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using System;
using System.ComponentModel;
using Android.Content;
using Android.Support.V4.View;
using Android.Support.V7.Widget;
using Android.Views;
using AColor = Android.Graphics.Color;
using AView = Android.Views.View;
namespace Xamarin.Forms.Platform.Android.AppCompat
{
public class FrameRenderer : CardView, IVisualElementRenderer, AView.IOnClickListener, AView.IOnTouchListener
{
readonly Lazy<GestureDetector> _gestureDetector;
readonly PanGestureHandler _panGestureHandler;
readonly PinchGestureHandler _pinchGestureHandler;
readonly Lazy<ScaleGestureDetector> _scaleDetector;
readonly TapGestureHandler _tapGestureHandler;
float _defaultElevation = -1f;
bool _disposed;
Frame _element;
InnerGestureListener _gestureListener;
VisualElementPackager _visualElementPackager;
VisualElementTracker _visualElementTracker;
public FrameRenderer() : base(Forms.Context)
{
_tapGestureHandler = new TapGestureHandler(() => Element);
_panGestureHandler = new PanGestureHandler(() => Element, Context.FromPixels);
_pinchGestureHandler = new PinchGestureHandler(() => Element);
_gestureDetector =
new Lazy<GestureDetector>(
() =>
new GestureDetector(
_gestureListener =
new InnerGestureListener(_tapGestureHandler.OnTap, _tapGestureHandler.TapGestureRecognizers, _panGestureHandler.OnPan, _panGestureHandler.OnPanStarted, _panGestureHandler.OnPanComplete)));
_scaleDetector =
new Lazy<ScaleGestureDetector>(
() => new ScaleGestureDetector(Context, new InnerScaleListener(_pinchGestureHandler.OnPinch, _pinchGestureHandler.OnPinchStarted, _pinchGestureHandler.OnPinchEnded), Handler));
}
protected CardView Control => this;
protected Frame Element
{
get { return _element; }
set
{
if (_element == value)
return;
Frame oldElement = _element;
_element = value;
OnElementChanged(new ElementChangedEventArgs<Frame>(oldElement, _element));
if (_element != null)
_element.SendViewInitialized(Control);
}
}
void IOnClickListener.OnClick(AView v)
{
_tapGestureHandler.OnSingleClick();
}
bool IOnTouchListener.OnTouch(AView v, MotionEvent e)
{
var handled = false;
if (_pinchGestureHandler.IsPinchSupported)
{
if (!_scaleDetector.IsValueCreated)
ScaleGestureDetectorCompat.SetQuickScaleEnabled(_scaleDetector.Value, true);
handled = _scaleDetector.Value.OnTouchEvent(e);
}
return _gestureDetector.Value.OnTouchEvent(e) || handled;
}
VisualElement IVisualElementRenderer.Element => Element;
public event EventHandler<VisualElementChangedEventArgs> ElementChanged;
SizeRequest IVisualElementRenderer.GetDesiredSize(int widthConstraint, int heightConstraint)
{
Context context = Context;
return new SizeRequest(new Size(context.ToPixels(20), context.ToPixels(20)));
}
void IVisualElementRenderer.SetElement(VisualElement element)
{
var frame = element as Frame;
if (frame == null)
throw new ArgumentException("Element must be of type Frame");
Element = frame;
if (!string.IsNullOrEmpty(Element.AutomationId))
ContentDescription = Element.AutomationId;
}
VisualElementTracker IVisualElementRenderer.Tracker => _visualElementTracker;
void IVisualElementRenderer.UpdateLayout()
{
VisualElementTracker tracker = _visualElementTracker;
tracker?.UpdateLayout();
}
ViewGroup IVisualElementRenderer.ViewGroup => this;
protected override void Dispose(bool disposing)
{
if (disposing && !_disposed)
{
_disposed = true;
if (_gestureListener != null)
{
_gestureListener.Dispose();
_gestureListener = null;
}
if (_visualElementTracker != null)
{
_visualElementTracker.Dispose();
_visualElementTracker = null;
}
if (_visualElementPackager != null)
{
_visualElementPackager.Dispose();
_visualElementPackager = null;
}
if (Element != null)
Element.PropertyChanged -= OnElementPropertyChanged;
}
base.Dispose(disposing);
}
protected virtual void OnElementChanged(ElementChangedEventArgs<Frame> e)
{
ElementChanged?.Invoke(this, new VisualElementChangedEventArgs(e.OldElement, e.NewElement));
if (e.OldElement != null)
e.OldElement.PropertyChanged -= OnElementPropertyChanged;
else
{
SetOnClickListener(this);
SetOnTouchListener(this);
}
if (e.NewElement != null)
{
if (_visualElementTracker == null)
{
_visualElementTracker = new VisualElementTracker(this);
_visualElementPackager = new VisualElementPackager(this);
_visualElementPackager.Load();
}
e.NewElement.PropertyChanged += OnElementPropertyChanged;
UpdateShadow();
UpdateBackgroundColor();
}
}
protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
{
if (Element == null)
return;
var children = Element.LogicalChildren;
for (var i = 0; i < children.Count; i++)
{
var visualElement = children[i] as VisualElement;
if (visualElement == null)
continue;
IVisualElementRenderer renderer = Android.Platform.GetRenderer(visualElement);
renderer?.UpdateLayout();
}
}
void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == Frame.HasShadowProperty.PropertyName)
UpdateShadow();
else if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName)
UpdateBackgroundColor();
}
void UpdateBackgroundColor()
{
Color bgColor = Element.BackgroundColor;
SetCardBackgroundColor(bgColor.IsDefault ? AColor.White : bgColor.ToAndroid());
}
void UpdateShadow()
{
float elevation = _defaultElevation;
if (elevation == -1f)
_defaultElevation = elevation = CardElevation;
if (Element.HasShadow)
CardElevation = elevation;
else
CardElevation = 0f;
}
}
}
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