OpenTween/TimelineListViewState.cs

   1 // OpenTween - Client of Twitter
   2 // Copyright (c) 2007-2011 kiri_feather (@kiri_feather) <kiri.feather@gmail.com>
   3 //           (c) 2008-2011 Moz (@syo68k)
   4 //           (c) 2008-2011 takeshik (@takeshik) <http://www.takeshik.org/>
   5 //           (c) 2010-2011 anis774 (@anis774) <http://d.hatena.ne.jp/anis774/>
   6 //           (c) 2010-2011 fantasticswallow (@f_swallow) <http://twitter.com/f_swallow>
   7 //           (c) 2011      kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
   8 // All rights reserved.
   9 //
  10 // This file is part of OpenTween.
  11 //
  12 // This program is free software; you can redistribute it and/or modify it
  13 // under the terms of the GNU General public License as published by the Free
  14 // Software Foundation; either version 3 of the License, or (at your option)
  15 // any later version.
  16 //
  17 // This program is distributed in the hope that it will be useful, but
  18 // WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19 // or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General public License
  20 // for more details.
  21 //
  22 // You should have received a copy of the GNU General public License along
  23 // with this program. If not, see <http://www.gnu.org/licenses/>, or write to
  24 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  25 // Boston, MA 02110-1301, USA.
  26
  27 #nullable enable
  28
  29 using System;
  30 using System.Collections.Generic;
  31 using System.Drawing;
  32 using System.Linq;
  33 using System.Windows.Forms;
  34 using OpenTween.Models;
  35 using OpenTween.OpenTweenCustomControl;
  36
  37 namespace OpenTween
  38 {
  39     public class TimelineListViewState
  40     {
  41         private readonly DetailsListView listView;
  42         private readonly TabModel tab;
  43
  44         private ListViewScroll savedScrollState;
  45         private ListViewSelection savedSelectionState;
  46
  47         internal readonly record struct ListViewScroll(
  48             ScrollLockMode ScrollLockMode,
  49             long? TopItemStatusId
  50         );
  51
  52         internal enum ScrollLockMode
  53         {
  54             /// <summary>固定しない</summary>
  55             None,
  56
  57             /// <summary>最上部に固定する</summary>
  58             FixedToTop,
  59
  60             /// <summary>最下部に固定する</summary>
  61             FixedToBottom,
  62
  63             /// <summary><see cref="ListViewScroll.TopItemStatusId"/> の位置に固定する</summary>
  64             FixedToItem,
  65         }
  66
  67         internal readonly record struct ListViewSelection(
  68             long[] SelectedStatusIds,
  69             long? SelectionMarkStatusId,
  70             long? FocusedStatusId
  71         );
  72
  73         public TimelineListViewState(DetailsListView listView, TabModel tab)
  74         {
  75             this.listView = listView;
  76             this.tab = tab;
  77         }
  78
  79         public void Save(bool lockScroll)
  80         {
  81             this.savedScrollState = this.SaveListViewScroll(lockScroll);
  82             this.savedSelectionState = this.SaveListViewSelection();
  83         }
  84
  85         public void Restore()
  86         {
  87             this.RestoreScroll();
  88             this.RestoreSelection();
  89         }
  90
  91         public void RestoreScroll()
  92             => this.RestoreListViewScroll(this.savedScrollState);
  93
  94         public void RestoreSelection()
  95             => this.RestoreListViewSelection(this.savedSelectionState);
  96
  97         /// <summary>
  98         /// <see cref="ListView"/> のスクロール位置に関する情報を <see cref="ListViewScroll"/> として返します
  99         /// </summary>
 100         private ListViewScroll SaveListViewScroll(bool lockScroll)
 101         {
 102             var lockMode = this.GetScrollLockMode(lockScroll);
 103             long? topItemStatusId = null;
 104
 105             if (lockMode == ScrollLockMode.FixedToItem)
 106             {
 107                 var topItemIndex = this.listView.TopItem?.Index ?? -1;
 108                 if (topItemIndex != -1 && topItemIndex < this.tab.AllCount)
 109                     topItemStatusId = this.tab.GetStatusIdAt(topItemIndex);
 110             }
 111
 112             return new ListViewScroll
 113             {
 114                 ScrollLockMode = lockMode,
 115                 TopItemStatusId = topItemStatusId,
 116             };
 117         }
 118
 119         private ScrollLockMode GetScrollLockMode(bool lockScroll)
 120         {
 121             if (this.tab.SortMode == ComparerMode.Id)
 122             {
 123                 if (this.tab.SortOrder == SortOrder.Ascending)
 124                 {
 125                     // Id昇順
 126                     if (lockScroll)
 127                         return ScrollLockMode.None;
 128
 129                     // 最下行が表示されていたら、最下行へ強制スクロール。最下行が表示されていなかったら制御しない
 130
 131                     // 一番下に表示されているアイテム
 132                     var bottomItem = this.listView.GetItemAt(0, this.listView.ClientSize.Height - 1);
 133                     if (bottomItem == null || bottomItem.Index == this.listView.VirtualListSize - 1)
 134                         return ScrollLockMode.FixedToBottom;
 135                     else
 136                         return ScrollLockMode.None;
 137                 }
 138                 else
 139                 {
 140                     // Id降順
 141                     if (lockScroll)
 142                         return ScrollLockMode.FixedToItem;
 143
 144                     // 最上行が表示されていたら、制御しない。最上行が表示されていなかったら、現在表示位置へ強制スクロール
 145                     var topItem = this.listView.TopItem;
 146                     if (topItem == null || topItem.Index == 0)
 147                         return ScrollLockMode.FixedToTop;
 148                     else
 149                         return ScrollLockMode.FixedToItem;
 150                 }
 151             }
 152             else
 153             {
 154                 return ScrollLockMode.FixedToItem;
 155             }
 156         }
 157
 158         /// <summary>
 159         /// <see cref="ListView"/> の選択状態を <see cref="ListViewSelection"/> として返します
 160         /// </summary>
 161         private ListViewSelection SaveListViewSelection()
 162         {
 163             if (this.listView.VirtualListSize == 0)
 164             {
 165                 return new ListViewSelection
 166                 {
 167                     SelectedStatusIds = Array.Empty<long>(),
 168                     SelectionMarkStatusId = null,
 169                     FocusedStatusId = null,
 170                 };
 171             }
 172
 173             return new ListViewSelection
 174             {
 175                 SelectedStatusIds = this.tab.SelectedStatusIds,
 176                 FocusedStatusId = this.GetFocusedStatusId(),
 177                 SelectionMarkStatusId = this.GetSelectionMarkStatusId(),
 178             };
 179         }
 180
 181         private long? GetFocusedStatusId()
 182         {
 183             var index = this.listView.FocusedItem?.Index ?? -1;
 184
 185             return index != -1 && index < this.tab.AllCount ? this.tab.GetStatusIdAt(index) : (long?)null;
 186         }
 187
 188         private long? GetSelectionMarkStatusId()
 189         {
 190             var index = this.listView.SelectionMark;
 191
 192             return index != -1 && index < this.tab.AllCount ? this.tab.GetStatusIdAt(index) : (long?)null;
 193         }
 194
 195         /// <summary>
 196         /// <see cref="SaveListViewScroll"/> によって保存されたスクロール位置を復元します
 197         /// </summary>
 198         private void RestoreListViewScroll(ListViewScroll listScroll)
 199         {
 200             if (this.listView.VirtualListSize == 0)
 201                 return;
 202
 203             switch (listScroll.ScrollLockMode)
 204             {
 205                 case ScrollLockMode.FixedToTop:
 206                     this.listView.EnsureVisible(0);
 207                     break;
 208                 case ScrollLockMode.FixedToBottom:
 209                     this.listView.EnsureVisible(this.listView.VirtualListSize - 1);
 210                     break;
 211                 case ScrollLockMode.FixedToItem:
 212                     var topIndex = listScroll.TopItemStatusId != null ? this.tab.IndexOf(listScroll.TopItemStatusId.Value) : -1;
 213                     if (topIndex != -1)
 214                     {
 215                         var topItem = this.listView.Items[topIndex];
 216                         try
 217                         {
 218                             this.listView.TopItem = topItem;
 219                         }
 220                         catch (NullReferenceException)
 221                         {
 222                             this.listView.EnsureVisible(this.listView.VirtualListSize - 1);
 223                             this.listView.EnsureVisible(topIndex);
 224                         }
 225                     }
 226                     break;
 227                 case ScrollLockMode.None:
 228                 default:
 229                     break;
 230             }
 231         }
 232
 233         /// <summary>
 234         /// <see cref="SaveListViewSelection"/> によって保存された選択状態を復元します
 235         /// </summary>
 236         private void RestoreListViewSelection(ListViewSelection listSelection)
 237         {
 238             var invalidateBounds = (Rectangle?)null;
 239
 240             var previousFocusedItem = this.listView.FocusedItem;
 241             if (previousFocusedItem != null)
 242                 invalidateBounds = previousFocusedItem.Bounds;
 243
 244             // status_id から ListView 上のインデックスに変換
 245             if (listSelection.SelectedStatusIds != null)
 246             {
 247                 var selectedIndices = this.tab.IndexOf(listSelection.SelectedStatusIds).Where(x => x != -1).ToArray();
 248                 this.listView.SelectItems(selectedIndices);
 249             }
 250
 251             if (listSelection.FocusedStatusId != null)
 252             {
 253                 var focusedIndex = this.tab.IndexOf(listSelection.FocusedStatusId.Value);
 254                 if (focusedIndex != -1)
 255                     this.listView.Items[focusedIndex].Focused = true;
 256             }
 257
 258             if (listSelection.SelectionMarkStatusId != null)
 259             {
 260                 var selectionMarkIndex = this.tab.IndexOf(listSelection.SelectionMarkStatusId.Value);
 261                 if (selectionMarkIndex != -1)
 262                     this.listView.SelectionMark = selectionMarkIndex;
 263             }
 264
 265             if (invalidateBounds != null)
 266                 this.listView.Invalidate(invalidateBounds.Value);
 267         }
 268     }
 269 }