Added possibility to control if fade animation should be enabled

FFImageLoading.Common/Config/Configuration.cs

@@ -9,7 +9,7 @@ namespace FFImageLoading.Config
     public class Configuration
     {
         public Configuration(int maxCacheSize = 0, HttpClient httpClient = null, IWorkScheduler scheduler = null, IMiniLogger logger = null,
-			IDiskCache diskCache = null, IDownloadCache downloadCache = null, bool loadWithTransparencyChannel = false)
+			IDiskCache diskCache = null, IDownloadCache downloadCache = null, bool loadWithTransparencyChannel = false, bool fadeAnimationEnabled=false)
         {
             MaxCacheSize = maxCacheSize;
             HttpClient = httpClient;
@@ -18,6 +18,7 @@ public Configuration(int maxCacheSize = 0, HttpClient httpClient = null, IWorkSc
             DiskCache = diskCache;
             DownloadCache = downloadCache;
 			LoadWithTransparencyChannel = loadWithTransparencyChannel;
+			FadeAnimationEnabled = fadeAnimationEnabled;
         }
 
         /// <summary>
@@ -61,6 +62,12 @@ public Configuration(int maxCacheSize = 0, HttpClient httpClient = null, IWorkSc
 		/// </summary>
 		/// <value><c>true</c> if FFIMageLoading loads images with transparency; otherwise, <c>false</c>.</value>
 		public bool LoadWithTransparencyChannel { get; private set; }
+
+		/// <summary>
+		/// Gets a value indicating whether this <see cref="FFImageLoading.Config.Configuration"/> fade animation enabled.
+		/// </summary>
+		/// <value><c>true</c> if fade animation enabled; otherwise, <c>false</c>.</value>
+		public bool FadeAnimationEnabled { get; private set; }
     }
 }
 

FFImageLoading.Common/Work/TaskParameter.cs

@@ -125,6 +125,8 @@ public void Dispose()
 
 		public bool? LoadTransparencyChannel { get; private set; }
 
+		public bool? FadeAnimationEnabled { get; private set; }
+
 		public TaskParameter Transform(ITransformation transformation)
 		{
 			if (transformation == null)
@@ -190,6 +192,17 @@ public TaskParameter TransparencyChannel(bool loadTransparencyChannel)
 			return this;
 		}
 
+		/// <summary>
+		/// Indicates if the fade animation should be enabled.
+		/// </summary>
+		/// <returns>The TaskParameter instance for chaining the call.</returns>
+		/// <param name="enabled">If set to <c>true</c> enabled.</param>
+		public TaskParameter FadeAnimation(bool enabled)
+		{
+			FadeAnimationEnabled = enabled;
+			return this;
+		}
+
 		/// <summary>
 		/// If image loading fails automatically retry it a number of times, with a specific delay.
 		/// </summary>

FFImageLoading.Droid/Work/ImageLoaderTask.cs

@@ -32,8 +32,6 @@ public ImageLoaderTask(IDownloadCache downloadCache, IMainThreadDispatcher mainT
 		{
 			DownloadCache = downloadCache;
 			_imageWeakReference = new WeakReference<ImageView>(imageView);
-
-			UseFadeInBitmap = true;
 		}
 
 		/// <summary>
@@ -105,7 +103,14 @@ await MainThreadDispatcher.PostAsync(() =>
 		/// Gets or sets a value indicating whether a fade in transition is used to show the image.
 		/// </summary>
 		/// <value><c>true</c> if a fade in transition is used; otherwise, <c>false</c>.</value>
-		public bool UseFadeInBitmap { get; set; }
+		public bool UseFadeInBitmap 
+		{ 
+			get
+			{
+				return Parameters.FadeAnimationEnabled.HasValue ? 
+					Parameters.FadeAnimationEnabled.Value : ImageService.Config.FadeAnimationEnabled;
+			}
+		}
 
 		protected IDownloadCache DownloadCache { get; private set; }
 
@@ -392,7 +397,7 @@ protected virtual async Task<WithLoadingResult<BitmapDrawable>> GetDrawableAsync
 									_loadingPlaceholderWeakReference.TryGetTarget(out placeholderDrawable);
 								}
 
-								return WithLoadingResult.Encapsulate<BitmapDrawable>(new FFBitmapDrawable(Context.Resources, bitmap, placeholderDrawable, FADE_TRANSITION_MILISECONDS), streamWithResult.Result);
+								return WithLoadingResult.Encapsulate<BitmapDrawable>(new FFBitmapDrawable(Context.Resources, bitmap, placeholderDrawable, FADE_TRANSITION_MILISECONDS, UseFadeInBitmap), streamWithResult.Result);
 							}
 						}
 						finally
@@ -612,12 +617,12 @@ public class FFBitmapDrawable : BitmapDrawable
 		private Drawable _placeholder;
 		private volatile bool _animating;
 
-		public FFBitmapDrawable(Resources res, Bitmap bitmap, Drawable placeholder, float fadingTime)
+		public FFBitmapDrawable(Resources res, Bitmap bitmap, Drawable placeholder, float fadingTime, bool fadeEnabled)
 			: base(res, bitmap)
 		{
 			_placeholder = placeholder;
 			_fadingTime = fadingTime;
-			_animating = true;
+			_animating = fadeEnabled;
 			_startTimeMillis = SystemClock.UptimeMillis();
 		}
 

FFImageLoading.Forms.Droid/CachedImageRenderer.cs

@@ -153,7 +153,12 @@ private void UpdateBitmap(Image previous = null)
 						}
 
 						// TransparencyChannel
-						imageLoader.TransparencyChannel(Element.TransparencyEnabled);
+						if (Element.TransparencyEnabled.HasValue)
+							imageLoader.TransparencyChannel(Element.TransparencyEnabled.Value);
+
+						// FadeAnimation
+						if (Element.FadeAnimationEnabled.HasValue)
+							imageLoader.FadeAnimation(Element.FadeAnimationEnabled.Value);
 
 						imageLoader.Finish((work) => ImageLoadingFinished(Element));
 						imageLoader.Into(Control);	

FFImageLoading.Forms.Touch/CachedImageRenderer.cs

@@ -165,7 +165,12 @@ private void SetImage(CachedImage oldElement = null)
 				}
 
 				// TransparencyChannel
-				imageLoader.TransparencyChannel(Element.TransparencyEnabled);
+				if (Element.TransparencyEnabled.HasValue)
+					imageLoader.TransparencyChannel(Element.TransparencyEnabled.Value);
+
+				// FadeAnimation
+				if (Element.FadeAnimationEnabled.HasValue)
+					imageLoader.FadeAnimation(Element.FadeAnimationEnabled.Value);
 
 				imageLoader.Finish((work) => ImageLoadingFinished(Element));
 				imageLoader.Into(Control);	

FFImageLoading.Forms/CachedImage.cs

@@ -97,23 +97,40 @@ public TimeSpan CacheDuration
 			}
 		}
 
-		public static readonly BindableProperty TransparencyEnabledProperty = BindableProperty.Create<CachedImage, bool> (w => w.TransparencyEnabled, false);
+		public static readonly BindableProperty TransparencyEnabledProperty = BindableProperty.Create<CachedImage, bool?> (w => w.TransparencyEnabled, null);
 
 		/// <summary>
 		/// Indicates if the transparency channel should be loaded. By default this value comes from ImageService.Config.LoadWithTransparencyChannel.
 		/// </summary>
-		public bool TransparencyEnabled
+		public bool? TransparencyEnabled
 		{
 			get
 			{
-				return (bool)GetValue(TransparencyEnabledProperty); 
+				return (bool?)GetValue(TransparencyEnabledProperty); 
 			}
 			set
 			{
 				SetValue(TransparencyEnabledProperty, value); 
 			}
 		}
 
+		public static readonly BindableProperty FadeAnimationEnabledProperty = BindableProperty.Create<CachedImage, bool?> (w => w.FadeAnimationEnabled, null);
+
+		/// <summary>
+		/// Indicates if the fade animation effect should be enabled. By default this value comes from ImageService.Config.FadeAnimationEnabled.
+		/// </summary>
+		public bool? FadeAnimationEnabled
+		{
+			get
+			{
+				return (bool?)GetValue(FadeAnimationEnabledProperty); 
+			}
+			set
+			{
+				SetValue(FadeAnimationEnabledProperty, value); 
+			}
+		}
+
 		public static readonly BindableProperty LoadingPlaceholderProperty = BindableProperty.Create<CachedImage, ImageSource> (w => w.LoadingPlaceholder, null);
 
 		/// <summary>