From 579140404be5c3fcec0d005e9b5ba36dea13f918 Mon Sep 17 00:00:00 2001
From: Alexander Marek <gentledepp@gmail.com>
Date: Fri, 18 Nov 2016 14:08:26 +0100
Subject: [PATCH] #148 fixed sigsegv crashes

---
 .../MvxAndroidLocalFileImageLoader.cs         | 34 +++++++++----------
 .../MvxDynamicImageHelper.cs                  |  9 ++++-
 .../MvxFileDownloadCache.cs                   |  2 +-
 3 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/DownloadCache/MvvmCross.Plugins.DownloadCache.Droid/MvxAndroidLocalFileImageLoader.cs b/DownloadCache/MvvmCross.Plugins.DownloadCache.Droid/MvxAndroidLocalFileImageLoader.cs
index a509fe2d..b0fed110 100644
--- a/DownloadCache/MvvmCross.Plugins.DownloadCache.Droid/MvxAndroidLocalFileImageLoader.cs
+++ b/DownloadCache/MvvmCross.Plugins.DownloadCache.Droid/MvxAndroidLocalFileImageLoader.cs
@@ -23,8 +23,8 @@ public class MvxAndroidLocalFileImageLoader
     {
         private const string ResourcePrefix = "res:";
 
-        private readonly IDictionary<CacheKey, WeakReference<Bitmap>> _memCache =
-            new Dictionary<CacheKey, WeakReference<Bitmap>>();
+        //private readonly IDictionary<CacheKey, WeakReference<Bitmap>> _memCache =
+        //    new Dictionary<CacheKey, WeakReference<Bitmap>>();
 
         public async Task<MvxImage<Bitmap>> Load(string localPath, bool shouldCache, int maxWidth, int maxHeight)
         {
@@ -166,20 +166,20 @@ private static int CalculateInSampleSize(BitmapFactory.Options options, int reqW
 
         private bool TryGetCachedBitmap(string localPath, int maxWidth, int maxHeight, out Bitmap bitmap)
         {
-            var key = new CacheKey(localPath, maxWidth, maxHeight);
-            WeakReference<Bitmap> reference;
+            //var key = new CacheKey(localPath, maxWidth, maxHeight);
+            //WeakReference<Bitmap> reference;
 
-            if (_memCache.TryGetValue(key, out reference))
-            {
-                Bitmap target;
-                if (reference.TryGetTarget(out target) && target != null && target.Handle != IntPtr.Zero && !target.IsRecycled)
-                {
-                    bitmap = target;
-                    return true;
-                }
+            //if (_memCache.TryGetValue(key, out reference))
+            //{
+            //    Bitmap target;
+            //    if (reference.TryGetTarget(out target) && target != null && target.Handle != IntPtr.Zero && !target.IsRecycled)
+            //    {
+            //        bitmap = target;
+            //        return true;
+            //    }
 
-                _memCache.Remove(key);
-            }
+            //    _memCache.Remove(key);
+            //}
 
             bitmap = null;
             return false;
@@ -187,10 +187,10 @@ private bool TryGetCachedBitmap(string localPath, int maxWidth, int maxHeight, o
 
         private void AddToCache(string localPath, int maxWidth, int maxHeight, Bitmap bitmap)
         {
-            if (bitmap == null) return;
+            //if (bitmap == null) return;
 
-            var key = new CacheKey(localPath, maxWidth, maxHeight);
-            _memCache[key] = new WeakReference<Bitmap>(bitmap);
+            //var key = new CacheKey(localPath, maxWidth, maxHeight);
+            //_memCache[key] = new WeakReference<Bitmap>(bitmap);
         }
 
         private class CacheKey
diff --git a/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxDynamicImageHelper.cs b/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxDynamicImageHelper.cs
index 2410326d..da99e9e3 100644
--- a/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxDynamicImageHelper.cs
+++ b/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxDynamicImageHelper.cs
@@ -20,6 +20,8 @@ public class MvxDynamicImageHelper<T>
         : IMvxImageHelper<T>
         where T : class
     {
+        private readonly IMvxMainThreadDispatcher _dispatcher;
+
         #region ImageState enum
 
         public enum ImageState
@@ -31,6 +33,11 @@ public enum ImageState
 
         #endregion ImageState enum
 
+        public MvxDynamicImageHelper(IMvxMainThreadDispatcher dispatcher)
+        {
+            _dispatcher = dispatcher;
+        }
+
         private ImageState _currentImageState = ImageState.DefaultShown;
 
 		private CancellationTokenSource _cancellationSource;
@@ -103,7 +110,7 @@ public void Dispose()
         private void FireImageChanged(T image)
         {
             var handler = ImageChanged;
-            handler?.Invoke(this, new MvxValueEventArgs<T>(image));
+            _dispatcher.RequestMainThreadAction(() => handler?.Invoke(this, new MvxValueEventArgs<T>(image)));
         }
 
         private async Task RequestImageAsync(string imageSource)
diff --git a/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxFileDownloadCache.cs b/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxFileDownloadCache.cs
index 8a78f99f..de8a3976 100644
--- a/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxFileDownloadCache.cs
+++ b/DownloadCache/MvvmCross.Plugins.DownloadCache/MvxFileDownloadCache.cs
@@ -402,7 +402,7 @@ public Timer(TimerCallback callback, object state, TimeSpan dueTime, TimeSpan pe
                     {
                         if (IsCancellationRequested)
                             break;
-                        Task.Run(() => tuple.Item1(tuple.Item2));
+                        await Task.Run(() => tuple.Item1(tuple.Item2));
                         await Task.Delay(period);
                     }
                 }, Tuple.Create(callback, state), CancellationToken.None,