OpenTween/OTPictureBox.cs

   1 // OpenTween - Client of Twitter
   2 // Copyright (c) 2013 kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
   3 // All rights reserved.
   4 //
   5 // This file is part of OpenTween.
   6 //
   7 // This program is free software; you can redistribute it and/or modify it
   8 // under the terms of the GNU General Public License as published by the Free
   9 // Software Foundation; either version 3 of the License, or (at your option)
  10 // any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 // or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  15 // for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this program. If not, see <http://www.gnu.org/licenses/>, or write to
  19 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  20 // Boston, MA 02110-1301, USA.
  21
  22 using System;
  23 using System.Collections.Generic;
  24 using System.Linq;
  25 using System.Text;
  26 using System.Windows.Forms;
  27 using System.ComponentModel;
  28 using System.Drawing;
  29 using System.Threading.Tasks;
  30 using System.Threading;
  31 using System.Net;
  32 using System.IO;
  33
  34 namespace OpenTween
  35 {
  36     public class OTPictureBox : PictureBox
  37     {
  38         [Localizable(true)]
  39         public new Image Image
  40         {
  41             get { return base.Image; }
  42             set
  43             {
  44                 base.Image = value;
  45                 this.SizeMode = this._SizeMode;
  46                 if (this.memoryImage != null)
  47                 {
  48                     this.memoryImage.Dispose();
  49                     this.memoryImage = null;
  50                 }
  51             }
  52         }
  53
  54         [Localizable(true)]
  55         public new string ImageLocation
  56         {
  57             get { return this._ImageLocation; }
  58             set
  59             {
  60                 if (value == null)
  61                 {
  62                     this.Image = null;
  63                     return;
  64                 }
  65                 this.LoadAsync(value);
  66             }
  67         }
  68         private string _ImageLocation;
  69
  70         /// <summary>
  71         /// 画像に応じた SizeMode を取得・設定する
  72         /// </summary>
  73         /// <remarks>
  74         /// ErrorImage と InitialImage は SizeMode の値に依らず中央等倍に表示する必要があるため、
  75         /// 画像に応じて SizeMode の状態を弄る
  76         /// </remarks>
  77         public new PictureBoxSizeMode SizeMode
  78         {
  79             get { return this._SizeMode; }
  80             set
  81             {
  82                 this._SizeMode = value;
  83                 if (base.Image == null || (base.Image != base.ErrorImage && base.Image != base.InitialImage))
  84                 {
  85                     base.SizeMode = value;
  86                 }
  87                 else
  88                 {
  89                     base.SizeMode = PictureBoxSizeMode.CenterImage;
  90                 }
  91             }
  92         }
  93         private PictureBoxSizeMode _SizeMode;
  94
  95         /// <summary>
  96         /// ImageLocation によりロードされた画像
  97         /// </summary>
  98         private MemoryImage memoryImage = null;
  99
 100         private Task loadAsyncTask = null;
 101         private CancellationTokenSource loadAsyncCancelTokenSource = null;
 102
 103         public new Task LoadAsync(string url)
 104         {
 105             this._ImageLocation = url;
 106
 107             if (this.loadAsyncTask != null && !this.loadAsyncTask.IsCompleted)
 108                 this.CancelAsync();
 109
 110             this.Image = base.InitialImage;
 111
 112             Uri uri;
 113             try
 114             {
 115                 uri = new Uri(url);
 116             }
 117             catch (UriFormatException)
 118             {
 119                 uri = new Uri(Path.GetFullPath(url));
 120             }
 121
 122             var client = new OTWebClient();
 123
 124             client.DownloadProgressChanged += (s, e) =>
 125             {
 126                 this.OnLoadProgressChanged(new ProgressChangedEventArgs(e.ProgressPercentage, e.UserState));
 127             };
 128
 129             this.loadAsyncCancelTokenSource = new CancellationTokenSource();
 130             var cancelToken = this.loadAsyncCancelTokenSource.Token;
 131             var loadImageTask = client.DownloadDataAsync(uri, cancelToken);
 132
 133             // UnobservedTaskException イベントを発生させないようにする
 134             loadImageTask.ContinueWith(t => { var ignore = t.Exception; }, TaskContinuationOptions.OnlyOnFaulted);
 135
 136             var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
 137
 138             return loadImageTask.ContinueWith(t => {
 139                 client.Dispose();
 140
 141                 if (t.IsFaulted) throw t.Exception;
 142
 143                 return MemoryImage.CopyFromBytes(t.Result);
 144             }, cancelToken)
 145             .ContinueWith(t =>
 146             {
 147                 if (!t.IsCanceled)
 148                 {
 149                     if (t.IsFaulted)
 150                     {
 151                         this.Image = base.ErrorImage;
 152                     }
 153                     else
 154                     {
 155                         this.Image = t.Result.Image;
 156                         this.memoryImage = t.Result;
 157                     }
 158                 }
 159
 160                 var exp = t.Exception != null ? t.Exception.Flatten() : null;
 161                 this.OnLoadCompleted(new AsyncCompletedEventArgs(exp, t.IsCanceled, null));
 162             }, uiScheduler);
 163         }
 164
 165         public new void CancelAsync()
 166         {
 167             if (this.loadAsyncTask == null || this.loadAsyncTask.IsCompleted)
 168                 return;
 169
 170             this.loadAsyncCancelTokenSource.Cancel();
 171
 172             try
 173             {
 174                 this.loadAsyncTask.Wait();
 175             }
 176             catch (AggregateException ae)
 177             {
 178                 ae.Handle(e =>
 179                 {
 180                     if (e is OperationCanceledException)
 181                         return true;
 182                     if (e is WebException)
 183                         return true;
 184
 185                     return false;
 186                 });
 187             }
 188         }
 189
 190         protected override void Dispose(bool disposing)
 191         {
 192             base.Dispose(disposing);
 193
 194             if (this.memoryImage != null)
 195                 this.memoryImage.Dispose();
 196
 197             if (this.loadAsyncCancelTokenSource != null)
 198                 this.loadAsyncCancelTokenSource.Dispose();
 199         }
 200     }
 201 }