From 8fbcbc3851f6cf4bb9d5a8502b95584eaffafbe2 Mon Sep 17 00:00:00 2001
From: Tim <tim.uniewski@gmail.com>
Date: Sat, 9 May 2020 21:13:09 +0200
Subject: [PATCH] Fix TemplateBinding for MinimumOpenPaneLenght and
 MaximumOpenPaneLength

didn't work.
---
 .../HamburgerMenu/HamburgerMenu.Properties.cs | 60 +++++++++++++++++--
 src/MahApps.Metro/Themes/HamburgerMenu.xaml   |  6 +-
 .../Themes/HamburgerMenuTemplate.xaml         |  5 +-
 3 files changed, 63 insertions(+), 8 deletions(-)

diff --git a/src/MahApps.Metro/Controls/HamburgerMenu/HamburgerMenu.Properties.cs b/src/MahApps.Metro/Controls/HamburgerMenu/HamburgerMenu.Properties.cs
index 50001ba315..20d1080f00 100644
--- a/src/MahApps.Metro/Controls/HamburgerMenu/HamburgerMenu.Properties.cs
+++ b/src/MahApps.Metro/Controls/HamburgerMenu/HamburgerMenu.Properties.cs
@@ -21,14 +21,66 @@ public partial class HamburgerMenu
 
         private static void OpenPaneLengthPropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
         {
-            if (args.NewValue != args.OldValue)
+            if (args.NewValue != args.OldValue && dependencyObject is HamburgerMenu hamburgerMenu && hamburgerMenu.ValidateOpenPaneLenth())
             {
-                (dependencyObject as HamburgerMenu)?.ChangeItemFocusVisualStyle();
+                hamburgerMenu.ChangeItemFocusVisualStyle();
+            }
+        }
+
+        private bool ValidateOpenPaneLenth()
+        {
+            if (this.ActualWidth > 0)
+            {
+                double minWidth = 0;
+
+                // Get the minimum needed width
+                if (this.DisplayMode == SplitViewDisplayMode.CompactInline || this.DisplayMode == SplitViewDisplayMode.CompactOverlay)
+                {
+                    minWidth = Math.Max(this.CompactPaneLength, this.MinimumOpenPaneLength);
+                }
+                else
+                {
+                    minWidth = Math.Max(0, this.MinimumOpenPaneLength);
+                }
+
+                if (minWidth < 0)
+                {
+                    minWidth = 0;
+                }
+
+                // Get the maximum allowed width
+                double maxWidth = Math.Min(this.ActualWidth, this.MaximumOpenPaneLength);
+
+                // Check if max < min
+                if (maxWidth < minWidth)
+                {
+                    minWidth = maxWidth;
+                }
+
+                // Check is OpenPaneLength is valid
+                if (OpenPaneLength < minWidth)
+                {
+                    SetCurrentValue(OpenPaneLengthProperty, minWidth);
+                    return false;
+                }
+                else if (OpenPaneLength > maxWidth)
+                {
+                    SetCurrentValue(OpenPaneLengthProperty, maxWidth);
+                    return false;
+                }
+                else
+                {
+                    return true;
+                }
+            }
+            else
+            {
+                return false;
             }
         }
 
         /// <summary>Identifies the <see cref="MinimumOpenPaneLength"/> dependency property.</summary>
-        public static readonly DependencyProperty MinimumOpenPaneLengthProperty = DependencyProperty.Register(nameof(MinimumOpenPaneLength), typeof(double), typeof(HamburgerMenu), new PropertyMetadata(100d));
+        public static readonly DependencyProperty MinimumOpenPaneLengthProperty = DependencyProperty.Register(nameof(MinimumOpenPaneLength), typeof(double), typeof(HamburgerMenu), new PropertyMetadata(100d, OpenPaneLengthPropertyChangedCallback));
 
         /// <summary>
         ///     Gets or sets the minimum width of the <see cref="SplitView" /> pane when it's fully expanded.
@@ -45,7 +97,7 @@ public double MinimumOpenPaneLength
 
 
         /// <summary>Identifies the <see cref="MaximumOpenPaneLength"/> dependency property.</summary>
-        public static readonly DependencyProperty MaximumOpenPaneLengthProperty = DependencyProperty.Register(nameof(MaximumOpenPaneLength), typeof(double), typeof(HamburgerMenu), new PropertyMetadata(500d));
+        public static readonly DependencyProperty MaximumOpenPaneLengthProperty = DependencyProperty.Register(nameof(MaximumOpenPaneLength), typeof(double), typeof(HamburgerMenu), new PropertyMetadata(500d, OpenPaneLengthPropertyChangedCallback));
 
         /// <summary>
         ///     Gets or sets the maximum width of the <see cref="SplitView" /> pane when it's fully expanded.
diff --git a/src/MahApps.Metro/Themes/HamburgerMenu.xaml b/src/MahApps.Metro/Themes/HamburgerMenu.xaml
index d0d6e417f1..bc25026ca1 100644
--- a/src/MahApps.Metro/Themes/HamburgerMenu.xaml
+++ b/src/MahApps.Metro/Themes/HamburgerMenu.xaml
@@ -4,14 +4,16 @@
 
     <ResourceDictionary.MergedDictionaries>
         <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Themes/HamburgerMenuTemplate.xaml" />
-        <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Themes/SplitView.xaml" />
     </ResourceDictionary.MergedDictionaries>
 
     <Style x:Key="MahApps.Styles.HamburgerMenu" TargetType="{x:Type Controls:HamburgerMenu}">
         <Setter Property="FocusVisualStyle" Value="{x:Null}" />
         <Setter Property="Focusable" Value="False" />
         <Setter Property="HamburgerButtonStyle" Value="{DynamicResource MahApps.Styles.Button.Hamburger}" />
-        <Setter Property="ResizeThumbStyle" Value="{StaticResource MahApps.Styles.MetroThumb.SplitView.Resize}" />
+        <Setter Property="ResizeThumbStyle" Value="{DynamicResource MahApps.Styles.MetroThumb.SplitView.Resize}" />
+        <Setter Property="MinimumOpenPaneLength" Value="100" />
+        <Setter Property="MaximumOpenPaneLength" Value="500" />
+        <Setter Property="CanResizeOpenPane" Value="True" />
         <Setter Property="HamburgerButtonTemplate">
             <Setter.Value>
                 <DataTemplate>
diff --git a/src/MahApps.Metro/Themes/HamburgerMenuTemplate.xaml b/src/MahApps.Metro/Themes/HamburgerMenuTemplate.xaml
index db00e6e05e..7aa6edbd67 100644
--- a/src/MahApps.Metro/Themes/HamburgerMenuTemplate.xaml
+++ b/src/MahApps.Metro/Themes/HamburgerMenuTemplate.xaml
@@ -11,6 +11,7 @@
         <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.ListBox.xaml" />
         <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.Scrollbars.xaml" />
         <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.TextBlock.xaml" />
+        <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Themes/SplitView.xaml" />
     </ResourceDictionary.MergedDictionaries>
 
     <system:Double x:Key="HamburgerMenuSelectionIndicatorThemeWidth">6</system:Double>
@@ -385,8 +386,8 @@
                                 IsPaneOpen="{Binding IsPaneOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
                                 IsTabStop="False"
                                 OpenPaneLength="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=OpenPaneLength, Mode=TwoWay}"
-                                MinimumOpenPaneLength="{TemplateBinding MinimumOpenPaneLength}"
-                                MaximumOpenPaneLength="{TemplateBinding MaximumOpenPaneLength}"
+                                MinimumOpenPaneLength="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=MinimumOpenPaneLength}"
+                                MaximumOpenPaneLength="{Binding RelativeSource={RelativeSource Mode=TemplatedParent}, Path=MaximumOpenPaneLength}"
                                 CanResizeOpenPane="{TemplateBinding CanResizeOpenPane}"
                                 ResizeThumbStyle="{TemplateBinding ResizeThumbStyle}"
                                 PaneBackground="{TemplateBinding PaneBackground}"