blob: 43dac1fe98e38101b629889ab8919f29b6235826 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
using System;
using System.ComponentModel;
using System.Threading.Tasks;
using Android.Graphics;
using Android.Views;
using AImageView = Android.Widget.ImageView;
using Xamarin.Forms.Internals;
namespace Xamarin.Forms.Platform.Android
{
internal interface IImageRendererController
{
void SkipInvalidate();
}
public class ImageRenderer : ViewRenderer<Image, AImageView>
{
bool _isDisposed;
readonly MotionEventHelper _motionEventHelper = new MotionEventHelper();
public ImageRenderer()
{
AutoPackage = false;
}
protected override void Dispose(bool disposing)
{
if (_isDisposed)
return;
_isDisposed = true;
base.Dispose(disposing);
}
protected override AImageView CreateNativeControl()
{
return new FormsImageView(Context);
}
protected override async void OnElementChanged(ElementChangedEventArgs<Image> e)
{
base.OnElementChanged(e);
if (e.OldElement == null)
{
var view = CreateNativeControl();
SetNativeControl(view);
}
_motionEventHelper.UpdateElement(e.NewElement);
await TryUpdateBitmap(e.OldElement);
UpdateAspect();
}
protected override async void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == Image.SourceProperty.PropertyName)
await TryUpdateBitmap();
else if (e.PropertyName == Image.AspectProperty.PropertyName)
UpdateAspect();
}
void UpdateAspect()
{
if (Element == null || Control == null || Control.IsDisposed())
{
return;
}
AImageView.ScaleType type = Element.Aspect.ToScaleType();
Control.SetScaleType(type);
}
protected virtual async Task TryUpdateBitmap(Image previous = null)
{
// By default we'll just catch and log any exceptions thrown by UpdateBitmap so they don't bring down
// the application; a custom renderer can override this method and handle exceptions from
// UpdateBitmap differently if it wants to
try
{
await UpdateBitmap(previous);
}
catch (Exception ex)
{
Log.Warning(nameof(ImageRenderer), "Error loading image: {0}", ex);
}
finally
{
((IImageController)Element)?.SetIsLoading(false);
}
}
protected async Task UpdateBitmap(Image previous = null)
{
if (Element == null || Control == null || Control.IsDisposed())
{
return;
}
await Control.UpdateBitmap(Element, previous);
}
public override bool OnTouchEvent(MotionEvent e)
{
if (base.OnTouchEvent(e))
return true;
return _motionEventHelper.HandleMotionEvent(Parent);
}
}
}
|
