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Diffstat (limited to 'Xamarin.Forms.Controls/ControlGalleryPages/PinchGestureTestPage.cs')
-rw-r--r--Xamarin.Forms.Controls/ControlGalleryPages/PinchGestureTestPage.cs91
1 files changed, 91 insertions, 0 deletions
diff --git a/Xamarin.Forms.Controls/ControlGalleryPages/PinchGestureTestPage.cs b/Xamarin.Forms.Controls/ControlGalleryPages/PinchGestureTestPage.cs
new file mode 100644
index 00000000..44dd6ae8
--- /dev/null
+++ b/Xamarin.Forms.Controls/ControlGalleryPages/PinchGestureTestPage.cs
@@ -0,0 +1,91 @@
+´╗┐using System;
+using System.Diagnostics;
+
+namespace Xamarin.Forms.Controls
+{
+ public class PinchToZoomContainer : ContentView
+ {
+ public PinchToZoomContainer ()
+ {
+
+ }
+
+ public void AddPinch ()
+ {
+
+ 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);
+ }
+
+ public bool AlwaysZoomCenter { get; set; }
+
+ double _currentScale = 1;
+ }
+
+ public class PinchGestureTestPage : ContentPage
+ {
+ public PinchGestureTestPage ()
+ {
+ var stack = new StackLayout { VerticalOptions = LayoutOptions.Start, HorizontalOptions = LayoutOptions.Center };
+ var textBoxScale = new Label { VerticalOptions = LayoutOptions.Start, HorizontalOptions = LayoutOptions.Center };
+ var textBox = new Label { VerticalOptions = LayoutOptions.Start, HorizontalOptions = LayoutOptions.Center };
+ var textBoxPoint = new Label { VerticalOptions = LayoutOptions.Start, HorizontalOptions = LayoutOptions.Center };
+ stack.Children.Add (textBox);
+ stack.Children.Add (textBoxScale);
+ stack.Children.Add (textBoxPoint);
+
+ var box = new Image { Source = "crimson.jpg", BackgroundColor = Color.Red, WidthRequest = 200, HeightRequest = 200, VerticalOptions = LayoutOptions.Center, HorizontalOptions = LayoutOptions.Center };
+
+ var zoomContainer = new PinchToZoomContainer ();
+ zoomContainer.Content = box;
+
+ var btn = new Button { Text = "add pinch gesture", Command = new Command (() => zoomContainer.AddPinch ()) };
+ var btnRemove = new Button { Text = "remove pinch gesture", Command = new Command (() => zoomContainer.GestureRecognizers.Clear ()) };
+
+ Content = new StackLayout { Children = { btn, btnRemove, new Grid { Children = { zoomContainer }, Padding = new Thickness (20) } } };
+ }
+
+ double _currentScale = 1;
+ }
+}
+