/
PerformanceTrackerRenderer.cs
77 lines (60 loc) · 1.89 KB
/
PerformanceTrackerRenderer.cs
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
using AView = Android.Views.View;
using System;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.ControlGallery.Android;
using Xamarin.Forms.Controls;
using Xamarin.Forms.Platform.Android;
using static Android.Views.ViewTreeObserver;
using Android.Views;
[assembly: ExportRenderer(typeof(PerformanceTracker), typeof(PerformanceTrackerRenderer))]
namespace Xamarin.Forms.ControlGallery.Android
{
public class PerformanceTrackerRenderer : ViewRenderer, IOnDrawListener
{
public PerformanceTrackerRenderer(global::Android.Content.Context context): base(context)
{
ViewTreeObserver.AddOnDrawListener(this);
}
PerformanceTracker PerformanceTracker => Element as PerformanceTracker;
void IOnDrawListener.OnDraw()
{
PerformanceTracker.Watcher.BeginTest(cleanup: () => UnsubscribeChildrenToDraw(this, this));
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == PerformanceTracker.ContentProperty.PropertyName)
{
PerformanceTracker.Watcher.ResetTest();
SubscribeChildrenToDraw(this, this);
}
}
static void SubscribeChildrenToDraw(AView view, IOnDrawListener observer)
{
if (view == null)
return;
view.ViewTreeObserver.AddOnDrawListener(observer);
var viewGroup = view as ViewGroup;
if (viewGroup == null)
return;
for (int i = 0; i < viewGroup.ChildCount; i++)
{
SubscribeChildrenToDraw(viewGroup.GetChildAt(i), observer);
}
}
static void UnsubscribeChildrenToDraw(AView view, IOnDrawListener observer)
{
if (view == null)
return;
view.ViewTreeObserver.RemoveOnDrawListener(observer);
var viewGroup = view as ViewGroup;
if (viewGroup == null)
return;
for (int i = 0; i < viewGroup.ChildCount; i++)
{
UnsubscribeChildrenToDraw(viewGroup.GetChildAt(i), observer);
}
}
}
}