WPF Cover Flow Tutorial : Part 6 (bis)

I'll start with some Cover refactoring :

• Class becomes internal
• I add the ICover interface, mainly for unit testing with a fake class implementing ICover :
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  1. public interface ICover  
  2. {  
  3.    void Animate(int index, bool animate);  
  4.    bool Matches(MeshGeometry3D mesh);  
  5.    void Destroy();  
  6. }  
• You may notice the new Destroy method. This is useful to be able to create or destroy objects at will. Relatively, covers now know about the containing ModelVisual3D.
• I also add a static IThumbnailManager to put elsewhere all the code dealing with thumbnails (like managing an IsolatedStorageFile for example)
• Animation is slightly modified : in some cases, no rotation is needed to allow faster browsing.

Here are the changes since Part 5 :

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1. public interface IThumbnailManager  
2. {  
3.     ImageSource GetThumbnail(string host, string path);  
4. }  
5. internal class Cover : ModelVisual3D, ICover  
6. {  
7.     ...  
8.     private static IThumbnailManager thumbCache;  
9.     private readonly ModelVisual3D visualModel;  
10.     ...  
11.     private readonly string imageName;  
12.     ...  
13.     private static ImageSource LoadImageSource(ImageInfo info)  
14.     {  
15.         if (thumbCache == null)  
16.             throw new InvalidOperationException("No thumbnail cache.");  
17.         return thumbCache.GetThumbnail(info.Host, info.Path);  
18.     }  
19.     ...  
20.     public Cover(ImageInfo info, int coverPos, int currentPos, ModelVisual3D model)  
21.     {  
22.         pos = coverPos;  
23.         imageName = new FileInfo(info.Path).Name;  
24.         visualModel = model;  
25.   
26.         imageSource = LoadImageSource(info);  
27.         modelGroup = new Model3DGroup();  
28.         modelGroup.Children.Add(new GeometryModel3D(Tessellate(), LoadImage(imageSource)));  
29.         modelGroup.Children.Add(new GeometryModel3D(TessellateMirror(), LoadImageMirror(imageSource)));  
30.   
31.         rotation = new AxisAngleRotation3D(new Vector3D(0, 1, 0), RotationAngle(currentPos));  
32.         translation = new TranslateTransform3D(TranslationX(currentPos), 0, TranslationZ(currentPos));  
33.         var transformGroup = new Transform3DGroup();  
34.         transformGroup.Children.Add(new RotateTransform3D(rotation));  
35.         transformGroup.Children.Add(translation);  
36.         modelGroup.Transform = transformGroup;  
37.   
38.         Content = modelGroup;  
39.   
40.         visualModel.Children.Add(this);  
41.     }  
42.     public static IThumbnailManager Cache  
43.     {  
44.         set { thumbCache = value; }  
45.     }  
46.     public void Animate(int index, bool animate)  
47.     {  
48.         if (animate || rotation.HasAnimatedProperties)  
49.         {  
50.             var rotateAnimation = new DoubleAnimation(RotationAngle(index), AnimationDuration);  
51.             var xAnimation = new DoubleAnimation(TranslationX(index), AnimationDuration);  
52.             var zAnimation = new DoubleAnimation(TranslationZ(index), AnimationDuration);  
53.             rotation.BeginAnimation(AxisAngleRotation3D.AngleProperty, rotateAnimation);  
54.             translation.BeginAnimation(TranslateTransform3D.OffsetXProperty, xAnimation);  
55.             translation.BeginAnimation(TranslateTransform3D.OffsetZProperty, zAnimation);  
56.         }  
57.         else  
58.         {  
59.             rotation.Angle = RotationAngle(index);  
60.             translation.OffsetX = TranslationX(index);  
61.             translation.OffsetZ = TranslationZ(index);  
62.         }  
63.     }  
64.     public void Destroy()  
65.     {  
66.         visualModel.Children.Remove(this);  
67.     }  
68.     public override string ToString()  
69.     {  
70.         return string.Format("{0} {1}", pos, imageName);  
71.     }  
72. }  

I also add an ICoverFactory (mainly for testing purposes) :

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1. public interface ICoverFactory  
2. {  
3.     ICover NewCover(string host, string path, int coverPos, int currentPos);  
4. }  
5. internal class ImageInfo  
6. {  
7.     public ImageInfo(string host, string path)  
8.     {  
9.         Host = host;  
10.         Path = path;  
11.     }  
12.     public string Host { get; private set; }  
13.     public string Path { get; private set; }  
14. }  
15. internal class CoverFactory : ICoverFactory  
16. {  
17.     private readonly ModelVisual3D visualModel;  
18.     public CoverFactory(ModelVisual3D visualModel)  
19.     {  
20.         this.visualModel = visualModel;  
21.     }  
22.     #region ICoverFactory Members  
23.     public ICover NewCover(string host, string path, int coverPos, int currentPos)  
24.     {  
25.         return new Cover(new ImageInfo(host, path), coverPos, currentPos, visualModel);  
26.     }  
27.     #endregion  
28. }  

The FlowControl class is greatly refactored to implement virtualization.

转载自：http://d3dal3.blogspot.com/2009/04/wpf-cover-flow-tutorial-part-6-bis.html