feat(display): Initial widget/status screen work.

* Battery and output status widgets
* Built in status screen combining them.
* Ability to define a custom status screen factory
  function.

1 files changed, 85 insertions, 0 deletions

diff --git a/app/src/display/widgets/battery_status.c b/app/src/display/widgets/battery_status.c
new file mode 100644
index 0000000..7b1afd1
--- /dev/null
+++ b/app/src/display/widgets/battery_status.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <bluetooth/services/bas.h>
+
+#include <logging/log.h>
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#include <zmk/display/widgets/battery_status.h>
+#include <zmk/usb.h>
+#include <zmk/events/usb-conn-state-changed.h>
+#include <zmk/event-manager.h>
+#include <zmk/events/battery-state-changed.h>
+
+static sys_slist_t widgets = SYS_SLIST_STATIC_INIT(&widgets);
+static lv_style_t label_style;
+
+void battery_status_init() {
+    if (label_style.text.font != NULL) {
+        return;
+    }
+
+    lv_style_copy(&label_style, &lv_style_plain);
+    label_style.text.color = LV_COLOR_BLACK;
+    label_style.text.font = &lv_font_roboto_16;
+    label_style.text.letter_space = 1;
+    label_style.text.line_space = 1;
+}
+
+void set_battery_symbol(lv_obj_t *label) {
+    char text[2] = "  ";
+    u8_t level = bt_gatt_bas_get_battery_level();
+
+#if IS_ENABLED(CONFIG_USB)
+    if (zmk_usb_is_powered()) {
+        strcpy(text, LV_SYMBOL_CHARGE);
+    }
+#endif /* IS_ENABLED(CONFIG_USB) */
+
+    if (level > 95) {
+        strcat(text, LV_SYMBOL_BATTERY_FULL);
+    } else if (level > 65) {
+        strcat(text, LV_SYMBOL_BATTERY_3);
+    } else if (level > 35) {
+        strcat(text, LV_SYMBOL_BATTERY_2);
+    } else if (level > 5) {
+        strcat(text, LV_SYMBOL_BATTERY_1);
+    } else {
+        strcat(text, LV_SYMBOL_BATTERY_EMPTY);
+    }
+    lv_label_set_text(label, text);
+}
+
+int zmk_widget_battery_status_init(struct zmk_widget_battery_status *widget, lv_obj_t *parent) {
+    battery_status_init();
+    widget->obj = lv_label_create(parent, NULL);
+    lv_label_set_style(widget->obj, LV_LABEL_STYLE_MAIN, &label_style);
+
+    lv_obj_set_size(widget->obj, 40, 15);
+    set_battery_symbol(widget->obj);
+
+    sys_slist_append(&widgets, &widget->node);
+
+    return 0;
+}
+
+lv_obj_t *zmk_widget_battery_status_obj(struct zmk_widget_battery_status *widget) {
+    LOG_DBG("Label: %p", widget->obj);
+    return widget->obj;
+}
+
+int battery_status_listener(const struct zmk_event_header *eh) {
+    struct zmk_widget_battery_status *widget;
+    SYS_SLIST_FOR_EACH_CONTAINER(&widgets, widget, node) { set_battery_symbol(widget->obj); }
+    return 0;
+}
+
+ZMK_LISTENER(widget_battery_status, battery_status_listener)
+ZMK_SUBSCRIPTION(widget_battery_status, battery_state_changed);
+#if IS_ENABLED(CONFIG_USB)
+ZMK_SUBSCRIPTION(widget_battery_status, usb_conn_state_changed);
+#endif /* IS_ENABLED(CONFIG_USB) */