search/Spinner.cs

   1 using System;
   2 using Gtk;
   3 using Gdk;
   4
   5 namespace Search {
   6
   7         public class Spinner : Gtk.Image {
   8
   9                 private Pixbuf idlePixbuf;
  10                 private Pixbuf [] frames;
  11                 private int currentFrame;
  12                 private uint timeoutId;
  13
  14                 private const int targetSize = 24;
  15                 private const int refreshRate = 125;
  16
  17                 ~Spinner ()
  18                 {
  19                         Stop ();
  20                 }
  21
  22                 Gtk.IconTheme theme;
  23
  24                 protected override void OnRealized ()
  25                 {
  26                         base.OnRealized ();
  27
  28                         theme = Gtk.IconTheme.GetForScreen (Screen);
  29                         theme.Changed += ThemeChanged;
  30                         LoadImages ();
  31                 }
  32
  33                 private void ThemeChanged (object obj, EventArgs args)
  34                 {
  35                         LoadImages ();
  36                 }
  37
  38                 private void LoadImages ()
  39                 {
  40                         int iconSize = targetSize;
  41
  42 #if false
  43                         // This code requires gtk-sharp 2.6, which we don't (yet) require
  44                         foreach (int size in theme.GetIconSizes ("gnome-spinner-rest")) {
  45                                 if (size >= targetSize) {
  46                                         iconSize = size;
  47                                         break;
  48                                 }
  49                         }
  50 #endif
  51
  52                         try {
  53                                 idlePixbuf = theme.LoadIcon ("gnome-spinner-rest", iconSize, 0);
  54                         } catch {
  55                                 Console.Error.WriteLine ("Could not load spinner image");
  56                                 frames = null;
  57                                 Pixbuf = null;
  58                                 return;
  59                         }
  60
  61                         Gdk.Pixbuf framesPixbuf;
  62                         try {
  63                                 framesPixbuf = theme.LoadIcon ("gnome-spinner", iconSize, 0);
  64                         } catch {
  65                                 Console.Error.WriteLine ("Could not load spinner image");
  66                                 frames = null;
  67                                 Pixbuf = idlePixbuf;
  68                                 return;
  69                         }
  70
  71                         int frameWidth = idlePixbuf.Width, frameHeight = idlePixbuf.Height;
  72                         int width = framesPixbuf.Width, height = framesPixbuf.Height;
  73                         if (width % frameWidth != 0 || height % frameHeight != 0) {
  74                                 Console.Error.WriteLine ("Spinner image is wrong size");
  75                                 frames = null;
  76                                 Pixbuf = idlePixbuf;
  77                                 return;
  78                         }
  79
  80                         int rows = height / frameHeight, cols = width / frameWidth;
  81
  82                         frames = new Pixbuf[rows * cols];
  83
  84                         for (int y = 0, n = 0; y < rows; y++) {
  85                                 for (int x = 0; x < cols; x++, n++) {
  86                                         frames[n] = new Pixbuf (framesPixbuf,
  87                                                                 x * frameWidth,
  88                                                                 y * frameHeight,
  89                                                                 frameWidth,
  90                                                                 frameHeight);
  91                                 }
  92                         }
  93
  94                         currentFrame = 0;
  95                         if (timeoutId != 0)
  96                                 Pixbuf = frames[currentFrame];
  97                         else
  98                                 Pixbuf = idlePixbuf;
  99                 }
 100
 101                 public void Start ()
 102                 {
 103                         if (!IsRealized)
 104                                 return;
 105                         if (frames == null || frames.Length == 0)
 106                                 return;
 107                         if (timeoutId != 0)
 108                                 return;
 109
 110                         timeoutId = GLib.Timeout.Add (refreshRate, TimeoutHandler);
 111                 }
 112
 113                 public void Stop ()
 114                 {
 115                         if (timeoutId == 0)
 116                                 return;
 117
 118                         GLib.Source.Remove (timeoutId);
 119                         timeoutId = 0;
 120                         Pixbuf = idlePixbuf;
 121                 }
 122
 123                 private bool TimeoutHandler ()
 124                 {
 125                         Pixbuf = frames[currentFrame];
 126                         currentFrame = (currentFrame + 1) % frames.Length;
 127                         return true;
 128                 }
 129         }
 130 }