update GUI, display 5V error

application.fam

@@ -6,12 +6,13 @@ App(
     requires=["gui"],
     stack_size=1 * 1024,
     order=90,
+    fap_libs=["assets"],
     fap_private_libs=[Lib(name="mh_z19_uart_tools")],
-	fap_icon="assets/co2_icon.png",
+    fap_icon="assets/co2_icon.png",
     fap_icon_assets="assets",
     fap_category="GPIO",
     fap_description="Read the CO2 concentration from the MH-Z19 sensor via UART interface",
     fap_author="glinnik21",
     fap_weburl="https://github.com/GLinnik21/flipper-zero-mh-z19-uart",
-    fap_version=(0, 2)
-)
+    fap_version=(0, 2),
+)

mh_z19_ui.c

@@ -1,5 +1,8 @@
 #include "mh_z19_ui.h"
 
+#include <assets_icons.h>
+#include <gui/elements.h>
+
 #include "mh_z19_app_i.h"
 
 void mh_z19_app_input_callback(InputEvent* event, void* context) {
@@ -11,15 +14,32 @@ void mh_z19_app_input_callback(InputEvent* event, void* context) {
 
 void mh_z19_app_draw_callback(Canvas* canvas, void* context) {
     furi_assert(context);
-
     MhZ19App* app = context;
     canvas_clear(canvas);
-    canvas_set_font(canvas, FontPrimary);
-    static char buffer[50];
 
-    furi_mutex_acquire(app->thread_data.mutex, FuriWaitForever);
-    snprintf(buffer, sizeof(buffer), "ppm: %lu", app->ppm);
-    furi_mutex_release(app->thread_data.mutex);
+    canvas_set_bitmap_mode(canvas, 1);
+
+    if(!app->power_data.is_5V_enabled) {
+        canvas_draw_icon(canvas, 5, 4, &I_Alert_9x8);
+        canvas_set_font(canvas, FontPrimary);
+        canvas_draw_str(canvas, 19, 12, "Oops! 5V is off");
+        canvas_set_font(canvas, FontSecondary);
+        elements_multiline_text(
+            canvas,
+            5,
+            28,
+            "Enable manually in\n"
+            "GPIO app -> 5V on GPIO -> ON\n"
+            "or put Flipper on charge.");
+    } else {
+        static char buffer[5] = {0};
+        furi_mutex_acquire(app->thread_data.mutex, FuriWaitForever);
+        snprintf(buffer, sizeof(buffer), "%lu", app->ppm);
+        furi_mutex_release(app->thread_data.mutex);
 
-    canvas_draw_str(canvas, 0, 10, buffer);
+        canvas_set_font(canvas, FontBigNumbers);
+        canvas_draw_str_aligned(canvas, 63, 31, AlignCenter, AlignCenter, buffer);
+        canvas_set_font(canvas, FontPrimary);
+        canvas_draw_str(canvas, 93, 37, "ppm");
+    }
 }

mh_z19_ui.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <gui/gui.h>
+#include <gui/canvas.h>
 #include <input/input.h>
 
 void mh_z19_app_draw_callback(Canvas* canvas, void* context);