KancolleSniffer/View/ListScroller.cs

   1 // Copyright (C) 2019 Kazuhiro Fujieda <fujieda@users.osdn.me>\r
   2 //\r
   3 // Licensed under the Apache License, Version 2.0 (the "License");\r
   4 // you may not use this file except in compliance with the License.\r
   5 // You may obtain a copy of the License at\r
   6 //\r
   7 //    http://www.apache.org/licenses/LICENSE-2.0\r
   8 //\r
   9 // Unless required by applicable law or agreed to in writing, software\r
  10 // distributed under the License is distributed on an "AS IS" BASIS,\r
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  12 // See the License for the specific language governing permissions and\r
  13 // limitations under the License.\r
  14 \r
  15 using System;\r
  16 using System.Drawing;\r
  17 using System.Windows.Forms;\r
  18 \r
  19 namespace KancolleSniffer.View\r
  20 {\r
  21     public class ListScroller\r
  22     {\r
  23         private readonly Panel _panel;\r
  24         private const int MarkWidth = 20;\r
  25 \r
  26         public int Padding { get; set; }\r
  27 \r
  28         public int Position { get; set; }\r
  29 \r
  30         public int Lines { get; set; }\r
  31 \r
  32         public int DataCount { get; set; }\r
  33 \r
  34         public event Action Update;\r
  35 \r
  36         public event Action StartScroll;\r
  37 \r
  38         public event Action EndScroll;\r
  39 \r
  40         public ListScroller(Panel panel, Control[] topLabels, Control[] bottomLabels)\r
  41         {\r
  42             _panel = panel;\r
  43             panel.Paint += (obj, ev) => DrawMark();\r
  44             SetTopEventHandler(topLabels);\r
  45             SetBottomEventHandler(bottomLabels);\r
  46         }\r
  47 \r
  48         public void SetTopEventHandler(Control[] top)\r
  49         {\r
  50             foreach (var label in top)\r
  51             {\r
  52                 label.MouseEnter += TopLineOnMouseEnter;\r
  53                 label.MouseLeave += TopLineOnMouseLeave;\r
  54             }\r
  55             _topScrollRepeatTimer.Tick += (obj, e) => ScrollUp();\r
  56         }\r
  57 \r
  58         public void SetBottomEventHandler(Control[] bottom)\r
  59         {\r
  60             foreach (var label in bottom)\r
  61             {\r
  62                 label.MouseEnter += BottomLineOnMouseEnter;\r
  63                 label.MouseLeave += BottomLineOnMouseLeave;\r
  64             }\r
  65             _bottomScrollRepeatTimer.Tick += (obj, e) => ScrollDown();\r
  66         }\r
  67 \r
  68         private readonly Timer _topScrollRepeatTimer = new Timer {Interval = 100};\r
  69         private readonly Timer _bottomScrollRepeatTimer = new Timer {Interval = 100};\r
  70 \r
  71         private void TopLineOnMouseEnter(object sender, EventArgs e)\r
  72         {\r
  73             if (IsTop)\r
  74                 return;\r
  75             StartScroll?.Invoke();\r
  76             _topScrollRepeatTimer.Start();\r
  77         }\r
  78 \r
  79         private void ScrollUp()\r
  80         {\r
  81             if (IsTop)\r
  82                 return;\r
  83             Position--;\r
  84             Update?.Invoke();\r
  85         }\r
  86 \r
  87         private bool IsTop => Position == 0;\r
  88 \r
  89         private void TopLineOnMouseLeave(object sender, EventArgs e)\r
  90         {\r
  91             EndScroll?.Invoke();\r
  92             _topScrollRepeatTimer.Stop();\r
  93         }\r
  94 \r
  95         private void BottomLineOnMouseEnter(object sender, EventArgs e)\r
  96         {\r
  97             if (!NeedScroll)\r
  98                 return;\r
  99             StartScroll?.Invoke();\r
 100             _bottomScrollRepeatTimer.Start();\r
 101         }\r
 102 \r
 103         private void ScrollDown()\r
 104         {\r
 105             if (!NeedScroll)\r
 106                 return;\r
 107             Position++;\r
 108             Update?.Invoke();\r
 109         }\r
 110 \r
 111         private bool NeedScroll => Position + Lines < DataCount;\r
 112 \r
 113         private void BottomLineOnMouseLeave(object sender, EventArgs e)\r
 114         {\r
 115             EndScroll?.Invoke();\r
 116             _bottomScrollRepeatTimer.Stop();\r
 117         }\r
 118 \r
 119         public void DrawMark()\r
 120         {\r
 121             var halfOfWidth = _panel.Width * 0.5f;\r
 122             var halfOfMark = Scaler.ScaleWidth(MarkWidth * 0.5f);\r
 123             var left = halfOfWidth - halfOfMark;\r
 124             var right = halfOfWidth + halfOfMark;\r
 125             var center = halfOfWidth;\r
 126             using (var g = _panel.CreateGraphics())\r
 127             {\r
 128                 DrawTopMark(g, left, right, center);\r
 129                 DrawBottomMark(g, left, right, center);\r
 130             }\r
 131         }\r
 132 \r
 133         private void DrawTopMark(Graphics g, float left, float right, float center)\r
 134         {\r
 135             var brush = Position > 0 ? Brushes.Black : new SolidBrush(_panel.BackColor);\r
 136             var top = -1;\r
 137             var base_ = Padding - 1;\r
 138             g.FillPolygon(brush,\r
 139                 new[]\r
 140                 {\r
 141                     new PointF(left, base_), new PointF(right, base_), new PointF(center, top),\r
 142                     new PointF(left, base_)\r
 143                 });\r
 144         }\r
 145 \r
 146         private void DrawBottomMark(Graphics g, float left, float right, float center)\r
 147         {\r
 148             var brush = Position + Lines < DataCount ? Brushes.Black : new SolidBrush(_panel.BackColor);\r
 149             var top = _panel.Height - 2;\r
 150             var base_ = _panel.Height - Padding - 1;\r
 151             g.FillPolygon(brush,\r
 152                 new[]\r
 153                 {\r
 154                     new PointF(left, base_), new PointF(right, base_), new PointF(center, top),\r
 155                     new PointF(left, base_)\r
 156                 });\r
 157         }\r
 158     }\r
 159 }