Clearer error handling, rounding values to nearest stop

src/ev_calculator.py

@@ -18,15 +18,84 @@ K = 12.5
 
 class EVCalculator:
 
+    DEFAULT_ISO_SPEED = 100
+
+    APERTURE_VALUES = {
+        1/32: "1/32",
+        1/22: "1/22",
+        1/16: "1/16",
+        1/11: "1/11",
+        1/8: "1/8",
+        1/5.6: "1/5.6",
+        1/4: "1/4",
+        1/2.8: "1/2.8",
+        1/2: "1/2",
+        1/1.4: "1/1.4"
+    }
+
+    SHUTTER_SPEED_VALUES = {
+        1/4000: "1/4000",
+        1/2000: "1/2000",
+        1/1000: "1/1000",
+        1/500: "1/500",
+        1/250: "1/250",
+        1/125: "1/125",
+        1/60: "1/60",
+        1/30: "1/30",
+        1/15: "1/15",
+        1/8: "1/8",
+        1/4: "1/4",
+        1/2: "1/2",
+        1: "1",
+        2: "2",
+        4: "4",
+        8: "8",
+        15: "15",
+        30: "30"
+    }
+
     def luxToEV(lux: float) -> float:
         # Wikipedia (https://en.wikipedia.org/wiki/Light_meter#Exposure_equations)
         # says E = 2.5 * (2^EV), so the inverse is EV = ln(2*E/5)/ln(2)
         return log(2*lux/5, 2)
 
     def calcShutterSpeed(isoSpeed: int, lux: float, aperture: float):
-        return (aperture*aperture*K)/(lux*isoSpeed)
+        result = (aperture*aperture*K)/(lux*isoSpeed)
+        print("aperture: {}, K: {}, lux: {}, isoSpeed: {}, result: {}".format(aperture, K, lux, isoSpeed, result))
+        return result
 
     def calcAperture(isoSpeed: int, lux: float, shutterSpeed: float):
         # shutterSpeed is in seconds
         return sqrt(lux*isoSpeed*shutterSpeed/K)
 
+
+    def toNearestStr(valueToRound: float, roundingValues: dict[float,str]) -> [str, bool]:
+        # Rounds to the nearest value in the provided ORDERED dict.
+        # The dict is expected to have a float value as key and the corresponding human readable string value as value
+        # Returns the string value and a boolean set to true if the value was in the list range.
+
+        roundingNumericValues = list(roundingValues.keys())
+        roundingStringValues = list(roundingValues.values())
+
+        first = roundingNumericValues[0]
+        last = roundingNumericValues[-1]
+
+        if valueToRound < first / 1.5:
+            # More than half stop below minimum value!
+            return [roundingStringValues[0], False]
+        if valueToRound > last * 1.5:
+            # More than half stop above maximum value!
+            return [roundingStringValues[-1], False]
+
+        # Note: range(roundingValues - 1) to exclude last element
+        for i in range(len(roundingNumericValues) - 1):
+            value = float(roundingNumericValues[i])
+            nextValue = float(roundingNumericValues[i + 1])
+            limit = (value + nextValue) / 2
+            if valueToRound <= limit:
+                return [roundingStringValues[i], True]
+        return [roundingStringValues[-1], True]
+
+
+
+

src/sensors_polling_timer.py

@@ -1,6 +1,7 @@
 from gi.repository import Gio, GLib
 from threading import Timer
 from enum import Enum
+import traceback
 
 # window.py
 #
@@ -46,6 +47,7 @@ class SensorsPollingTimer(Timer):
                     self.function(value, unit)    # Invoke callback
 
         except Exception as e:
+            print(traceback.format_exc(e))
             if not self.onError:
                 print("SensorsPollingTimer: error occurred, but no onError callback defined")
                 return

src/style.css

@@ -1,5 +1,5 @@
 label.lumos-big-result {
-	font-size: 80px;
+	font-size: 60px;
 	font-weight: 800;
 }
 

src/widgets/aperture_priority_page.py

@@ -26,25 +26,15 @@ class AperturePriorityPage(Gtk.Box):
     __gtype_name__ = 'AperturePriorityPage'
 
     # Values of aperture dropdown entries defined in the .ui file
-    __aperture_priority_speed_dropdown_values = [
-        1/32,
-        1/22,
-        1/16,
-        1/11,
-        1/8,
-        1/5.6,
-        1/4,
-        1/2.8,
-        1/2,
-        1/1.4
-    ]
+    # TODO: Load dropdown strings from APERTURE_VALUES.values()
+    __aperture_priority_speed_dropdown_values = list(EVCalculator.APERTURE_VALUES.keys())
 
     # Widgets
     aperture_priority_aperture_dropdown = Gtk.Template.Child()
     aperture_priority_time_label = Gtk.Template.Child()
 
     __sensorValue = None
-    __isoSpeed = 100
+    __isoSpeed = EVCalculator.DEFAULT_ISO_SPEED
 
     def onValuesChanged(self, isoSpeed: int, sensorValue: float, sensorUnit: str):
         # Check the unit is absolute ("lux")
@@ -64,9 +54,16 @@ class AperturePriorityPage(Gtk.Box):
     def updateView(self):
         apertureValue = self.__aperture_priority_speed_dropdown_values[self.aperture_priority_aperture_dropdown.get_selected()]
         shutterSpeed = EVCalculator.calcShutterSpeed(self.__isoSpeed, self.__sensorValue, apertureValue)
-        # TODO: Round shutter speed value to nearest existing value and set label color to red if outside 1 stop range
-        self.aperture_priority_time_label.set_label("1/ {:.5f}".format(shutterSpeed))
+
+        # Round shutter speed value to nearest existing value and set label color to red if outside 1 stop range
+        [nearestValue, isInsideRange] = EVCalculator.toNearestStr(shutterSpeed, EVCalculator.SHUTTER_SPEED_VALUES)
+
+        if isInsideRange:
+            self.aperture_priority_time_label.set_label(nearestValue)
+        else:
+            self.aperture_priority_time_label.set_label("<span foreground=\"red\">{}</span>".format(nearestValue))
 
     @Gtk.Template.Callback()
     def onApertureChanged(self, dropDown: Gtk.DropDown, _: any):
         self.updateView()
+

src/widgets/aperture_priority_page.ui

@@ -30,6 +30,7 @@
     <child>
       <object class="GtkLabel" id="aperture_priority_time_label">
         <property name="label" translatable="no">--s</property>
+        <property name="use-markup">true</property>
         <style>
           <class name="lumos-big-result"/>
         </style>

src/widgets/time_priority_page.py

@@ -52,7 +52,7 @@ class TimePriorityPage(Gtk.Box):
     time_priority_aperture_label = Gtk.Template.Child()
 
     __sensorValue = None
-    __isoSpeed = 100
+    __isoSpeed = EVCalculator.DEFAULT_ISO_SPEED
 
     def onValuesChanged(self, isoSpeed: int, sensorValue: float, sensorUnit: str):
         # Check the unit is absolute ("lux")
@@ -71,8 +71,13 @@ class TimePriorityPage(Gtk.Box):
     def updateView(self):
         shutterSpeed = self.__time_priority_speed_dropdown_values[self.time_priority_speed_dropdown.get_selected()]
         apertureValue = EVCalculator.calcAperture(self.__isoSpeed, self.__sensorValue, shutterSpeed)
-        # TODO: Round aperture value to nearest existing value and set label color to red if outside 1 stop range
-        self.time_priority_aperture_label.set_label("f/ {:.2f}".format(apertureValue))
+
+        # Round aperture value to nearest existing value and set label color to red if outside range
+        [nearestValue, isInsideRange] = EVCalculator.toNearestStr(shutterSpeed, EVCalculator.APERTURE_VALUES)
+        if isInsideRange:
+            self.time_priority_aperture_label.set_label(nearestValue)
+        else:
+            self.time_priority_aperture_label.set_label("<span foreground=\"red\">{}</span>".format(nearestValue))
 
     @Gtk.Template.Callback()
     def onShutterSpeedChanged(self, dropDown: Gtk.DropDown, _: any):

src/widgets/time_priority_page.ui

@@ -30,6 +30,7 @@
     <child>
       <object class="GtkLabel" id="time_priority_aperture_label">
         <property name="label" translatable="no">f/--</property>
+        <property name="use-markup">true</property>
         <style>
           <class name="lumos-big-result"/>
         </style>

src/window.py

@@ -69,7 +69,6 @@ class LumosWindow(Adw.ApplicationWindow):
             self.sensor_unit_error_banner.set_revealed(True)
 
     def onError(self, e: Exception):
-        print(e)
         self.lastError = e
         self.error_banner.set_revealed(True)