Fixing warnings and nullables

Source/Meadow.Foundation.Core/Communications/ByteCommsSensorBase.cs

@@ -14,7 +14,7 @@ public abstract class ByteCommsSensorBase<UNIT> :
         /// <summary>
         /// Bus communications object, i.e. an I2cCommunications or SpiCommunications
         /// </summary>
-        protected IByteCommunications? BusComms { get; set; }
+        protected IByteCommunications BusComms { get; set; }
 
         /// <summary>
         /// The read buffer
@@ -69,8 +69,7 @@ protected ByteCommsSensorBase(
         /// </summary>
         /// <param name="readBufferSize">Read buffer size</param>
         /// <param name="writeBufferSize">Write buffer size</param>
-        protected ByteCommsSensorBase(
-            int readBufferSize = 8, int writeBufferSize = 8)
+        protected ByteCommsSensorBase(int readBufferSize = 8, int writeBufferSize = 8)
         {
             Init(readBufferSize, writeBufferSize);
         }

Source/Meadow.Foundation.Core/Communications/SerialTextFile.cs

@@ -54,7 +54,7 @@ public class SerialTextFile
         /// <summary>
         /// A complete line of text has been read, send this to the event subscriber.
         /// </summary>
-        public event LineReceived OnLineReceived = delegate { };
+        public event LineReceived OnLineReceived = default!;
 
         #endregion Events and delegates
 

Source/Meadow.Foundation.Core/Communications/SpiCommunications.cs

@@ -12,7 +12,7 @@ public class SpiCommunications : ISpiCommunications
         /// <summary>
         /// The SPI chip select port
         /// </summary>
-        public IDigitalOutputPort ChipSelect { get; }
+        public IDigitalOutputPort? ChipSelect { get; }
 
         /// <summary>
         /// The chip select mode (active high or active low)

Source/Meadow.Foundation.Core/Relays/Relay.cs

@@ -10,7 +10,7 @@ namespace Meadow.Foundation.Relays
     public class Relay : IRelay
     {
         /// <inheritdoc/>
-        public event EventHandler<bool> OnRelayChanged = delegate { };
+        public event EventHandler<bool> OnRelayChanged = default!;
 
         /// <summary>
         /// Returns digital output port

Source/Meadow.Foundation.Core/SamplingSensorBase.cs

@@ -21,7 +21,7 @@ public abstract class SamplingSensorBase<UNIT> : ObservableBase<UNIT>, ISampling
         /// <summary>
         /// Event handler for updated values
         /// </summary>
-        public event EventHandler<IChangeResult<UNIT>> Updated = delegate { };
+        public event EventHandler<IChangeResult<UNIT>> Updated = default!;
 
         /// <summary>
         /// Sampling cancellation token source

Source/Meadow.Foundation.Core/Sensors/Buttons/PushButtonBase.cs

@@ -18,22 +18,22 @@ public abstract class PushButtonBase : IButton, IDisposable
         /// <summary>
         /// Raised when a press starts
         /// </summary>
-        public event EventHandler PressStarted = delegate { };
+        public event EventHandler PressStarted = default!;
 
         /// <summary>
         /// Raised when a press ends
         /// </summary>
-        public event EventHandler PressEnded = delegate { };
+        public event EventHandler PressEnded = default!;
 
         /// <summary>
         /// Raised when the button is released after a press
         /// </summary>
-        public event EventHandler Clicked = delegate { };
+        public event EventHandler Clicked = default!;
 
         /// <summary>
         /// Raised when the button is pressed for LongClickedThreshold or longer and then releases
         /// </summary>
-        public event EventHandler LongClicked = delegate { };
+        public event EventHandler LongClicked = default!;
 
         /// <summary>
         /// Track if we created the input port in the PushButton instance (true)

Source/Meadow.Foundation.Core/Sensors/HallEffect/DigitalTachometer.cs

@@ -12,7 +12,7 @@ public class LinearHallEffectTachometer
         /// Event raised when the RPM change is greater than the 
         /// RPMChangeNotificationThreshold value.
         /// </summary>
-        public event EventHandler<ChangeResult<float>> RPMsChanged = delegate { };
+        public event EventHandler<ChangeResult<float>> RPMsChanged = default!;
 
         /// <summary>
         /// Any changes to the RPMs that are greater than the RPM change

Source/Meadow.Foundation.Core/Sensors/Hid/DigitalJoystick.cs

@@ -18,7 +18,7 @@ public class DigitalJoystick : IDigitalJoystick
         /// <summary>
         /// Raised when the digital joystick position changes
         /// </summary>
-        public event EventHandler<ChangeResult<DigitalJoystickPosition>> Updated = delegate { };
+        public event EventHandler<ChangeResult<DigitalJoystickPosition>> Updated = default!;
 
         /// <summary>
         /// The PushButton class for the up digital joystick switch

Source/Meadow.Foundation.Core/Sensors/Light/AnalogLightSensor.cs

@@ -20,7 +20,7 @@ public partial class AnalogLightSensor
         /// <summary>
         /// Raised when the value of the reading changes.
         /// </summary>
-        public event EventHandler<IChangeResult<Illuminance>> IlluminanceUpdated = delegate { };
+        public event EventHandler<IChangeResult<Illuminance>> IlluminanceUpdated = default!;
 
         /// <summary>
         /// Illuminance sensor calibration

Source/Meadow.Foundation.Core/Sensors/Rotary/RotaryEncoder.cs

@@ -13,7 +13,7 @@ public class RotaryEncoder : IRotaryEncoder
     /// <summary>
     /// Raised when the rotary encoder is rotated and returns a RotaryTurnedEventArgs object which describes the direction of rotation.
     /// </summary>
-    public event EventHandler<RotaryChangeResult> Rotated = delegate { };
+    public event EventHandler<RotaryChangeResult> Rotated = default!;
 
     /// <summary>
     /// Returns the pin connected to the A-phase output on the rotary encoder.

Source/Meadow.Foundation.Core/Sensors/Rotary/RotaryEncoderWithButton.cs

@@ -24,22 +24,22 @@ public class RotaryEncoderWithButton : RotaryEncoder, IRotaryEncoderWithButton
     /// <summary>
     /// Raised when the button circuit is re-opened after it has been closed
     /// </summary>
-    public event EventHandler Clicked = delegate { };
+    public event EventHandler Clicked = default!;
 
     /// <summary>
     /// Raised when a press ends
     /// </summary>
-    public event EventHandler PressEnded = delegate { };
+    public event EventHandler PressEnded = default!;
 
     /// <summary>
     /// Raised when a press starts
     /// </summary>
-    public event EventHandler PressStarted = delegate { };
+    public event EventHandler PressStarted = default!;
 
     /// <summary>
     /// Raised when the button circuit is pressed for LongPressDuration
     /// </summary>
-    public event EventHandler LongClicked = delegate { };
+    public event EventHandler LongClicked = default!;
 
     /// <summary>
     /// The minimum duration for a long press

Source/Meadow.Foundation.Core/Sensors/Switches/DipSwitch.cs

@@ -25,7 +25,7 @@ public class DipSwitch
         /// <summary>
         /// Raised when one of the switches is switched on or off.
         /// </summary>
-        public event ArrayEventHandler Changed = delegate { };
+        public event ArrayEventHandler Changed = default!;
 
         /// <summary>
         /// Creates a new DipSwitch connected to the specified switchPins, with the InterruptMode and ResisterMode specified by the type parameters.

Source/Meadow.Foundation.Core/Sensors/Switches/SpdtSwitch.cs

@@ -28,7 +28,7 @@ public bool IsOn
         /// <summary>
         /// Raised when the switch circuit is opened or closed.
         /// </summary>
-        public event EventHandler Changed = delegate { };
+        public event EventHandler Changed = default!;
 
         /// <summary>
         /// Instantiates a new SpdtSwitch object with the center pin connected to the specified digital pin, one pin connected to common/ground and one pin connected to high/3.3V.

Source/Meadow.Foundation.Core/Sensors/Switches/SpstSwitch.cs

@@ -26,7 +26,7 @@ public bool IsOn
         /// <summary>
         /// Raised when the switch circuit is opened or closed.
         /// </summary>
-        public event EventHandler Changed = delegate { };
+        public event EventHandler Changed = default!;
 
         /// <summary>
         /// Returns the DigitalInputPort.

Source/Meadow.Foundation.Core/Sensors/Temperature/AnalogTemperature.cs

@@ -35,7 +35,7 @@ public partial class AnalogTemperature : SamplingSensorBase<Units.Temperature>,
         /// <summary>
         /// Raised when the value of the reading changes.
         /// </summary>
-        public event EventHandler<IChangeResult<Units.Temperature>> TemperatureUpdated = delegate { };
+        public event EventHandler<IChangeResult<Units.Temperature>> TemperatureUpdated = default!;
 
         ///<Summary>
         /// AnalogInputPort connected to temperature sensor

Source/Meadow.Foundation.Libraries_and_Frameworks/Displays.TextDisplayMenu/Driver/BaseClasses/NumericBase.cs

@@ -17,7 +17,7 @@ public abstract class NumericBase : InputBase
         /// <summary>
         /// Raised when the numeric value changes
         /// </summary>
-        public override event ValueChangedHandler ValueChanged = delegate { };
+        public override event ValueChangedHandler ValueChanged = default!;
 
         /// <summary>
         /// Create a new NumericBase object

Source/Meadow.Foundation.Libraries_and_Frameworks/Displays.TextDisplayMenu/Driver/BaseClasses/TimeBase.cs

@@ -7,7 +7,14 @@ namespace Meadow.Foundation.Displays.UI.InputTypes
     /// </summary>
     public abstract class TimeBase : InputBase
     {
+        /// <summary>
+        /// Value for each time part
+        /// </summary>
         protected int[] timeParts;
+
+        /// <summary>
+        /// The current position
+        /// </summary>
         protected byte position = 0;
 
         /// <summary>
@@ -19,7 +26,7 @@ public abstract class TimeBase : InputBase
         /// Raised if the input value changes
         /// </summary>
 
-        public override event ValueChangedHandler ValueChanged = delegate { };
+        public override event ValueChangedHandler ValueChanged = default!;
 
         /// <summary>
         /// Create a new TimeBase object

Source/Meadow.Foundation.Libraries_and_Frameworks/Displays.TextDisplayMenu/Driver/InputTypes/Date.cs

@@ -13,7 +13,7 @@ public class Date : InputBase
         /// <summary>
         /// Raised when the date value changes
         /// </summary>
-        public override event ValueChangedHandler ValueChanged;
+        public override event ValueChangedHandler ValueChanged = default!;
 
         /// <summary>
         /// Create a new Date input object
@@ -39,6 +39,11 @@ byte CursorPosition
         {
             get
             {
+                if (display == null)
+                {
+                    return 0;
+                }
+
                 return position switch
                 {
                     0 => (byte)(display.DisplayConfig.Width - 7),

Source/Meadow.Foundation.Libraries_and_Frameworks/Displays.TextDisplayMenu/Driver/InputTypes/ListBase.cs

@@ -20,7 +20,7 @@ public abstract class ListBase : InputBase
         /// <summary>
         /// The value changed event handler
         /// </summary>
-        public override event ValueChangedHandler ValueChanged = delegate { };
+        public override event ValueChangedHandler ValueChanged = default!;
 
         /// <summary>
         /// The output display text

Source/Meadow.Foundation.Libraries_and_Frameworks/Displays.TextDisplayMenu/Driver/TextDisplayMenu.cs

@@ -26,12 +26,12 @@ public class TextDisplayMenu
         /// <summary>
         /// Raised when the menu receives a selected input
         /// </summary>
-        public event MenuSelectedHandler Selected = delegate { };
+        public event MenuSelectedHandler Selected = default!;
 
         /// <summary>
         /// Raised when a value changes
         /// </summary>
-        public event ValueChangedHandler ValueChanged = delegate { };
+        public event ValueChangedHandler ValueChanged = default!;
 
         /// <summary>
         /// Raised when the user exits the menu

Source/Meadow.Foundation.Libraries_and_Frameworks/Graphics.MicroGraphics/Driver/MicroGraphics.cs

@@ -1362,7 +1362,13 @@ public void DrawBuffer(int x, int y, IPixelBuffer buffer)
         public void DrawImage(int x, int y, Image image,
             HorizontalAlignment alignmentH = HorizontalAlignment.Left,
             VerticalAlignment alignmentV = VerticalAlignment.Top)
-            => DrawBuffer(x, y, image.DisplayBuffer, alignmentH, alignmentV);
+        {
+            if (image.DisplayBuffer is not null)
+            {
+                DrawBuffer(x, y, image.DisplayBuffer, alignmentH, alignmentV);
+            }
+            throw new Exception("Image does not have a display buffer");
+        }
 
         /// <summary>
         /// Draw an Image onto the display buffer at the specified location
@@ -1371,7 +1377,13 @@ public void DrawImage(int x, int y, Image image,
         /// <param name="y">x location of target to draw buffer</param>
         /// <param name="image">the source image to write to the display buffer</param>
         public void DrawImage(int x, int y, Image image)
-            => DrawBuffer(x, y, image.DisplayBuffer);
+        {
+            if (image.DisplayBuffer is not null)
+            {
+                DrawBuffer(x, y, image.DisplayBuffer);
+            }
+            throw new Exception("Image does not have a display buffer");
+        }
 
         /// <summary>
         /// Draw an Image onto the display buffer at (0, 0)

Source/Meadow.Foundation.Libraries_and_Frameworks/Graphics.MicroLayout/Driver/ClickableControl.cs

@@ -10,7 +10,7 @@ public abstract class ClickableControl : ThemedControl, IClickableControl
     /// <summary>
     /// Occurs when the clickable control is clicked.
     /// </summary>
-    public event EventHandler Clicked = delegate { };
+    public event EventHandler Clicked = default!;
 
     private bool _pressed = false;
 

Source/Meadow.Foundation.Libraries_and_Frameworks/Graphics.MicroLayout/Samples/HMI_Sample/Program.cs

@@ -6,7 +6,7 @@ namespace Meadow.Foundation.Displays.UI;
 
 public class MeadowApp : App<Windows>
 {
-    private DisplayScreen _screen;
+    private DisplayScreen? _screen;
 
     public static async Task Main(string[] args)
     {
@@ -144,4 +144,4 @@ private LineChartSeries GetCosineSeries(double xScale = 4, double yScale = 1.5,
 
         return series;
     }
-}
+}

Source/Meadow.Foundation.Libraries_and_Frameworks/Graphics.MicroLayout/Samples/Ili9488Charts_Sample/MeadowApp.cs

@@ -8,7 +8,7 @@
 public class MeadowApp : App<Windows>
 {
     private Ft232h expander = new Ft232h();
-    private DisplayScreen screen;
+    private DisplayScreen? screen;
 
     public override Task Initialize()
     {
@@ -41,7 +41,7 @@ public override Task Run()
 
     public void Text()
     {
-        var label = new Label(0, 0, screen.Width, screen.Height);
+        var label = new Label(0, 0, screen!.Width, screen.Height);
         label.Font = new Font12x20();
         label.HorizontalAlignment = HorizontalAlignment.Center;
         label.VerticalAlignment = VerticalAlignment.Center;
@@ -54,7 +54,7 @@ public void Text()
 
     public void TextOnBox()
     {
-        var box = new Box(0, 0, screen.Width / 4, screen.Height);
+        var box = new Box(0, 0, screen!.Width / 4, screen.Height);
         box.ForeColor = Color.Red;
         var label = new Label(0, 0, screen.Width / 4, screen.Height);
         label.HorizontalAlignment = HorizontalAlignment.Center;
@@ -75,7 +75,7 @@ public void TextOnBox()
 
     public void Sweep()
     {
-        var box = new Box(0, 0, screen.Width / 4, screen.Height);
+        var box = new Box(0, 0, screen!.Width / 4, screen.Height);
         box.ForeColor = Color.Red;
 
         screen.Controls.Add(box);

Source/Meadow.Foundation.Libraries_and_Frameworks/Graphics.MicroLayout/Samples/MAX7219_Sample/MeadowApp.cs

@@ -8,7 +8,7 @@
 public class MeadowApp : App<Windows>
 {
     private readonly Ft232h expander = new Ft232h();
-    private DisplayScreen screen;
+    private DisplayScreen? screen;
 
     public override Task Initialize()
     {
@@ -33,7 +33,7 @@ public override Task Run()
 
     public void Text()
     {
-        var label = new Label(0, 0, screen.Width, screen.Height);
+        var label = new Label(0, 0, screen!.Width, screen.Height);
         label.HorizontalAlignment = Meadow.Foundation.Graphics.HorizontalAlignment.Center;
         label.VerticalAlignment = Meadow.Foundation.Graphics.VerticalAlignment.Center;
         label.TextColor = Color.White;
@@ -45,7 +45,7 @@ public void Text()
 
     public void TextOnBox()
     {
-        var box = new Box(0, 0, screen.Width / 4, screen.Height);
+        var box = new Box(0, 0, screen!.Width / 4, screen.Height);
         box.ForeColor = Color.Red;
         var label = new Label(0, 0, screen.Width / 4, screen.Height);
         label.HorizontalAlignment = Meadow.Foundation.Graphics.HorizontalAlignment.Center;
@@ -66,7 +66,7 @@ public void TextOnBox()
 
     public void Sweep()
     {
-        var box = new Box(0, 0, screen.Width / 4, screen.Height);
+        var box = new Box(0, 0, screen!.Width / 4, screen.Height);
         box.ForeColor = Color.Red;
 
         screen.Controls.Add(box);