diff options
Diffstat (limited to 'Xamarin.Forms.Controls/ControlGalleryPages/PanGestureGalleryPage.cs')
| -rw-r--r-- | Xamarin.Forms.Controls/ControlGalleryPages/PanGestureGalleryPage.cs | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/Xamarin.Forms.Controls/ControlGalleryPages/PanGestureGalleryPage.cs b/Xamarin.Forms.Controls/ControlGalleryPages/PanGestureGalleryPage.cs new file mode 100644 index 00000000..b37e8e48 --- /dev/null +++ b/Xamarin.Forms.Controls/ControlGalleryPages/PanGestureGalleryPage.cs @@ -0,0 +1,96 @@ +using System; +using System.Collections.Generic; +using System.Linq; +using System.Text; +using System.Threading.Tasks; + +namespace Xamarin.Forms.Controls +{ + public class PanGestureGalleryPage : ContentPage + { + public class PanContainer : ContentView + { + public PanContainer () + { + var pan = new PanGestureRecognizer + { + TouchPoints = 1 + }; + + pan.PanUpdated += (object s, PanUpdatedEventArgs e) => + { + switch (e.StatusType) { + + case GestureStatus.Started: break; + + case GestureStatus.Running: + Content.TranslationX = e.TotalX; + Content.TranslationY = e.TotalY; + break; + + default: + Content.TranslationX = Content.TranslationY = 0; + break; + } + }; + + var pinch = new PinchGestureRecognizer (); + + double xOffset = 0; + double yOffset = 0; + double startScale = 1; + + pinch.PinchUpdated += (sender, e) => + { + + if (e.Status == GestureStatus.Started) { + startScale = Content.Scale; + Content.AnchorX = Content.AnchorY = 0; + } + if (e.Status == GestureStatus.Running) { + + _currentScale += (e.Scale - 1) * startScale; + _currentScale = Math.Max (1, _currentScale); + + var renderedX = Content.X + xOffset; + var deltaX = renderedX / Width; + var deltaWidth = Width / (Content.Width * startScale); + var originX = (e.ScaleOrigin.X - deltaX) * deltaWidth; + + var renderedY = Content.Y + yOffset; + var deltaY = renderedY / Height; + var deltaHeight = Height / (Content.Height * startScale); + var originY = (e.ScaleOrigin.Y - deltaY) * deltaHeight; + + double targetX = xOffset - (originX * Content.Width) * (_currentScale - startScale); + double targetY = yOffset - (originY * Content.Height) * (_currentScale - startScale); + + Content.TranslationX = targetX.Clamp (-Content.Width * (_currentScale - 1), 0); + Content.TranslationY = targetY.Clamp (-Content.Height * (_currentScale - 1), 0); + + Content.Scale = _currentScale; + } + if (e.Status == GestureStatus.Completed) { + xOffset = Content.TranslationX; + yOffset = Content.TranslationY; + } + }; + + GestureRecognizers.Add (pinch); + + GestureRecognizers.Add (pan); + } + + double _currentScale = 1; + } + + public PanGestureGalleryPage () + { + var image = new Image { Source = "http://placehold.it/2000x2000", BackgroundColor = Color.Gray, WidthRequest = 2000, HeightRequest = 2000, VerticalOptions = LayoutOptions.Center, HorizontalOptions = LayoutOptions.Center }; + + var panme = new PanContainer { Content = image }; + + Content = new StackLayout { Children = { new Label { Text = "Use two fingers to pinch. Use one finger to pan." }, panme }, Padding = new Thickness (20) }; + } + } +}
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