fix(combobox): PlaceholderText not displaying

unoplatform · Aug 21, 2020 · 63a6d15 · 63a6d15
1 parent 8ef6ac4
commit 63a6d15
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.cs b/src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.cs
@@ -46,6 +46,7 @@ public partial class ComboBox : ListViewBase // TODO: Selector
 		private IPopup _popup;
 		private Border _popupBorder;
 		private ContentPresenter _contentPresenter;
+		private TextBlock _placeholderTextBlock;
 		private ContentPresenter _headerContentPresenter;
 
 		/// <summary>
@@ -79,6 +80,7 @@ protected override void OnApplyTemplate()
 			_popup = this.GetTemplateChild("Popup") as IPopup;
 			_popupBorder = this.GetTemplateChild("PopupBorder") as Border;
 			_contentPresenter = this.GetTemplateChild("ContentPresenter") as ContentPresenter;
+			_placeholderTextBlock = this.GetTemplateChild("PlaceholderTextBlock") as TextBlock;
 
 			if (_popup is PopupBase popup)
 			{
@@ -93,6 +95,8 @@ protected override void OnApplyTemplate()
 
 			if (_contentPresenter != null)
 			{
+				_contentPresenter.SynchronizeContentWithOuterTemplatedParent = false;
+
 				_contentPresenter.SetBinding(
 					ContentPresenter.ContentTemplateProperty,
 					new Binding(new PropertyPath("ItemTemplate"), null)
@@ -272,7 +276,7 @@ private void UpdateContentPresenter()
 					_selectionParentInDropdown = null;
 				}
 
-				_contentPresenter.Content = item;
+				_contentPresenter.Content = item ?? _placeholderTextBlock;
 
 				if (itemView != null && itemView.GetVisualTreeParent() != _contentPresenter)
 				{

diff --git a/src/Uno.UI/UI/Xaml/Controls/ContentPresenter/ContentPresenter.cs b/src/Uno.UI/UI/Xaml/Controls/ContentPresenter/ContentPresenter.cs
@@ -53,6 +53,12 @@ private void InitializeContentPresenter()
 		{
 		}
 
+		/// <summary>
+		/// Indicates if the content should inherit templated parent from the presenter, or its templated parent.
+		/// </summary>
+		/// <remarks>Clear this flag to let the control nested directly under this ContentPresenter to inherit the correct templated parent</remarks>
+		internal bool SynchronizeContentWithOuterTemplatedParent { get; set; } = true;
+
 		/// <summary>
 		/// Determines if the current ContentPresenter is hosting a native control.
 		/// </summary>
@@ -697,7 +703,9 @@ private void SynchronizeContentTemplatedParent()
 				{
 					var templatedParent = _contentTemplateRoot is ImplicitTextBlock
 						? this // ImplicitTextBlock is a special case that requires its TemplatedParent to be the ContentPresenter
-						: (this.TemplatedParent as IFrameworkElement)?.TemplatedParent;
+						: !SynchronizeContentWithOuterTemplatedParent && _dataTemplateUsedLastUpdate == null
+							? this.TemplatedParent
+							: (this.TemplatedParent as IFrameworkElement)?.TemplatedParent;
 
 					binder.TemplatedParent = templatedParent;
 				}