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;
99 private MeasureSpecification parentMeasureSpecificationWidth;
100 private MeasureSpecification parentMeasureSpecificationHeight;
102 private IntPtr _rootFlex; // Pointer to the unmanged flex layout class.
104 internal const float FlexUndefined = 10E20F; // Auto setting which is equivalent to WrapContent.
106 internal struct MeasuredSize
108 public MeasuredSize(float x, float y)
118 /// Gets the alignment self of the child view.
120 /// <seealso cref="SetFlexAlignmentSelf(View, AlignmentType)"/>
121 /// <param name="view">The child view.</param>
122 /// <returns> The value of alignment self.</returns>
123 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
124 /// <since_tizen> 8 </since_tizen>
125 public static AlignmentType GetFlexAlignmentSelf(View view) => GetAttachedValue<AlignmentType>(view, FlexAlignmentSelfProperty);
128 /// Gets the position type of the child view.
130 /// <seealso cref="SetFlexPositionType(View, PositionType)"/>
131 /// <param name="view">The child view.</param>
132 /// <returns> The value of position type</returns>
133 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
134 /// <since_tizen> 8 </since_tizen>
135 public static PositionType GetFlexPositionType(View view) => GetAttachedValue<PositionType>(view, FlexPositionTypeProperty);
138 /// Gets the aspect ratio of the child view.
140 /// <seealso cref="SetFlexAspectRatio(View, float)"/>
141 /// <param name="view">The child view.</param>
142 /// <returns> The value of aspect ratio</returns>
143 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
144 /// <since_tizen> 8 </since_tizen>
145 public static float GetFlexAspectRatio(View view) => GetAttachedValue<float>(view, FlexAspectRatioProperty);
148 /// Gets the basis of the child view.
150 /// <seealso cref="SetFlexBasis(View, float)"/>
151 /// <param name="view">The child view.</param>
152 /// <returns> The value of basis</returns>
153 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
154 /// <since_tizen> 8 </since_tizen>
155 public static float GetFlexBasis(View view) => GetAttachedValue<float>(view, FlexBasisProperty);
158 /// Gets the shrink of the child view.
160 /// <seealso cref="SetFlexShrink(View, float)"/>
161 /// <param name="view">The child view.</param>
162 /// <returns> The value of shrink</returns>
163 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
164 /// <since_tizen> 8 </since_tizen>
165 public static float GetFlexShrink(View view) => GetAttachedValue<float>(view, FlexShrinkProperty);
168 /// Gets the grow of the child view.
170 /// <seealso cref="SetFlexGrow(View, float)"/>
171 /// <param name="view">The child view.</param>
172 /// <returns> The value of grow</returns>
173 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
174 /// <since_tizen> 8 </since_tizen>
175 public static float GetFlexGrow(View view) => GetAttachedValue<float>(view, FlexGrowProperty);
178 /// Sets the alignment self of the child view.<br/>
179 /// Alignment self has the same options and effect as <see cref="ItemsAlignment"/> but instead of affecting the children within a container,
180 /// you can apply this property to a single child to change its alignment within its parent.<br/>
181 /// Alignment self overrides any option set by the parent with <see cref="ItemsAlignment"/>.
183 /// <param name="view">The child view.</param>
184 /// <param name="value">The value of alignment self.</param>
185 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
186 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="AlignmentType"/>.</exception>
187 /// <since_tizen> 8 </since_tizen>
188 public static void SetFlexAlignmentSelf(View view, AlignmentType value) => SetAttachedValue(view, FlexAlignmentSelfProperty, value);
191 /// Sets the position type of the child view.<br/>
192 /// The position type of an element defines how it is positioned within its parent.
193 /// By default a child is positioned relatively. This means a child is positioned according to the normal flow of the layout,
194 /// and then offset relative to that position based on the values of <see cref="View.Margin"/>.<br/>
195 /// When positioned absolutely an element doesn't take part in the normal layout flow.
196 /// It is instead laid out independent of its siblings. The position is determined based on the <see cref="View.Margin"/>.
198 /// <param name="view">The child view.</param>
199 /// <param name="value">The value of position type.</param>
200 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
201 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="PositionType"/>.</exception>
202 /// <since_tizen> 8 </since_tizen>
203 public static void SetFlexPositionType(View view, PositionType value) => SetAttachedValue(view, FlexPositionTypeProperty, value);
206 /// Sets the aspect ratio of the child view.
207 /// Aspect ratio Defines as the ratio between the width and the height of a node
208 /// e.g. if a node has an aspect ratio of 2 then its width is twice the size of its height.<br/>
209 /// Aspect ratio accepts any floating point value > 0. this has higher priority than flex grow.
211 /// <param name="view">The child view.</param>
212 /// <param name="value">The value of aspect ratio</param>
213 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
214 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than or equal to 0.0f.</exception>
215 /// <since_tizen> 8 </since_tizen>
216 public static void SetFlexAspectRatio(View view, float value) => SetAttachedValue(view, FlexAspectRatioProperty, value);
219 /// Sets the flex basis of the child view.
220 /// Flex basis is an axis-independent way of providing the default size of an item along the main axis.<br/>
221 /// 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"/>
222 /// or setting the height of a child if its parent is a container with <see cref="FlexDirection.Column"/>.<br/>
223 /// 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.
225 /// <param name="view">The child view.</param>
226 /// <param name="value">The value of basis</param>
227 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
228 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
229 /// <since_tizen> 8 </since_tizen>
230 public static void SetFlexBasis(View view, float value) => SetAttachedValue(view, FlexBasisProperty, value);
233 /// Sets the flex shrink of the child view.
234 /// 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/>
235 /// 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.
236 /// These two properties also work well together by allowing children to grow and shrink as needed.<br/>
237 /// 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.
239 /// <param name="view">The child view.</param>
240 /// <param name="value">The value of shrink</param>
241 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
242 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
243 /// <since_tizen> 8 </since_tizen>
244 public static void SetFlexShrink(View view, float value) => SetAttachedValue(view, FlexShrinkProperty, value);
247 /// Sets the grow of the child view.
248 /// Flex grow describes how any space within a container should be distributed among its children along the main axis.
249 /// After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.<br/>
250 /// Flex grow accepts any floating point value >= 0, with 0 being the default value.<br/>
251 /// A container will distribute any remaining space among its children weighted by the child's flex grow value.
253 /// <param name="view">The child view.</param>
254 /// <param name="value">The value of flex</param>
255 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
256 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than 0.0f.</exception>
257 /// <since_tizen> 8 </since_tizen>
258 public static void SetFlexGrow(View view, float value) => SetAttachedValue(view, FlexGrowProperty, value);
260 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
261 internal delegate void ChildMeasureCallback(global::System.IntPtr child, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize);
263 event ChildMeasureCallback measureChildDelegate; // Stores a delegate to the child measure callback. Used for all children of this FlexLayout.
265 internal FlexLayout(global::System.IntPtr cPtr, bool cMemoryOwn)
267 swigCMemOwn = cMemoryOwn;
268 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(this, cPtr);
269 _rootFlex = Interop.FlexLayout.New();
270 measureChildDelegate = new ChildMeasureCallback(measureChild);
273 internal static global::System.Runtime.InteropServices.HandleRef getCPtr(FlexLayout obj)
275 return (obj == null) ? new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero) : obj.swigCPtr;
279 /// Hidden API (Inhouse API).
282 [EditorBrowsable(EditorBrowsableState.Never)]
283 ~FlexLayout() => Dispose(false);
286 /// <since_tizen> 6 </since_tizen>
287 public new void Dispose()
290 System.GC.SuppressFinalize(this);
294 /// Hidden API (Inhouse API).
298 /// Following the guide of https://docs.microsoft.com/en-us/dotnet/standard/garbage-collection/implementing-dispose.
299 /// This will replace "protected virtual void Dispose(DisposeTypes type)" which is exactly same in functionality.
301 /// <param name="disposing">true in order to free managed objects</param>
302 // Protected implementation of Dispose pattern.
303 [EditorBrowsable(EditorBrowsableState.Never)]
304 protected override void Dispose(bool disposing)
313 // TODO: dispose managed state (managed objects).
314 // Explicit call. user calls Dispose()
316 //Throw excpetion if Dispose() is called in separate thread.
317 if (!Window.IsInstalled())
319 throw new System.InvalidOperationException("This API called from separate thread. This API must be called from MainThread.");
324 Dispose(DisposeTypes.Implicit);
328 Dispose(DisposeTypes.Explicit);
333 // Implicit call. user doesn't call Dispose(), so this object is added into DisposeQueue to be disposed automatically.
334 if (!isDisposeQueued)
336 isDisposeQueued = true;
337 DisposeQueue.Instance.Add(this);
341 // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
342 // TODO: set large fields to null.
343 base.Dispose(disposing);
347 /// <since_tizen> 6 </since_tizen>
348 protected virtual void Dispose(DisposeTypes type)
355 if (type == DisposeTypes.Explicit)
358 //Release your own managed resources here.
359 //You should release all of your own disposable objects here.
362 //Release your own unmanaged resources here.
363 //You should not access any managed member here except static instance.
364 //because the execution order of Finalizes is non-deterministic.
365 if (swigCPtr.Handle != global::System.IntPtr.Zero)
370 ReleaseSwigCPtr(swigCPtr);
372 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero);
379 /// Hidden API (Inhouse API).
380 /// Release swigCPtr.
382 /// This will not be public opened.
383 [EditorBrowsable(EditorBrowsableState.Never)]
384 protected virtual void ReleaseSwigCPtr(System.Runtime.InteropServices.HandleRef swigCPtr)
386 Interop.FlexLayout.DeleteFlexLayout(swigCPtr);
390 /// Creates a FlexLayout object.
392 /// <since_tizen> 6 </since_tizen>
393 public FlexLayout() : this(Interop.FlexLayout.New(), true)
395 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
398 internal static FlexLayout DownCast(BaseHandle handle)
400 FlexLayout ret = new FlexLayout(Interop.FlexLayout.DownCast(BaseHandle.getCPtr(handle)), true);
401 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
405 internal FlexLayout(FlexLayout other) : this(Interop.FlexLayout.NewFlexLayout(FlexLayout.getCPtr(other)), true)
407 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
410 internal FlexLayout.AlignmentType GetFlexAlignment()
412 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexAlignment(swigCPtr);
413 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
417 internal FlexLayout.AlignmentType GetFlexItemsAlignment()
419 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.GetFlexItemsAlignment(swigCPtr);
420 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
425 /// Gets/Sets the flex direction in the layout.
426 /// The direction of the main-axis which determines the direction that flex items are laid out.
428 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
429 /// <since_tizen> 6 </since_tizen>
430 public FlexDirection Direction
432 get => (FlexDirection)Interop.FlexLayout.GetFlexDirection(swigCPtr);
435 if (value < FlexDirection.Column || value > FlexDirection.RowReverse)
436 throw new InvalidEnumArgumentException(nameof(Direction));
438 Interop.FlexLayout.SetFlexDirection(swigCPtr, (int)value);
444 /// Gets/Sets the justification in the layout.
445 /// Justify content describes how to align children within the main axis of their container.<br/>
446 /// 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"/>
447 /// or vertically within a container with <see cref="Direction"/> set to <see cref="FlexDirection.Column"/>.
449 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
450 /// <since_tizen> 6 </since_tizen>
451 public FlexJustification Justification
453 get => (FlexJustification)Interop.FlexLayout.GetFlexJustification(swigCPtr);
456 if (value < FlexJustification.FlexStart || value > FlexJustification.SpaceAround)
457 throw new InvalidEnumArgumentException(nameof(Justification));
459 Interop.FlexLayout.SetFlexJustification(swigCPtr, (int)value);
465 /// Gets/Sets the wrap in the layout.
466 /// 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/>
467 /// By default children are forced into a single line (which can shrink elements).<br/>
468 /// 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/>
469 /// When wrapping lines <see cref="Alignment"/> can be used to specify how the lines are placed in the container.
471 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
472 /// <since_tizen> 6 </since_tizen>
473 public FlexWrapType WrapType
475 get => (FlexWrapType)Interop.FlexLayout.GetFlexWrap(swigCPtr);
478 if (value != FlexWrapType.NoWrap && value != FlexWrapType.Wrap)
479 throw new InvalidEnumArgumentException(nameof(WrapType));
481 Interop.FlexLayout.SetFlexWrap(swigCPtr, (int)value);
488 /// Gets/Sets the alignment of the layout content.
489 /// Alignment defines the distribution of lines along the cross-axis.<br/>
490 /// This only has effect when items are wrapped to multiple lines using flex wrap.
492 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
493 /// <since_tizen> 6 </since_tizen>
494 public AlignmentType Alignment
496 get => GetFlexAlignment();
499 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
500 throw new InvalidEnumArgumentException(nameof(Alignment));
502 Interop.FlexLayout.SetFlexAlignment(swigCPtr, (int)value);
508 /// Gets/Sets the alignment of the layout items.
509 /// Items alignment describes how to align children along the cross axis of their container.<br/>
510 /// Align items is very similar to <see cref="Justification"/> but instead of applying to the main axis, align items applies to the cross axis.
512 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
513 /// <since_tizen> 6 </since_tizen>
514 public AlignmentType ItemsAlignment
516 get => GetFlexItemsAlignment();
519 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
520 throw new InvalidEnumArgumentException(nameof(ItemsAlignment));
522 Interop.FlexLayout.SetFlexItemsAlignment(swigCPtr, (int)value);
528 /// Enumeration for the direction of the main axis in the flex container.
529 /// This determines the direction that flex items are laid out in the flex container.
531 /// <since_tizen> 6 </since_tizen>
532 public enum FlexDirection
535 /// The flexible items are displayed vertically as a column
539 /// The flexible items are displayed vertically as a column, but in reverse order
543 /// The flexible items are displayed horizontally as a row
547 /// The flexible items are displayed horizontally as a row, but in reverse order
553 /// Enumeration for the alignment of the flex items when the items do not use all available space on the main-axis.
555 /// <since_tizen> 6 </since_tizen>
556 public enum FlexJustification
559 /// Items are positioned at the beginning of the container.
563 /// Items are positioned at the center of the container.
567 /// Items are positioned at the end of the container.
571 /// Items are positioned with equal space between the lines.
575 /// Items are positioned with equal space before, between, and after the lines.<br/>
576 /// Compared to <see cref="FlexJustification.SpaceBetween"/> using <see cref="FlexJustification.SpaceAround"/>
577 /// will result in space being distributed to the beginning of the first child and end of the last child.
583 /// Enumeration for the wrap type of the flex container when there is no enough room for all the items on one flex line.
585 /// <since_tizen> 6 </since_tizen>
586 public enum FlexWrapType
589 /// Flex items laid out in single line (shrunk to fit the flex container along the main axis)
593 /// Flex items laid out in multiple lines if needed
599 /// 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.
601 /// <since_tizen> 6 </since_tizen>
602 public enum AlignmentType
605 /// Inherits the same alignment from the parent
609 /// At the beginning of the container
613 /// At the center of the container
617 /// At the end of the container
621 /// Stretch to fit the container
627 /// Enumeration for the position type of the flex item how it is positioned within its parent.
629 /// <since_tizen> 8 </since_tizen>
630 public enum PositionType
633 /// Flex items laid out relatively.
637 /// Flex items laid out absolutely.
642 private void measureChild(global::System.IntPtr childPtr, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize)
644 // We need to measure child layout
645 View child = Registry.GetManagedBaseHandleFromNativePtr(childPtr) as View;
646 // independent child will be measured in LayoutGroup.OnMeasureIndependentChildren().
647 if (child?.ExcludeLayouting ?? true)
649 measureSize.width = 0;
650 measureSize.height = 0;
654 LayoutItem childLayout = child.Layout;
656 MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
657 new MeasureSpecification(
658 new LayoutLength(parentMeasureSpecificationWidth.Size - (child.Margin.Start + child.Margin.End)),
659 parentMeasureSpecificationWidth.Mode),
660 new LayoutLength(Padding.Start + Padding.End),
661 new LayoutLength(child.WidthSpecification));
663 MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
664 new MeasureSpecification(
665 new LayoutLength(parentMeasureSpecificationHeight.Size - (child.Margin.Top + child.Margin.Bottom)),
666 parentMeasureSpecificationHeight.Mode),
667 new LayoutLength(Padding.Top + Padding.Bottom),
668 new LayoutLength(child.HeightSpecification));
670 childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
672 measureSize.width = childLayout.MeasuredWidth.Size.AsRoundedValue();
673 measureSize.height = childLayout.MeasuredHeight.Size.AsRoundedValue();
676 void InsertChild(LayoutItem child)
678 // Store created node for child
679 IntPtr childPtr = Interop.FlexLayout.AddChildWithMargin(swigCPtr, View.getCPtr(child.Owner), Extents.getCPtr(child.Owner.Margin), measureChildDelegate, LayoutChildren.Count - 1);
680 HandleRef childHandleRef = new HandleRef(child.Owner, childPtr);
681 SetAttachedValue(child.Owner, FlexItemProperty, childHandleRef);
685 /// Callback when child is added to container.<br />
686 /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
688 /// <param name="child">The Layout child.</param>
689 /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
690 /// <since_tizen> 6 </since_tizen>
691 protected override void OnChildAdd(LayoutItem child)
695 throw new ArgumentNullException(nameof(child));
701 /// Callback when child is removed from container.<br />
703 /// <param name="child">The Layout child.</param>
704 /// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
705 /// <since_tizen> 6 </since_tizen>
706 protected override void OnChildRemove(LayoutItem child)
710 throw new ArgumentNullException(nameof(child));
712 // When child View is removed from it's parent View (that is a Layout) then remove it from the layout too.
713 // FlexLayout refers to the child as a View not LayoutItem.
714 Interop.FlexLayout.RemoveChild(swigCPtr, child.Owner.SwigCPtr);
718 /// Measure the layout and its content to determine the measured width and the measured height.<br />
720 /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
721 /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
722 /// <since_tizen> 6 </since_tizen>
723 protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
725 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
726 Extents padding = Owner.Padding;
728 Interop.FlexLayout.SetPadding(swigCPtr, Extents.getCPtr(padding));
730 float width = FlexUndefined; // Behaves as WrapContent (Flex Auto)
731 float height = FlexUndefined; // Behaves as WrapContent (Flex Auto)
733 if (widthMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || widthMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
735 width = widthMeasureSpec.Size.AsDecimal();
738 if (heightMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || heightMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
740 height = heightMeasureSpec.Size.AsDecimal();
743 // Save measureSpec to measure children.
744 // In other Layout, we can pass it as parameter to measuring child but in FlexLayout we can't
745 // because measurChild function is called by native callback.
746 parentMeasureSpecificationWidth = widthMeasureSpec;
747 parentMeasureSpecificationHeight = heightMeasureSpec;
749 Extents zeroMargin = new Extents();
751 // Assign child properties
752 for (int i = 0; i < LayoutChildren.Count; i++)
754 LayoutItem layoutItem = LayoutChildren[i];
755 View Child = layoutItem?.Owner;
756 HandleRef childHandleRef = (HandleRef)Child.GetValue(FlexItemProperty);
757 if (childHandleRef.Handle == IntPtr.Zero || Child == null)
760 AlignmentType flexAlignemnt = GetFlexAlignmentSelf(Child);
761 PositionType positionType = GetFlexPositionType(Child);
762 float flexAspectRatio = GetFlexAspectRatio(Child);
763 float flexBasis = GetFlexBasis(Child);
764 float flexShrink = GetFlexShrink(Child);
765 float flexGrow = GetFlexGrow(Child);
766 Extents childMargin = Child.ExcludeLayouting ? zeroMargin : layoutItem.Margin;
768 Interop.FlexLayout.SetMargin(childHandleRef, Extents.getCPtr(childMargin));
769 Interop.FlexLayout.SetFlexAlignmentSelf(childHandleRef, (int)flexAlignemnt);
770 Interop.FlexLayout.SetFlexPositionType(childHandleRef, (int)positionType);
771 Interop.FlexLayout.SetFlexAspectRatio(childHandleRef, flexAspectRatio);
772 Interop.FlexLayout.SetFlexBasis(childHandleRef, flexBasis);
773 Interop.FlexLayout.SetFlexShrink(childHandleRef, flexShrink);
774 Interop.FlexLayout.SetFlexGrow(childHandleRef, flexGrow);
777 Interop.FlexLayout.CalculateLayout(swigCPtr, width, height, isLayoutRtl);
778 zeroMargin.Dispose();
780 LayoutLength flexLayoutWidth = new LayoutLength(Interop.FlexLayout.GetWidth(swigCPtr));
781 LayoutLength flexLayoutHeight = new LayoutLength(Interop.FlexLayout.GetHeight(swigCPtr));
783 Debug.WriteLineIf(LayoutDebugFlex, "FlexLayout OnMeasure width:" + flexLayoutWidth.AsRoundedValue()
784 + " height:" + flexLayoutHeight.AsRoundedValue());
786 SetMeasuredDimensions(GetDefaultSize(flexLayoutWidth, widthMeasureSpec),
787 GetDefaultSize(flexLayoutHeight, heightMeasureSpec));
791 /// Assign a size and position to each of its children.<br />
793 /// <param name="changed">This is a new size or position for this layout.</param>
794 /// <param name="left">Left position, relative to parent.</param>
795 /// <param name="top"> Top position, relative to parent.</param>
796 /// <param name="right">Right position, relative to parent.</param>
797 /// <param name="bottom">Bottom position, relative to parent.</param>
798 /// <since_tizen> 6 </since_tizen>
799 protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
802 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
803 LayoutLength width = right - left;
804 LayoutLength height = bottom - top;
806 // Call to FlexLayout implementation to calculate layout values for later retrieval.
807 Interop.FlexLayout.CalculateLayout(swigCPtr, width.AsDecimal(), height.AsDecimal(), isLayoutRtl);
809 for (int childIndex = 0; childIndex < LayoutChildren.Count; childIndex++)
811 LayoutItem childLayout = LayoutChildren[childIndex];
812 if (!childLayout?.Owner?.ExcludeLayouting ?? false)
814 // Get the frame for the child, start, top, end, bottom.
815 Vector4 frame = new Vector4(Interop.FlexLayout.GetNodeFrame(swigCPtr, childIndex), true);
816 childLayout.Layout(new LayoutLength(frame.X), new LayoutLength(frame.Y), new LayoutLength(frame.Z), new LayoutLength(frame.W));
822 } // namesspace Tizen.NUI