OpenTween/TweetThumbnail.cs

   1 // OpenTween - Client of Twitter
   2 // Copyright (c) 2023 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 #nullable enable
  23
  24 using System;
  25 using System.Collections.Generic;
  26 using System.Linq;
  27 using System.Text;
  28 using System.Threading;
  29 using System.Threading.Tasks;
  30 using OpenTween.Models;
  31 using OpenTween.Thumbnail;
  32
  33 namespace OpenTween
  34 {
  35     public class TweetThumbnail : NotifyPropertyChangedBase
  36     {
  37         private ThumbnailGenerator? thumbGenerator;
  38         private bool thumbnailAvailable;
  39         private PostId? currentPostId;
  40         private ThumbnailInfo[] thumbnails = Array.Empty<ThumbnailInfo>();
  41         private Task<MemoryImage>?[] loadImageTasks = Array.Empty<Task<MemoryImage>?>();
  42         private int selectedIndex = 0;
  43
  44         public bool ThumbnailAvailable
  45         {
  46             get => this.thumbnailAvailable;
  47             set => this.SetProperty(ref this.thumbnailAvailable, value);
  48         }
  49
  50         public int SelectedIndex
  51         {
  52             get => this.selectedIndex;
  53             set
  54             {
  55                 if (this.ThumbnailAvailable)
  56                 {
  57                     if (value < 0 || value >= this.Thumbnails.Length)
  58                         throw new ArgumentOutOfRangeException(nameof(value));
  59                 }
  60                 else
  61                 {
  62                     if (value != 0)
  63                         throw new ArgumentOutOfRangeException(nameof(value));
  64                 }
  65                 this.SetProperty(ref this.selectedIndex, value);
  66             }
  67         }
  68
  69         public ThumbnailInfo[] Thumbnails
  70             => this.ThumbnailAvailable ? this.thumbnails : throw new InvalidOperationException("Thumbnail is not available.");
  71
  72         public ThumbnailInfo CurrentThumbnail
  73             => this.Thumbnails[this.selectedIndex];
  74
  75         private ThumbnailGenerator ThumbGenerator
  76             => this.thumbGenerator ?? throw this.NotInitializedException();
  77
  78         public void Initialize(ThumbnailGenerator thumbnailGenerator)
  79             => this.thumbGenerator = thumbnailGenerator;
  80
  81         public async Task PrepareThumbnails(PostClass post, CancellationToken token)
  82         {
  83             if (this.currentPostId == post.StatusId)
  84                 return;
  85
  86             this.currentPostId = post.StatusId;
  87             this.ThumbnailAvailable = false;
  88
  89             var thumbnails = (await this.GetThumbailInfoAsync(post, token)).ToArray();
  90
  91             if (this.currentPostId != post.StatusId)
  92                 return;
  93
  94             this.DisposeImages();
  95             this.SelectedIndex = 0;
  96             this.thumbnails = thumbnails;
  97             this.loadImageTasks = new Task<MemoryImage>?[thumbnails.Length];
  98
  99             if (thumbnails.Length > 0)
 100                 this.ThumbnailAvailable = true;
 101         }
 102
 103         public Task<MemoryImage> LoadSelectedThumbnail()
 104         {
 105             var runningTask = this.loadImageTasks[this.selectedIndex];
 106             if (runningTask != null)
 107                 return runningTask;
 108
 109             var newTask = Task.Run(() => this.thumbnails[this.selectedIndex].LoadThumbnailImageAsync());
 110             this.loadImageTasks[this.selectedIndex] = newTask;
 111
 112             return newTask;
 113         }
 114
 115         public string GetUrlForImageSearch()
 116             => this.CurrentThumbnail.FullSizeImageUrl ?? this.CurrentThumbnail.ThumbnailImageUrl;
 117
 118         public Uri GetImageSearchUriGoogle()
 119         {
 120             var imageUrl = this.GetUrlForImageSearch();
 121             return new(@"https://lens.google.com/uploadbyurl?url=" + Uri.EscapeDataString(imageUrl));
 122         }
 123
 124         public Uri GetImageSearchUriSauceNao()
 125         {
 126             var imageUrl = this.GetUrlForImageSearch();
 127             return new(@"https://saucenao.com/search.php?url=" + Uri.EscapeDataString(imageUrl));
 128         }
 129
 130         public void ScrollUp()
 131         {
 132             if (!this.ThumbnailAvailable)
 133                 return;
 134             if (this.SelectedIndex == 0)
 135                 return;
 136
 137             this.SelectedIndex--;
 138         }
 139
 140         public void ScrollDown()
 141         {
 142             if (!this.ThumbnailAvailable)
 143                 return;
 144             if (this.SelectedIndex == this.Thumbnails.Length - 1)
 145                 return;
 146
 147             this.SelectedIndex++;
 148         }
 149
 150         private Exception NotInitializedException()
 151             => new InvalidOperationException("Cannot call before initialization");
 152
 153         private async Task<IEnumerable<ThumbnailInfo>> GetThumbailInfoAsync(PostClass post, CancellationToken token)
 154             => await Task.Run(() => this.ThumbGenerator.GetThumbnailsAsync(post, token));
 155
 156         private void DisposeImages()
 157         {
 158             var oldImageTasks = this.loadImageTasks.OfType<Task<MemoryImage>>().ToArray();
 159
 160             static async Task DisposeTaskResults(Task<MemoryImage>[] tasks)
 161             {
 162                 try
 163                 {
 164                     await Task.WhenAll(tasks).ConfigureAwait(false);
 165                 }
 166                 catch
 167                 {
 168                 }
 169
 170                 foreach (var task in tasks)
 171                 {
 172                     if (task.IsFaulted || task.IsCanceled)
 173                         continue;
 174
 175                     task.Result.Dispose();
 176                 }
 177             }
 178
 179             _ = DisposeTaskResults(oldImageTasks);
 180         }
 181     }
 182 }