search/Tiles/ThumbnailFactory.cs

   1 using System;
   2 using System.Collections;
   3 using System.IO;
   4 using System.Threading;
   5
   6 namespace Search.Tiles {
   7
   8         public class ThumbnailFactory : Gtk.Object {
   9
  10                 private Gnome.ThumbnailFactory factory = new Gnome.ThumbnailFactory (Gnome.ThumbnailSize.Normal);
  11                 private Thread thread;
  12                 private ArrayList in_queue = new ArrayList ();
  13                 private ArrayList out_queue = new ArrayList ();
  14
  15                 public ThumbnailFactory ()
  16                 {
  17                         Gtk.Quit.AddDestroy (1, this);
  18                 }
  19
  20                 protected override void OnDestroyed ()
  21                 {
  22                         // Force the thumbnailing thread to exit cleanly once it
  23                         // finishes the current thumbnail
  24                         lock (in_queue)
  25                                 in_queue.Clear ();
  26                 }
  27
  28                 private class ThumbnailRequest {
  29                         public Gtk.Image Image;
  30                         public Beagle.Hit Hit;
  31                         public int Size;
  32                         public bool Succeeded;
  33
  34                         public ThumbnailRequest (Gtk.Image image, Beagle.Hit hit, int size)
  35                         {
  36                                 Image = image;
  37                                 Hit = hit;
  38                                 Size = size;
  39                         }
  40
  41                         public static ThumbnailRequest Select (IEnumerable thumbnails)
  42                         {
  43                                 ThumbnailRequest first = null;
  44                                 Gtk.Widget w;
  45
  46                                 foreach (ThumbnailRequest req in thumbnails) {
  47
  48                                         // FIXME: we ought to be able to just look at
  49                                         // req.Image.IsMapped. But for some reason, the
  50                                         // images are still showing up as mapped even
  51                                         // when their parents aren't, which seems
  52                                         // impossible to me from looking at the code,
  53                                         // but...
  54                                         for (w = req.Image; w != null; w = w.Parent) {
  55                                                 if (!w.IsMapped)
  56                                                         break;
  57                                         }
  58                                         if (w == null)
  59                                                 return req;
  60
  61                                         if (first == null)
  62                                                 first = req;
  63                                 }
  64                                 return first;
  65                         }
  66                 }
  67
  68                 public bool SetThumbnailIcon (Gtk.Image image, Beagle.Hit hit, int size)
  69                 {
  70                         DateTime mtime = (hit.FileInfo != null) ? hit.FileInfo.LastWriteTime : DateTime.Now;
  71
  72                         if (hit.MimeType == null ||
  73                             !factory.CanThumbnail (hit.UriAsString, hit.MimeType, mtime))
  74                                 return false;
  75
  76                         string thumbnail = Gnome.Thumbnail.PathForUri (hit.UriAsString, Gnome.ThumbnailSize.Normal);
  77                         bool failed_thumb = factory.HasValidFailedThumbnail (hit.UriAsString, mtime);
  78
  79                         if (! File.Exists (thumbnail) && ! failed_thumb) {
  80                                 lock (in_queue) {
  81                                         in_queue.Add (new ThumbnailRequest (image, hit, size));
  82                                         if (thread == null) {
  83                                                 thread = new Thread (GenerateThumbnails);
  84                                                 thread.Start ();
  85                                         }
  86                                 }
  87                                 return false;
  88                         }
  89
  90                         if (failed_thumb)
  91                                 return false;
  92
  93                         Gdk.Pixbuf icon = new Gdk.Pixbuf (thumbnail);
  94                         if (icon == null)
  95                                 return false;
  96
  97                         int width = icon.Width, height = icon.Height;
  98                         if (icon.Height > size) {
  99                                 if (icon.Width > icon.Height) {
 100                                         width = size;
 101                                         height = (size * icon.Height) / icon.Width;
 102                                 } else {
 103                                         height = size;
 104                                         width = (size * icon.Width) / icon.Height;
 105                                 }
 106                         } else if (icon.Width > size) {
 107                                 width = size;
 108                                 height = (size * icon.Height) / icon.Width;
 109                         }
 110                         icon = icon.ScaleSimple (width, height, Gdk.InterpType.Bilinear);
 111
 112                         image.Pixbuf = icon;
 113                         return true;
 114                 }
 115
 116                 private void GenerateThumbnails ()
 117                 {
 118                         ThumbnailRequest req;
 119
 120                         while (true) {
 121                                 lock (in_queue) {
 122                                         if (in_queue.Count == 0) {
 123                                                 thread = null;
 124                                                 return;
 125                                         }
 126
 127                                         req = ThumbnailRequest.Select (in_queue);
 128                                         in_queue.Remove (req);
 129                                 }
 130
 131                                 Gdk.Pixbuf icon = factory.GenerateThumbnail (req.Hit.UriAsString, req.Hit.MimeType);
 132
 133                                 if (icon == null) {
 134                                         if (req.Hit.FileInfo != null)
 135                                                 factory.CreateFailedThumbnail (req.Hit.UriAsString, req.Hit.FileInfo.LastWriteTime);
 136                                 } else {
 137                                         factory.SaveThumbnail (icon, req.Hit.UriAsString, DateTime.Now);
 138                                         req.Succeeded = true;
 139                                 }
 140
 141                                 lock (out_queue)
 142                                         out_queue.Add (req);
 143                                 GLib.Idle.Add (FinishSetThumbnail);
 144                         }
 145                 }
 146
 147                 private bool FinishSetThumbnail ()
 148                 {
 149                         ThumbnailRequest req;
 150                         lock (out_queue) {
 151                                 req = (ThumbnailRequest)out_queue[0];
 152                                 out_queue.RemoveAt (0);
 153                         }
 154
 155                         if (req.Succeeded)
 156                                 SetThumbnailIcon (req.Image, req.Hit, req.Size);
 157
 158                         return false;
 159                 }
 160         }
 161 }