1 /* Copyright (c) 2021 Samsung Electronics Co., Ltd.
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
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 using System.ComponentModel;
19 using Tizen.NUI.BaseComponents;
20 using System.Runtime.InteropServices;
21 using System.Diagnostics;
22 using Tizen.NUI.Binding;
27 /// This class implements a flex layout.
28 /// The flex layout implementation is based on open source Facebook Yoga layout engine.
29 /// For more information about the flex layout API and how to use it please refer to https://yogalayout.com/docs/
30 /// We implement the subset of the API in the class below.
32 public class FlexLayout : LayoutGroup
37 [EditorBrowsable(EditorBrowsableState.Never)]
38 internal static readonly BindableProperty FlexItemProperty = BindableProperty.CreateAttached("FlexItem", typeof(HandleRef), typeof(FlexLayout), default(HandleRef));
41 /// FlexAlignmentSelfProperty
43 [EditorBrowsable(EditorBrowsableState.Never)]
44 public static readonly BindableProperty FlexAlignmentSelfProperty = BindableProperty.CreateAttached("FlexAlignmentSelf", typeof(AlignmentType), typeof(FlexLayout), AlignmentType.Auto, validateValue: ValidateEnum((int)AlignmentType.Auto, (int)AlignmentType.Stretch), propertyChanged: OnChildPropertyChanged);
47 /// FlexPositionTypeProperty
49 [EditorBrowsable(EditorBrowsableState.Never)]
50 public static readonly BindableProperty FlexPositionTypeProperty = BindableProperty.CreateAttached("FlexPositionType", typeof(PositionType), typeof(FlexLayout), PositionType.Relative, validateValue: ValidateEnum((int)PositionType.Relative, (int)PositionType.Absolute),
51 propertyChanged: (bindable, oldValue, newValue) =>
53 if (bindable is View view)
55 view.ExcludeLayouting = (PositionType)newValue == PositionType.Absolute;
58 defaultValueCreator: (bindable) =>
60 var view = (View)bindable;
61 if (view.ExcludeLayouting)
62 return PositionType.Absolute;
64 return PositionType.Relative;
69 /// AspectRatioProperty
71 [EditorBrowsable(EditorBrowsableState.Never)]
72 public static readonly BindableProperty FlexAspectRatioProperty = BindableProperty.CreateAttached("FlexAspectRatio", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value > 0, propertyChanged: OnChildPropertyChanged);
77 [EditorBrowsable(EditorBrowsableState.Never)]
78 public static readonly BindableProperty FlexBasisProperty = BindableProperty.CreateAttached("FlexBasis", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
81 /// FlexShrinkProperty
83 [EditorBrowsable(EditorBrowsableState.Never)]
84 public static readonly BindableProperty FlexShrinkProperty = BindableProperty.CreateAttached("FlexShrink", typeof(float), typeof(FlexLayout), 1.0f, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
89 [EditorBrowsable(EditorBrowsableState.Never)]
90 public static readonly BindableProperty FlexGrowProperty = BindableProperty.CreateAttached("FlexGrow", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
92 private global::System.Runtime.InteropServices.HandleRef swigCPtr;
93 private bool swigCMemOwn;
94 private bool disposed;
95 private bool isDisposeQueued = false;
97 private MeasureSpecification parentMeasureSpecificationWidth;
98 private MeasureSpecification parentMeasureSpecificationHeight;
100 private IntPtr _rootFlex; // Pointer to the unmanaged flex layout class.
102 internal const float FlexUndefined = 10E20F; // Auto setting which is equivalent to WrapContent.
104 internal struct MeasuredSize
106 public MeasuredSize(float x, float y)
116 /// Gets the alignment self of the child view.
118 /// <seealso cref="SetFlexAlignmentSelf(View, AlignmentType)"/>
119 /// <param name="view">The child view.</param>
120 /// <returns> The value of alignment self.</returns>
121 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
122 /// <since_tizen> 8 </since_tizen>
123 public static AlignmentType GetFlexAlignmentSelf(View view) => GetAttachedValue<AlignmentType>(view, FlexAlignmentSelfProperty);
126 /// Gets the position type of the child view.
128 /// <seealso cref="SetFlexPositionType(View, PositionType)"/>
129 /// <param name="view">The child view.</param>
130 /// <returns> The value of position type</returns>
131 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
132 /// <since_tizen> 8 </since_tizen>
133 public static PositionType GetFlexPositionType(View view) => GetAttachedValue<PositionType>(view, FlexPositionTypeProperty);
136 /// Gets the aspect ratio of the child view.
138 /// <seealso cref="SetFlexAspectRatio(View, float)"/>
139 /// <param name="view">The child view.</param>
140 /// <returns> The value of aspect ratio</returns>
141 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
142 /// <since_tizen> 8 </since_tizen>
143 public static float GetFlexAspectRatio(View view) => GetAttachedValue<float>(view, FlexAspectRatioProperty);
146 /// Gets the basis of the child view.
148 /// <seealso cref="SetFlexBasis(View, float)"/>
149 /// <param name="view">The child view.</param>
150 /// <returns> The value of basis</returns>
151 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
152 /// <since_tizen> 8 </since_tizen>
153 public static float GetFlexBasis(View view) => GetAttachedValue<float>(view, FlexBasisProperty);
156 /// Gets the shrink of the child view.
158 /// <seealso cref="SetFlexShrink(View, float)"/>
159 /// <param name="view">The child view.</param>
160 /// <returns> The value of shrink</returns>
161 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
162 /// <since_tizen> 8 </since_tizen>
163 public static float GetFlexShrink(View view) => GetAttachedValue<float>(view, FlexShrinkProperty);
166 /// Gets the grow of the child view.
168 /// <seealso cref="SetFlexGrow(View, float)"/>
169 /// <param name="view">The child view.</param>
170 /// <returns> The value of grow</returns>
171 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
172 /// <since_tizen> 8 </since_tizen>
173 public static float GetFlexGrow(View view) => GetAttachedValue<float>(view, FlexGrowProperty);
176 /// Sets the alignment self of the child view.<br/>
177 /// Alignment self has the same options and effect as <see cref="ItemsAlignment"/> but instead of affecting the children within a container,
178 /// you can apply this property to a single child to change its alignment within its parent.<br/>
179 /// Alignment self overrides any option set by the parent with <see cref="ItemsAlignment"/>.
181 /// <param name="view">The child view.</param>
182 /// <param name="value">The value of alignment self.</param>
183 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
184 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="AlignmentType"/>.</exception>
185 /// <since_tizen> 8 </since_tizen>
186 public static void SetFlexAlignmentSelf(View view, AlignmentType value) => SetAttachedValue(view, FlexAlignmentSelfProperty, value);
189 /// Sets the position type of the child view.<br/>
190 /// The position type of an element defines how it is positioned within its parent.
191 /// By default a child is positioned relatively. This means a child is positioned according to the normal flow of the layout,
192 /// and then offset relative to that position based on the values of <see cref="View.Margin"/>.<br/>
193 /// When positioned absolutely an element doesn't take part in the normal layout flow.
194 /// It is instead laid out independent of its siblings. The position is determined based on the <see cref="View.Margin"/>.
196 /// <param name="view">The child view.</param>
197 /// <param name="value">The value of position type.</param>
198 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
199 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="PositionType"/>.</exception>
200 /// <since_tizen> 8 </since_tizen>
201 public static void SetFlexPositionType(View view, PositionType value) => SetAttachedValue(view, FlexPositionTypeProperty, value);
204 /// Sets the aspect ratio of the child view.
205 /// Aspect ratio Defines as the ratio between the width and the height of a node
206 /// e.g. if a node has an aspect ratio of 2 then its width is twice the size of its height.<br/>
207 /// Aspect ratio accepts any floating point value > 0. this has higher priority than flex grow.
209 /// <param name="view">The child view.</param>
210 /// <param name="value">The value of aspect ratio</param>
211 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
212 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than or equal to 0.0f.</exception>
213 /// <since_tizen> 8 </since_tizen>
214 public static void SetFlexAspectRatio(View view, float value) => SetAttachedValue(view, FlexAspectRatioProperty, value);
217 /// Sets the flex basis of the child view.
218 /// Flex basis is an axis-independent way of providing the default size of an item along the main axis.<br/>
219 /// Setting the flex basis of a child is similar to setting the width of that child if its parent is a container with <see cref="FlexDirection.Row"/>
220 /// or setting the height of a child if its parent is a container with <see cref="FlexDirection.Column"/>.<br/>
221 /// The flex basis of an item is the default size of that item, the size of the item before any flex grow and flex shrink calculations are performed.
223 /// <param name="view">The child view.</param>
224 /// <param name="value">The value of basis</param>
225 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
226 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
227 /// <since_tizen> 8 </since_tizen>
228 public static void SetFlexBasis(View view, float value) => SetAttachedValue(view, FlexBasisProperty, value);
231 /// Sets the flex shrink of the child view.
232 /// Flex shrink describes how to shrink children along the main axis in the case that the total size of the children overflow the size of the container on the main axis.<br/>
233 /// Flex shrink is very similar to flex grow and can be thought of in the same way if any overflowing size is considered to be negative remaining space.
234 /// These two properties also work well together by allowing children to grow and shrink as needed.<br/>
235 /// Flex shrink accepts any floating point value >= 0, with 1 being the default value. A container will shrink its children weighted by the child's flex shrink value.
237 /// <param name="view">The child view.</param>
238 /// <param name="value">The value of shrink</param>
239 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
240 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
241 /// <since_tizen> 8 </since_tizen>
242 public static void SetFlexShrink(View view, float value) => SetAttachedValue(view, FlexShrinkProperty, value);
245 /// Sets the grow of the child view.
246 /// Flex grow describes how any space within a container should be distributed among its children along the main axis.
247 /// After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.<br/>
248 /// Flex grow accepts any floating point value >= 0, with 0 being the default value.<br/>
249 /// A container will distribute any remaining space among its children weighted by the child's flex grow value.
251 /// <param name="view">The child view.</param>
252 /// <param name="value">The value of flex</param>
253 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
254 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
255 /// <since_tizen> 8 </since_tizen>
256 public static void SetFlexGrow(View view, float value) => SetAttachedValue(view, FlexGrowProperty, value);
258 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
259 internal delegate void ChildMeasureCallback(global::System.IntPtr child, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize);
261 event ChildMeasureCallback measureChildDelegate; // Stores a delegate to the child measure callback. Used for all children of this FlexLayout.
263 internal FlexLayout(global::System.IntPtr cPtr, bool cMemoryOwn)
265 swigCMemOwn = cMemoryOwn;
266 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(this, cPtr);
267 _rootFlex = Interop.FlexLayout.New();
268 measureChildDelegate = new ChildMeasureCallback(measureChild);
271 internal static global::System.Runtime.InteropServices.HandleRef getCPtr(FlexLayout obj)
273 return (obj == null) ? new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero) : obj.swigCPtr;
277 /// Hidden API (Inhouse API).
280 [EditorBrowsable(EditorBrowsableState.Never)]
281 ~FlexLayout() => Dispose(false);
284 /// <since_tizen> 6 </since_tizen>
285 public new void Dispose()
288 System.GC.SuppressFinalize(this);
292 /// Hidden API (Inhouse API).
296 /// Following the guide of https://docs.microsoft.com/en-us/dotnet/standard/garbage-collection/implementing-dispose.
297 /// This will replace "protected virtual void Dispose(DisposeTypes type)" which is exactly same in functionality.
299 /// <param name="disposing">true in order to free managed objects</param>
300 // Protected implementation of Dispose pattern.
301 [EditorBrowsable(EditorBrowsableState.Never)]
302 protected override void Dispose(bool disposing)
311 // TODO: dispose managed state (managed objects).
312 // Explicit call. user calls Dispose()
314 //Throw exception if Dispose() is called in separate thread.
315 if (!Window.IsInstalled())
317 throw new System.InvalidOperationException("This API called from separate thread. This API must be called from MainThread.");
322 Dispose(DisposeTypes.Implicit);
326 Dispose(DisposeTypes.Explicit);
331 // Implicit call. user doesn't call Dispose(), so this object is added into DisposeQueue to be disposed automatically.
332 if (!isDisposeQueued)
334 isDisposeQueued = true;
335 DisposeQueue.Instance.Add(this);
339 // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
340 // TODO: set large fields to null.
341 base.Dispose(disposing);
345 /// <since_tizen> 6 </since_tizen>
346 protected virtual void Dispose(DisposeTypes type)
353 if (type == DisposeTypes.Explicit)
356 //Release your own managed resources here.
357 //You should release all of your own disposable objects here.
360 //Release your own unmanaged resources here.
361 //You should not access any managed member here except static instance.
362 //because the execution order of Finalizes is non-deterministic.
363 if (swigCPtr.Handle != global::System.IntPtr.Zero)
368 ReleaseSwigCPtr(swigCPtr);
370 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero);
377 /// Hidden API (Inhouse API).
378 /// Release swigCPtr.
380 /// This will not be public opened.
381 [EditorBrowsable(EditorBrowsableState.Never)]
382 protected virtual void ReleaseSwigCPtr(System.Runtime.InteropServices.HandleRef swigCPtr)
384 Interop.FlexLayout.DeleteFlexLayout(swigCPtr);
388 /// Creates a FlexLayout object.
390 /// <since_tizen> 6 </since_tizen>
391 public FlexLayout() : this(Interop.FlexLayout.New(), true)
393 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
396 internal FlexLayout.AlignmentType GetFlexAlignment()
398 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexAlignment(swigCPtr);
399 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
403 internal FlexLayout.AlignmentType GetFlexItemsAlignment()
405 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexItemsAlignment(swigCPtr);
406 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
411 /// Gets/Sets the flex direction in the layout.
412 /// The direction of the main-axis which determines the direction that flex items are laid out.
414 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
415 /// <since_tizen> 6 </since_tizen>
416 public FlexDirection Direction
418 get => (FlexDirection)Interop.FlexLayout.GetFlexDirection(swigCPtr);
421 if (value < FlexDirection.Column || value > FlexDirection.RowReverse)
422 throw new InvalidEnumArgumentException(nameof(Direction));
424 Interop.FlexLayout.SetFlexDirection(swigCPtr, (int)value);
430 /// Gets/Sets the justification in the layout.
431 /// Justify content describes how to align children within the main axis of their container.<br/>
432 /// For example, you can use this property to center a child horizontally within a container with <see cref="Direction"/> set to <see cref="FlexDirection.Row"/>
433 /// or vertically within a container with <see cref="Direction"/> set to <see cref="FlexDirection.Column"/>.
435 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
436 /// <since_tizen> 6 </since_tizen>
437 public FlexJustification Justification
439 get => (FlexJustification)Interop.FlexLayout.GetFlexJustification(swigCPtr);
442 if (value < FlexJustification.FlexStart || value > FlexJustification.SpaceEvenly)
443 throw new InvalidEnumArgumentException(nameof(Justification));
445 Interop.FlexLayout.SetFlexJustification(swigCPtr, (int)value);
451 /// Gets/Sets the wrap in the layout.
452 /// The flex wrap property is set on containers and controls what happens when children overflow the size of the container along the main axis.<br/>
453 /// By default children are forced into a single line (which can shrink elements).<br/>
454 /// If wrapping is allowed items are wrapped into multiple lines along the main axis if needed. wrap reverse behaves the same, but the order of the lines is reversed.<br/>
455 /// When wrapping lines <see cref="Alignment"/> can be used to specify how the lines are placed in the container.
457 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
458 /// <since_tizen> 6 </since_tizen>
459 public FlexWrapType WrapType
461 get => (FlexWrapType)Interop.FlexLayout.GetFlexWrap(swigCPtr);
464 if (value != FlexWrapType.NoWrap && value != FlexWrapType.Wrap)
465 throw new InvalidEnumArgumentException(nameof(WrapType));
467 Interop.FlexLayout.SetFlexWrap(swigCPtr, (int)value);
474 /// Gets/Sets the alignment of the layout content.
475 /// Alignment defines the distribution of lines along the cross-axis.<br/>
476 /// This only has effect when items are wrapped to multiple lines using flex wrap.
478 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
479 /// <since_tizen> 6 </since_tizen>
480 public AlignmentType Alignment
482 get => GetFlexAlignment();
485 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
486 throw new InvalidEnumArgumentException(nameof(Alignment));
488 Interop.FlexLayout.SetFlexAlignment(swigCPtr, (int)value);
494 /// Gets/Sets the alignment of the layout items.
495 /// Items alignment describes how to align children along the cross axis of their container.<br/>
496 /// Align items is very similar to <see cref="Justification"/> but instead of applying to the main axis, align items applies to the cross axis.
498 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
499 /// <since_tizen> 6 </since_tizen>
500 public AlignmentType ItemsAlignment
502 get => GetFlexItemsAlignment();
505 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
506 throw new InvalidEnumArgumentException(nameof(ItemsAlignment));
508 Interop.FlexLayout.SetFlexItemsAlignment(swigCPtr, (int)value);
514 /// Enumeration for the direction of the main axis in the flex container.
515 /// This determines the direction that flex items are laid out in the flex container.
517 /// <since_tizen> 6 </since_tizen>
518 public enum FlexDirection
521 /// The flexible items are displayed vertically as a column
525 /// The flexible items are displayed vertically as a column, but in reverse order
529 /// The flexible items are displayed horizontally as a row
533 /// The flexible items are displayed horizontally as a row, but in reverse order
539 /// Enumeration for the alignment of the flex items when the items do not use all available space on the main-axis.
541 /// <since_tizen> 6 </since_tizen>
542 public enum FlexJustification
545 /// Items are positioned at the beginning of the container.
549 /// Items are positioned at the center of the container.
553 /// Items are positioned at the end of the container.
557 /// Items are positioned with equal space between the lines.
561 /// Items are positioned with equal space before, and after the lines.<br/>
565 /// Items are positioned with equal space before, between, and after the lines.<br/>
566 /// Spaces are distributed equally to the beginning of the first child, between each child, and the end of the last child.
568 /// <since_tizen> 9 </since_tizen>
573 /// Enumeration for the wrap type of the flex container when there is no enough room for all the items on one flex line.
575 /// <since_tizen> 6 </since_tizen>
576 public enum FlexWrapType
579 /// Flex items laid out in single line (shrunk to fit the flex container along the main axis)
583 /// Flex items laid out in multiple lines if needed
589 /// Enumeration for the alignment of the flex items or lines when the items or lines do not use all the available space on the cross-axis.
591 /// <since_tizen> 6 </since_tizen>
592 public enum AlignmentType
595 /// Inherits the same alignment from the parent
599 /// At the beginning of the container
603 /// At the center of the container
607 /// At the end of the container
611 /// Stretch to fit the container
617 /// Enumeration for the position type of the flex item how it is positioned within its parent.
619 /// <since_tizen> 8 </since_tizen>
620 public enum PositionType
623 /// Flex items laid out relatively.
627 /// Flex items laid out absolutely.
633 [EditorBrowsable(EditorBrowsableState.Never)]
634 public override LayoutItem Clone()
636 var layout = new FlexLayout();
638 foreach (var prop in layout.GetType().GetProperties())
640 if (prop.GetSetMethod() != null)
642 prop.SetValue(layout, this.GetType().GetProperty(prop.Name).GetValue(this));
649 private void measureChild(global::System.IntPtr childPtr, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize)
651 // We need to measure child layout
652 View child = Registry.GetManagedBaseHandleFromNativePtr(childPtr) as View;
653 // independent child will be measured in LayoutGroup.OnMeasureIndependentChildren().
654 if ((child == null) || (child?.ExcludeLayouting ?? true))
656 measureSize.width = 0;
657 measureSize.height = 0;
661 LayoutItem childLayout = child.Layout;
662 Extents margin = child.Margin;
664 MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
665 new MeasureSpecification(
666 new LayoutLength(parentMeasureSpecificationWidth.Size - (margin.Start + margin.End)),
667 parentMeasureSpecificationWidth.Mode),
668 new LayoutLength(Padding.Start + Padding.End),
669 new LayoutLength(child.WidthSpecification));
671 MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
672 new MeasureSpecification(
673 new LayoutLength(parentMeasureSpecificationHeight.Size - (margin.Top + margin.Bottom)),
674 parentMeasureSpecificationHeight.Mode),
675 new LayoutLength(Padding.Top + Padding.Bottom),
676 new LayoutLength(child.HeightSpecification));
678 childLayout?.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
680 measureSize.width = (childLayout == null) ? 0 : childLayout.MeasuredWidth.Size.AsRoundedValue();
681 measureSize.height = (childLayout == null) ? 0 : childLayout.MeasuredHeight.Size.AsRoundedValue();
684 void InsertChild(LayoutItem child)
686 // Store created node for child
687 IntPtr childPtr = Interop.FlexLayout.AddChildWithMargin(swigCPtr, View.getCPtr(child.Owner), Extents.getCPtr(child.Owner.Margin), measureChildDelegate, LayoutChildren.Count - 1);
688 HandleRef childHandleRef = new HandleRef(child.Owner, childPtr);
689 SetAttachedValue(child.Owner, FlexItemProperty, childHandleRef);
693 /// Callback when child is added to container.<br />
694 /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
696 /// <param name="child">The Layout child.</param>
697 /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
698 /// <since_tizen> 6 </since_tizen>
699 protected override void OnChildAdd(LayoutItem child)
703 throw new ArgumentNullException(nameof(child));
709 /// Callback when child is removed from container.<br />
711 /// <param name="child">The Layout child.</param>
712 /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
713 /// <since_tizen> 6 </since_tizen>
714 protected override void OnChildRemove(LayoutItem child)
718 throw new ArgumentNullException(nameof(child));
720 // When child View is removed from it's parent View (that is a Layout) then remove it from the layout too.
721 // FlexLayout refers to the child as a View not LayoutItem.
722 Interop.FlexLayout.RemoveChild(swigCPtr, child.Owner.SwigCPtr);
726 /// Measure the layout and its content to determine the measured width and the measured height.<br />
728 /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
729 /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
730 /// <since_tizen> 6 </since_tizen>
731 protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
733 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
734 Extents padding = Owner.Padding;
736 Interop.FlexLayout.SetPadding(swigCPtr, Extents.getCPtr(padding));
738 float width = FlexUndefined; // Behaves as WrapContent (Flex Auto)
739 float height = FlexUndefined; // Behaves as WrapContent (Flex Auto)
741 if (widthMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly)
743 width = widthMeasureSpec.Size.AsDecimal();
746 if (heightMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly)
748 height = heightMeasureSpec.Size.AsDecimal();
751 // Save measureSpec to measure children.
752 // In other Layout, we can pass it as parameter to measuring child but in FlexLayout we can't
753 // because measurChild function is called by native callback.
754 parentMeasureSpecificationWidth = widthMeasureSpec;
755 parentMeasureSpecificationHeight = heightMeasureSpec;
757 Extents zeroMargin = new Extents();
759 // Assign child properties
760 for (int i = 0; i < LayoutChildren.Count; i++)
762 LayoutItem layoutItem = LayoutChildren[i];
763 View Child = layoutItem?.Owner;
764 HandleRef childHandleRef = (HandleRef)Child.GetValue(FlexItemProperty);
765 if (childHandleRef.Handle == IntPtr.Zero || Child == null)
768 AlignmentType flexAlignemnt = GetFlexAlignmentSelf(Child);
769 PositionType positionType = GetFlexPositionType(Child);
770 float flexAspectRatio = GetFlexAspectRatio(Child);
771 float flexBasis = GetFlexBasis(Child);
772 float flexShrink = GetFlexShrink(Child);
773 float flexGrow = GetFlexGrow(Child);
774 Extents childMargin = Child.ExcludeLayouting ? zeroMargin : layoutItem.Margin;
776 Interop.FlexLayout.SetMargin(childHandleRef, Extents.getCPtr(childMargin));
777 Interop.FlexLayout.SetFlexAlignmentSelf(childHandleRef, (int)flexAlignemnt);
778 Interop.FlexLayout.SetFlexPositionType(childHandleRef, (int)positionType);
779 Interop.FlexLayout.SetFlexAspectRatio(childHandleRef, flexAspectRatio);
780 Interop.FlexLayout.SetFlexBasis(childHandleRef, flexBasis);
781 Interop.FlexLayout.SetFlexShrink(childHandleRef, flexShrink);
782 Interop.FlexLayout.SetFlexGrow(childHandleRef, flexGrow);
785 Interop.FlexLayout.CalculateLayout(swigCPtr, width, height, isLayoutRtl);
786 zeroMargin.Dispose();
788 LayoutLength flexLayoutWidth = new LayoutLength(Interop.FlexLayout.GetWidth(swigCPtr));
789 LayoutLength flexLayoutHeight = new LayoutLength(Interop.FlexLayout.GetHeight(swigCPtr));
791 NUILog.Debug("FlexLayout OnMeasure width:" + flexLayoutWidth.AsRoundedValue() + " height:" + flexLayoutHeight.AsRoundedValue());
793 SetMeasuredDimensions(GetDefaultSize(flexLayoutWidth, widthMeasureSpec),
794 GetDefaultSize(flexLayoutHeight, heightMeasureSpec));
798 /// Assign a size and position to each of its children.<br />
800 /// <param name="changed">This is a new size or position for this layout.</param>
801 /// <param name="left">Left position, relative to parent.</param>
802 /// <param name="top"> Top position, relative to parent.</param>
803 /// <param name="right">Right position, relative to parent.</param>
804 /// <param name="bottom">Bottom position, relative to parent.</param>
805 /// <since_tizen> 6 </since_tizen>
806 protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
809 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
810 LayoutLength width = right - left;
811 LayoutLength height = bottom - top;
813 // Call to FlexLayout implementation to calculate layout values for later retrieval.
814 Interop.FlexLayout.CalculateLayout(swigCPtr, width.AsDecimal(), height.AsDecimal(), isLayoutRtl);
816 for (int childIndex = 0; childIndex < LayoutChildren.Count; childIndex++)
818 LayoutItem childLayout = LayoutChildren[childIndex];
819 if (!childLayout?.Owner?.ExcludeLayouting ?? false)
821 // Get the frame for the child, start, top, end, bottom.
822 Vector4 frame = new Vector4(Interop.FlexLayout.GetNodeFrame(swigCPtr, childIndex), true);
824 // Child view's size is calculated in OnLayout() without considering child layout's measured size unlike other layouts' OnLayout().
825 // This causes that the grand child view's size is calculated incorrectly if the child and grand child have MatchParent Specification.
826 // e.g. Let parent view's width be 200 and parent has 2 children.
827 // Then, child layout's measured width becomes 200 and child view's width becomes 100. (by dali-toolkit's YOGA APIs)
828 // Then, grand child layout's measured width becomes 200 and grand child view's width becomes 200. (by NUI Layout)
830 // To resolve the above issue, child layout's measured size is set with the child view's size calculated by dali-toolkit's YOGA APIs.
831 MeasureSpecification widthSpec = new MeasureSpecification(new LayoutLength(frame.Z - frame.X), MeasureSpecification.ModeType.Exactly);
832 MeasureSpecification heightSpec = new MeasureSpecification(new LayoutLength(frame.W - frame.Y), MeasureSpecification.ModeType.Exactly);
833 MeasureChildWithoutPadding(childLayout, widthSpec, heightSpec);
835 childLayout.Layout(new LayoutLength(frame.X), new LayoutLength(frame.Y), new LayoutLength(frame.Z), new LayoutLength(frame.W));
841 } // namesspace Tizen.NUI