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

   1 /* Copyright (c) 2020 Samsung Electronics Co., Ltd.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  * http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  *
  15  */
  16 using System;
  17 using System.ComponentModel;
  18 using Tizen.NUI.BaseComponents;
  19 using Tizen.NUI.Binding;
  20
  21 namespace Tizen.NUI
  22 {
  23     /// <summary>
  24     /// RelativeLayout calculates the size and position of all the children based on their relationship to each other.
  25     /// </summary>
  26     /// <since_tizen> 9 </since_tizen>
  27     public partial class RelativeLayout : LayoutGroup
  28     {
  29         /// <summary>
  30         /// LeftTargetProperty
  31         /// </summary>
  32         [EditorBrowsable(EditorBrowsableState.Never)]
  33         public static readonly BindableProperty LeftTargetProperty = BindableProperty.CreateAttached("LeftTarget", typeof(View), typeof(RelativeLayout), null, propertyChanged: OnChildPropertyChanged);
  34
  35         /// <summary>
  36         /// RightTargetProperty
  37         /// </summary>
  38         [EditorBrowsable(EditorBrowsableState.Never)]
  39         public static readonly BindableProperty RightTargetProperty = BindableProperty.CreateAttached("RightTarget", typeof(View), typeof(RelativeLayout), null, propertyChanged: OnChildPropertyChanged);
  40
  41         /// <summary>
  42         /// TopTargetProperty
  43         /// </summary>
  44         [EditorBrowsable(EditorBrowsableState.Never)]
  45         public static readonly BindableProperty TopTargetProperty = BindableProperty.CreateAttached("TopTarget", typeof(View), typeof(RelativeLayout), null, propertyChanged: OnChildPropertyChanged);
  46
  47         /// <summary>
  48         /// BottomTargetProperty
  49         /// </summary>
  50         [EditorBrowsable(EditorBrowsableState.Never)]
  51         public static readonly BindableProperty BottomTargetProperty = BindableProperty.CreateAttached("BottomTarget", typeof(View), typeof(RelativeLayout), null, propertyChanged: OnChildPropertyChanged);
  52
  53         /// <summary>
  54         /// LeftRelativeOffsetProperty
  55         /// </summary>
  56         [EditorBrowsable(EditorBrowsableState.Never)]
  57         public static readonly BindableProperty LeftRelativeOffsetProperty = BindableProperty.CreateAttached("LeftRelativeOffset", typeof(float), typeof(RelativeLayout), 0.0f, propertyChanged: OnChildPropertyChanged);
  58
  59         /// <summary>
  60         /// RightRelativeOffsetProperty
  61         /// </summary>
  62         [EditorBrowsable(EditorBrowsableState.Never)]
  63         public static readonly BindableProperty RightRelativeOffsetProperty = BindableProperty.CreateAttached("RightRelativeOffset", typeof(float), typeof(RelativeLayout), 1.0f, propertyChanged: OnChildPropertyChanged);
  64
  65         /// <summary>
  66         /// TopRelativeOffsetProperty
  67         /// </summary>
  68         [EditorBrowsable(EditorBrowsableState.Never)]
  69         public static readonly BindableProperty TopRelativeOffsetProperty = BindableProperty.CreateAttached("TopRelativeOffset", typeof(float), typeof(RelativeLayout), 0.0f, propertyChanged: OnChildPropertyChanged);
  70
  71         /// <summary>
  72         /// BottomRelativeOffsetProperty
  73         /// </summary>
  74         [EditorBrowsable(EditorBrowsableState.Never)]
  75         public static readonly BindableProperty BottomRelativeOffsetProperty = BindableProperty.CreateAttached("BottomRelativeOffset", typeof(float), typeof(RelativeLayout), 1.0f, propertyChanged: OnChildPropertyChanged);
  76
  77         /// <summary>
  78         /// HorizontalAlignmentProperty
  79         /// </summary>
  80         [EditorBrowsable(EditorBrowsableState.Never)]
  81         public static readonly BindableProperty HorizontalAlignmentProperty = BindableProperty.CreateAttached("HorizontalAlignment", typeof(Alignment), typeof(RelativeLayout), default(Alignment), propertyChanged: OnChildPropertyChanged);
  82
  83         /// <summary>
  84         /// VerticalAlignmentProperty
  85         /// </summary>
  86         [EditorBrowsable(EditorBrowsableState.Never)]
  87         public static readonly BindableProperty VerticalAlignmentProperty = BindableProperty.CreateAttached("VerticalAlignment", typeof(Alignment), typeof(RelativeLayout), default(Alignment), propertyChanged: OnChildPropertyChanged);
  88
  89         /// <summary>
  90         /// FillHorizontalProperty
  91         /// </summary>
  92         [EditorBrowsable(EditorBrowsableState.Never)]
  93         public static readonly BindableProperty FillHorizontalProperty = BindableProperty.CreateAttached("FillHorizontal", typeof(bool), typeof(RelativeLayout), false, propertyChanged: OnChildPropertyChanged);
  94
  95         /// <summary>
  96         /// FillVerticalProperty
  97         /// </summary>
  98         [EditorBrowsable(EditorBrowsableState.Never)]
  99         public static readonly BindableProperty FillVerticalProperty = BindableProperty.CreateAttached("FillVertical", typeof(bool), typeof(RelativeLayout), false, propertyChanged: OnChildPropertyChanged);
 100
 101         /// <summary>
 102         /// Constructor
 103         /// </summary>
 104         /// <since_tizen> 9 </since_tizen>
 105         public RelativeLayout() { }
 106
 107         /// <summary>
 108         /// Gets left target object whose size and position is being used as reference.
 109         /// </summary>
 110         /// <param name="view">The child view whose size and position is being changed.</param>
 111         /// <returns>The object whose size and position is being used as reference.</returns>
 112         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 113         /// <since_tizen> 9 </since_tizen>
 114         [Binding.TypeConverter(typeof(RelativeTargetConverter))]
 115         public static View GetLeftTarget(BindableObject view) => GetAttachedValue<View>(view, LeftTargetProperty);
 116
 117         /// <summary>
 118         /// Gets right target object whose size and position is being used as reference.
 119         /// </summary>
 120         /// <param name="view">The child view whose size and position is being changed.</param>
 121         /// <returns>The object whose size and position is being used as reference.</returns>
 122         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 123         /// <since_tizen> 9 </since_tizen>
 124         [Binding.TypeConverter(typeof(RelativeTargetConverter))]
 125         public static View GetRightTarget(BindableObject view) => GetAttachedValue<View>(view, RightTargetProperty);
 126
 127         /// <summary>
 128         /// Gets top target object whose size and position is being used as reference.
 129         /// </summary>
 130         /// <param name="view">The child view whose size and position is being changed.</param>
 131         /// <returns>The object whose size and position is being used as reference.</returns>
 132         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 133         /// <since_tizen> 9 </since_tizen>
 134         [Binding.TypeConverter(typeof(RelativeTargetConverter))]
 135         public static View GetTopTarget(BindableObject view) => GetAttachedValue<View>(view, TopTargetProperty);
 136
 137         /// <summary>
 138         /// Gets bottom target object whose size and position is being used as reference.
 139         /// </summary>
 140         /// <param name="view">The child view whose size and position is being changed.</param>
 141         /// <returns>The object whose size and position is being used as reference.</returns>
 142         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 143         /// <since_tizen> 9 </since_tizen>
 144         [Binding.TypeConverter(typeof(RelativeTargetConverter))]
 145         public static View GetBottomTarget(BindableObject view) => GetAttachedValue<View>(view, BottomTargetProperty);
 146
 147         /// <summary>
 148         /// Gets left relative offset.
 149         /// </summary>
 150         /// <param name="view">The child view whose size and position is being changed.</param>
 151         /// <returns>The ratio between left and right of the <seealso cref="LeftTargetProperty"/>.</returns>
 152         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 153         /// <since_tizen> 9 </since_tizen>
 154         public static float GetLeftRelativeOffset(View view) => GetAttachedValue<float>(view, LeftRelativeOffsetProperty);
 155
 156         /// <summary>
 157         /// Gets right relative offset.
 158         /// </summary>
 159         /// <param name="view">The child view whose size and position is being changed.</param>
 160         /// <returns>The ratio between left and right of the <seealso cref="RightTargetProperty"/>.</returns>
 161         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 162         /// <since_tizen> 9 </since_tizen>
 163         public static float GetRightRelativeOffset(View view) => GetAttachedValue<float>(view, RightRelativeOffsetProperty);
 164
 165         /// <summary>
 166         /// Gets top relative offset.
 167         /// </summary>
 168         /// <param name="view">The child view whose size and position is being changed.</param>
 169         /// <returns>The ratio between top and bottom of the <seealso cref="TopTargetProperty"/>.</returns>
 170         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 171         /// <since_tizen> 9 </since_tizen>
 172         public static float GetTopRelativeOffset(View view) => GetAttachedValue<float>(view, TopRelativeOffsetProperty);
 173
 174         /// <summary>
 175         /// Gets bottom relative offset.
 176         /// </summary>
 177         /// <param name="view">The child view whose size and position is being changed.</param>
 178         /// <returns>The ratio between top and bottom of the <seealso cref="BottomTargetProperty"/>.</returns>
 179         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 180         /// <since_tizen> 9 </since_tizen>
 181         public static float GetBottomRelativeOffset(View view) => GetAttachedValue<float>(view, BottomRelativeOffsetProperty);
 182
 183         /// <summary>
 184         /// Gets the horizontal alignment
 185         /// </summary>
 186         /// <param name="view">The child view.</param>
 187         /// <returns>The horizontal alignment of <paramref name="view"/>.</returns>
 188         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 189         /// <since_tizen> 9 </since_tizen>
 190         public static Alignment GetHorizontalAlignment(View view) => GetAttachedValue<Alignment>(view, HorizontalAlignmentProperty);
 191
 192         /// <summary>
 193         /// Gets the vertical alignment
 194         /// </summary>
 195         /// <param name="view">The child view.</param>
 196         /// <returns>The vertical alignment of <paramref name="view"/>.</returns>
 197         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 198         /// <since_tizen> 9 </since_tizen>
 199         public static Alignment GetVerticalAlignment(View view) => GetAttachedValue<Alignment>(view, VerticalAlignmentProperty);
 200
 201         /// <summary>
 202         /// Gets the boolean value whether child fills its horizontal space.
 203         /// </summary>
 204         /// <param name="view">The child view.</param>
 205         /// <returns>True if to fill the space, false otherwise.</returns>
 206         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 207         /// <since_tizen> 9 </since_tizen>
 208         public static bool GetFillHorizontal(View view) => GetAttachedValue<bool>(view, FillHorizontalProperty);
 209
 210         /// <summary>
 211         /// Gets the boolean value whether child fills its vertical space.
 212         /// </summary>
 213         /// <param name="view">The child view.</param>
 214         /// <returns>True if to fill the space, false otherwise.</returns>
 215         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 216         /// <since_tizen> 9 </since_tizen>
 217         public static bool GetFillVertical(View view) => GetAttachedValue<bool>(view, FillVerticalProperty);
 218
 219         /// <summary>
 220         /// Specifies the left side edge of the child view relative to the target view. <br/>
 221         /// null <paramref name="reference"/> means parent relative layout.
 222         /// </summary>
 223         /// <param name="view">The child view whose size and position is being changed.</param>
 224         /// <param name="reference">The object whose size and position is being used as reference.</param>
 225         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 226         /// <since_tizen> 9 </since_tizen>
 227         public static void SetLeftTarget(View view, View reference) => SetAttachedValue(view, LeftTargetProperty, reference);
 228
 229         /// <summary>
 230         /// Specifies the right side edge of the child view relative to the target view. <br/>
 231         /// null <paramref name="reference"/> means parent relative layout.
 232         /// </summary>
 233         /// <param name="view">The child view whose size and position is being changed.</param>
 234         /// <param name="reference">The object whose size and position is being used as reference.</param>
 235         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 236         /// <since_tizen> 9 </since_tizen>
 237         public static void SetRightTarget(View view, View reference) => SetAttachedValue(view, RightTargetProperty, reference);
 238
 239         /// <summary>
 240         /// Specifies the top side edge of the child view relative to the target view. <br/>
 241         /// null <paramref name="reference"/> means parent relative layout.
 242         /// </summary>
 243         /// <param name="view">The child view whose size and position is being changed.</param>
 244         /// <param name="reference">The object whose size and position is being used as reference.</param>
 245         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 246         /// <since_tizen> 9 </since_tizen>
 247         public static void SetTopTarget(View view, View reference) => SetAttachedValue(view, TopTargetProperty, reference);
 248
 249         /// <summary>
 250         /// Specifies the bottom side edge of the child view relative to the target view. <br/>
 251         /// null <paramref name="reference"/> means parent relative layout.
 252         /// </summary>
 253         /// <param name="view">The child view whose size and position is being changed.</param>
 254         /// <param name="reference">The object whose size and position is being used as reference.</param>
 255         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 256         /// <since_tizen> 9 </since_tizen>
 257         public static void SetBottomTarget(View view, View reference) => SetAttachedValue(view, BottomTargetProperty, reference);
 258
 259         /// <summary>
 260         /// Sets the relative offset for left target.
 261         /// When <paramref name="value"/> is 0 the left edges of the left target and <paramref name="view"/> are aligned.<br/>
 262         /// When <paramref name="value"/> is 1 the left edge of the <paramref name="view"/> is aligned to the right edge of the left target.
 263         /// </summary>
 264         /// <param name="view">The child view whose size and position is being changed.</param>
 265         /// <param name="value">The ratio between left and right of the <seealso cref="LeftTargetProperty"/>.</param>
 266         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 267         /// <since_tizen> 9 </since_tizen>
 268         public static void SetLeftRelativeOffset(View view, float value) => SetAttachedValue(view, LeftRelativeOffsetProperty, value);
 269
 270         /// <summary>
 271         /// Sets the relative offset for right target.
 272         /// When <paramref name="value"/> is 0 the right edge of the <paramref name="view"/> is aligned to the left edge of the right target.<br/>
 273         /// When <paramref name="value"/> is 1 the right edges of the right target and <paramref name="view"/> are aligned.
 274         /// </summary>
 275         /// <param name="view">The child view whose size and position is being changed.</param>
 276         /// <param name="value">The ratio between left and right of the <seealso cref="RightTargetProperty"/>.</param>
 277         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 278         /// <since_tizen> 9 </since_tizen>
 279         public static void SetRightRelativeOffset(View view, float value) => SetAttachedValue(view, RightRelativeOffsetProperty, value);
 280
 281         /// <summary>
 282         /// Sets the relative offset for top target.
 283         /// When <paramref name="value"/> is 0 the top edges of the top target and <paramref name="view"/> are aligned.<br/>
 284         /// When <paramref name="value"/> is 1 the top edge of the <paramref name="view"/> is aligned to the bottom edge of the top target.
 285         /// </summary>
 286         /// <param name="view">The child view whose size and position is being changed.</param>
 287         /// <param name="value">The ratio between left and right of the <seealso cref="TopTargetProperty"/>.</param>
 288         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 289         /// <since_tizen> 9 </since_tizen>
 290         public static void SetTopRelativeOffset(View view, float value) => SetAttachedValue(view, TopRelativeOffsetProperty, value);
 291
 292         /// <summary>
 293         /// Sets the relative offset for bottom target.
 294         /// When <paramref name="value"/> is 0 the bottom edge of the <paramref name="view"/> is aligned to the top edge of the bottom target.<br/>
 295         /// When <paramref name="value"/> is 1 the bottom edges of the bottom target and <paramref name="view"/> are aligned.
 296         /// </summary>
 297         /// <param name="view">The child view whose size and position is being changed.</param>
 298         /// <param name="value">The ratio between left and right of the <seealso cref="BottomTargetProperty"/>.</param>
 299         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 300         /// <since_tizen> 9 </since_tizen>
 301         public static void SetBottomRelativeOffset(View view, float value) => SetAttachedValue(view, BottomRelativeOffsetProperty, value);
 302
 303         /// <summary>
 304         /// Sets the horizontal alignment of this child view.
 305         /// </summary>
 306         /// <param name="view">The child view.</param>
 307         /// <param name="value">The horizontal alignment of <paramref name="view"/>.</param>
 308         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 309         /// <since_tizen> 9 </since_tizen>
 310         public static void SetHorizontalAlignment(View view, Alignment value) => SetAttachedValue(view, HorizontalAlignmentProperty, value);
 311
 312         /// <summary>
 313         /// Sets the vertical alignment of this child view.
 314         /// </summary>
 315         /// <param name="view">The child view.</param>
 316         /// <param name="value">The vertical alignment of <paramref name="view"/>.</param>
 317         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 318         /// <since_tizen> 9 </since_tizen>
 319         public static void SetVerticalAlignment(View view, Alignment value) => SetAttachedValue(view, VerticalAlignmentProperty, value);
 320
 321         /// <summary>
 322         /// Sets the boolean value whether child fills its horizontal space.
 323         /// </summary>
 324         /// <param name="view">The child view.</param>
 325         /// <param name="value">True if to fill the space, false otherwise.</param>
 326         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 327         /// <since_tizen> 9 </since_tizen>
 328         public static void SetFillHorizontal(View view, bool value) => SetAttachedValue(view, FillHorizontalProperty, value);
 329
 330         /// <summary>
 331         /// Sets the boolean value whether child fills its vertical space.
 332         /// </summary>
 333         /// <param name="view">The child view.</param>
 334         /// <param name="value">True if to fill the space, false otherwise.</param>
 335         /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
 336         /// <since_tizen> 9 </since_tizen>
 337         public static void SetFillVertical(View view, bool value) => SetAttachedValue(view, FillVerticalProperty, value);
 338
 339         /// <inheritdoc/>
 340         /// <since_tizen> 9 </since_tizen>
 341         protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
 342         {
 343             MeasuredSize.StateType childWidthState = MeasuredSize.StateType.MeasuredSizeOK;
 344             MeasuredSize.StateType childHeightState = MeasuredSize.StateType.MeasuredSizeOK;
 345
 346             for (int i = 0; i < LayoutChildren.Count; i++)
 347             {
 348                 LayoutItem childLayout = LayoutChildren[i];
 349                 if (childLayout != null)
 350                 {
 351                     MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
 352
 353                     if (childLayout.MeasuredWidth.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
 354                     {
 355                         childWidthState = MeasuredSize.StateType.MeasuredSizeTooSmall;
 356                     }
 357                     if (childLayout.MeasuredHeight.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
 358                     {
 359                         childHeightState = MeasuredSize.StateType.MeasuredSizeTooSmall;
 360                     }
 361                 }
 362             }
 363
 364             (float childrenWidth, float childrenHeight) = CalculateChildrenSize(widthMeasureSpec.Size.AsDecimal(), heightMeasureSpec.Size.AsDecimal());
 365             SetMeasuredDimensions(ResolveSizeAndState(new LayoutLength(childrenWidth), widthMeasureSpec, childWidthState),
 366                                   ResolveSizeAndState(new LayoutLength(childrenHeight), heightMeasureSpec, childHeightState));
 367
 368             // There are 2 cases which require to calculate children's MeasuredWidth/Height as follows.
 369             //
 370             // 1. Text with Ellipsis true
 371             //    TextLabel and TextField calculate MeasuredWidth/Height to cover their text string if they have WrapContent.
 372             //    This causes children's Ellipsis cannot be displayed with RelativeLayout.
 373             //    To resolve the above, RelativeLayout recalculates its children's MeasuredWidth/Height based on the children's space calculated by RelativeLayout APIs.
 374             //
 375             // 2. FillHorizontal/Vertical true
 376             //    If children set FillHorizontal/Vertical true, then children's MeasuredWidth/Height are not correctly alculated.
 377             //    Instead, children's size and position are correctly calculated in OnLayout().
 378             //    This causes that the grand children's MeasuredWidth/Height are calculated incorrectly.
 379             //    To resolve the above, RelativeLayout calculates its children's MeasuredWidth/Height based on the children's geometry calculated by RelativeLayout APIs.
 380             //
 381             //    e.g.
 382             //    Let parent have RelativeLayout and parent's size be 1920x1080.
 383             //    Let child have WrapContent with SetFillHorizontal/Vertical true.
 384             //    Let grand child have MatchParent.
 385             //    Then, child's size is 1920x1080 but child's MeasuredWidth/Height is 0x0.
 386             //    Then, grand child's MeasuredWidth/Height is 0x0 and size is 0x0.
 387             //
 388             // TODO: Not to do duplicate operations in OnLayout() again.
 389             bool needClearCache = false;
 390
 391             for (int i = 0; i < LayoutChildren.Count; i++)
 392             {
 393                 LayoutItem childLayout = LayoutChildren[i];
 394                 if (childLayout != null)
 395                 {
 396                     bool ellipsisText = false;
 397                     bool needMeasuredWidth = false;
 398                     bool needMeasuredHeight = false;
 399
 400                     if (((childLayout.Owner is TextLabel textLabel) && textLabel.Ellipsis) || ((childLayout.Owner is TextField textField) && textField.Ellipsis))
 401                     {
 402                         ellipsisText = true;
 403                         needClearCache = true;
 404                     }
 405                     else
 406                     {
 407                         if (RelativeLayout.GetFillHorizontal(childLayout.Owner))
 408                         {
 409                             needMeasuredWidth = true;
 410                             needClearCache = true;
 411                         }
 412
 413                         if (RelativeLayout.GetFillVertical(childLayout.Owner))
 414                         {
 415                             needMeasuredHeight = true;
 416                             needClearCache = true;
 417                         }
 418                     }
 419
 420                     if ((ellipsisText == false) && (needMeasuredWidth == false) && (needMeasuredHeight == false))
 421                     {
 422                         continue;
 423                     }
 424
 425                     float width = childLayout.MeasuredWidth.Size.AsDecimal();
 426                     float height = childLayout.MeasuredWidth.Size.AsDecimal();
 427
 428                     if (ellipsisText)
 429                     {
 430                         Geometry horizontalSpace = GetHorizontalSpace(childLayout.Owner);
 431
 432                         if ((width > horizontalSpace.Size) || ((width < horizontalSpace.Size) && RelativeLayout.GetFillVertical(childLayout.Owner)))
 433                         {
 434                             width = horizontalSpace.Size;
 435                         }
 436
 437                         Geometry verticalSpace = GetVerticalSpace(childLayout.Owner);
 438
 439                         if ((height > verticalSpace.Size) || ((height < verticalSpace.Size) && RelativeLayout.GetFillHorizontal(childLayout.Owner)))
 440                         {
 441                             height = verticalSpace.Size;
 442                         }
 443                     }
 444                     else
 445                     {
 446                         if (needMeasuredWidth)
 447                         {
 448                             Geometry horizontalGeometry = GetHorizontalLayout(childLayout.Owner);
 449                             width = horizontalGeometry.Size;
 450                         }
 451
 452                         if (needMeasuredHeight)
 453                         {
 454                             Geometry verticalGeometry = GetVerticalLayout(childLayout.Owner);
 455                             height = verticalGeometry.Size;
 456                         }
 457                     }
 458
 459                     // Padding sizes are added because Padding sizes will be subtracted in MeasureChild().
 460                     MeasureSpecification childWidthMeasureSpec = new MeasureSpecification(new LayoutLength(width + Padding.Start + Padding.End), MeasureSpecification.ModeType.Exactly);
 461                     MeasureSpecification childHeightMeasureSpec = new MeasureSpecification(new LayoutLength(height + Padding.Top + Padding.Bottom), MeasureSpecification.ModeType.Exactly);
 462
 463                     // To calculate the grand children's Measure() with the mode type Exactly,
 464                     // children's Measure() is called with MatchParent if the children have WrapContent.
 465                     //
 466                     // i.e.
 467                     // If children have Wrapcontent and the grand children have MatchParent,
 468                     // then grand children's MeasuredWidth/Height do not fill the children
 469                     // because the grand children's Measure() is called with the mode type AtMost.
 470                     int origWidthSpecification = childLayout.Owner.WidthSpecification;
 471                     int origHeightSpecification = childLayout.Owner.HeightSpecification;
 472
 473                     if (ellipsisText || needMeasuredWidth)
 474                     {
 475                         origWidthSpecification = childLayout.Owner.WidthSpecification;
 476                         childLayout.Owner.WidthSpecification = LayoutParamPolicies.MatchParent;
 477                     }
 478                     if (ellipsisText || needMeasuredHeight)
 479                     {
 480                         origHeightSpecification = childLayout.Owner.HeightSpecification;
 481                         childLayout.Owner.HeightSpecification = LayoutParamPolicies.MatchParent;
 482                     }
 483
 484                     MeasureChildWithMargins(childLayout, childWidthMeasureSpec, new LayoutLength(0), childHeightMeasureSpec, new LayoutLength(0));
 485
 486                     if (ellipsisText || needMeasuredWidth)
 487                     {
 488                         childLayout.Owner.WidthSpecification = origWidthSpecification;
 489                     }
 490                     if (ellipsisText || needMeasuredHeight)
 491                     {
 492                         childLayout.Owner.HeightSpecification = origHeightSpecification;
 493                     }
 494                 }
 495             }
 496
 497             if (needClearCache)
 498             {
 499                 HorizontalRelativeCache.Clear();
 500                 VerticalRelativeCache.Clear();
 501             }
 502         }
 503
 504         /// <inheritdoc/>
 505         /// <since_tizen> 9 </since_tizen>
 506         protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
 507         {
 508             for (int i = 0; i < LayoutChildren.Count; i++)
 509             {
 510                 LayoutItem childLayout = LayoutChildren[i];
 511                 if (childLayout != null)
 512                 {
 513                     Geometry horizontalGeometry = GetHorizontalLayout(childLayout.Owner);
 514                     Geometry verticalGeometry = GetVerticalLayout(childLayout.Owner);
 515
 516                     LayoutLength childLeft = new LayoutLength(horizontalGeometry.Position + Padding.Start + childLayout.Margin.Start);
 517                     LayoutLength childRight = new LayoutLength(horizontalGeometry.Position + horizontalGeometry.Size + Padding.Start - childLayout.Margin.End);
 518                     LayoutLength childTop = new LayoutLength(verticalGeometry.Position + Padding.Top + childLayout.Margin.Top);
 519                     LayoutLength childBottom = new LayoutLength(verticalGeometry.Position + verticalGeometry.Size + Padding.Top - childLayout.Margin.Bottom);
 520
 521                     childLayout.Layout(childLeft, childTop, childRight, childBottom);
 522                 }
 523             }
 524             HorizontalRelativeCache.Clear();
 525             VerticalRelativeCache.Clear();
 526         }
 527
 528         /// <summary>The alignment of the relative layout child.</summary>
 529         /// <since_tizen> 9 </since_tizen>
 530         public enum Alignment
 531         {
 532             /// <summary>At the start of the container.</summary>
 533             /// <since_tizen> 9 </since_tizen>
 534             Start = 0,
 535             /// <summary>At the center of the container.</summary>
 536             /// <since_tizen> 9 </since_tizen>
 537             Center = 1,
 538             /// <summary>At the end of the container.</summary>
 539             /// <since_tizen> 9 </since_tizen>
 540             End = 2,
 541         }
 542     }
 543
 544     // Extension Method of RelativeLayout.Alignment.
 545     internal static partial class RelativeLayoutAlignmentExtension
 546     {
 547         public static float ToFloat(this RelativeLayout.Alignment align)
 548         {
 549             return 0.5f * (float)align;
 550         }
 551     }
 552 }