 @@
 #include "init.h"
 #include "buttons.h"
 #include "apps/main_clock.h"
+#include "apps/home_menu.h"
 
 int current_app = 0;
 
-#define NUMBER_OF_APPS 1
+#define NUMBER_OF_APPS 2
 #define APP_DATA_BUFFER_LEN 256
-int (*APPS_FUNC_INIT[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_init};
-int (*APPS_FUNC_RENDER[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_render};
-int (*APPS_FUNC_BTNPRESS[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size, uint gpio) = {main_clock_btnpressed};
-int (*APPS_FUNC_BGREFRESH[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_bgrefresh};
-int (*APPS_FUNC_DESTROY[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_destroy};
+int (*APPS_FUNC_INIT[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {home_menu_init, main_clock_init};
+int (*APPS_FUNC_RENDER[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {home_menu_render, main_clock_render};
+int (*APPS_FUNC_BTNPRESS[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size, uint gpio) = {home_menu_btnpressed, main_clock_btnpressed};
+int (*APPS_FUNC_BGREFRESH[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size, char in_foreground) = {home_menu_bgrefresh, main_clock_bgrefresh};
+int (*APPS_FUNC_DESTROY[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {home_menu_destroy, main_clock_destroy};
 char APPS_DATA[NUMBER_OF_APPS][APP_DATA_BUFFER_LEN];
-int APPS_DESTROY_ON_EXIT[NUMBER_OF_APPS] = {1};
-int APPS_IS_INIT[NUMBER_OF_APPS] = {0};
+int APPS_DESTROY_ON_EXIT[NUMBER_OF_APPS] = {0, 1};
+int APPS_IS_INIT[NUMBER_OF_APPS] = {0, 0}; // Only run in background if init
 
 int app_init(int app_id) {
-    APPS_IS_INIT[app_id] = 1;
-    return (*APPS_FUNC_INIT[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
+    oledFill(&oled, 0,1); // Clear OLED
+    if (!APPS_IS_INIT[app_id]) {
+        APPS_IS_INIT[app_id] = 1;
+        return (*APPS_FUNC_INIT[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
+    }
 }
 
 int app_render(int app_id) {
@@ -36,13 +40,38 @@ int app_btnpressed(int app_id, uint gpio) {
 }
 
 int app_destroy(int app_id) {
+    // TODO: reset APPS_DATA for the app
+    if (APPS_IS_INIT[app_id]) {
+        APPS_IS_INIT[app_id] = 0;
+        return (*APPS_FUNC_DESTROY[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
+    }
+}
+
+int app_bgrefresh(int app_id) {
     if (APPS_IS_INIT[app_id])
-        return (*APPS_FUNC_INIT[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
+        return (*APPS_FUNC_BGREFRESH[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]), app_id==current_app);
+}
+
+bool apps_bgrefresh(struct repeating_timer *t) {  // TODO: Refresh done on core1
+    for (int i=0; i < NUMBER_OF_APPS; i++) {
+        app_bgrefresh(i);
+    }
+    return true;
+}
+
+void app_switch(int old_appid, int new_appid) {
+    if (APPS_DESTROY_ON_EXIT[old_appid]) {
+        app_destroy(old_appid);
+    }
+    app_init(new_appid);
+    current_app = new_appid;
 }
 
 int main() {
     init_all();
     init_buttons();
+    struct repeating_timer timer;
+    add_repeating_timer_ms(250, apps_bgrefresh, NULL, &timer);
 
     app_init(current_app);