search/Tiles/TileActivator.cs

   1 using System;
   2 using System.Collections;
   3 using System.Reflection;
   4 using Mono.Posix;
   5
   6 using Beagle.Util;
   7
   8 namespace Search.Tiles {
   9
  10         // FIXME: Should we call this something else?
  11         public abstract class TileActivator : IComparable {
  12
  13                 private ArrayList flavors;
  14
  15                 protected TileActivator ()
  16                 {
  17                         this.flavors = new ArrayList ();
  18                 }
  19
  20                 public abstract Tile BuildTile (Beagle.Hit hit, Beagle.Query query);
  21
  22                 public int Weight = 0;
  23
  24                 protected void AddSupportedFlavor (HitFlavor flavor)
  25                 {
  26                         flavors.Add (flavor);
  27                 }
  28
  29                 public virtual bool Validate (Beagle.Hit hit)
  30                 {
  31                         if (flavors.Count < 1)
  32                                 return false;
  33
  34                         Weight = 0;
  35
  36                         HitFlavor best = null;
  37
  38                         foreach (HitFlavor flavor in flavors) {
  39                                 if (! flavor.IsMatch (hit))
  40                                         continue;
  41
  42                                 if (best == null) {
  43                                         best = flavor;
  44                                         continue;
  45                                 }
  46
  47                                 if (flavor.Weight > best.Weight) {
  48                                         best = flavor;
  49                                 }
  50                         }
  51
  52                         if (best != null) {
  53                                 Weight += best.Weight;
  54                                 return true;
  55                         }
  56
  57                         return false;
  58                 }
  59
  60                 public int CompareTo (object o)
  61                 {
  62                         TileActivator other = (TileActivator)o;
  63
  64                         if (other == null)
  65                                 return 1;
  66
  67                         return (this.Weight - other.Weight);
  68                 }
  69         }
  70
  71         // FIXME: Rename this and move out of this file
  72         public static class TileActivatorOrg {
  73
  74                 private static ArrayList activators;
  75
  76                 static TileActivatorOrg ()
  77                 {
  78                         activators = new ArrayList ();
  79
  80                         foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies ()) {
  81
  82                                 foreach (Type type in ReflectionFu.GetTypesFromAssemblyAttribute (assembly, typeof (TileActivatorTypesAttribute))) {
  83                                         try {
  84                                                 activators.Add ((TileActivator) Activator.CreateInstance (type));
  85                                         } catch (Exception e) {
  86                                                 Console.WriteLine ("Caught exception while instantiating tile");
  87                                                 Console.WriteLine (e);
  88                                         }
  89                                 }
  90                         }
  91                 }
  92
  93                 public static Tile MakeTile (Beagle.Hit hit, Beagle.Query query)
  94                 {
  95                         TileActivator best = null;
  96
  97                         try {
  98                                 foreach (TileActivator activator in activators) {
  99                                         if (! activator.Validate (hit))
 100                                                 continue;
 101
 102                                         if (best == null) {
 103                                                 best = activator;
 104                                                 continue;
 105                                         }
 106
 107                                         if (activator.Weight > best.Weight)
 108                                                 best = activator;
 109                                 }
 110
 111                                 if (best != null)
 112                                         return best.BuildTile (hit, query);
 113                         } catch (Exception e) {
 114                                 Console.WriteLine ("Error instantiating tile:\n{0}", e);
 115                         }
 116
 117                         return null;
 118                 }
 119         }
 120
 121         [AttributeUsage (AttributeTargets.Assembly)]
 122         public class TileActivatorTypesAttribute : TypeCacheAttribute {
 123                 public TileActivatorTypesAttribute (params Type[] types) : base (types) { }
 124         }
 125 }