src/Tizen.NUI/src/internal/Layouting/LayoutGroup.cs

   1 /*
   2  * Copyright (c) 2018 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
  18 using System.ComponentModel;
  19 using Tizen.NUI.BaseComponents;
  20
  21 namespace Tizen.NUI
  22 {
  23     /// <summary>
  24     /// [Draft] LayoutGroup class providing container functionality.
  25     /// </summary>
  26     internal class LayoutGroup : LayoutGroupWrapper
  27     {
  28         public LayoutGroup() : base(new LayoutGroupWrapperImpl())
  29         {
  30             // Initialize delegates of LayoutItem
  31             LayoutItemInitialize(layoutGroupWrapperImpl);
  32
  33             layoutGroupWrapperImpl.OnMeasure = new LayoutGroupWrapperImpl.OnMeasureDelegate(OnMeasure);
  34             layoutGroupWrapperImpl.OnLayout = new LayoutGroupWrapperImpl.OnLayoutDelegate(OnLayout);
  35             layoutGroupWrapperImpl.OnSizeChanged = new LayoutGroupWrapperImpl.OnSizeChangedDelegate(OnSizeChanged);
  36             layoutGroupWrapperImpl.OnChildAdd = new LayoutGroupWrapperImpl.OnChildAddDelegate(OnChildAdd);
  37             layoutGroupWrapperImpl.OnChildRemove = new LayoutGroupWrapperImpl.OnChildRemoveDelegate(OnChildRemove);
  38             layoutGroupWrapperImpl.DoInitialize = new LayoutGroupWrapperImpl.DoInitializeDelegate(DoInitialize);
  39             layoutGroupWrapperImpl.DoRegisterChildProperties = new LayoutGroupWrapperImpl.DoRegisterChildPropertiesDelegate(DoRegisterChildProperties);
  40             layoutGroupWrapperImpl.MeasureChildren = new LayoutGroupWrapperImpl.MeasureChildrenDelegate(MeasureChildren);
  41             layoutGroupWrapperImpl.MeasureChild = new LayoutGroupWrapperImpl.MeasureChildDelegate(MeasureChild);
  42             layoutGroupWrapperImpl.MeasureChildWithMargins = new LayoutGroupWrapperImpl.MeasureChildWithMarginsDelegate(MeasureChildWithMargins);
  43         }
  44
  45         /// <summary>
  46         /// Remove all layout children.<br />
  47         /// </summary>
  48         public void RemoveAll()
  49         {
  50             layoutGroupWrapperImpl.RemoveAll();
  51         }
  52
  53         /// <summary>
  54         /// Get the child layout id of the given child.<br />
  55         /// </summary>
  56         /// <param name="child">The given Layout child.</param>
  57         internal uint GetChildId(LayoutItemWrapperImpl child)
  58         {
  59             return layoutGroupWrapperImpl.GetChildId(child);
  60         }
  61
  62         /// <summary>
  63         /// Calculate the right measure spec for this child.
  64         /// Does the hard part of MeasureChildren: figuring out the MeasureSpec to
  65         /// pass to a particular child. This method figures out the right MeasureSpec
  66         /// for one dimension (height or width) of one child view.<br />
  67         /// </summary>
  68         /// <param name="measureSpec">The requirements for this view.</param>
  69         /// <param name="padding">The padding of this view for the current dimension and margins, if applicable.</param>
  70         /// <param name="childDimension"> How big the child wants to be in the current dimension.</param>
  71         /// <returns>a MeasureSpec for the child.</returns>
  72         public static LayoutMeasureSpec GetChildMeasureSpec(LayoutMeasureSpec measureSpec, LayoutLength padding, LayoutLength childDimension)
  73         {
  74             return LayoutGroupWrapperImpl.GetChildMeasureSpec(measureSpec, padding, childDimension);
  75         }
  76
  77         /// <summary>
  78         /// Measure the layout and its content to determine the measured width and the measured height.<br />
  79         /// If this method is overridden, it is the subclass's responsibility to make
  80         /// sure the measured height and width are at least the layout's minimum height
  81         /// and width. <br />
  82         /// </summary>
  83         /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
  84         /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
  85         protected override void OnMeasure(LayoutMeasureSpec widthMeasureSpec, LayoutMeasureSpec heightMeasureSpec)
  86         {
  87             Log.Info("NUI", "OnMeasure\n");
  88             LayoutLength childWidth  = new LayoutLength( 0 );
  89             LayoutLength childHeight =  new LayoutLength( 0 );
  90
  91             LayoutLength measuredWidth = childWidth;
  92             LayoutLength measuredHeight = childHeight;
  93
  94             for( uint i = 0; i < ChildCount; ++i )
  95             {
  96                 var childLayout = GetChildAt( i );
  97
  98                 if( childLayout )
  99                 {
 100                     MeasureChild( childLayout, widthMeasureSpec, heightMeasureSpec );
 101                     childWidth = childLayout.MeasuredWidth;
 102                     childHeight = childLayout.MeasuredHeight;
 103                     // Layout takes size of largest width and height dimension of children
 104                     measuredWidth.Value = System.Math.Max( measuredWidth.Value, childWidth.Value );
 105                     measuredHeight.Value = System.Math.Max( measuredHeight.Value, childHeight.Value );
 106                 }
 107             }
 108
 109             if( 0 == ChildCount )
 110             {
 111                 // Must be a leaf as has no children
 112                 measuredWidth = GetDefaultSize( SuggestedMinimumWidth, widthMeasureSpec );
 113                 measuredHeight = GetDefaultSize( SuggestedMinimumHeight, heightMeasureSpec );
 114             }
 115
 116             SetMeasuredDimensions( new MeasuredSize( measuredWidth ),
 117                                     new MeasuredSize( measuredHeight ) );
 118         }
 119
 120         /// <summary>
 121         /// Called from Layout() when this layout should assign a size and position to each of its children.<br />
 122         /// Derived classes with children should override this method and call Layout() on each of their children.<br />
 123         /// </summary>
 124         /// <param name="changed">This is a new size or position for this layout.</param>
 125         /// <param name="left">Left position, relative to parent.</param>
 126         /// <param name="top"> Top position, relative to parent.</param>
 127         /// <param name="right">Right position, relative to parent.</param>
 128         /// <param name="bottom">Bottom position, relative to parent.</param>
 129         protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 130         {
 131             Log.Info("NUI", "OnLayout\n");
 132
 133             for( uint i = 0; i < ChildCount; ++i )
 134             {
 135                 var childLayout = GetChildAt( i );
 136                 if( childLayout )
 137                 {
 138                     View childOwner = childLayout.GetOwner();
 139
 140                     // Use position if explicitly set to child otherwise will be top left.
 141                     var childLeft = new LayoutLength( childOwner.Position2D.X );
 142                     var childTop = new LayoutLength( childOwner.Position2D.Y );
 143
 144                     View owner = GetOwner();
 145
 146                     if ( owner )
 147                     {
 148                         // Margin and Padding only supported when child anchor point is TOP_LEFT.
 149                         if ( owner.PivotPoint == PivotPoint.TopLeft || ( owner.PositionUsesPivotPoint == false ) )
 150                         {
 151                           childLeft = childLeft + owner.Padding.Start + childOwner.Margin.Start;
 152                           childTop = childTop + owner.Padding.Top + childOwner.Margin.Top;
 153                         }
 154                     }
 155                     childLayout.Layout( childLeft, childTop, childLeft + childLayout.MeasuredWidth, childTop + childLayout.MeasuredHeight );
 156                 }
 157             }
 158         }
 159
 160         /// <summary>
 161         /// Virtual method to inform derived classes when the layout size changed.<br />
 162         /// </summary>
 163         /// <param name="newSize">The new size of the layout.</param>
 164         /// <param name="oldSize">The old size of the layout.</param>
 165         protected virtual void OnSizeChanged(LayoutSize newSize, LayoutSize oldSize)
 166         {
 167
 168         }
 169
 170         /// <summary>
 171         /// Callback when child is added to container.<br />
 172         /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
 173         /// </summary>
 174         /// <param name="child">The Layout child.</param>
 175         internal virtual void OnChildAdd(LayoutItemWrapperImpl child)
 176         {
 177         }
 178
 179         /// <summary>
 180         /// Callback when child is removed from container.<br />
 181         /// </summary>
 182         /// <param name="child">The Layout child.</param>
 183         internal virtual void OnChildRemove(LayoutItemWrapperImpl child)
 184         {
 185         }
 186
 187         /// <summary>
 188         /// Second stage initialization method for deriving classes to override.<br />
 189         /// </summary>
 190         protected virtual void DoInitialize()
 191         {
 192         }
 193
 194         /// <summary>
 195         /// Method for derived classes to implement in order to register child property types with the container.<br />
 196         /// </summary>
 197         /// <param name="containerType">The fully qualified typename of the container.</param>
 198         protected virtual void DoRegisterChildProperties(string containerType)
 199         {
 200         }
 201
 202         /// <summary>
 203         /// Ask all of the children of this view to measure themselves, taking into
 204         /// account both the MeasureSpec requirements for this view and its padding.<br />
 205         /// The heavy lifting is done in GetChildMeasureSpec.<br />
 206         /// </summary>
 207         /// <param name="widthMeasureSpec">The width requirements for this view.</param>
 208         /// <param name="heightMeasureSpec">The height requirements for this view.</param>
 209         protected virtual void MeasureChildren(LayoutMeasureSpec widthMeasureSpec, LayoutMeasureSpec heightMeasureSpec)
 210         {
 211             layoutGroupWrapperImpl.MeasureChildrenNative(widthMeasureSpec, heightMeasureSpec);
 212         }
 213
 214         /// <summary>
 215         /// Ask one of the children of this view to measure itself, taking into
 216         /// account both the MeasureSpec requirements for this view and its padding.<br />
 217         /// The heavy lifting is done in GetChildMeasureSpec.<br />
 218         /// </summary>
 219         /// <param name="child">The child to measure.</param>
 220         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 221         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 222         protected virtual void MeasureChild(LayoutItem child, LayoutMeasureSpec parentWidthMeasureSpec, LayoutMeasureSpec parentHeightMeasureSpec)
 223         {
 224             layoutGroupWrapperImpl.MeasureChildNative(child, parentWidthMeasureSpec, parentHeightMeasureSpec);
 225         }
 226
 227         /// <summary>
 228         /// Ask one of the children of this view to measure itself, taking into
 229         /// account both the MeasureSpec requirements for this view and its padding.<br />
 230         /// and margins. The child must have MarginLayoutParams The heavy lifting is
 231         /// done in GetChildMeasureSpec.<br />
 232         /// </summary>
 233         /// <param name="child">The child to measure.</param>
 234         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 235         /// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
 236         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 237         /// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
 238         protected virtual void MeasureChildWithMargins(LayoutItem child, LayoutMeasureSpec parentWidthMeasureSpec, LayoutLength widthUsed, LayoutMeasureSpec parentHeightMeasureSpec, LayoutLength heightUsed)
 239         {
 240             layoutGroupWrapperImpl.MeasureChildWithMarginsNative(child, parentWidthMeasureSpec, widthUsed, parentHeightMeasureSpec, heightUsed);
 241         }
 242     }
 243 }