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

   1 /*
   2  * Copyright (c) 2021 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;
  18 using System.Collections.Generic;
  19 using System.ComponentModel;
  20 using System.Linq;
  21
  22 using Tizen.NUI.BaseComponents;
  23 using Tizen.NUI.Binding.Internals;
  24 using static Tizen.NUI.Binding.BindableObject;
  25
  26 namespace Tizen.NUI
  27 {
  28     /// <summary>
  29     /// [Draft] LayoutGroup class providing container functionality.
  30     /// </summary>
  31     public class LayoutGroup : LayoutItem, ILayoutParent
  32     {
  33         /// <summary>
  34         /// [Draft] List of child layouts in this container.
  35         /// </summary>
  36         /// <since_tizen> 6 </since_tizen>
  37         protected List<LayoutItem> LayoutChildren { get; } // Children of this LayoutGroup
  38
  39         /// <summary>
  40         /// [Draft] Constructor
  41         /// </summary>
  42         /// <since_tizen> 6 </since_tizen>
  43         public LayoutGroup()
  44         {
  45             LayoutChildren = new List<LayoutItem>();
  46         }
  47
  48         /// <summary>
  49         /// returns an enumerable collection of the child layouts that owner's <see cref="View.ExcludeLayouting"/> is false.
  50         /// </summary>
  51         /// <returns>An enumerable collection of the child layouts that affected by this layout.</returns>
  52         [EditorBrowsable(EditorBrowsableState.Never)]
  53         protected IEnumerable<LayoutItem> IterateLayoutChildren()
  54         {
  55             return LayoutChildren.Where<LayoutItem>(childLayout => childLayout.SetPositionByLayout);
  56         }
  57
  58         /// <summary>
  59         /// From ILayoutParent.<br />
  60         /// </summary>
  61         /// <exception cref="ArgumentNullException"> Thrown when childLayout is null. </exception>
  62         /// <since_tizen> 6 </since_tizen>
  63         /// <param name="childLayout">LayoutItem to add to the layout group.</param>
  64         public virtual void Add(LayoutItem childLayout)
  65         {
  66             if (null == childLayout)
  67             {
  68                 throw new ArgumentNullException(nameof(childLayout));
  69             }
  70             LayoutChildren.Add(childLayout);
  71             childLayout.SetParent(this);
  72             // Child added to use a Add transition.
  73             childLayout.ConditionForAnimation = ConditionForAnimation | TransitionCondition.Add;
  74             // Child's parent sets all other children not being added to a ChangeOnAdd transition.
  75             SetConditionsForAnimationOnLayoutGroup(TransitionCondition.ChangeOnAdd);
  76             OnChildAdd(childLayout);
  77             RequestLayout();
  78         }
  79
  80         /// <summary>
  81         /// Remove all layout children.<br />
  82         /// </summary>
  83         /// <since_tizen> 6 </since_tizen>
  84         public void RemoveAll()
  85         {
  86             foreach (LayoutItem childLayout in LayoutChildren)
  87             {
  88                 childLayout.ConditionForAnimation = ConditionForAnimation | TransitionCondition.Remove;
  89                 childLayout.Owner = null;
  90             }
  91             LayoutChildren.Clear();
  92             // todo ensure child LayoutItems are still not parented to this group.
  93             RequestLayout();
  94         }
  95
  96         /// <summary>
  97         /// From ILayoutParent
  98         /// </summary>
  99         /// <param name="layoutItem">LayoutItem to remove from the layout group.</param>
 100         /// <since_tizen> 6 </since_tizen>
 101         public virtual void Remove(LayoutItem layoutItem)
 102         {
 103             bool childRemoved = false;
 104             foreach (LayoutItem childLayout in LayoutChildren.ToList())
 105             {
 106                 if (childLayout == layoutItem)
 107                 {
 108                     childLayout.ClearReplaceFlag();
 109                     LayoutChildren.Remove(childLayout);
 110
 111                     if (LayoutWithTransition)
 112                     {
 113                         if (!childLayout.IsReplaceFlag())
 114                         {
 115                             NUIApplication.GetDefaultWindow().LayoutController.AddToRemovalStack(childLayout);
 116                         }
 117
 118                         childLayout.ConditionForAnimation = childLayout.ConditionForAnimation | TransitionCondition.Remove;
 119                         // Add LayoutItem to the transition stack so can animate it out.
 120                         NUIApplication.GetDefaultWindow().LayoutController.AddTransitionDataEntry(new LayoutData(layoutItem, ConditionForAnimation, 0, 0, 0, 0));
 121                     }
 122
 123                     // Reset condition for animation ready for next transition when required.
 124                     // SetFrame usually would do this but this LayoutItem is being removed.
 125                     childLayout.ConditionForAnimation = TransitionCondition.Unspecified;
 126                     childRemoved = true;
 127
 128                     break;
 129                 }
 130             }
 131
 132             if (childRemoved)
 133             {
 134                 // If child removed then set all siblings not being added to a ChangeOnRemove transition.
 135                 SetConditionsForAnimationOnLayoutGroup(TransitionCondition.ChangeOnRemove);
 136             }
 137             OnChildRemove(layoutItem);
 138             RequestLayout();
 139         }
 140
 141         /// <summary>
 142         /// Sets the order of the child layout in the layout group.
 143         /// </summary>
 144         /// <param name="child">the child layout in the layout group</param>
 145         /// <param name="order">the order of the child layout in the layout group</param>
 146         [EditorBrowsable(EditorBrowsableState.Never)]
 147         public void ChangeLayoutChildOrder(LayoutItem child, int order)
 148         {
 149             if ((child != null) && (LayoutChildren.Count > order))
 150             {
 151                 LayoutChildren.Remove(child);
 152                 LayoutChildren.Insert(order, child);
 153                 RequestLayout();
 154             }
 155         }
 156
 157         // Attaches to View ChildAdded signal so called when a View is added to a view.
 158         private void AddChildToLayoutGroup(View child)
 159         {
 160             if (View.LayoutingDisabled)
 161             {
 162                 return;
 163             }
 164             // Only give children a layout if their parent is an explicit container or a pure View.
 165             // Pure View meaning not derived from a View, e.g a Legacy container.
 166             // layoutSet flag is true when the View became a layout using the set Layout API opposed to automatically due to it's parent.
 167             // First time the set Layout API is used by any View the Window no longer has layoutingDisabled.
 168
 169             // If child already has a Layout then don't change it.
 170             if (null == child.Layout)
 171             {
 172                 // If child view does not have Layout, then default layout is automatically set to the child view.
 173                 // The Layout is automatically added to this LayoutGroup when child view sets Layout.
 174                 child.Layout = child.CreateDefaultLayout();
 175             }
 176             else
 177             {
 178                 Add(child.Layout);
 179             }
 180             // Parent transitions are not attached to children.
 181         }
 182
 183         /// <summary>
 184         /// If the child has a layout then it is removed from the parent layout.
 185         /// </summary>
 186         /// <param name="child">Child View to remove.</param>
 187         internal void RemoveChildFromLayoutGroup(View child)
 188         {
 189             if (child.Layout != null)
 190             {
 191                 Remove(child.Layout);
 192             }
 193         }
 194
 195         /// <summary>
 196         /// Set all children in a LayoutGroup to the supplied condition.
 197         /// Children with Add or Remove conditions should not be changed.
 198         /// </summary>
 199         private void SetConditionsForAnimationOnLayoutGroup(TransitionCondition conditionToSet)
 200         {
 201             foreach (LayoutItem childLayout in LayoutChildren)
 202             {
 203                 switch (conditionToSet)
 204                 {
 205                     case TransitionCondition.ChangeOnAdd:
 206                         {
 207                             // If other children also being added (TransitionCondition.Add) then do not change their
 208                             // conditions, Continue to use their Add transitions.
 209                             if (childLayout.ConditionForAnimation.HasFlag(TransitionCondition.Add))
 210                             {
 211                                 break;  // Child being Added so don't update it's condition
 212                             }
 213                             else
 214                             {
 215                                 // Set siblings for the child being added to use the ChangeOnAdd transition.
 216                                 childLayout.ConditionForAnimation = TransitionCondition.ChangeOnAdd;
 217                             }
 218                             break;
 219                         }
 220                     case TransitionCondition.ChangeOnRemove:
 221                         {
 222                             if (childLayout.ConditionForAnimation.HasFlag(TransitionCondition.Remove))
 223                             {
 224                                 break; // Child being Removed so don't update it's condition
 225                             }
 226                             else
 227                             {
 228                                 childLayout.ConditionForAnimation = TransitionCondition.ChangeOnRemove;
 229                             }
 230                             break;
 231                         }
 232                     case TransitionCondition.LayoutChanged:
 233                         {
 234                             childLayout.ConditionForAnimation = TransitionCondition.LayoutChanged;
 235                             break;
 236                         }
 237                 }
 238             }
 239
 240         }
 241
 242         /// <summary>
 243         /// Callback for View.ChildAdded event
 244         /// </summary>
 245         /// <param name="sender">The object triggering the event.</param>
 246         /// <param name="childAddedEvent">Arguments from the event.</param>
 247         void OnChildAddedToOwner(object sender, View.ChildAddedEventArgs childAddedEvent)
 248         {
 249             AddChildToLayoutGroup(childAddedEvent.Added);
 250         }
 251
 252         /// <summary>
 253         /// Callback for View.ChildRemoved event
 254         /// </summary>
 255         /// <param name="sender">The object triggering the event.</param>
 256         /// <param name="childRemovedEvent">Arguments from the event.</param>
 257         void OnChildRemovedFromOwner(object sender, View.ChildRemovedEventArgs childRemovedEvent)
 258         {
 259             RemoveChildFromLayoutGroup(childRemovedEvent.Removed);
 260         }
 261
 262         /// <summary>
 263         /// Calculate the right measure spec for this child.
 264         /// Does the hard part of MeasureChildren: figuring out the MeasureSpec to
 265         /// pass to a particular child. This method figures out the right MeasureSpec
 266         /// for one dimension (height or width) of one child view.<br />
 267         /// </summary>
 268         /// <param name="parentMeasureSpec">The requirements for this view. MeasureSpecification.</param>
 269         /// <param name="padding">The padding of this view for the current dimension and margins, if applicable. LayoutLength.</param>
 270         /// <param name="childDimension"> How big the child wants to be in the current dimension. LayoutLength.</param>
 271         /// <returns>a MeasureSpec for the child.</returns>
 272         public static MeasureSpecification GetChildMeasureSpecification(MeasureSpecification parentMeasureSpec, LayoutLength padding, LayoutLength childDimension)
 273         {
 274             MeasureSpecification.ModeType specMode = parentMeasureSpec.Mode;
 275             MeasureSpecification.ModeType resultMode = MeasureSpecification.ModeType.Unspecified;
 276
 277             // Child only can use parent's size without parent's padding and own margin.
 278             LayoutLength resultSize = new LayoutLength(Math.Max(0.0f, (parentMeasureSpec.Size - padding).AsDecimal()));
 279             switch (specMode)
 280             {
 281                 // Parent has imposed an exact size on us
 282                 case MeasureSpecification.ModeType.Exactly:
 283                     {
 284                         if ((int)childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent)
 285                         {
 286                             resultMode = MeasureSpecification.ModeType.Exactly;
 287                         }
 288                         else if ((int)childDimension.AsRoundedValue() == LayoutParamPolicies.WrapContent)
 289                         {
 290                             resultMode = MeasureSpecification.ModeType.AtMost;
 291                         }
 292                         else
 293                         {
 294                             resultSize = childDimension;
 295                             resultMode = MeasureSpecification.ModeType.Exactly;
 296                         }
 297
 298                         break;
 299                     }
 300
 301                 // Parent has imposed a maximum size on us
 302                 case MeasureSpecification.ModeType.AtMost:
 303                     {
 304                         if (childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent)
 305                         {
 306                             // Crashed. Cannot calculate.
 307
 308                             // Child wants to be our size, but our size is not fixed.
 309                             // Constrain child to not be bigger than us.
 310                             resultMode = MeasureSpecification.ModeType.AtMost;
 311                         }
 312                         else if (childDimension.AsRoundedValue() == LayoutParamPolicies.WrapContent)
 313                         {
 314                             // Child wants to determine its own size. It can't be
 315                             // bigger than us.
 316
 317                             // Don't need parent's size. Size of this child will be determined by its children.
 318                             resultMode = MeasureSpecification.ModeType.AtMost;
 319                         }
 320                         else
 321                         {
 322                             // Child wants a specific size... so be it
 323                             resultSize = childDimension;
 324                             resultMode = MeasureSpecification.ModeType.Exactly;
 325                         }
 326
 327                         break;
 328                     }
 329
 330                 // Parent asked to see how big we want to be
 331                 case MeasureSpecification.ModeType.Unspecified:
 332                     {
 333                         if ((childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent))
 334                         {
 335                             // Child wants to be our size... find out how big it should be
 336
 337                             // There is no one who has exact size in parent hierarchy.
 338                             // Cannot calculate.
 339                             resultMode = MeasureSpecification.ModeType.Unspecified;
 340                         }
 341                         else if (childDimension.AsRoundedValue() == (LayoutParamPolicies.WrapContent))
 342                         {
 343                             // Child wants to determine its own size.... find out how big
 344                             // it should be
 345                             resultMode = MeasureSpecification.ModeType.Unspecified;
 346                         }
 347                         else
 348                         {
 349                             // Child wants a specific size... let him have it
 350                             resultSize = childDimension;
 351                             resultMode = MeasureSpecification.ModeType.Exactly;
 352                         }
 353                         break;
 354                     }
 355             } // switch
 356
 357             return new MeasureSpecification(resultSize, resultMode);
 358         }
 359
 360         /// <summary>
 361         /// Measure the layout and its content to determine the measured width and the measured height.<br />
 362         /// If this method is overridden, it is the subclass's responsibility to make
 363         /// sure the measured height and width are at least the layout's minimum height
 364         /// and width. <br />
 365         /// </summary>
 366         /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
 367         /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
 368         /// <since_tizen> 6 </since_tizen>
 369         protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 370         {
 371             LayoutLength measuredWidth = new LayoutLength(0.0f);
 372             LayoutLength measuredHeight = new LayoutLength(0.0f);
 373
 374             // Layout takes size of largest child width and largest child height dimensions
 375             foreach (LayoutItem childLayout in LayoutChildren)
 376             {
 377                 if (childLayout != null)
 378                 {
 379                     MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
 380                     LayoutLength childWidth = new LayoutLength(childLayout.MeasuredWidth.Size);
 381                     LayoutLength childHeight = new LayoutLength(childLayout.MeasuredHeight.Size);
 382
 383                     Extents childMargin = childLayout.Margin;
 384                     measuredWidth = new LayoutLength(Math.Max(measuredWidth.AsDecimal(), childWidth.AsDecimal() + childMargin.Start + childMargin.End));
 385                     measuredHeight = new LayoutLength(Math.Max(measuredHeight.AsDecimal(), childHeight.AsDecimal() + childMargin.Top + childMargin.Bottom));
 386                 }
 387             }
 388
 389             if (0 == LayoutChildren.Count)
 390             {
 391                 // Must be a leaf as has no children
 392                 measuredWidth = GetDefaultSize(SuggestedMinimumWidth, widthMeasureSpec);
 393                 measuredHeight = GetDefaultSize(SuggestedMinimumHeight, heightMeasureSpec);
 394             }
 395
 396             SetMeasuredDimensions(new MeasuredSize(measuredWidth, MeasuredSize.StateType.MeasuredSizeOK),
 397                                    new MeasuredSize(measuredHeight, MeasuredSize.StateType.MeasuredSizeOK));
 398         }
 399
 400         internal override void OnMeasureIndependentChildren(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 401         {
 402             foreach (var childLayout in LayoutChildren)
 403             {
 404                 if (!childLayout.SetPositionByLayout)
 405                 {
 406                     MeasureChildWithoutPadding(childLayout, widthMeasureSpec, heightMeasureSpec);
 407                 }
 408             }
 409         }
 410
 411         /// <summary>
 412         /// Called from Layout() when this layout should assign a size and position to each of its children.<br />
 413         /// Derived classes with children should override this method and call Layout() on each of their children.<br />
 414         /// </summary>
 415         /// <param name="changed">This is a new size or position for this layout.</param>
 416         /// <param name="left">Left position, relative to parent.</param>
 417         /// <param name="top"> Top position, relative to parent.</param>
 418         /// <param name="right">Right position, relative to parent.</param>
 419         /// <param name="bottom">Bottom position, relative to parent.</param>
 420         /// <since_tizen> 6 </since_tizen>
 421         protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 422         {
 423             foreach (LayoutItem childLayout in LayoutChildren)
 424             {
 425                 if (childLayout != null)
 426                 {
 427                     // Use position if explicitly set to child otherwise will be top left.
 428                     var childLeft = new LayoutLength(childLayout.Owner.PositionX);
 429                     var childTop = new LayoutLength(childLayout.Owner.PositionY);
 430
 431                     View owner = Owner;
 432
 433                     if (owner != null)
 434                     {
 435                         // Margin and Padding only supported when child anchor point is TOP_LEFT.
 436                         if (owner.PivotPoint == PivotPoint.TopLeft || (owner.PositionUsesPivotPoint == false))
 437                         {
 438                             childLeft = childLeft + owner.Padding.Start + childLayout.Margin.Start;
 439                             childTop = childTop + owner.Padding.Top + childLayout.Margin.Top;
 440                         }
 441                     }
 442                     childLayout.Layout(childLeft, childTop, childLeft + childLayout.MeasuredWidth.Size, childTop + childLayout.MeasuredHeight.Size);
 443                 }
 444             }
 445         }
 446
 447         /// <summary>
 448         /// Layout independent children those Owners have true ExcludeLayouting. <br />
 449         /// These children are required not to be affected by this layout. <br />
 450         /// </summary>
 451         internal override void OnLayoutIndependentChildren(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 452         {
 453             foreach (var childLayout in LayoutChildren)
 454             {
 455                 if (!childLayout.SetPositionByLayout)
 456                 {
 457                     LayoutLength childWidth = childLayout.MeasuredWidth.Size;
 458                     LayoutLength childHeight = childLayout.MeasuredHeight.Size;
 459
 460                     LayoutLength childPositionX = new LayoutLength(childLayout.Owner.PositionX);
 461                     LayoutLength childPositionY = new LayoutLength(childLayout.Owner.PositionY);
 462
 463                     childLayout.Layout(childPositionX, childPositionY, childPositionX + childWidth, childPositionY + childHeight, true);
 464                 }
 465             }
 466         }
 467
 468         /// <summary>
 469         /// Overridden method called when the layout is attached to an owner.<br />
 470         /// </summary>
 471         /// <since_tizen> 6 </since_tizen>
 472         protected override void OnAttachedToOwner()
 473         {
 474             // Layout takes ownership of it's owner's children.
 475             foreach (View view in Owner.Children)
 476             {
 477                 AddChildToLayoutGroup(view);
 478             }
 479
 480             // Connect to owner ChildAdded signal.
 481             Owner.ChildAdded += OnChildAddedToOwner;
 482
 483             // Removing Child from the owners View will directly call the LayoutGroup removal API.
 484         }
 485
 486         /// <summary>
 487         /// Virtual method to allow derived classes to remove any children before it is removed from
 488         /// its parent.
 489         /// </summary>
 490         [EditorBrowsable(EditorBrowsableState.Never)]
 491         protected override void OnUnparent()
 492         {
 493             // Disconnect to owner ChildAdded signal.
 494             Owner.ChildAdded -= OnChildAddedToOwner;
 495         }
 496
 497         // Virtual Methods that can be overridden by derived classes.
 498
 499         /// <summary>
 500         /// Callback when child is added to container.<br />
 501         /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
 502         /// </summary>
 503         /// <param name="child">The Layout child.</param>
 504         /// <since_tizen> 6 </since_tizen>
 505         protected virtual void OnChildAdd(LayoutItem child)
 506         {
 507         }
 508
 509         /// <summary>
 510         /// Callback when child is removed from container.<br />
 511         /// </summary>
 512         /// <param name="child">The Layout child.</param>
 513         /// <since_tizen> 6 </since_tizen>
 514         protected virtual void OnChildRemove(LayoutItem child)
 515         {
 516         }
 517
 518         /// <summary>
 519         /// Ask all of the children of this view to measure themselves, taking into
 520         /// account both the MeasureSpec requirements for this view and its padding.<br />
 521         /// The heavy lifting is done in GetChildMeasureSpec.<br />
 522         /// </summary>
 523         /// <param name="widthMeasureSpec">The width requirements for this view.</param>
 524         /// <param name="heightMeasureSpec">The height requirements for this view.</param>
 525         /// <since_tizen> 6 </since_tizen>
 526         protected virtual void MeasureChildren(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 527         {
 528             foreach (LayoutItem childLayout in LayoutChildren)
 529             {
 530                 MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
 531             }
 532         }
 533
 534         /// <summary>
 535         /// Ask one of the children of this view to measure itself, taking into
 536         /// account both the MeasureSpec requirements for this view and its padding.<br />
 537         /// The heavy lifting is done in GetChildMeasureSpecification.<br />
 538         /// </summary>
 539         /// <param name="child">The child to measure.</param>
 540         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 541         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 542         /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
 543         /// <since_tizen> 6 </since_tizen>
 544         protected virtual void MeasureChild(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
 545         {
 546             if (null == child)
 547             {
 548                 throw new ArgumentNullException(nameof(child));
 549             }
 550
 551             View childOwner = child.Owner;
 552
 553             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 554                         new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
 555                         new LayoutLength(Padding.Start + Padding.End),
 556                         new LayoutLength(childOwner.WidthSpecification));
 557
 558             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 559                         new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
 560                         new LayoutLength(Padding.Top + Padding.Bottom),
 561                         new LayoutLength(childOwner.HeightSpecification));
 562
 563             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 564         }
 565
 566         /// <summary>
 567         /// Ask one of the children of this view to measure itself, taking into
 568         /// account both the MeasureSpec requirements for this view and its padding.<br />
 569         /// and margins. The heavy lifting is done in GetChildMeasureSpecification.<br />
 570         /// </summary>
 571         /// <param name="child">The child to measure.</param>
 572         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 573         /// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
 574         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 575         /// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
 576         /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
 577         /// <since_tizen> 6 </since_tizen>
 578         protected virtual void MeasureChildWithMargins(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, LayoutLength widthUsed, MeasureSpecification parentHeightMeasureSpec, LayoutLength heightUsed)
 579         {
 580             if (null == child)
 581             {
 582                 throw new ArgumentNullException(nameof(child));
 583             }
 584
 585             View childOwner = child.Owner;
 586             Extents margin = childOwner.Margin;
 587
 588             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 589                         new MeasureSpecification(
 590                             new LayoutLength(parentWidthMeasureSpec.Size + widthUsed - (margin.Start + margin.End)),
 591                             parentWidthMeasureSpec.Mode),
 592                         new LayoutLength(Padding.Start + Padding.End),
 593                         new LayoutLength(childOwner.WidthSpecification));
 594
 595             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 596                         new MeasureSpecification(
 597                             new LayoutLength(parentHeightMeasureSpec.Size + heightUsed - (margin.Top + margin.Bottom)),
 598                             parentHeightMeasureSpec.Mode),
 599                         new LayoutLength(Padding.Top + Padding.Bottom),
 600                         new LayoutLength(childOwner.HeightSpecification));
 601             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 602
 603         }
 604
 605         /// <summary>
 606         /// Ask one of the children of this view to measure itself, taking into
 607         /// account both the MeasureSpec requirements for this view and without its padding.<br />
 608         /// and margins. The heavy lifting is done in GetChildMeasureSpecification.<br />
 609         /// </summary>
 610         /// <param name="child">The child to measure.</param>
 611         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 612         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 613         [EditorBrowsable(EditorBrowsableState.Never)]
 614         protected void MeasureChildWithoutPadding(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
 615         {
 616             View childOwner = child.Owner;
 617
 618             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 619                         new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
 620                         new LayoutLength(0),
 621                         new LayoutLength(childOwner.WidthSpecification));
 622
 623             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 624                         new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
 625                         new LayoutLength(0),
 626                         new LayoutLength(childOwner.HeightSpecification));
 627
 628             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 629         }
 630
 631         /// <summary>
 632         /// Gets the value that is contained in the attached BindableProperty.
 633         /// </summary>
 634         /// <typeparam name="T">The return type of property</typeparam>
 635         /// <param name="bindable">The bindable object.</param>
 636         /// <param name="property">The BindableProperty for which to get the value.</param>
 637         /// <returns>The value that is contained in the attached BindableProperty.</returns>
 638         [EditorBrowsable(EditorBrowsableState.Never)]
 639         public static T GetAttachedValue<T>(Binding.BindableObject bindable, Binding.BindableProperty property)
 640         {
 641             if (bindable == null)
 642                 throw new ArgumentNullException(nameof(bindable));
 643
 644             return (T)bindable.GetValue(property);
 645         }
 646
 647         /// <summary>
 648         /// Sets the value of the attached property.
 649         /// </summary>
 650         /// <param name="bindable">The bindable object.</param>
 651         /// <param name="property">The BindableProperty on which to assign a value.</param>
 652         /// <param name="value">The value to set.</param>
 653         [EditorBrowsable(EditorBrowsableState.Never)]
 654         public static void SetAttachedValue(Binding.BindableObject bindable, Binding.BindableProperty property, object value)
 655         {
 656             if (bindable == null)
 657                 throw new ArgumentNullException(nameof(bindable));
 658
 659             bindable.SetValueCore(property, value, SetValueFlags.None, SetValuePrivateFlags.ManuallySet, false);
 660         }
 661         internal static void OnChildPropertyChanged(Binding.BindableObject bindable, object oldValue, object newValue)
 662         {
 663             // Unused parameters
 664             _ = oldValue;
 665             _ = newValue;
 666
 667             View view = bindable as View;
 668             view?.Layout?.RequestLayout();
 669         }
 670
 671         internal static Binding.BindableProperty.ValidateValueDelegate ValidateEnum(int enumMin, int enumMax)
 672         {
 673             return (Binding.BindableObject bindable, object value) =>
 674             {
 675                 int @enum = (int)value;
 676                 return enumMin <= @enum && @enum <= enumMax;
 677             };
 678         }
 679     }
 680 }