1 /* Copyright (c) 2020 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 static bool LayoutDebugFlex = false; // Debug flag
94 private global::System.Runtime.InteropServices.HandleRef swigCPtr;
95 private bool swigCMemOwn;
96 private bool disposed;
97 private bool isDisposeQueued = false;
98 private bool disposedThis = false;
100 private MeasureSpecification parentMeasureSpecificationWidth;
101 private MeasureSpecification parentMeasureSpecificationHeight;
103 private IntPtr _rootFlex; // Pointer to the unmanged flex layout class.
105 internal const float FlexUndefined = 10E20F; // Auto setting which is equivalent to WrapContent.
107 internal struct MeasuredSize
109 public MeasuredSize(float x, float y)
119 /// Gets the alignment self of the child view.
121 /// <seealso cref="SetFlexAlignmentSelf(View, AlignmentType)"/>
122 /// <param name="view">The child view.</param>
123 /// <returns> The value of alignment self.</returns>
124 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
125 /// <since_tizen> 8 </since_tizen>
126 public static AlignmentType GetFlexAlignmentSelf(View view) => GetAttachedValue<AlignmentType>(view, FlexAlignmentSelfProperty);
129 /// Gets the position type of the child view.
131 /// <seealso cref="SetFlexPositionType(View, PositionType)"/>
132 /// <param name="view">The child view.</param>
133 /// <returns> The value of position type</returns>
134 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
135 /// <since_tizen> 8 </since_tizen>
136 public static PositionType GetFlexPositionType(View view) => GetAttachedValue<PositionType>(view, FlexPositionTypeProperty);
139 /// Gets the aspect ratio of the child view.
141 /// <seealso cref="SetFlexAspectRatio(View, float)"/>
142 /// <param name="view">The child view.</param>
143 /// <returns> The value of aspect ratio</returns>
144 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
145 /// <since_tizen> 8 </since_tizen>
146 public static float GetFlexAspectRatio(View view) => GetAttachedValue<float>(view, FlexAspectRatioProperty);
149 /// Gets the basis of the child view.
151 /// <seealso cref="SetFlexBasis(View, float)"/>
152 /// <param name="view">The child view.</param>
153 /// <returns> The value of basis</returns>
154 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
155 /// <since_tizen> 8 </since_tizen>
156 public static float GetFlexBasis(View view) => GetAttachedValue<float>(view, FlexBasisProperty);
159 /// Gets the shrink of the child view.
161 /// <seealso cref="SetFlexShrink(View, float)"/>
162 /// <param name="view">The child view.</param>
163 /// <returns> The value of shrink</returns>
164 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
165 /// <since_tizen> 8 </since_tizen>
166 public static float GetFlexShrink(View view) => GetAttachedValue<float>(view, FlexShrinkProperty);
169 /// Gets the grow of the child view.
171 /// <seealso cref="SetFlexGrow(View, float)"/>
172 /// <param name="view">The child view.</param>
173 /// <returns> The value of grow</returns>
174 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
175 /// <since_tizen> 8 </since_tizen>
176 public static float GetFlexGrow(View view) => GetAttachedValue<float>(view, FlexGrowProperty);
179 /// Sets the alignment self of the child view.<br/>
180 /// Alignment self has the same options and effect as <see cref="ItemsAlignment"/> but instead of affecting the children within a container,
181 /// you can apply this property to a single child to change its alignment within its parent.<br/>
182 /// Alignment self overrides any option set by the parent with <see cref="ItemsAlignment"/>.
184 /// <param name="view">The child view.</param>
185 /// <param name="value">The value of alignment self.</param>
186 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
187 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="AlignmentType"/>.</exception>
188 /// <since_tizen> 8 </since_tizen>
189 public static void SetFlexAlignmentSelf(View view, AlignmentType value) => SetAttachedValue(view, FlexAlignmentSelfProperty, value);
192 /// Sets the position type of the child view.<br/>
193 /// The position type of an element defines how it is positioned within its parent.
194 /// By default a child is positioned relatively. This means a child is positioned according to the normal flow of the layout,
195 /// and then offset relative to that position based on the values of <see cref="View.Margin"/>.<br/>
196 /// When positioned absolutely an element doesn't take part in the normal layout flow.
197 /// It is instead laid out independent of its siblings. The position is determined based on the <see cref="View.Margin"/>.
199 /// <param name="view">The child view.</param>
200 /// <param name="value">The value of position type.</param>
201 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
202 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="PositionType"/>.</exception>
203 /// <since_tizen> 8 </since_tizen>
204 public static void SetFlexPositionType(View view, PositionType value) => SetAttachedValue(view, FlexPositionTypeProperty, value);
207 /// Sets the aspect ratio of the child view.
208 /// Aspect ratio Defines as the ratio between the width and the height of a node
209 /// e.g. if a node has an aspect ratio of 2 then its width is twice the size of its height.<br/>
210 /// Aspect ratio accepts any floating point value > 0. this has higher priority than flex grow.
212 /// <param name="view">The child view.</param>
213 /// <param name="value">The value of aspect ratio</param>
214 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
215 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than or equal to 0.0f.</exception>
216 /// <since_tizen> 8 </since_tizen>
217 public static void SetFlexAspectRatio(View view, float value) => SetAttachedValue(view, FlexAspectRatioProperty, value);
220 /// Sets the flex basis of the child view.
221 /// Flex basis is an axis-independent way of providing the default size of an item along the main axis.<br/>
222 /// 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"/>
223 /// or setting the height of a child if its parent is a container with <see cref="FlexDirection.Column"/>.<br/>
224 /// 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.
226 /// <param name="view">The child view.</param>
227 /// <param name="value">The value of basis</param>
228 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
229 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
230 /// <since_tizen> 8 </since_tizen>
231 public static void SetFlexBasis(View view, float value) => SetAttachedValue(view, FlexBasisProperty, value);
234 /// Sets the flex shrink of the child view.
235 /// 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/>
236 /// 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.
237 /// These two properties also work well together by allowing children to grow and shrink as needed.<br/>
238 /// 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.
240 /// <param name="view">The child view.</param>
241 /// <param name="value">The value of shrink</param>
242 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
243 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
244 /// <since_tizen> 8 </since_tizen>
245 public static void SetFlexShrink(View view, float value) => SetAttachedValue(view, FlexShrinkProperty, value);
248 /// Sets the grow of the child view.
249 /// Flex grow describes how any space within a container should be distributed among its children along the main axis.
250 /// After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.<br/>
251 /// Flex grow accepts any floating point value >= 0, with 0 being the default value.<br/>
252 /// A container will distribute any remaining space among its children weighted by the child's flex grow value.
254 /// <param name="view">The child view.</param>
255 /// <param name="value">The value of flex</param>
256 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
257 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
258 /// <since_tizen> 8 </since_tizen>
259 public static void SetFlexGrow(View view, float value) => SetAttachedValue(view, FlexGrowProperty, value);
261 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
262 internal delegate void ChildMeasureCallback(global::System.IntPtr child, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize);
264 event ChildMeasureCallback measureChildDelegate; // Stores a delegate to the child measure callback. Used for all children of this FlexLayout.
266 internal FlexLayout(global::System.IntPtr cPtr, bool cMemoryOwn)
268 swigCMemOwn = cMemoryOwn;
269 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(this, cPtr);
270 _rootFlex = Interop.FlexLayout.New();
271 measureChildDelegate = new ChildMeasureCallback(measureChild);
274 internal static global::System.Runtime.InteropServices.HandleRef getCPtr(FlexLayout obj)
276 return (obj == null) ? new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero) : obj.swigCPtr;
280 /// Hidden API (Inhouse API).
283 [EditorBrowsable(EditorBrowsableState.Never)]
284 ~FlexLayout() => Dispose(false);
287 /// <since_tizen> 6 </since_tizen>
288 public new void Dispose()
291 System.GC.SuppressFinalize(this);
295 /// Hidden API (Inhouse API).
299 /// Following the guide of https://docs.microsoft.com/en-us/dotnet/standard/garbage-collection/implementing-dispose.
300 /// This will replace "protected virtual void Dispose(DisposeTypes type)" which is exactly same in functionality.
302 /// <param name="disposing">true in order to free managed objects</param>
303 // Protected implementation of Dispose pattern.
304 [EditorBrowsable(EditorBrowsableState.Never)]
305 protected override void Dispose(bool disposing)
314 // TODO: dispose managed state (managed objects).
315 // Explicit call. user calls Dispose()
317 //Throw excpetion if Dispose() is called in separate thread.
318 if (!Window.IsInstalled())
320 throw new System.InvalidOperationException("This API called from separate thread. This API must be called from MainThread.");
325 Dispose(DisposeTypes.Implicit);
329 Dispose(DisposeTypes.Explicit);
334 // Implicit call. user doesn't call Dispose(), so this object is added into DisposeQueue to be disposed automatically.
335 if (!isDisposeQueued)
337 isDisposeQueued = true;
338 DisposeQueue.Instance.Add(this);
342 // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
343 // TODO: set large fields to null.
345 base.Dispose(disposing);
349 /// <since_tizen> 6 </since_tizen>
350 protected virtual void Dispose(DisposeTypes type)
357 if (type == DisposeTypes.Explicit)
360 //Release your own managed resources here.
361 //You should release all of your own disposable objects here.
364 //Release your own unmanaged resources here.
365 //You should not access any managed member here except static instance.
366 //because the execution order of Finalizes is non-deterministic.
367 if (swigCPtr.Handle != global::System.IntPtr.Zero)
372 ReleaseSwigCPtr(swigCPtr);
374 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero);
381 /// Hidden API (Inhouse API).
382 /// Release swigCPtr.
384 /// This will not be public opened.
385 [EditorBrowsable(EditorBrowsableState.Never)]
386 protected virtual void ReleaseSwigCPtr(System.Runtime.InteropServices.HandleRef swigCPtr)
388 Interop.FlexLayout.DeleteFlexLayout(swigCPtr);
392 /// Creates a FlexLayout object.
394 /// <since_tizen> 6 </since_tizen>
395 public FlexLayout() : this(Interop.FlexLayout.New(), true)
397 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
400 internal static FlexLayout DownCast(BaseHandle handle)
402 FlexLayout ret = new FlexLayout(Interop.FlexLayout.DownCast(BaseHandle.getCPtr(handle)), true);
403 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
407 internal FlexLayout(FlexLayout other) : this(Interop.FlexLayout.NewFlexLayout(FlexLayout.getCPtr(other)), true)
409 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
412 internal FlexLayout.AlignmentType GetFlexAlignment()
414 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexAlignment(swigCPtr);
415 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
419 internal FlexLayout.AlignmentType GetFlexItemsAlignment()
421 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexItemsAlignment(swigCPtr);
422 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
427 /// Gets/Sets the flex direction in the layout.
428 /// The direction of the main-axis which determines the direction that flex items are laid out.
430 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
431 /// <since_tizen> 6 </since_tizen>
432 public FlexDirection Direction
434 get => (FlexDirection)Interop.FlexLayout.GetFlexDirection(swigCPtr);
437 if (value < FlexDirection.Column || value > FlexDirection.RowReverse)
438 throw new InvalidEnumArgumentException(nameof(Direction));
440 Interop.FlexLayout.SetFlexDirection(swigCPtr, (int)value);
446 /// Gets/Sets the justification in the layout.
447 /// Justify content describes how to align children within the main axis of their container.<br/>
448 /// 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"/>
449 /// or vertically within a container with <see cref="Direction"/> set to <see cref="FlexDirection.Column"/>.
451 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
452 /// <since_tizen> 6 </since_tizen>
453 public FlexJustification Justification
455 get => (FlexJustification)Interop.FlexLayout.GetFlexJustification(swigCPtr);
458 if (value < FlexJustification.FlexStart || value > FlexJustification.SpaceAround)
459 throw new InvalidEnumArgumentException(nameof(Justification));
461 Interop.FlexLayout.SetFlexJustification(swigCPtr, (int)value);
467 /// Gets/Sets the wrap in the layout.
468 /// 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/>
469 /// By default children are forced into a single line (which can shrink elements).<br/>
470 /// 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/>
471 /// When wrapping lines <see cref="Alignment"/> can be used to specify how the lines are placed in the container.
473 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
474 /// <since_tizen> 6 </since_tizen>
475 public FlexWrapType WrapType
477 get => (FlexWrapType)Interop.FlexLayout.GetFlexWrap(swigCPtr);
480 if (value != FlexWrapType.NoWrap && value != FlexWrapType.Wrap)
481 throw new InvalidEnumArgumentException(nameof(WrapType));
483 Interop.FlexLayout.SetFlexWrap(swigCPtr, (int)value);
490 /// Gets/Sets the alignment of the layout content.
491 /// Alignment defines the distribution of lines along the cross-axis.<br/>
492 /// This only has effect when items are wrapped to multiple lines using flex wrap.
494 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
495 /// <since_tizen> 6 </since_tizen>
496 public AlignmentType Alignment
498 get => GetFlexAlignment();
501 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
502 throw new InvalidEnumArgumentException(nameof(Alignment));
504 Interop.FlexLayout.SetFlexAlignment(swigCPtr, (int)value);
510 /// Gets/Sets the alignment of the layout items.
511 /// Items alignment describes how to align children along the cross axis of their container.<br/>
512 /// Align items is very similar to <see cref="Justification"/> but instead of applying to the main axis, align items applies to the cross axis.
514 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
515 /// <since_tizen> 6 </since_tizen>
516 public AlignmentType ItemsAlignment
518 get => GetFlexItemsAlignment();
521 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
522 throw new InvalidEnumArgumentException(nameof(ItemsAlignment));
524 Interop.FlexLayout.SetFlexItemsAlignment(swigCPtr, (int)value);
530 /// Enumeration for the direction of the main axis in the flex container.
531 /// This determines the direction that flex items are laid out in the flex container.
533 /// <since_tizen> 6 </since_tizen>
534 public enum FlexDirection
537 /// The flexible items are displayed vertically as a column
541 /// The flexible items are displayed vertically as a column, but in reverse order
545 /// The flexible items are displayed horizontally as a row
549 /// The flexible items are displayed horizontally as a row, but in reverse order
555 /// Enumeration for the alignment of the flex items when the items do not use all available space on the main-axis.
557 /// <since_tizen> 6 </since_tizen>
558 public enum FlexJustification
561 /// Items are positioned at the beginning of the container.
565 /// Items are positioned at the center of the container.
569 /// Items are positioned at the end of the container.
573 /// Items are positioned with equal space between the lines.
577 /// Items are positioned with equal space before, between, and after the lines.<br/>
578 /// Compared to <see cref="FlexJustification.SpaceBetween"/> using <see cref="FlexJustification.SpaceAround"/>
579 /// will result in space being distributed to the beginning of the first child and end of the last child.
585 /// Enumeration for the wrap type of the flex container when there is no enough room for all the items on one flex line.
587 /// <since_tizen> 6 </since_tizen>
588 public enum FlexWrapType
591 /// Flex items laid out in single line (shrunk to fit the flex container along the main axis)
595 /// Flex items laid out in multiple lines if needed
601 /// 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.
603 /// <since_tizen> 6 </since_tizen>
604 public enum AlignmentType
607 /// Inherits the same alignment from the parent
611 /// At the beginning of the container
615 /// At the center of the container
619 /// At the end of the container
623 /// Stretch to fit the container
629 /// Enumeration for the position type of the flex item how it is positioned within its parent.
631 /// <since_tizen> 8 </since_tizen>
632 public enum PositionType
635 /// Flex items laid out relatively.
639 /// Flex items laid out absolutely.
644 private void measureChild(global::System.IntPtr childPtr, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize)
646 // We need to measure child layout
647 View child = Registry.GetManagedBaseHandleFromNativePtr(childPtr) as View;
648 // independent child will be measured in LayoutGroup.OnMeasureIndependentChildren().
649 if (child?.ExcludeLayouting ?? true)
651 measureSize.width = 0;
652 measureSize.height = 0;
656 LayoutItem childLayout = child.Layout;
658 MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
659 new MeasureSpecification(
660 new LayoutLength(parentMeasureSpecificationWidth.Size - (child.Margin.Start + child.Margin.End)),
661 parentMeasureSpecificationWidth.Mode),
662 new LayoutLength(Padding.Start + Padding.End),
663 new LayoutLength(child.WidthSpecification));
665 MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
666 new MeasureSpecification(
667 new LayoutLength(parentMeasureSpecificationHeight.Size - (child.Margin.Top + child.Margin.Bottom)),
668 parentMeasureSpecificationHeight.Mode),
669 new LayoutLength(Padding.Top + Padding.Bottom),
670 new LayoutLength(child.HeightSpecification));
672 childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
674 measureSize.width = childLayout.MeasuredWidth.Size.AsRoundedValue();
675 measureSize.height = childLayout.MeasuredHeight.Size.AsRoundedValue();
678 void InsertChild(LayoutItem child)
680 // Store created node for child
681 IntPtr childPtr = Interop.FlexLayout.AddChildWithMargin(swigCPtr, View.getCPtr(child.Owner), Extents.getCPtr(child.Owner.Margin), measureChildDelegate, LayoutChildren.Count - 1);
682 HandleRef childHandleRef = new HandleRef(child.Owner, childPtr);
683 SetAttachedValue(child.Owner, FlexItemProperty, childHandleRef);
687 /// Callback when child is added to container.<br />
688 /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
690 /// <param name="child">The Layout child.</param>
691 /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
692 /// <since_tizen> 6 </since_tizen>
693 protected override void OnChildAdd(LayoutItem child)
697 throw new ArgumentNullException(nameof(child));
703 /// Callback when child is removed from container.<br />
705 /// <param name="child">The Layout child.</param>
706 /// <since_tizen> 6 </since_tizen>
707 protected override void OnChildRemove(LayoutItem child)
709 // When child View is removed from it's parent View (that is a Layout) then remove it from the layout too.
710 // FlexLayout refers to the child as a View not LayoutItem.
711 Interop.FlexLayout.RemoveChild(swigCPtr, child);
715 /// Measure the layout and its content to determine the measured width and the measured height.<br />
717 /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
718 /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
719 /// <since_tizen> 6 </since_tizen>
720 protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
722 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
723 Extents padding = Owner.Padding;
725 Interop.FlexLayout.SetPadding(swigCPtr, Extents.getCPtr(padding));
727 float width = FlexUndefined; // Behaves as WrapContent (Flex Auto)
728 float height = FlexUndefined; // Behaves as WrapContent (Flex Auto)
730 if (widthMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || widthMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
732 width = widthMeasureSpec.Size.AsDecimal();
735 if (heightMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || heightMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
737 height = heightMeasureSpec.Size.AsDecimal();
740 // Save measureSpec to measure children.
741 // In other Layout, we can pass it as parameter to measuring child but in FlexLayout we can't
742 // because measurChild function is called by native callback.
743 parentMeasureSpecificationWidth = widthMeasureSpec;
744 parentMeasureSpecificationHeight = heightMeasureSpec;
746 Extents zeroMargin = new Extents();
748 // Assign child properties
749 for (int i = 0; i < LayoutChildren.Count; i++)
751 LayoutItem layoutItem = LayoutChildren[i];
752 View Child = layoutItem?.Owner;
753 HandleRef childHandleRef = (HandleRef)Child.GetValue(FlexItemProperty);
754 if (childHandleRef.Handle == IntPtr.Zero || Child == null)
757 AlignmentType flexAlignemnt = GetFlexAlignmentSelf(Child);
758 PositionType positionType = GetFlexPositionType(Child);
759 float flexAspectRatio = GetFlexAspectRatio(Child);
760 float flexBasis = GetFlexBasis(Child);
761 float flexShrink = GetFlexShrink(Child);
762 float flexGrow = GetFlexGrow(Child);
763 Extents childMargin = Child.ExcludeLayouting ? zeroMargin : layoutItem.Margin;
765 Interop.FlexLayout.SetMargin(childHandleRef, Extents.getCPtr(childMargin));
766 Interop.FlexLayout.SetFlexAlignmentSelf(childHandleRef, (int)flexAlignemnt);
767 Interop.FlexLayout.SetFlexPositionType(childHandleRef, (int)positionType);
768 Interop.FlexLayout.SetFlexAspectRatio(childHandleRef, flexAspectRatio);
769 Interop.FlexLayout.SetFlexBasis(childHandleRef, flexBasis);
770 Interop.FlexLayout.SetFlexShrink(childHandleRef, flexShrink);
771 Interop.FlexLayout.SetFlexGrow(childHandleRef, flexGrow);
774 Interop.FlexLayout.CalculateLayout(swigCPtr, width, height, isLayoutRtl);
775 zeroMargin.Dispose();
777 LayoutLength flexLayoutWidth = new LayoutLength(Interop.FlexLayout.GetWidth(swigCPtr));
778 LayoutLength flexLayoutHeight = new LayoutLength(Interop.FlexLayout.GetHeight(swigCPtr));
780 Debug.WriteLineIf(LayoutDebugFlex, "FlexLayout OnMeasure width:" + flexLayoutWidth.AsRoundedValue()
781 + " height:" + flexLayoutHeight.AsRoundedValue());
783 SetMeasuredDimensions(GetDefaultSize(flexLayoutWidth, widthMeasureSpec),
784 GetDefaultSize(flexLayoutHeight, heightMeasureSpec));
788 /// Assign a size and position to each of its children.<br />
790 /// <param name="changed">This is a new size or position for this layout.</param>
791 /// <param name="left">Left position, relative to parent.</param>
792 /// <param name="top"> Top position, relative to parent.</param>
793 /// <param name="right">Right position, relative to parent.</param>
794 /// <param name="bottom">Bottom position, relative to parent.</param>
795 /// <since_tizen> 6 </since_tizen>
796 protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
799 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
800 LayoutLength width = right - left;
801 LayoutLength height = bottom - top;
803 // Call to FlexLayout implementation to calculate layout values for later retrieval.
804 Interop.FlexLayout.CalculateLayout(swigCPtr, width.AsDecimal(), height.AsDecimal(), isLayoutRtl);
806 for (int childIndex = 0; childIndex < LayoutChildren.Count; childIndex++)
808 LayoutItem childLayout = LayoutChildren[childIndex];
809 if (!childLayout?.Owner?.ExcludeLayouting ?? false)
811 // Get the frame for the child, start, top, end, bottom.
812 Vector4 frame = new Vector4(Interop.FlexLayout.GetNodeFrame(swigCPtr, childIndex), true);
813 childLayout.Layout(new LayoutLength(frame.X), new LayoutLength(frame.Y), new LayoutLength(frame.Z), new LayoutLength(frame.W));
818 } // namesspace Tizen.NUI