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
 142         /// <summary>
 143         /// Sets the sibling order of the layout item so the layout can be defined within the same parent.
 144         /// </summary>
 145         /// <param name="order">the sibling order of the layout item</param>
 146         /// <since_tizen> 6 </since_tizen>
 147         /// This will be public opened in tizen_next after ACR done. Before ACR, need to be hidden as inhouse API.
 148         [EditorBrowsable(EditorBrowsableState.Never)]
 149         public void ChangeLayoutSiblingOrder(int order)
 150         {
 151             if (Owner != null)
 152             {
 153                 var ownerParent = Owner.GetParent() as View;
 154                 if (ownerParent != null)
 155                 {
 156                     var parent = ownerParent.Layout as LayoutGroup;
 157
 158                     if (parent != null && parent.LayoutChildren.Count > order)
 159                     {
 160                         parent.LayoutChildren.Remove(this);
 161                         parent.LayoutChildren.Insert(order, this);
 162                     }
 163                 }
 164             }
 165             RequestLayout();
 166         }
 167
 168         // Attaches to View ChildAdded signal so called when a View is added to a view.
 169         private void AddChildToLayoutGroup(View child)
 170         {
 171             if (View.LayoutingDisabled)
 172             {
 173                 return;
 174             }
 175             // Only give children a layout if their parent is an explicit container or a pure View.
 176             // Pure View meaning not derived from a View, e.g a Legacy container.
 177             // layoutSet flag is true when the View became a layout using the set Layout API opposed to automatically due to it's parent.
 178             // First time the set Layout API is used by any View the Window no longer has layoutingDisabled.
 179
 180             // If child already has a Layout then don't change it.
 181             if (null == child.Layout)
 182             {
 183                 // Only wrap View with a Layout if a child a pure View or Layout explicitly set on this Layout
 184                 if ((true == Owner.LayoutSet || GetType() == typeof(View)))
 185                 {
 186                     // If child of this layout is a pure View then assign it a LayoutGroup
 187                     // If the child is derived from a View then it may be a legacy or existing container hence will do layouting itself.
 188                     child.Layout = child.CreateDefaultLayout();
 189                 }
 190             }
 191             else
 192             {
 193                 Add(child.Layout);
 194             }
 195             // Parent transitions are not attached to children.
 196         }
 197
 198         /// <summary>
 199         /// If the child has a layout then it is removed from the parent layout.
 200         /// </summary>
 201         /// <param name="child">Child View to remove.</param>
 202         internal void RemoveChildFromLayoutGroup(View child)
 203         {
 204             if (child.Layout != null)
 205             {
 206                 Remove(child.Layout);
 207             }
 208         }
 209
 210         /// <summary>
 211         /// Set all children in a LayoutGroup to the supplied condition.
 212         /// Children with Add or Remove conditions should not be changed.
 213         /// </summary>
 214         private void SetConditionsForAnimationOnLayoutGroup(TransitionCondition conditionToSet)
 215         {
 216             foreach (LayoutItem childLayout in LayoutChildren)
 217             {
 218                 switch (conditionToSet)
 219                 {
 220                     case TransitionCondition.ChangeOnAdd:
 221                         {
 222                             // If other children also being added (TransitionCondition.Add) then do not change their
 223                             // conditions, Continue to use their Add transitions.
 224                             if (childLayout.ConditionForAnimation.HasFlag(TransitionCondition.Add))
 225                             {
 226                                 break;  // Child being Added so don't update it's condition
 227                             }
 228                             else
 229                             {
 230                                 // Set siblings for the child being added to use the ChangeOnAdd transition.
 231                                 childLayout.ConditionForAnimation = TransitionCondition.ChangeOnAdd;
 232                             }
 233                             break;
 234                         }
 235                     case TransitionCondition.ChangeOnRemove:
 236                         {
 237                             if (childLayout.ConditionForAnimation.HasFlag(TransitionCondition.Remove))
 238                             {
 239                                 break; // Child being Removed so don't update it's condition
 240                             }
 241                             else
 242                             {
 243                                 childLayout.ConditionForAnimation = TransitionCondition.ChangeOnRemove;
 244                             }
 245                             break;
 246                         }
 247                     case TransitionCondition.LayoutChanged:
 248                         {
 249                             childLayout.ConditionForAnimation = TransitionCondition.LayoutChanged;
 250                             break;
 251                         }
 252                 }
 253             }
 254
 255         }
 256
 257         /// <summary>
 258         /// Callback for View.ChildAdded event
 259         /// </summary>
 260         /// <param name="sender">The object triggering the event.</param>
 261         /// <param name="childAddedEvent">Arguments from the event.</param>
 262         void OnChildAddedToOwner(object sender, View.ChildAddedEventArgs childAddedEvent)
 263         {
 264             AddChildToLayoutGroup(childAddedEvent.Added);
 265         }
 266
 267         /// <summary>
 268         /// Callback for View.ChildRemoved event
 269         /// </summary>
 270         /// <param name="sender">The object triggering the event.</param>
 271         /// <param name="childRemovedEvent">Arguments from the event.</param>
 272         void OnChildRemovedFromOwner(object sender, View.ChildRemovedEventArgs childRemovedEvent)
 273         {
 274             RemoveChildFromLayoutGroup(childRemovedEvent.Removed);
 275         }
 276
 277         /// <summary>
 278         /// Calculate the right measure spec for this child.
 279         /// Does the hard part of MeasureChildren: figuring out the MeasureSpec to
 280         /// pass to a particular child. This method figures out the right MeasureSpec
 281         /// for one dimension (height or width) of one child view.<br />
 282         /// </summary>
 283         /// <param name="parentMeasureSpec">The requirements for this view. MeasureSpecification.</param>
 284         /// <param name="padding">The padding of this view for the current dimension and margins, if applicable. LayoutLength.</param>
 285         /// <param name="childDimension"> How big the child wants to be in the current dimension. LayoutLength.</param>
 286         /// <returns>a MeasureSpec for the child.</returns>
 287         public static MeasureSpecification GetChildMeasureSpecification(MeasureSpecification parentMeasureSpec, LayoutLength padding, LayoutLength childDimension)
 288         {
 289             MeasureSpecification.ModeType specMode = parentMeasureSpec.Mode;
 290             MeasureSpecification.ModeType resultMode = MeasureSpecification.ModeType.Unspecified;
 291
 292             // Child only can use parent's size without parent's padding and own margin.
 293             LayoutLength resultSize = new LayoutLength(Math.Max(0.0f, (parentMeasureSpec.Size - padding).AsDecimal()));
 294             switch (specMode)
 295             {
 296                 // Parent has imposed an exact size on us
 297                 case MeasureSpecification.ModeType.Exactly:
 298                     {
 299                         if ((int)childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent)
 300                         {
 301                             resultMode = MeasureSpecification.ModeType.Exactly;
 302                         }
 303                         else if ((int)childDimension.AsRoundedValue() == LayoutParamPolicies.WrapContent)
 304                         {
 305                             resultMode = MeasureSpecification.ModeType.AtMost;
 306                         }
 307                         else
 308                         {
 309                             resultSize = childDimension;
 310                             resultMode = MeasureSpecification.ModeType.Exactly;
 311                         }
 312
 313                         break;
 314                     }
 315
 316                 // Parent has imposed a maximum size on us
 317                 case MeasureSpecification.ModeType.AtMost:
 318                     {
 319                         if (childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent)
 320                         {
 321                             // Crashed. Cannot calculate.
 322
 323                             // Child wants to be our size, but our size is not fixed.
 324                             // Constrain child to not be bigger than us.
 325                             resultMode = MeasureSpecification.ModeType.AtMost;
 326                         }
 327                         else if (childDimension.AsRoundedValue() == LayoutParamPolicies.WrapContent)
 328                         {
 329                             // Child wants to determine its own size. It can't be
 330                             // bigger than us.
 331
 332                             // Don't need parent's size. Size of this child will be determined by its children.
 333                             resultMode = MeasureSpecification.ModeType.AtMost;
 334                         }
 335                         else
 336                         {
 337                             // Child wants a specific size... so be it
 338                             resultSize = childDimension;
 339                             resultMode = MeasureSpecification.ModeType.Exactly;
 340                         }
 341
 342                         break;
 343                     }
 344
 345                 // Parent asked to see how big we want to be
 346                 case MeasureSpecification.ModeType.Unspecified:
 347                     {
 348                         if ((childDimension.AsRoundedValue() == LayoutParamPolicies.MatchParent))
 349                         {
 350                             // Child wants to be our size... find out how big it should be
 351
 352                             // There is no one who has exact size in parent hierarchy.
 353                             // Cannot calculate.
 354                             resultMode = MeasureSpecification.ModeType.Unspecified;
 355                         }
 356                         else if (childDimension.AsRoundedValue() == (LayoutParamPolicies.WrapContent))
 357                         {
 358                             // Child wants to determine its own size.... find out how big
 359                             // it should be
 360                             resultMode = MeasureSpecification.ModeType.Unspecified;
 361                         }
 362                         else
 363                         {
 364                             // Child wants a specific size... let him have it
 365                             resultSize = childDimension;
 366                             resultMode = MeasureSpecification.ModeType.Exactly;
 367                         }
 368                         break;
 369                     }
 370             } // switch
 371
 372             return new MeasureSpecification(resultSize, resultMode);
 373         }
 374
 375         /// <summary>
 376         /// Measure the layout and its content to determine the measured width and the measured height.<br />
 377         /// If this method is overridden, it is the subclass's responsibility to make
 378         /// sure the measured height and width are at least the layout's minimum height
 379         /// and width. <br />
 380         /// </summary>
 381         /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
 382         /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
 383         /// <since_tizen> 6 </since_tizen>
 384         protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 385         {
 386             LayoutLength measuredWidth = new LayoutLength(0.0f);
 387             LayoutLength measuredHeight = new LayoutLength(0.0f);
 388
 389             // Layout takes size of largest child width and largest child height dimensions
 390             foreach (LayoutItem childLayout in LayoutChildren)
 391             {
 392                 if (childLayout != null)
 393                 {
 394                     MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
 395                     LayoutLength childWidth = new LayoutLength(childLayout.MeasuredWidth.Size);
 396                     LayoutLength childHeight = new LayoutLength(childLayout.MeasuredHeight.Size);
 397
 398                     Extents childMargin = childLayout.Margin;
 399                     measuredWidth = new LayoutLength(Math.Max(measuredWidth.AsDecimal(), childWidth.AsDecimal() + childMargin.Start + childMargin.End));
 400                     measuredHeight = new LayoutLength(Math.Max(measuredHeight.AsDecimal(), childHeight.AsDecimal() + childMargin.Top + childMargin.Bottom));
 401                 }
 402             }
 403
 404             if (0 == LayoutChildren.Count)
 405             {
 406                 // Must be a leaf as has no children
 407                 measuredWidth = GetDefaultSize(SuggestedMinimumWidth, widthMeasureSpec);
 408                 measuredHeight = GetDefaultSize(SuggestedMinimumHeight, heightMeasureSpec);
 409             }
 410
 411             SetMeasuredDimensions(new MeasuredSize(measuredWidth, MeasuredSize.StateType.MeasuredSizeOK),
 412                                    new MeasuredSize(measuredHeight, MeasuredSize.StateType.MeasuredSizeOK));
 413         }
 414
 415         internal override void OnMeasureIndependentChildren(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 416         {
 417             foreach (var childLayout in LayoutChildren)
 418             {
 419                 if (!childLayout.SetPositionByLayout)
 420                 {
 421                     MeasureChildWithoutPadding(childLayout, widthMeasureSpec, heightMeasureSpec);
 422                 }
 423             }
 424         }
 425
 426         /// <summary>
 427         /// Called from Layout() when this layout should assign a size and position to each of its children.<br />
 428         /// Derived classes with children should override this method and call Layout() on each of their children.<br />
 429         /// </summary>
 430         /// <param name="changed">This is a new size or position for this layout.</param>
 431         /// <param name="left">Left position, relative to parent.</param>
 432         /// <param name="top"> Top position, relative to parent.</param>
 433         /// <param name="right">Right position, relative to parent.</param>
 434         /// <param name="bottom">Bottom position, relative to parent.</param>
 435         /// <since_tizen> 6 </since_tizen>
 436         protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 437         {
 438             foreach (LayoutItem childLayout in LayoutChildren)
 439             {
 440                 if (childLayout != null)
 441                 {
 442                     // Use position if explicitly set to child otherwise will be top left.
 443                     var childLeft = new LayoutLength(childLayout.Owner.PositionX);
 444                     var childTop = new LayoutLength(childLayout.Owner.PositionY);
 445
 446                     View owner = Owner;
 447
 448                     if (owner != null)
 449                     {
 450                         // Margin and Padding only supported when child anchor point is TOP_LEFT.
 451                         if (owner.PivotPoint == PivotPoint.TopLeft || (owner.PositionUsesPivotPoint == false))
 452                         {
 453                             childLeft = childLeft + owner.Padding.Start + childLayout.Margin.Start;
 454                             childTop = childTop + owner.Padding.Top + childLayout.Margin.Top;
 455                         }
 456                     }
 457                     childLayout.Layout(childLeft, childTop, childLeft + childLayout.MeasuredWidth.Size, childTop + childLayout.MeasuredHeight.Size);
 458                 }
 459             }
 460         }
 461
 462         /// <summary>
 463         /// Layout independent children those Owners have true ExcludeLayouting. <br />
 464         /// These children are required not to be affected by this layout. <br />
 465         /// </summary>
 466         internal override void OnLayoutIndependentChildren(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 467         {
 468             foreach (var childLayout in LayoutChildren)
 469             {
 470                 if (!childLayout.SetPositionByLayout)
 471                 {
 472                     LayoutLength childWidth = childLayout.MeasuredWidth.Size;
 473                     LayoutLength childHeight = childLayout.MeasuredHeight.Size;
 474
 475                     LayoutLength childPositionX = new LayoutLength(childLayout.Owner.PositionX);
 476                     LayoutLength childPositionY = new LayoutLength(childLayout.Owner.PositionY);
 477
 478                     childLayout.Layout(childPositionX, childPositionY, childPositionX + childWidth, childPositionY + childHeight, true);
 479                 }
 480             }
 481         }
 482
 483         /// <summary>
 484         /// Overridden method called when the layout is attached to an owner.<br />
 485         /// </summary>
 486         /// <since_tizen> 6 </since_tizen>
 487         protected override void OnAttachedToOwner()
 488         {
 489             // Layout takes ownership of it's owner's children.
 490             foreach (View view in Owner.Children)
 491             {
 492                 AddChildToLayoutGroup(view);
 493             }
 494
 495             // Connect to owner ChildAdded signal.
 496             Owner.ChildAdded += OnChildAddedToOwner;
 497
 498             // Removing Child from the owners View will directly call the LayoutGroup removal API.
 499         }
 500
 501         /// <summary>
 502         /// Virtual method to allow derived classes to remove any children before it is removed from
 503         /// its parent.
 504         /// </summary>
 505         [EditorBrowsable(EditorBrowsableState.Never)]
 506         protected override void OnUnparent()
 507         {
 508             // Disconnect to owner ChildAdded signal.
 509             Owner.ChildAdded -= OnChildAddedToOwner;
 510         }
 511
 512         // Virtual Methods that can be overridden by derived classes.
 513
 514         /// <summary>
 515         /// Callback when child is added to container.<br />
 516         /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
 517         /// </summary>
 518         /// <param name="child">The Layout child.</param>
 519         /// <since_tizen> 6 </since_tizen>
 520         protected virtual void OnChildAdd(LayoutItem child)
 521         {
 522         }
 523
 524         /// <summary>
 525         /// Callback when child is removed from container.<br />
 526         /// </summary>
 527         /// <param name="child">The Layout child.</param>
 528         /// <since_tizen> 6 </since_tizen>
 529         protected virtual void OnChildRemove(LayoutItem child)
 530         {
 531         }
 532
 533         /// <summary>
 534         /// Ask all of the children of this view to measure themselves, taking into
 535         /// account both the MeasureSpec requirements for this view and its padding.<br />
 536         /// The heavy lifting is done in GetChildMeasureSpec.<br />
 537         /// </summary>
 538         /// <param name="widthMeasureSpec">The width requirements for this view.</param>
 539         /// <param name="heightMeasureSpec">The height requirements for this view.</param>
 540         /// <since_tizen> 6 </since_tizen>
 541         protected virtual void MeasureChildren(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 542         {
 543             foreach (LayoutItem childLayout in LayoutChildren)
 544             {
 545                 MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
 546             }
 547         }
 548
 549         /// <summary>
 550         /// Ask one of the children of this view to measure itself, taking into
 551         /// account both the MeasureSpec requirements for this view and its padding.<br />
 552         /// The heavy lifting is done in GetChildMeasureSpecification.<br />
 553         /// </summary>
 554         /// <param name="child">The child to measure.</param>
 555         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 556         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 557         /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
 558         /// <since_tizen> 6 </since_tizen>
 559         protected virtual void MeasureChild(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
 560         {
 561             if (null == child)
 562             {
 563                 throw new ArgumentNullException(nameof(child));
 564             }
 565
 566             View childOwner = child.Owner;
 567
 568             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 569                         new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
 570                         new LayoutLength(Padding.Start + Padding.End),
 571                         new LayoutLength(childOwner.WidthSpecification));
 572
 573             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 574                         new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
 575                         new LayoutLength(Padding.Top + Padding.Bottom),
 576                         new LayoutLength(childOwner.HeightSpecification));
 577
 578             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 579         }
 580
 581         /// <summary>
 582         /// Ask one of the children of this view to measure itself, taking into
 583         /// account both the MeasureSpec requirements for this view and its padding.<br />
 584         /// and margins. The heavy lifting is done in GetChildMeasureSpecification.<br />
 585         /// </summary>
 586         /// <param name="child">The child to measure.</param>
 587         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 588         /// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
 589         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 590         /// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
 591         /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
 592         /// <since_tizen> 6 </since_tizen>
 593         protected virtual void MeasureChildWithMargins(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, LayoutLength widthUsed, MeasureSpecification parentHeightMeasureSpec, LayoutLength heightUsed)
 594         {
 595             if (null == child)
 596             {
 597                 throw new ArgumentNullException(nameof(child));
 598             }
 599
 600             View childOwner = child.Owner;
 601             Extents margin = childOwner.Margin;
 602
 603             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 604                         new MeasureSpecification(
 605                             new LayoutLength(parentWidthMeasureSpec.Size + widthUsed - (margin.Start + margin.End)),
 606                             parentWidthMeasureSpec.Mode),
 607                         new LayoutLength(Padding.Start + Padding.End),
 608                         new LayoutLength(childOwner.WidthSpecification));
 609
 610             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 611                         new MeasureSpecification(
 612                             new LayoutLength(parentHeightMeasureSpec.Size + heightUsed - (margin.Top + margin.Bottom)),
 613                             parentHeightMeasureSpec.Mode),
 614                         new LayoutLength(Padding.Top + Padding.Bottom),
 615                         new LayoutLength(childOwner.HeightSpecification));
 616             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 617
 618         }
 619
 620         /// <summary>
 621         /// Ask one of the children of this view to measure itself, taking into
 622         /// account both the MeasureSpec requirements for this view and without its padding.<br />
 623         /// and margins. The heavy lifting is done in GetChildMeasureSpecification.<br />
 624         /// </summary>
 625         /// <param name="child">The child to measure.</param>
 626         /// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
 627         /// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
 628         [EditorBrowsable(EditorBrowsableState.Never)]
 629         protected void MeasureChildWithoutPadding(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
 630         {
 631             View childOwner = child.Owner;
 632
 633             MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
 634                         new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
 635                         new LayoutLength(0),
 636                         new LayoutLength(childOwner.WidthSpecification));
 637
 638             MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
 639                         new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
 640                         new LayoutLength(0),
 641                         new LayoutLength(childOwner.HeightSpecification));
 642
 643             child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
 644         }
 645
 646         /// <summary>
 647         /// Gets the value that is contained in the attached BindableProperty.
 648         /// </summary>
 649         /// <typeparam name="T">The return type of property</typeparam>
 650         /// <param name="bindable">The bindable object.</param>
 651         /// <param name="property">The BindableProperty for which to get the value.</param>
 652         /// <returns>The value that is contained in the attached BindableProperty.</returns>
 653         [EditorBrowsable(EditorBrowsableState.Never)]
 654         public static T GetAttachedValue<T>(Binding.BindableObject bindable, Binding.BindableProperty property)
 655         {
 656             if (bindable == null)
 657                 throw new ArgumentNullException(nameof(bindable));
 658
 659             return (T)bindable.GetValue(property);
 660         }
 661
 662         /// <summary>
 663         /// Sets the value of the attached property.
 664         /// </summary>
 665         /// <param name="bindable">The bindable object.</param>
 666         /// <param name="property">The BindableProperty on which to assign a value.</param>
 667         /// <param name="value">The value to set.</param>
 668         [EditorBrowsable(EditorBrowsableState.Never)]
 669         public static void SetAttachedValue(Binding.BindableObject bindable, Binding.BindableProperty property, object value)
 670         {
 671             if (bindable == null)
 672                 throw new ArgumentNullException(nameof(bindable));
 673
 674             bindable.SetValueCore(property, value, SetValueFlags.None, SetValuePrivateFlags.ManuallySet, false);
 675         }
 676         internal static void OnChildPropertyChanged(Binding.BindableObject bindable, object oldValue, object newValue)
 677         {
 678             // Unused parameters
 679             _ = oldValue;
 680             _ = newValue;
 681
 682             View view = bindable as View;
 683             view?.Layout?.RequestLayout();
 684         }
 685
 686         internal static Binding.BindableProperty.ValidateValueDelegate ValidateEnum(int enumMin, int enumMax)
 687         {
 688             return (Binding.BindableObject bindable, object value) =>
 689             {
 690                 int @enum = (int)value;
 691                 return enumMin <= @enum && @enum <= enumMax;
 692             };
 693         }
 694     }
 695 }