Merge pull request #831 from WildernessLabs/more-warnings

Warnings and null validation

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

@@ -10,7 +10,7 @@ public abstract class InputBase : IMenuInputItem
         /// <summary>
         /// The ITextDisplay object
         /// </summary>
-        protected ITextDisplay? display = null;
+        protected ITextDisplay display;
 
         /// <summary>
         /// Is the item initialized
@@ -58,9 +58,9 @@ public void Init(ITextDisplay display)
         /// <param name="text">The new text to display</param>
         protected void UpdateInputLine(string text)
         {
-            display?.ClearLine(1);
-            display?.WriteLine(text, 1, true);
-            display?.Show();
+            display.ClearLine(1);
+            display.WriteLine(text, 1, true);
+            display.Show();
         }
 
         /// <summary>

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

@@ -42,7 +42,7 @@ public class MenuItem
         /// The menu item value
         /// </summary>
         [JsonPropertyName("value")]
-        public object Value { get; set; }
+        public object? Value { get; set; }
 
         /// <summary>
         /// Does the item have sub items

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

@@ -52,8 +52,7 @@ public class TextDisplayMenu
         public TextDisplayMenu(ITextDisplay display, byte[] menuJson, bool showBackOnRoot = false)
         {
             this.showBackOnRoot = showBackOnRoot;
-            var items = ParseMenuData(menuJson);
-
+            var items = ParseMenuData(menuJson) ?? throw new ArgumentNullException("Menu data is null");
             Init(display, CreateMenuPage(items, showBackOnRoot));
         }
 
@@ -208,16 +207,23 @@ protected string GetItemText(MenuItem item, bool isSelected)
                 }
             }
 
-            itemText = displayText.Substring(0, (displayText.Length >= display.DisplayConfig.Width - 1) ? display.DisplayConfig.Width - 1 : displayText.Length);
-
-            if (isSelected || item.HasSubItems)
+            if (display == null)
             {
-                // calculate any necessary padding to put selector on far right
-                int paddingLength = (display.DisplayConfig.Width / display.DisplayConfig.FontScale - 1 - displayText.Length);
-                string padding = string.Empty;
-                if (paddingLength > 0) { padding = new string(' ', paddingLength); }
+                itemText = displayText;
+            }
+            else
+            {
+                itemText = displayText.Substring(0, (displayText.Length >= display.DisplayConfig.Width - 1) ? display.DisplayConfig.Width - 1 : displayText.Length);
+
+                if (isSelected || item.HasSubItems)
+                {
+                    // calculate any necessary padding to put selector on far right
+                    int paddingLength = (display.DisplayConfig.Width / display.DisplayConfig.FontScale - 1 - displayText.Length);
+                    string padding = string.Empty;
+                    if (paddingLength > 0) { padding = new string(' ', paddingLength); }
 
-                itemText += padding + (isSelected ? "*" : ">");
+                    itemText += padding + (isSelected ? "*" : ">");
+                }
             }
 
             return itemText;
@@ -288,9 +294,9 @@ public bool Back()
                 currentInputItem.Back();
                 return true;
             }
-            else if (pageStack.Count > 0)
+            else if (pageStack?.Count > 0)
             {
-                MenuPage parent = pageStack.Pop() as MenuPage;
+                MenuPage? parent = pageStack?.Pop() as MenuPage;
                 currentMenuPage = parent;
                 ShowCurrentPage();
                 return true;
@@ -316,13 +322,17 @@ public bool Select()
                 currentInputItem.Select();
                 return true;
             }
+            else if (currentMenuPage == null)
+            {
+                return false;
+            }
             else
             {
-                currentMenuPage.Select();
+                currentMenuPage!.Select();
             }
 
             if (currentMenuPage.ScrollPosition == 0
-                && pageStack.Count == 0
+                && pageStack?.Count == 0
                 && showBackOnRoot
                 && Exited != null)
             {
@@ -332,9 +342,9 @@ public bool Select()
             }
 
             // if currently on a subpage and user selects back, pop back to parent page.
-            if (currentMenuPage.ScrollPosition == 0 && pageStack.Count > 0)
+            if (currentMenuPage.ScrollPosition == 0 && pageStack?.Count > 0)
             {
-                MenuPage parent = pageStack.Pop() as MenuPage;
+                MenuPage? parent = pageStack.Pop() as MenuPage;
                 currentMenuPage = parent;
                 ShowCurrentPage();
                 return true;
@@ -346,49 +356,53 @@ public bool Select()
             // go to the submenu if children are present
             if (menuItem.HasSubItems)
             {
-                pageStack.Push(currentMenuPage);
+                pageStack?.Push(currentMenuPage);
                 // currentMenuPage = child.SubMenu;
                 currentMenuPage = CreateMenuPage(menuItem.SubItems, true);
                 ShowCurrentPage();
                 return true;
             }
             // if there is a command, notify the subscribers 
-            else if (menuItem.Command != string.Empty)
+            else if (menuItem?.Command != string.Empty)
             {
-                Selected?.Invoke(this, new MenuSelectedEventArgs(menuItem.Command));
+                Selected?.Invoke(this, new MenuSelectedEventArgs(menuItem!.Command));
                 return true;
             }
             // if there is a type, then let the type handle the input
             else if (menuItem.Type != string.Empty)
             {
-                pageStack.Push(currentMenuPage);
+                pageStack?.Push(currentMenuPage);
 
                 isEditMode = true;
 
                 currentInputItem = GetMenuInputItemFromName(menuItem.Type);
 
                 // setup callback
-                currentInputItem.ValueChanged += delegate (object sender, ValueChangedEventArgs e)
+                if (currentInputItem != null)
                 {
-                    // set the value and notify the eager listeners
-                    menuItem.Value = e.Value;
-                    ValueChanged?.Invoke(this, new ValueChangedEventArgs(menuItem.Id, menuItem.Value));
-
-                    // reload the parent menu
-                    var parent = pageStack.Pop() as MenuPage;
-                    currentMenuPage = parent;
-                    currentInputItem = null;
-                    ShowCurrentPage();
-                    isEditMode = false;
-                };
+                    currentInputItem.ValueChanged += delegate (object sender, ValueChangedEventArgs e)
+                    {
+                        // set the value and notify the eager listeners
+                        menuItem.Value = e.Value;
+                        ValueChanged?.Invoke(this, new ValueChangedEventArgs(menuItem.Id, menuItem.Value));
+
+                        // reload the parent menu
+                        var parent = pageStack?.Pop() as MenuPage;
+                        currentMenuPage = parent;
+                        currentInputItem = null;
+                        ShowCurrentPage();
+                        isEditMode = false;
+                    };
+                }
+
 
                 // initialize input mode and get new value
-                if (display != null)
+                if (currentInputItem != null && display != null)
                 {
                     currentInputItem.Init(display);
                 }
 
-                currentInputItem.GetInput(menuItem.Id, menuItem.Value);
+                currentInputItem?.GetInput(menuItem.Id, menuItem.Value);
                 return true;
             }
             else
@@ -462,7 +476,7 @@ public void UpdateItemValue(Hashtable values)
         private void UpdateMenuItemValue(string id, object value)
         {
             MenuItem? node = null;
-            foreach (var menuItem in rootMenuPage.MenuItems)
+            foreach (var menuItem in rootMenuPage!.MenuItems)
             {
                 node = FindNodeById(menuItem, id);
                 if (node != null) { break; }
@@ -484,7 +498,7 @@ private void UpdateMenuItemValue(string id, object value)
             {
                 return menuItem;
             }
-            else if (menuItem.SubItems.Length > 0)
+            else if (menuItem != null && menuItem.SubItems?.Length > 0)
             {
                 foreach (var subMenuItem in menuItem.SubItems)
                 {

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

@@ -73,6 +73,7 @@ public int BitDepth
         /// </summary>
         public PixelBufferBase()
         {
+            Buffer = new byte[0];
         }
 
         /// <summary>
@@ -113,7 +114,7 @@ public PixelBufferBase(int width, int height, byte[] buffer)
         /// <param name="replaceIfExists">If true, will recreates the buffer if it already exists</param>
         public void InitializeBuffer(bool replaceIfExists = false)
         {
-            if (Buffer == null || replaceIfExists)
+            if (Buffer == null || Buffer.Length == 0 || replaceIfExists)
             {
                 Buffer = new byte[ByteCount];
             }
@@ -357,7 +358,7 @@ protected virtual void Dispose(bool disposing)
                 {
                     if (disposing)
                     {
-                        Buffer = null;
+                        Buffer = new byte[0];
                     }
                 }
             }

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

@@ -57,7 +57,7 @@ public class GraphicsPath
         /// <summary>
         /// The collection of points 
         /// </summary>
-        public Point[] Points;
+        public Point[]? Points;
 
         /// <summary>
         /// The number of verbs/actions used
@@ -76,6 +76,11 @@ public Rect Bounds
         {
             get
             {
+                if (Points == null)
+                {
+                    return new Rect(0, 0, 0, 0);
+                }
+
                 Point min = Points[0];
                 Point max = Points[0];
 

Source/Meadow.Foundation.Peripherals/Displays.Lcd.CharacterDisplay/Driver/CharacterDisplay.cs

@@ -13,7 +13,7 @@ public class CharacterDisplay : ITextDisplay
         /// <summary>
         /// The display configuration for text display menu
         /// </summary>
-        public TextDisplayConfig? DisplayConfig => characterDisplay?.DisplayConfig;
+        public TextDisplayConfig DisplayConfig => characterDisplay!.DisplayConfig;
 
         /// <summary>
         /// Create a new character display object using GPIO

Source/Meadow.Foundation.Peripherals/Displays.Ssd130x/Driver/Ssd130xBase.cs

@@ -24,12 +24,12 @@ public abstract partial class Ssd130xBase : IGraphicsDisplay, ISpiPeripheral, II
         /// <summary>
         /// The width of the display in pixels
         /// </summary>
-        public int Width => imageBuffer.Width;
+        public int Width => imageBuffer!.Width;
 
         /// <summary>
         /// The height of the display in pixels
         /// </summary>
-        public int Height => imageBuffer.Height;
+        public int Height => imageBuffer!.Height;
 
         /// <summary>
         /// The buffer the holds the pixel data for the display
@@ -122,7 +122,7 @@ public SpiClockConfiguration.Mode SpiBusMode
         /// <summary>
         /// Read buffer
         /// </summary>
-        protected byte[] readBuffer;
+        protected byte[]? readBuffer;
 
         /// <summary>
         /// Display command buffer
@@ -132,12 +132,12 @@ public SpiClockConfiguration.Mode SpiBusMode
         /// <summary>
         /// Page buffer to hold one page of data
         /// </summary>
-        protected byte[] pageBuffer;
+        protected byte[]? pageBuffer;
 
         /// <summary>
         /// Sequence of command bytes that must be sent to the display before
         /// </summary>
-        protected byte[] showPreamble;
+        protected byte[]? showPreamble;
 
         /// <summary>
         /// Invert the entire display (true) or return to normal mode (false)
@@ -255,7 +255,7 @@ public void Show()
             else//  I2C
             {   //  Send the buffer page by page
                 //  This can be optimized when we move to Memory<byte>
-                pageBuffer[0] = 0x40;
+                pageBuffer![0] = 0x40;
 
                 for (ushort index = 0; index < imageBuffer.ByteCount; index += PAGE_SIZE)
                 {

Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.As1115/Driver/As1115.cs

@@ -26,14 +26,14 @@ public partial class As1115 : IGraphicsDisplay, II2cPeripheral, IDisposable
         /// <summary>
         /// Readonly collection that contains all 16 key scan button objects
         /// </summary>
-        public ReadOnlyDictionary<KeyScanButtonType, KeyScanButton> KeyScanButtons { get; protected set; }
+        public ReadOnlyDictionary<KeyScanButtonType, KeyScanButton>? KeyScanButtons { get; protected set; }
 
         /// <summary>
         /// Helper method to get IButton object references for keyscan buttons
         /// </summary>
         /// <param name="buttonType">The button type</param>
         /// <returns>The button object reference</returns>
-        public IButton GetButton(KeyScanButtonType buttonType) => KeyScanButtons[buttonType];
+        public IButton GetButton(KeyScanButtonType buttonType) => KeyScanButtons![buttonType];
 
         /// <summary>
         /// Last button pressed, used internally to raise key up events
@@ -148,7 +148,7 @@ private void InterruptPort_Changed(object sender, DigitalPortResult e)
             {
                 KeyScanPressStarted?.Invoke(this, new KeyScanEventArgs(keyScanButton, data[0], data[1]));
 
-                KeyScanButtons[keyScanButton].Update(true);
+                KeyScanButtons![keyScanButton].Update(true);
 
                 lastButtonPressed = keyScanButton;
             }
@@ -158,7 +158,7 @@ private void InterruptPort_Changed(object sender, DigitalPortResult e)
 
                 if (lastButtonPressed != KeyScanButtonType.None)
                 {
-                    KeyScanButtons[lastButtonPressed].Update(false);
+                    KeyScanButtons![lastButtonPressed].Update(false);
                 }
             }
         }

Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.Sc16is7x2/Driver/Sc16is7x2.Sc16is7x2Channel.cs

@@ -14,6 +14,7 @@ public class Sc16is7x2Channel : ISerialPort
     {
         /// <inheritdoc/>
         public event SerialDataReceivedEventHandler DataReceived = default!;
+
         /// <inheritdoc/>
         public event EventHandler BufferOverrun = default!;
 

Source/Meadow.Foundation.Peripherals/ICs.IOExpanders.SerialWombat/Driver/SerialWombatBase.BiDirectionalPort.cs

@@ -12,7 +12,7 @@ public class BiDirectionalPort : BiDirectionalPortBase
             /// <summary>
             /// Serial Wombat controller
             /// </summary>
-            private readonly SerialWombatBase _controller;
+            private readonly SerialWombatBase? _controller;
 
             /// <summary>
             /// The port direction
@@ -36,8 +36,8 @@ protected BiDirectionalPort(
             /// </summary>
             public override bool State
             {
-                get => _controller.ReadPublicData((byte)Pin.Key) != 0;
-                set => _controller.ConfigureOutputPin((byte)Pin.Key, value, OutputType.PushPull);
+                get => _controller!.ReadPublicData((byte)Pin.Key) != 0;
+                set => _controller!.ConfigureOutputPin((byte)Pin.Key, value, OutputType.PushPull);
             }
         }
     }