simplify display time task:

- drawTime onEnable
- disable drawColon onDisable
- don't display time at startup, by default temperature is displayed now

include/display.h

@@ -12,16 +12,20 @@
 #define BRIGHTNESS_STEP 1
 #define BRIGHTNESS_NIGHT BRIGHTNESS_MIN
 #define BRIGHTNESS_DAY 11
-#define DISPLAY_TIME 2000
-#define DISPLAY_TEMP_TIME 5000
+#define SECONDS(value) value*1000
 
 namespace Display {
 
-  void display();
-  Task tDisplay(500, TASK_FOREVER, display, &ts, true);
+  void displayTime();
+  void drawTime();
+  void drawColon(bool);
+  Task tDisplayTime(500, TASK_FOREVER, displayTime, &ts, false, []() {
+    drawTime();
+    return true;
+  }, []() {
+    drawColon(false);
+  });
 
-  int currentHour = -1;
-  int currentMin = -1;
   bool hourFormat24 = false;
   void (*hourFormatChangedCallback)();
   void onHourFormatChanged(void (*f)()) {
@@ -71,6 +75,7 @@ namespace Display {
 
   void drawColon(bool colonOn) {
     if (colonOn) {
+      static int currentHour = -1;
       if (currentHour != hour()) {
         currentHour = hour();
         if (currentHour == 8) {
@@ -81,6 +86,7 @@ namespace Display {
           Brightness::set(BRIGHTNESS_NIGHT);
         }
       }
+      static int currentMin = -1;
       if (currentMin != minute()) {
         currentMin = minute();
         drawTime();
@@ -89,8 +95,8 @@ namespace Display {
     clockDisplay.drawColon(colonOn);
   }
 
-  void display() {
-    static bool colonOn = false;
+  void displayTime() {
+    static bool colonOn = true;
 
     drawColon(colonOn);
     clockDisplay.writeDisplay();
@@ -99,30 +105,24 @@ namespace Display {
   }
 
   void displayTemp(float value) {
-    tDisplay.disable();
-    drawColon(false);
+    tDisplayTime.disable();
     clockDisplay.printFloat(value, 1);
     clockDisplay.writeDisplay();
-    drawTime();
-    tDisplay.enableDelayed(DISPLAY_TEMP_TIME);
+    tDisplayTime.enableDelayed(SECONDS(10));
   }
 
   void displayValue(uint8_t value) {
-    tDisplay.disable();
-    drawColon(false);
+    tDisplayTime.disable();
     clockDisplay.print(value, HEX);
     clockDisplay.writeDisplay();
-    drawTime();
-    tDisplay.enableDelayed(DISPLAY_TIME);
+    tDisplayTime.enableDelayed(SECONDS(2));
   }
 
   void displayText(const char c[]) {
-    tDisplay.disable();
-    drawColon(false);
+    tDisplayTime.disable();
     clockDisplay.println(c);
     clockDisplay.writeDisplay();
-    drawTime();
-    tDisplay.enableDelayed(DISPLAY_TIME);
+    tDisplayTime.enableDelayed(SECONDS(2));
   }
 
   void changeHourFormat24(bool format24) {
@@ -134,7 +134,5 @@ namespace Display {
   void setup() {
     clockDisplay.begin(DISPLAY_ADDRESS);
     clockDisplay.setBrightness(Brightness::current);
-    drawTime();
-    display();
   }
 }