From 28b9aa2be6df1e34adec6947d0b17b4a1f137063 Mon Sep 17 00:00:00 2001
From: Rui Marinho <me@ruimarinho.net>
Date: Mon, 25 Jan 2021 20:02:06 +0000
Subject: [PATCH 1/3] [Controls] Add test sample for #13296
---
.../CarouselXamlGallery.xaml | 5 +-
.../CarouselXamlGallery.xaml.cs | 60 ++++++++++++-------
2 files changed, 43 insertions(+), 22 deletions(-)
diff --git a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml
index 9bfad68e3db..471ff6ff319 100644
--- a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml
+++ b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml
@@ -12,6 +12,7 @@
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
+ <RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition />
@@ -29,9 +30,11 @@
<Button Command="{Binding RemoveCommand}" AutomationId="btnRemove" Text="{Binding Path=Selected.Index, StringFormat='Remove {0}'}" BackgroundColor="LightGray" TextColor="Black" />
<Button Command="{Binding NextCommand}" AutomationId="btnNext" Text=">" FontAttributes="Bold" BackgroundColor="LightGray" TextColor="Black" />
</StackLayout>
+ <Button Grid.Row="5" Text="Clear" Command="{Binding ClearCommand}" AutomationId="btnClear"/>
+ <Button Grid.Row="5" Grid.Column="1" Text="Set" Command="{Binding SetCommand}" AutomationId="btnSet"/>
<CarouselView
x:Name="carousel"
- Grid.Row="5" Grid.ColumnSpan="2"
+ Grid.Row="6" Grid.ColumnSpan="2"
Loop="{Binding IsLoop}"
AutomationId="TheCarouselView"
ItemsSource="{Binding Items}"
diff --git a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
index ee01055a2e7..6d23065af9a 100644
--- a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
+++ b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
@@ -35,27 +35,7 @@ public CarouselViewModel(CarouselXamlSampleType type, bool loop, int initialItem
IsLoop = loop;
_type = type;
- var items = new List<CarouselItem>();
- for (int i = 0; i < initialItems; i++)
- {
- switch (_type)
- {
- case CarouselXamlSampleType.Peek:
- items.Add(new CarouselItem(i, "cardBackground.png"));
- break;
- default:
- items.Add(new CarouselItem(i));
- break;
- }
- }
-
- MessagingCenter.Subscribe<ExampleTemplateCarousel>(this, "remove", (obj) => Items.Remove(obj.BindingContext as CarouselItem));
-
- Items = new ObservableCollection<CarouselItem>(items);
- Count = Items.Count - 1;
-
- if (startCurrentItem != -1)
- Selected = Items[startCurrentItem];
+ SetItems(initialItems, startCurrentItem);
}
public bool IsLoop
@@ -124,6 +104,44 @@ public CarouselItem Selected
Selected = newItem;
}
});
+
+ public ICommand ClearCommand => new Command(ClearItems);
+
+ public ICommand SetCommand => new Command(() =>
+ {
+ SetItems(10, 5);
+ });
+
+ void ClearItems()
+ {
+ Items.Clear();
+ Selected = null;
+ }
+
+ void SetItems(int initialItems, int startCurrentItem)
+ {
+ var items = new List<CarouselItem>();
+ for (int i = 0; i < initialItems; i++)
+ {
+ switch (_type)
+ {
+ case CarouselXamlSampleType.Peek:
+ items.Add(new CarouselItem(i, "cardBackground.png"));
+ break;
+ default:
+ items.Add(new CarouselItem(i));
+ break;
+ }
+ }
+
+ MessagingCenter.Subscribe<ExampleTemplateCarousel>(this, "remove", (obj) => Items.Remove(obj.BindingContext as CarouselItem));
+
+ Items = new ObservableCollection<CarouselItem>(items);
+ Count = Items.Count - 1;
+
+ if (startCurrentItem != -1)
+ Selected = Items[startCurrentItem];
+ }
}
[Preserve(AllMembers = true)]
From 20dcaf3733d9959196708eeb1e830e04a26fdf2d Mon Sep 17 00:00:00 2001
From: Rui Marinho <me@ruimarinho.net>
Date: Mon, 25 Jan 2021 20:52:41 +0000
Subject: [PATCH 2/3] [Android] Don't Scroll to item if it's null
---
.../CarouselViewGalleries/CarouselXamlGallery.xaml.cs | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
index 6d23065af9a..cb73cecd92c 100644
--- a/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
+++ b/Xamarin.Forms.Controls/GalleryPages/CollectionViewGalleries/CarouselViewGalleries/CarouselXamlGallery.xaml.cs
@@ -160,5 +160,10 @@ public CarouselItem(int index, string image = null)
public string Image { get; set; }
public string FeaturedImage { get; set; }
+
+ public override string ToString()
+ {
+ return Index.ToString();
+ }
}
}
From 94d918d8cbbde5aee34c14764070017a56c3021d Mon Sep 17 00:00:00 2001
From: Rui Marinho <me@ruimarinho.net>
Date: Tue, 26 Jan 2021 11:17:02 +0000
Subject: [PATCH 3/3] [Android] Don't scroll if item is null
---
.../CollectionView/CarouselViewRenderer.cs | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/Xamarin.Forms.Platform.Android/CollectionView/CarouselViewRenderer.cs b/Xamarin.Forms.Platform.Android/CollectionView/CarouselViewRenderer.cs
index 4bf5d6a63d6..52bb1862ac5 100644
--- a/Xamarin.Forms.Platform.Android/CollectionView/CarouselViewRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/CollectionView/CarouselViewRenderer.cs
@@ -504,7 +504,12 @@ void SetCurrentItem(int carouselPosition)
void UpdateFromCurrentItem()
{
- var currentItemPosition = ItemsViewAdapter.ItemsSource.GetPosition(Carousel.CurrentItem);
+ var currentItem = Carousel?.CurrentItem;
+
+ if (currentItem == null)
+ return;
+
+ var currentItemPosition = ItemsViewAdapter.ItemsSource.GetPosition(currentItem);
var carouselPosition = Carousel.Position;
if (_gotoPosition == -1 && currentItemPosition != carouselPosition)