src/Tizen.NUI.Components/Controls/FlexibleView/GridLayoutManager.cs

   1 /*
   2  * Copyright(c) 2019 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17 using System.ComponentModel;
  18
  19 namespace Tizen.NUI.Components
  20 {
  21     /// <summary>
  22     /// Layout collection of views in a grid.
  23     /// </summary>
  24     /// <since_tizen> 6 </since_tizen>
  25     /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  26     [EditorBrowsable(EditorBrowsableState.Never)]
  27     public class GridLayoutManager : LinearLayoutManager
  28     {
  29         private const int DEFAULT_SPAN_COUNT = -1;
  30
  31         private int mSpanCount = DEFAULT_SPAN_COUNT;
  32
  33         /// <summary>
  34         /// Creates a GridLayoutManager with orientation.
  35         /// </summary>
  36         /// <param name="spanCount">The number of columns or rows in the grid</param>
  37         /// <param name="orientation">Layout orientation.Should be HORIZONTAL or VERTICAL</param>
  38         /// <since_tizen> 6 </since_tizen>
  39         /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  40         [EditorBrowsable(EditorBrowsableState.Never)]
  41         public GridLayoutManager(int spanCount, int orientation) : base(orientation)
  42         {
  43             mSpanCount = spanCount;
  44         }
  45
  46         internal override void EnsureAnchorReady(FlexibleViewRecycler recycler, AnchorInfo anchorInfo, int itemDirection)
  47         {
  48             bool layingOutInPrimaryDirection = (itemDirection == LayoutState.ITEM_DIRECTION_TAIL);
  49             int span = anchorInfo.Position % mSpanCount;
  50             if (layingOutInPrimaryDirection)
  51             {
  52                 // choose span 0
  53                 while (span > 0 && anchorInfo.Position > 0)
  54                 {
  55                     anchorInfo.Position--;
  56                     span = anchorInfo.Position;
  57                 }
  58             }
  59             else
  60             {
  61                 // choose the max span we can get. hopefully last one
  62                 int indexLimit = ChildCount - 1;
  63                 int pos = anchorInfo.Position;
  64                 int bestSpan = span;
  65                 while (pos < indexLimit)
  66                 {
  67                     int next = (pos + 1) % mSpanCount;
  68                     if (next > bestSpan)
  69                     {
  70                         pos += 1;
  71                         bestSpan = next;
  72                     }
  73                     else
  74                     {
  75                         break;
  76                     }
  77                 }
  78                 anchorInfo.Position = pos;
  79             }
  80         }
  81
  82         /// <summary>
  83         /// Retrieves a position that neighbor to current position by direction.
  84         /// </summary>
  85         /// <param name="position">The anchor adapter position</param>
  86         /// <param name="direction">The direction.</param>
  87         /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  88         [EditorBrowsable(EditorBrowsableState.Never)]
  89         protected override int GetNextPosition(int position, FlexibleViewLayoutManager.Direction direction)
  90         {
  91             if (mOrientation == HORIZONTAL)
  92             {
  93                 switch (direction)
  94                 {
  95                     case FlexibleViewLayoutManager.Direction.Left:
  96                         if (position >= mSpanCount)
  97                         {
  98                             return position - mSpanCount;
  99                         }
 100                         break;
 101                     case FlexibleViewLayoutManager.Direction.Right:
 102                         if (position < ItemCount - mSpanCount)
 103                         {
 104                             return position + mSpanCount;
 105                         }
 106                         break;
 107                     case FlexibleViewLayoutManager.Direction.Up:
 108                         if (position % mSpanCount > 0)
 109                         {
 110                             return position - 1;
 111                         }
 112                         break;
 113                     case FlexibleViewLayoutManager.Direction.Down:
 114                         if (position < ItemCount - 1 && (position % mSpanCount < mSpanCount - 1))
 115                         {
 116                             return position + 1;
 117                         }
 118                         break;
 119                 }
 120             }
 121             else
 122             {
 123                 switch (direction)
 124                 {
 125                     case FlexibleViewLayoutManager.Direction.Left:
 126                         if (position % mSpanCount > 0)
 127                         {
 128                             return position - 1;
 129                         }
 130                         break;
 131                     case FlexibleViewLayoutManager.Direction.Right:
 132                         if (position < ItemCount - 1 && (position % mSpanCount < mSpanCount - 1))
 133                         {
 134                             return position + 1;
 135                         }
 136                         break;
 137                     case FlexibleViewLayoutManager.Direction.Up:
 138                         if (position >= mSpanCount)
 139                         {
 140                             return position - mSpanCount;
 141                         }
 142                         break;
 143                     case FlexibleViewLayoutManager.Direction.Down:
 144                         if (position < ItemCount - mSpanCount)
 145                         {
 146                             return position + mSpanCount;
 147                         }
 148                         break;
 149                 }
 150             }
 151
 152             return NO_POSITION;
 153         }
 154
 155         internal override void LayoutChunk(FlexibleViewRecycler recycler,
 156             LayoutState layoutState, LayoutChunkResult result)
 157         {
 158             bool layingOutInPrimaryDirection =
 159                 layoutState.ItemDirection == LayoutState.ITEM_DIRECTION_TAIL;
 160
 161             int count = mSpanCount;
 162             for (int i = 0; i < count; i++)
 163             {
 164                 FlexibleViewViewHolder holder = layoutState.Next(recycler);
 165                 if (holder == null)
 166                 {
 167                     result.Finished = true;
 168                     return;
 169                 }
 170
 171                 if (layingOutInPrimaryDirection)
 172                     AddView(holder);
 173                 else
 174                     AddView(holder, 0);
 175
 176                 result.Consumed = mOrientationHelper.GetViewHolderMeasurement(holder);
 177
 178                 float left, top, width, height;
 179                 if (mOrientation == VERTICAL)
 180                 {
 181                     width = (Width - PaddingLeft - PaddingRight) / count;
 182                     height = result.Consumed;
 183                     if (layoutState.LayoutDirection == LayoutState.LAYOUT_END)
 184                     {
 185                         left = PaddingLeft + width * i;
 186                         top = layoutState.Offset;
 187                     }
 188                     else
 189                     {
 190                         left = PaddingLeft + width * (count - 1 - i);
 191                         top = layoutState.Offset - height;
 192                     }
 193                     LayoutChild(holder, left, top, width, height);
 194                 }
 195                 else
 196                 {
 197                     width = result.Consumed;
 198                     height = (Height - PaddingTop - PaddingBottom) / count;
 199                     if (layoutState.LayoutDirection == LayoutState.LAYOUT_END)
 200                     {
 201                         top = PaddingTop + height * i;
 202                         left = layoutState.Offset;
 203                     }
 204                     else
 205                     {
 206                         top = PaddingTop + height * (count - 1 - i);
 207                         left = layoutState.Offset - width;
 208                     }
 209                     LayoutChild(holder, left, top, width, height);
 210                 }
 211             }
 212         }
 213
 214
 215     }
 216 }