Add central OnDependencyPropertyChanged method in ColorPicker

Author: robloo

Microsoft.Toolkit.Uwp.UI.Controls.Input/ColorPicker/ColorPicker.Properties.cs

@@ -20,7 +20,9 @@ public partial class ColorPicker
                 nameof(CustomPaletteColors),
                 typeof(ObservableCollection<Windows.UI.Color>),
                 typeof(ColorPicker),
-                new PropertyMetadata(null));
+                new PropertyMetadata(
+                    null,
+                    (s, e) => (s as ColorPicker)?.OnDependencyPropertyChanged(s, e)));
 
         /// <summary>
         /// Gets the list of custom palette colors.
@@ -38,7 +40,9 @@ public ObservableCollection<Windows.UI.Color> CustomPaletteColors
                 nameof(CustomPaletteColumnCount),
                 typeof(int),
                 typeof(ColorPicker),
-                new PropertyMetadata(4));
+                new PropertyMetadata(
+                    4,
+                    (s, e) => (s as ColorPicker)?.OnDependencyPropertyChanged(s, e)));
 
         /// <summary>
         /// Gets or sets the number of colors in each row (section) of the custom color palette.
@@ -64,7 +68,9 @@ public int CustomPaletteColumnCount
                 nameof(CustomPalette),
                 typeof(IColorPalette),
                 typeof(ColorPicker),
-                new PropertyMetadata(null));
+                new PropertyMetadata(
+                    null,
+                    (s, e) => (s as ColorPicker)?.OnDependencyPropertyChanged(s, e)));
 
         /// <summary>
         /// Gets or sets the custom color palette.
@@ -91,7 +97,9 @@ public IColorPalette CustomPalette
                 nameof(IsColorPaletteVisible),
                 typeof(bool),
                 typeof(ColorPicker),
-                new PropertyMetadata(true));
+                new PropertyMetadata(
+                    true,
+                    (s, e) => (s as ColorPicker)?.OnDependencyPropertyChanged(s, e)));
 
         /// <summary>
         /// Gets or sets a value indicating whether the color palette is visible.

Microsoft.Toolkit.Uwp.UI.Controls.Input/ColorPicker/ColorPicker.cs

@@ -66,8 +66,6 @@ public partial class ColorPicker : Microsoft.UI.Xaml.Controls.ColorPicker
         private const int ColorUpdateInterval = 30; // Milliseconds
 
         private long tokenColor;
-        private long tokenCustomPalette;
-        private long tokenIsColorPaletteVisible;
 
         private bool callbacksConnected = false;
         private bool eventsConnected    = false;
@@ -252,23 +250,19 @@ private T GetTemplateChild<T>(string childName, bool isRequired = false)
         /// <param name="connected">True to connect callbacks, otherwise false.</param>
         private void ConnectCallbacks(bool connected)
         {
-            if ((connected == true) &&
-                (this.callbacksConnected == false))
+            if (connected == true &&
+                this.callbacksConnected == false)
             {
                 // Add callbacks for dependency properties
-                this.tokenColor                 = this.RegisterPropertyChangedCallback(ColorProperty,                 OnColorChanged);
-                this.tokenCustomPalette         = this.RegisterPropertyChangedCallback(CustomPaletteProperty,         OnCustomPaletteChanged);
-                this.tokenIsColorPaletteVisible = this.RegisterPropertyChangedCallback(IsColorPaletteVisibleProperty, OnIsColorPaletteVisibleChanged);
+                this.tokenColor = this.RegisterPropertyChangedCallback(ColorProperty, OnColorChanged);
 
                 this.callbacksConnected = true;
             }
-            else if ((connected == false) &&
-                     (this.callbacksConnected == true))
+            else if (connected == false &&
+                     this.callbacksConnected == true)
             {
                 // Remove callbacks for dependency properties
-                this.UnregisterPropertyChangedCallback(ColorProperty,                 this.tokenColor);
-                this.UnregisterPropertyChangedCallback(CustomPaletteProperty,         this.tokenCustomPalette);
-                this.UnregisterPropertyChangedCallback(IsColorPaletteVisibleProperty, this.tokenIsColorPaletteVisible);
+                this.UnregisterPropertyChangedCallback(ColorProperty, this.tokenColor);
 
                 this.callbacksConnected = false;
             }
@@ -282,8 +276,8 @@ private void ConnectCallbacks(bool connected)
         /// <param name="connected">True to connect event handlers, otherwise false.</param>
         private void ConnectEvents(bool connected)
         {
-            if ((connected == true) &&
-                (this.eventsConnected == false))
+            if (connected == true &&
+                this.eventsConnected == false)
             {
                 // Add all events
                 if (this.ColorSpectrumControl != null) { this.ColorSpectrumControl.ColorChanged += ColorSpectrum_ColorChanged; }
@@ -336,8 +330,8 @@ private void ConnectEvents(bool connected)
 
                 this.eventsConnected = true;
             }
-            else if ((connected == false) &&
-                     (this.eventsConnected == true))
+            else if (connected == false &&
+                     this.eventsConnected == true)
             {
                 // Remove all events
                 if (this.ColorSpectrumControl != null) { this.ColorSpectrumControl.ColorChanged -= ColorSpectrum_ColorChanged; }
@@ -1112,6 +1106,41 @@ private void ValidateSelectedPanel()
             return;
         }
 
+        private void OnDependencyPropertyChanged(object sender, DependencyPropertyChangedEventArgs args)
+        {
+            DependencyObject senderControl = sender as DependencyObject;
+
+            /* Note: ColorProperty is defined in the base class and cannot be used here
+             * See the OnColorChanged callback below
+             */
+
+            if (object.ReferenceEquals(args.Property, CustomPaletteProperty))
+            {
+                IColorPalette palette = this.CustomPalette;
+
+                if (palette != null)
+                {
+                    this.CustomPaletteColumnCount = palette.ColorCount;
+                    this.CustomPaletteColors.Clear();
+
+                    for (int shadeIndex = 0; shadeIndex < palette.ShadeCount; shadeIndex++)
+                    {
+                        for (int colorIndex = 0; colorIndex < palette.ColorCount; colorIndex++)
+                        {
+                            this.CustomPaletteColors.Add(palette.GetColor(colorIndex, shadeIndex));
+                        }
+                    }
+                }
+            }
+            else if (object.ReferenceEquals(args.Property, IsColorPaletteVisibleProperty))
+            {
+                this.UpdateVisualState(false);
+                this.ValidateSelectedPanel();
+            }
+
+            return;
+        }
+
         /***************************************************************************************
          *
          * Color Update Timer
@@ -1194,39 +1223,6 @@ private void OnColorChanged(DependencyObject d, DependencyProperty e)
             return;
         }
 
-        /// <summary>
-        /// Callback for when the <see cref="CustomPalette"/> dependency property value changes.
-        /// </summary>
-        private void OnCustomPaletteChanged(DependencyObject d, DependencyProperty e)
-        {
-            IColorPalette palette = this.CustomPalette;
-
-            if (palette != null)
-            {
-                this.CustomPaletteColumnCount = palette.ColorCount;
-                this.CustomPaletteColors.Clear();
-
-                for (int shadeIndex = 0; shadeIndex < palette.ShadeCount; shadeIndex++)
-                {
-                    for (int colorIndex = 0; colorIndex < palette.ColorCount; colorIndex++)
-                    {
-                        this.CustomPaletteColors.Add(palette.GetColor(colorIndex, shadeIndex));
-                    }
-                }
-            }
-
-            return;
-        }
-
-        /// <summary>
-        /// Callback for when the <see cref="IsColorPaletteVisible"/> dependency property value changes.
-        /// </summary>
-        private void OnIsColorPaletteVisibleChanged(DependencyObject d, DependencyProperty e)
-        {
-            this.UpdateVisualState(false);
-            return;
-        }
-
         /***************************************************************************************
          *
          * Event Handling