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 string ThumbnailFile;
  31                         public Beagle.Hit Hit;
  32                         public int Size;
  33                         public bool Succeeded;
  34
  35                         public ThumbnailRequest (Gtk.Image image, string thumbnail_file, Beagle.Hit hit, int size)
  36                         {
  37                                 Image = image;
  38                                 ThumbnailFile = thumbnail_file;
  39                                 Hit = hit;
  40                                 Size = size;
  41                         }
  42
  43                         public static ThumbnailRequest Select (IEnumerable thumbnails)
  44                         {
  45                                 ThumbnailRequest first = null;
  46                                 Gtk.Widget w;
  47
  48                                 foreach (ThumbnailRequest req in thumbnails) {
  49
  50                                         // FIXME: we ought to be able to just look at
  51                                         // req.Image.IsMapped. But for some reason, the
  52                                         // images are still showing up as mapped even
  53                                         // when their parents aren't, which seems
  54                                         // impossible to me from looking at the code,
  55                                         // but...
  56                                         for (w = req.Image; w != null; w = w.Parent) {
  57                                                 if (!w.IsMapped)
  58                                                         break;
  59                                         }
  60                                         if (w == null)
  61                                                 return req;
  62
  63                                         if (first == null)
  64                                                 first = req;
  65                                 }
  66                                 return first;
  67                         }
  68                 }
  69
  70                 public bool SetThumbnailIcon (Gtk.Image image, Beagle.Hit hit, int size)
  71                 {
  72                         DateTime mtime = (hit.FileInfo != null) ? hit.FileInfo.LastWriteTime : DateTime.Now;
  73
  74                         if (hit.MimeType == null ||
  75                             !factory.CanThumbnail (hit.EscapedUri, hit.MimeType, mtime))
  76                                 return false;
  77
  78                         string thumbnail = Gnome.Thumbnail.PathForUri (hit.EscapedUri, Gnome.ThumbnailSize.Normal);
  79                         bool failed_thumb = factory.HasValidFailedThumbnail (hit.EscapedUri, mtime);
  80
  81                         if (! File.Exists (thumbnail) && ! failed_thumb) {
  82                                 lock (in_queue) {
  83                                         in_queue.Add (new ThumbnailRequest (image, thumbnail, hit, size));
  84                                         if (thread == null) {
  85                                                 thread = new Thread (GenerateThumbnails);
  86                                                 thread.Start ();
  87                                         }
  88                                 }
  89                                 return false;
  90                         }
  91
  92                         if (failed_thumb)
  93                                 return false;
  94
  95                         Gdk.Pixbuf icon = new Gdk.Pixbuf (thumbnail);
  96                         if (icon == null)
  97                                 return false;
  98
  99                         int width = icon.Width, height = icon.Height;
 100                         if (icon.Height > size) {
 101                                 if (icon.Width > icon.Height) {
 102                                         width = size;
 103                                         height = (size * icon.Height) / icon.Width;
 104                                 } else {
 105                                         height = size;
 106                                         width = (size * icon.Width) / icon.Height;
 107                                 }
 108                         } else if (icon.Width > size) {
 109                                 width = size;
 110                                 height = (size * icon.Height) / icon.Width;
 111                         }
 112                         icon = icon.ScaleSimple (width, height, Gdk.InterpType.Bilinear);
 113
 114                         image.Pixbuf = icon;
 115                         return true;
 116                 }
 117
 118                 private void GenerateThumbnails ()
 119                 {
 120                         ThumbnailRequest req;
 121
 122                         while (true) {
 123                                 lock (in_queue) {
 124                                         if (in_queue.Count == 0) {
 125                                                 thread = null;
 126                                                 return;
 127                                         }
 128
 129                                         req = ThumbnailRequest.Select (in_queue);
 130                                         in_queue.Remove (req);
 131                                 }
 132
 133                                 Gdk.Pixbuf icon = factory.GenerateThumbnail (req.Hit.EscapedUri, req.Hit.MimeType);
 134
 135                                 if (icon == null) {
 136                                         if (req.Hit.FileInfo != null)
 137                                                 factory.CreateFailedThumbnail (req.Hit.EscapedUri, req.Hit.FileInfo.LastWriteTime);
 138                                 } else {
 139                                         factory.SaveThumbnail (icon, req.Hit.EscapedUri, DateTime.Now);
 140
 141                                         if (File.Exists (req.ThumbnailFile))
 142                                                 req.Succeeded = true;
 143                                 }
 144
 145                                 lock (out_queue)
 146                                         out_queue.Add (req);
 147                                 GLib.Idle.Add (FinishSetThumbnail);
 148                         }
 149                 }
 150
 151                 private bool FinishSetThumbnail ()
 152                 {
 153                         ThumbnailRequest req;
 154                         lock (out_queue) {
 155                                 req = (ThumbnailRequest)out_queue[0];
 156                                 out_queue.RemoveAt (0);
 157                         }
 158
 159                         if (req.Succeeded)
 160                                 SetThumbnailIcon (req.Image, req.Hit, req.Size);
 161
 162                         return false;
 163                 }
 164         }
 165 }