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.

18 files changed, 362 insertions, 24 deletions

diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index de19f81..ff9d59d 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -28,7 +28,6 @@ target_sources(app PRIVATE src/kscan.c)
 target_sources(app PRIVATE src/matrix_transform.c)
 target_sources(app PRIVATE src/hid.c)
 target_sources(app PRIVATE src/sensors.c)
-target_sources_ifdef(CONFIG_ZMK_DISPLAY app PRIVATE src/display.c)
 target_sources(app PRIVATE src/event_manager.c)
 target_sources_ifdef(CONFIG_ZMK_EXT_POWER app PRIVATE src/ext_power_generic.c)
 target_sources(app PRIVATE src/events/position_state_changed.c)
@@ -69,4 +68,6 @@ target_sources(app PRIVATE src/hid_listener.c)
 target_sources_ifdef(CONFIG_SETTINGS app PRIVATE src/settings.c)
 target_sources(app PRIVATE src/main.c)
 
+add_subdirectory(src/display/)
+
 zephyr_cc_option(-Wfatal-errors)
diff --git a/app/Kconfig b/app/Kconfig
index af61f49..5751f02 100644
--- a/app/Kconfig
+++ b/app/Kconfig
@@ -168,14 +168,7 @@ endmenu
 
 menu "Display/LED Options"
 
-config ZMK_DISPLAY
-	bool "ZMK display support"
-	default n
-	select DISPLAY
-	select LVGL
-	select LVGL_THEMES
-	select LVGL_THEME_MONO
-	select LVGL_OBJ_LABEL
+rsource "src/display/Kconfig"
 
 config ZMK_RGB_UNDERGLOW
 	bool "RGB Adressable LED Underglow"
@@ -330,5 +323,6 @@ rsource "boards/shields/*/Kconfig.shield"
 osource "$(ZMK_CONFIG)/boards/shields/*/Kconfig.defconfig"
 osource "$(ZMK_CONFIG)/boards/shields/*/Kconfig.shield"
 
+
 source "Kconfig.zephyr"
 
diff --git a/app/dts/bindings/zmk,keymap.yaml b/app/dts/bindings/zmk,keymap.yaml
index fb6d914..56821de 100644
--- a/app/dts/bindings/zmk,keymap.yaml
+++ b/app/dts/bindings/zmk,keymap.yaml
@@ -7,6 +7,9 @@ child-binding:
   description: "A layer to be used in a keymap"
 
   properties:
+    label:
+      type: string
+      required: false
     bindings:
       type: phandle-array
       required: true
diff --git a/app/include/zmk/ble.h b/app/include/zmk/ble.h
index 56980c6..90afbda 100644
--- a/app/include/zmk/ble.h
+++ b/app/include/zmk/ble.h
@@ -14,7 +14,9 @@ int zmk_ble_prof_next();
 int zmk_ble_prof_prev();
 int zmk_ble_prof_select(u8_t index);
 
+int zmk_ble_active_profile_index();
 bt_addr_le_t *zmk_ble_active_profile_addr();
+bool zmk_ble_active_profile_is_open();
 bool zmk_ble_active_profile_is_connected();
 char *zmk_ble_active_profile_name();
 
diff --git a/app/include/zmk/display/status_screen.h b/app/include/zmk/display/status_screen.h
new file mode 100644
index 0000000..34660ad
--- /dev/null
+++ b/app/include/zmk/display/status_screen.h
@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2020 Peter Johanson <peter@peterjohanson.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <lvgl.h>
+
+lv_obj_t *zmk_display_status_screen();
\ No newline at end of file
diff --git a/app/include/zmk/display/widgets/battery_status.h b/app/include/zmk/display/widgets/battery_status.h
new file mode 100644
index 0000000..b87e87e
--- /dev/null
+++ b/app/include/zmk/display/widgets/battery_status.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <lvgl.h>
+#include <kernel.h>
+
+struct zmk_widget_battery_status {
+    sys_snode_t node;
+    lv_obj_t *obj;
+};
+
+int zmk_widget_battery_status_init(struct zmk_widget_battery_status *widget, lv_obj_t *parent);
+lv_obj_t *zmk_widget_battery_status_obj(struct zmk_widget_battery_status *widget);
\ No newline at end of file
diff --git a/app/include/zmk/display/widgets/output_status.h b/app/include/zmk/display/widgets/output_status.h
new file mode 100644
index 0000000..66f0927
--- /dev/null
+++ b/app/include/zmk/display/widgets/output_status.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <lvgl.h>
+#include <kernel.h>
+
+struct zmk_widget_output_status {
+    sys_snode_t node;
+    lv_obj_t *obj;
+};
+
+int zmk_widget_output_status_init(struct zmk_widget_output_status *widget, lv_obj_t *parent);
+lv_obj_t *zmk_widget_output_status_obj(struct zmk_widget_output_status *widget);
\ No newline at end of file
diff --git a/app/include/zmk/endpoints.h b/app/include/zmk/endpoints.h
index aad688e..c252ef0 100644
--- a/app/include/zmk/endpoints.h
+++ b/app/include/zmk/endpoints.h
@@ -16,5 +16,6 @@ enum zmk_endpoint {
 
 int zmk_endpoints_select(enum zmk_endpoint endpoint);
 int zmk_endpoints_toggle();
+enum zmk_endpoint zmk_endpoints_selected();
 
 int zmk_endpoints_send_report(u8_t usage_report);
diff --git a/app/src/ble.c b/app/src/ble.c
index b00bd5c..817cb84 100644
--- a/app/src/ble.c
+++ b/app/src/ble.c
@@ -100,7 +100,7 @@ static void raise_profile_changed_event_callback(struct k_work *work) {
 
 K_WORK_DEFINE(raise_profile_changed_event_work, raise_profile_changed_event_callback);
 
-static bool active_profile_is_open() {
+bool zmk_ble_active_profile_is_open() {
     return !bt_addr_le_cmp(&profiles[active_profile].peer, BT_ADDR_LE_ANY);
 }
 
@@ -169,7 +169,7 @@ int update_advertising() {
     struct bt_conn *conn;
     enum advertising_type desired_adv = ZMK_ADV_NONE;
 
-    if (active_profile_is_open()) {
+    if (zmk_ble_active_profile_is_open()) {
         desired_adv = ZMK_ADV_CONN;
     } else if (!zmk_ble_active_profile_is_connected()) {
         desired_adv = ZMK_ADV_CONN;
@@ -226,6 +226,8 @@ int zmk_ble_clear_bonds() {
     return 0;
 };
 
+int zmk_ble_active_profile_index() { return active_profile; }
+
 int zmk_ble_prof_select(u8_t index) {
     LOG_DBG("profile %d", index);
     if (active_profile == index) {
@@ -448,8 +450,8 @@ static enum bt_security_err auth_pairing_accept(struct bt_conn *conn,
     struct bt_conn_info info;
     bt_conn_get_info(conn, &info);
 
-    LOG_DBG("role %d, open? %s", info.role, active_profile_is_open() ? "yes" : "no");
-    if (info.role == BT_CONN_ROLE_SLAVE && !active_profile_is_open()) {
+    LOG_DBG("role %d, open? %s", info.role, zmk_ble_active_profile_is_open() ? "yes" : "no");
+    if (info.role == BT_CONN_ROLE_SLAVE && !zmk_ble_active_profile_is_open()) {
         LOG_WRN("Rejecting pairing request to taken profile %d", active_profile);
         return BT_SECURITY_ERR_PAIR_NOT_ALLOWED;
     }
@@ -472,7 +474,7 @@ static void auth_pairing_complete(struct bt_conn *conn, bool bonded) {
     }
 
 #if !IS_ENABLED(CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL)
-    if (!active_profile_is_open()) {
+    if (!zmk_ble_active_profile_is_open()) {
         LOG_ERR("Pairing completed but current profile is not open: %s", log_strdup(addr));
         bt_unpair(BT_ID_DEFAULT, dst);
         return;
diff --git a/app/src/display/CMakeLists.txt b/app/src/display/CMakeLists.txt
new file mode 100644
index 0000000..d14f7d0
--- /dev/null
+++ b/app/src/display/CMakeLists.txt
@@ -0,0 +1,5 @@
+
+target_sources_ifdef(CONFIG_ZMK_DISPLAY app PRIVATE main.c)
+target_sources_ifdef(CONFIG_ZMK_DISPLAY_STATUS_SCREEN_BUILT_IN app PRIVATE status_screen.c)
+
+add_subdirectory(widgets/)
\ No newline at end of file
diff --git a/app/src/display/Kconfig b/app/src/display/Kconfig
new file mode 100644
index 0000000..2e8cd2c
--- /dev/null
+++ b/app/src/display/Kconfig
@@ -0,0 +1,32 @@
+
+menuconfig ZMK_DISPLAY
+    bool "Enable ZMK Display"
+    default n
+    select DISPLAY
+    select LVGL
+	select LVGL_THEMES
+	select LVGL_THEME_MONO
+
+if ZMK_DISPLAY
+
+choice LVGL_TXT_ENC
+    default LVGL_TXT_ENC_UTF8
+
+endchoice
+
+choice ZMK_DISPLAY_STATUS_SCREEN
+    prompt "Default status screen for displays"
+    default ZMK_DISPLAY_STATUS_SCREEN_BUILT_IN
+
+config ZMK_DISPLAY_STATUS_SCREEN_BUILT_IN
+    bool "Built in status screen"
+    select LVGL_OBJ_LABEL
+
+config ZMK_DISPLAY_STATUS_SCREEN_CUSTOM
+    bool "Custom status screen"
+
+endchoice
+
+rsource "widgets/Kconfig"
+
+endif
diff --git a/app/src/display.c b/app/src/display/main.c
index ecd1908..001061f 100644
--- a/app/src/display.c
+++ b/app/src/display/main.c
@@ -14,16 +14,17 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <drivers/display.h>
 #include <lvgl.h>
 
+#include <zmk/display/status_screen.h>
+
 #define ZMK_DISPLAY_NAME CONFIG_LVGL_DISPLAY_DEV_NAME
 
 static struct device *display;
 
 static lv_obj_t *screen;
 
-int zmk_display_init() {
-    lv_obj_t *hello_world_label;
-    lv_obj_t *count_label;
+__attribute__((weak)) lv_obj_t *zmk_display_status_screen() { return NULL; }
 
+int zmk_display_init() {
     LOG_DBG("");
 
     display = device_get_binding(ZMK_DISPLAY_NAME);
@@ -32,18 +33,19 @@ int zmk_display_init() {
         return -EINVAL;
     }
 
-    screen = lv_obj_create(NULL, NULL);
+    screen = zmk_display_status_screen();
+
+    if (screen == NULL) {
+        LOG_ERR("No status screen provided");
+        return 0;
+    }
+
     lv_scr_load(screen);
 
-    hello_world_label = lv_label_create(lv_scr_act(), NULL);
-    lv_label_set_text(hello_world_label, "ZMK v0.1.0");
-    lv_obj_align(hello_world_label, NULL, LV_ALIGN_CENTER, 0, 0);
-    count_label = lv_label_create(lv_scr_act(), NULL);
-    lv_label_set_text(count_label, CONFIG_ZMK_KEYBOARD_NAME);
-    lv_obj_align(count_label, NULL, LV_ALIGN_IN_BOTTOM_MID, 0, 0);
     lv_task_handler();
     display_blanking_off(display);
 
+    LOG_DBG("");
     return 0;
 }
 
diff --git a/app/src/display/status_screen.c b/app/src/display/status_screen.c
new file mode 100644
index 0000000..1ce1e83
--- /dev/null
+++ b/app/src/display/status_screen.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 Peter Johanson <peter@peterjohanson.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zmk/display/widgets/output_status.h>
+#include <zmk/display/widgets/battery_status.h>
+#include <zmk/display/status_screen.h>
+
+#include <logging/log.h>
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#if IS_ENABLED(CONFIG_ZMK_WIDGET_BATTERY_STATUS)
+static struct zmk_widget_battery_status battery_status_widget;
+#endif
+
+#if IS_ENABLED(CONFIG_ZMK_WIDGET_OUTPUT_STATUS)
+static struct zmk_widget_output_status output_status_widget;
+#endif
+
+lv_obj_t *zmk_display_status_screen() {
+    lv_obj_t *screen;
+    lv_obj_t *zmk_version_label;
+
+    screen = lv_obj_create(NULL, NULL);
+
+    zmk_version_label = lv_label_create(screen, NULL);
+
+#if IS_ENABLED(CONFIG_ZMK_WIDGET_BATTERY_STATUS)
+    zmk_widget_battery_status_init(&battery_status_widget, screen);
+    lv_obj_align(zmk_widget_battery_status_obj(&battery_status_widget), NULL, LV_ALIGN_IN_TOP_RIGHT,
+                 0, 0);
+#endif
+
+#if IS_ENABLED(CONFIG_ZMK_WIDGET_OUTPUT_STATUS)
+    zmk_widget_output_status_init(&output_status_widget, screen);
+    lv_obj_align(zmk_widget_output_status_obj(&output_status_widget), NULL, LV_ALIGN_IN_TOP_LEFT, 0,
+                 0);
+#endif
+
+    lv_label_set_text(zmk_version_label, "ZMK v0.1.0");
+    lv_obj_align(zmk_version_label, NULL, LV_ALIGN_IN_BOTTOM_MID, 0, 0);
+
+    return screen;
+}
diff --git a/app/src/display/widgets/CMakeLists.txt b/app/src/display/widgets/CMakeLists.txt
new file mode 100644
index 0000000..32ef761
--- /dev/null
+++ b/app/src/display/widgets/CMakeLists.txt
@@ -0,0 +1,3 @@
+
+target_sources_ifdef(CONFIG_ZMK_WIDGET_BATTERY_STATUS app PRIVATE battery_status.c)
+target_sources_ifdef(CONFIG_ZMK_WIDGET_OUTPUT_STATUS app PRIVATE output_status.c)
diff --git a/app/src/display/widgets/Kconfig b/app/src/display/widgets/Kconfig
new file mode 100644
index 0000000..1dbffb5
--- /dev/null
+++ b/app/src/display/widgets/Kconfig
@@ -0,0 +1,18 @@
+
+menu "ZMK Display Widgets"
+
+config ZMK_WIDGET_BATTERY_STATUS
+    bool "Widget for battery charge information, using small icons"
+    depends on BT
+    default y if BT
+    select LVGL_OBJ_LABEL
+    select LVGL_BUILD_IN_FONT_ROBOTO_16
+
+config ZMK_WIDGET_OUTPUT_STATUS
+    bool "Widget for keyboard output status icons"
+    depends on BT
+    default y if BT
+    select LVGL_OBJ_LABEL
+    select LVGL_BUILD_IN_FONT_ROBOTO_16
+    
+endmenu
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) */
diff --git a/app/src/display/widgets/output_status.c b/app/src/display/widgets/output_status.c
new file mode 100644
index 0000000..b00d3fc
--- /dev/null
+++ b/app/src/display/widgets/output_status.c
@@ -0,0 +1,95 @@
+/*
+ * 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/output_status.h>
+#include <zmk/event-manager.h>
+#include <zmk/events/usb-conn-state-changed.h>
+#include <zmk/events/ble-active-profile-changed.h>
+#include <zmk/usb.h>
+#include <zmk/ble.h>
+#include <zmk/endpoints.h>
+
+static sys_slist_t widgets = SYS_SLIST_STATIC_INIT(&widgets);
+static lv_style_t label_style;
+
+void output_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_status_symbol(lv_obj_t *label) {
+    enum zmk_endpoint selected_endpoint = zmk_endpoints_selected();
+    bool active_profile_connected = zmk_ble_active_profile_is_connected();
+    bool active_profie_bonded = !zmk_ble_active_profile_is_open();
+    u8_t active_profile_index = zmk_ble_active_profile_index();
+    char text[6] = {};
+
+    switch (selected_endpoint) {
+    case ZMK_ENDPOINT_USB:
+        LOG_DBG("USB, BOY!");
+        strcat(text, LV_SYMBOL_USB "   ");
+        break;
+    case ZMK_ENDPOINT_BLE:
+        if (active_profie_bonded) {
+            if (active_profile_connected) {
+                LOG_DBG("Bonded & connected!");
+                sprintf(text, LV_SYMBOL_WIFI "%i " LV_SYMBOL_OK, active_profile_index);
+            } else {
+                LOG_DBG("Bonded but not connected!");
+                sprintf(text, LV_SYMBOL_WIFI "%i " LV_SYMBOL_CLOSE, active_profile_index);
+            }
+        } else {
+            LOG_DBG("NOT Bonded!");
+            sprintf(text, LV_SYMBOL_WIFI "%i " LV_SYMBOL_SETTINGS, active_profile_index);
+        }
+        break;
+    }
+
+    lv_label_set_text(label, text);
+}
+
+int zmk_widget_output_status_init(struct zmk_widget_output_status *widget, lv_obj_t *parent) {
+    output_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_status_symbol(widget->obj);
+
+    sys_slist_append(&widgets, &widget->node);
+
+    return 0;
+}
+
+lv_obj_t *zmk_widget_output_status_obj(struct zmk_widget_output_status *widget) {
+    return widget->obj;
+}
+
+int output_status_listener(const struct zmk_event_header *eh) {
+    struct zmk_widget_output_status *widget;
+    SYS_SLIST_FOR_EACH_CONTAINER(&widgets, widget, node) { set_status_symbol(widget->obj); }
+    return 0;
+}
+
+ZMK_LISTENER(widget_output_status, output_status_listener)
+#if defined(CONFIG_USB)
+ZMK_SUBSCRIPTION(widget_output_status, usb_conn_state_changed);
+#endif
+#if defined(CONFIG_ZMK_BLE)
+ZMK_SUBSCRIPTION(widget_output_status, ble_active_profile_changed);
+#endif
diff --git a/app/src/endpoints.c b/app/src/endpoints.c
index 406d23b..4367dd2 100644
--- a/app/src/endpoints.c
+++ b/app/src/endpoints.c
@@ -47,6 +47,8 @@ int zmk_endpoints_select(enum zmk_endpoint endpoint) {
     return 0;
 }
 
+enum zmk_endpoint zmk_endpoints_selected() { return current_endpoint; }
+
 int zmk_endpoints_toggle() {
     enum zmk_endpoint new_endpoint =
         (preferred_endpoint == ZMK_ENDPOINT_USB) ? ZMK_ENDPOINT_BLE : ZMK_ENDPOINT_USB;