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, global::System.IDisposable
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), propertyChanged: OnChildPropertyChanged);
53 /// AspectRatioProperty
55 [EditorBrowsable(EditorBrowsableState.Never)]
56 public static readonly BindableProperty FlexAspectRatioProperty = BindableProperty.CreateAttached("FlexAspectRatio", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value > 0, propertyChanged: OnChildPropertyChanged);
61 [EditorBrowsable(EditorBrowsableState.Never)]
62 public static readonly BindableProperty FlexBasisProperty = BindableProperty.CreateAttached("FlexBasis", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
65 /// FlexShrinkProperty
67 [EditorBrowsable(EditorBrowsableState.Never)]
68 public static readonly BindableProperty FlexShrinkProperty = BindableProperty.CreateAttached("FlexShrink", typeof(float), typeof(FlexLayout), 1.0f, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
73 [EditorBrowsable(EditorBrowsableState.Never)]
74 public static readonly BindableProperty FlexGrowProperty = BindableProperty.CreateAttached("FlexGrow", typeof(float), typeof(FlexLayout), FlexUndefined, validateValue: (bindable, value) => (float)value >= 0, propertyChanged: OnChildPropertyChanged);
76 private static bool LayoutDebugFlex = false; // Debug flag
78 private global::System.Runtime.InteropServices.HandleRef swigCPtr;
79 private bool swigCMemOwn;
80 private bool disposed;
81 private bool isDisposeQueued = false;
83 private MeasureSpecification parentMeasureSpecificationWidth;
84 private MeasureSpecification parentMeasureSpecificationHeight;
86 private IntPtr _rootFlex; // Pointer to the unmanged flex layout class.
88 internal const float FlexUndefined = 10E20F; // Auto setting which is equivalent to WrapContent.
90 internal struct MeasuredSize
92 public MeasuredSize(float x, float y)
102 /// Gets the alignment self of the child view.
104 /// <seealso cref="SetFlexAlignmentSelf(View, AlignmentType)"/>
105 /// <param name="view">The child view.</param>
106 /// <returns> The value of alignment self.</returns>
107 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
108 /// <since_tizen> 8 </since_tizen>
109 public static AlignmentType GetFlexAlignmentSelf(View view) => GetAttachedValue<AlignmentType>(view, FlexAlignmentSelfProperty);
112 /// Gets the position type of the child view.
114 /// <seealso cref="SetFlexPositionType(View, PositionType)"/>
115 /// <param name="view">The child view.</param>
116 /// <returns> The value of position type</returns>
117 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
118 /// <since_tizen> 8 </since_tizen>
119 public static PositionType GetFlexPositionType(View view) => GetAttachedValue<PositionType>(view, FlexPositionTypeProperty);
122 /// Gets the aspect ratio of the child view.
124 /// <seealso cref="SetFlexAspectRatio(View, float)"/>
125 /// <param name="view">The child view.</param>
126 /// <returns> The value of aspect ratio</returns>
127 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
128 /// <since_tizen> 8 </since_tizen>
129 public static float GetFlexAspectRatio(View view) => GetAttachedValue<float>(view, FlexAspectRatioProperty);
132 /// Gets the basis of the child view.
134 /// <seealso cref="SetFlexBasis(View, float)"/>
135 /// <param name="view">The child view.</param>
136 /// <returns> The value of basis</returns>
137 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
138 /// <since_tizen> 8 </since_tizen>
139 public static float GetFlexBasis(View view) => GetAttachedValue<float>(view, FlexBasisProperty);
142 /// Gets the shrink of the child view.
144 /// <seealso cref="SetFlexShrink(View, float)"/>
145 /// <param name="view">The child view.</param>
146 /// <returns> The value of shrink</returns>
147 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
148 /// <since_tizen> 8 </since_tizen>
149 public static float GetFlexShrink(View view) => GetAttachedValue<float>(view, FlexShrinkProperty);
152 /// Gets the grow of the child view.
154 /// <seealso cref="SetFlexGrow(View, float)"/>
155 /// <param name="view">The child view.</param>
156 /// <returns> The value of grow</returns>
157 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
158 /// <since_tizen> 8 </since_tizen>
159 public static float GetFlexGrow(View view) => GetAttachedValue<float>(view, FlexGrowProperty);
162 /// Sets the alignment self of the child view.<br/>
163 /// Alignment self has the same options and effect as <see cref="ItemsAlignment"/> but instead of affecting the children within a container,
164 /// you can apply this property to a single child to change its alignment within its parent.<br/>
165 /// Alignment self overrides any option set by the parent with <see cref="ItemsAlignment"/>.
167 /// <param name="view">The child view.</param>
168 /// <param name="value">The value of alignment self.</param>
169 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
170 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="AlignmentType"/>.</exception>
171 /// <since_tizen> 8 </since_tizen>
172 public static void SetFlexAlignmentSelf(View view, AlignmentType value) => SetAttachedValue(view, FlexAlignmentSelfProperty, value);
175 /// Sets the position type of the child view.<br/>
176 /// The position type of an element defines how it is positioned within its parent.
177 /// By default a child is positioned relatively. This means a child is positioned according to the normal flow of the layout,
178 /// and then offset relative to that position based on the values of <see cref="View.Margin"/>.<br/>
179 /// When positioned absolutely an element doesn't take part in the normal layout flow.
180 /// It is instead laid out independent of its siblings. The position is determined based on the <see cref="View.Margin"/>.
182 /// <param name="view">The child view.</param>
183 /// <param name="value">The value of position type.</param>
184 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
185 /// <exception cref="ArgumentException">The <paramref name="value"/> should be <see cref="PositionType"/>.</exception>
186 /// <since_tizen> 8 </since_tizen>
187 public static void SetFlexPositionType(View view, PositionType value) => SetAttachedValue(view, FlexPositionTypeProperty, value);
190 /// Sets the aspect ratio of the child view.
191 /// Aspect ratio Defines as the ratio between the width and the height of a node
192 /// e.g. if a node has an aspect ratio of 2 then its width is twice the size of its height.<br/>
193 /// Aspect ratio accepts any floating point value > 0. this has higher priority than flex grow.
195 /// <param name="view">The child view.</param>
196 /// <param name="value">The value of aspect ratio</param>
197 /// <exception cref="ArgumentNullException">The <paramref name="view"/> cannot be null.</exception>
198 /// <exception cref="ArgumentException">The <paramref name="value"/> cannot be less than or equal to 0.0f.</exception>
199 /// <since_tizen> 8 </since_tizen>
200 public static void SetFlexAspectRatio(View view, float value) => SetAttachedValue(view, FlexAspectRatioProperty, value);
203 /// Sets the flex basis of the child view.
204 /// Flex basis is an axis-independent way of providing the default size of an item along the main axis.<br/>
205 /// 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"/>
206 /// or setting the height of a child if its parent is a container with <see cref="FlexDirection.Column"/>.<br/>
207 /// 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.
209 /// <param name="view">The child view.</param>
210 /// <param name="value">The value of basis</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 0.0f.</exception>
213 /// <since_tizen> 8 </since_tizen>
214 public static void SetFlexBasis(View view, float value) => SetAttachedValue(view, FlexBasisProperty, value);
217 /// Sets the flex shrink of the child view.
218 /// 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/>
219 /// 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.
220 /// These two properties also work well together by allowing children to grow and shrink as needed.<br/>
221 /// 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.
223 /// <param name="view">The child view.</param>
224 /// <param name="value">The value of shrink</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 SetFlexShrink(View view, float value) => SetAttachedValue(view, FlexShrinkProperty, value);
231 /// Sets the grow of the child view.
232 /// Flex grow describes how any space within a container should be distributed among its children along the main axis.
233 /// After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.<br/>
234 /// Flex grow accepts any floating point value >= 0, with 0 being the default value.<br/>
235 /// A container will distribute any remaining space among its children weighted by the child's flex grow value.
237 /// <param name="view">The child view.</param>
238 /// <param name="value">The value of flex</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 SetFlexGrow(View view, float value) => SetAttachedValue(view, FlexGrowProperty, value);
244 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
245 internal delegate void ChildMeasureCallback(global::System.IntPtr child, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize);
247 event ChildMeasureCallback measureChildDelegate; // Stores a delegate to the child measure callback. Used for all children of this FlexLayout.
249 internal FlexLayout(global::System.IntPtr cPtr, bool cMemoryOwn)
251 swigCMemOwn = cMemoryOwn;
252 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(this, cPtr);
253 _rootFlex = Interop.FlexLayout.FlexLayout_New();
254 measureChildDelegate = new ChildMeasureCallback(measureChild);
257 internal static global::System.Runtime.InteropServices.HandleRef getCPtr(FlexLayout obj)
259 return (obj == null) ? new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero) : obj.swigCPtr;
263 /// <since_tizen> 6 </since_tizen>
264 public void Dispose()
266 // Throw exception if Dispose() is called in separate thread.
267 if (!Window.IsInstalled())
269 throw new System.InvalidOperationException("This API called from separate thread. This API must be called from MainThread.");
274 Dispose(DisposeTypes.Implicit);
278 Dispose(DisposeTypes.Explicit);
279 System.GC.SuppressFinalize(this);
284 /// <since_tizen> 6 </since_tizen>
285 protected virtual void Dispose(DisposeTypes type)
292 if (type == DisposeTypes.Explicit)
295 // Release your own managed resources here.
296 // You should release all of your own disposable objects here.
300 // Release your own unmanaged resources here.
301 // You should not access any managed member here except static instance.
302 // because the execution order of Finalizes is non-deterministic.
303 if (swigCPtr.Handle != global::System.IntPtr.Zero)
308 Interop.FlexLayout.delete_FlexLayout(swigCPtr);
310 swigCPtr = new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero);
316 /// Creates a FlexLayout object.
318 /// <since_tizen> 6 </since_tizen>
319 public FlexLayout() : this(Interop.FlexLayout.FlexLayout_New(), true)
321 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
324 internal static FlexLayout DownCast(BaseHandle handle)
326 FlexLayout ret = new FlexLayout(Interop.FlexLayout.FlexLayout_DownCast(BaseHandle.getCPtr(handle)), true);
327 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
331 internal FlexLayout(FlexLayout other) : this(Interop.FlexLayout.new_FlexLayout__SWIG_1(FlexLayout.getCPtr(other)), true)
333 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
336 internal FlexLayout.AlignmentType GetFlexAlignment()
338 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.FlexLayout_GetFlexAlignment(swigCPtr);
339 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
343 internal FlexLayout.AlignmentType GetFlexItemsAlignment()
345 FlexLayout.AlignmentType ret = (FlexLayout.AlignmentType)Interop.FlexLayout.FlexLayout_GetFlexItemsAlignment(swigCPtr);
346 if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
351 /// Gets/Sets the flex direction in the layout.
352 /// The direction of the main-axis which determines the direction that flex items are laid out.
354 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
355 /// <since_tizen> 6 </since_tizen>
356 public FlexDirection Direction
358 get => (FlexDirection)Interop.FlexLayout.FlexLayout_GetFlexDirection(swigCPtr);
361 if (value < FlexDirection.Column || value > FlexDirection.RowReverse)
362 throw new InvalidEnumArgumentException(nameof(Direction));
364 Interop.FlexLayout.FlexLayout_SetFlexDirection(swigCPtr, (int)value);
370 /// Gets/Sets the justification in the layout.
371 /// Justify content describes how to align children within the main axis of their container.<br/>
372 /// 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"/>
373 /// or vertically within a container with <see cref="Direction"/> set to <see cref="FlexDirection.Column"/>.
375 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
376 /// <since_tizen> 6 </since_tizen>
377 public FlexJustification Justification
379 get => (FlexJustification)Interop.FlexLayout.FlexLayout_GetFlexJustification(swigCPtr);
382 if (value < FlexJustification.FlexStart || value > FlexJustification.SpaceAround)
383 throw new InvalidEnumArgumentException(nameof(Justification));
385 Interop.FlexLayout.FlexLayout_SetFlexJustification(swigCPtr, (int)value);
391 /// Gets/Sets the wrap in the layout.
392 /// 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/>
393 /// By default children are forced into a single line (which can shrink elements).<br/>
394 /// 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/>
395 /// When wrapping lines <see cref="Alignment"/> can be used to specify how the lines are placed in the container.
397 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
398 /// <since_tizen> 6 </since_tizen>
399 public FlexWrapType WrapType
401 get => (FlexWrapType)Interop.FlexLayout.FlexLayout_GetFlexWrap(swigCPtr);
404 if (value != FlexWrapType.NoWrap && value != FlexWrapType.Wrap)
405 throw new InvalidEnumArgumentException(nameof(WrapType));
407 Interop.FlexLayout.FlexLayout_SetFlexWrap(swigCPtr, (int)value);
414 /// Gets/Sets the alignment of the layout content.
415 /// Alignment defines the distribution of lines along the cross-axis.<br/>
416 /// This only has effect when items are wrapped to multiple lines using flex wrap.
418 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
419 /// <since_tizen> 6 </since_tizen>
420 public AlignmentType Alignment
422 get => GetFlexAlignment();
425 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
426 throw new InvalidEnumArgumentException(nameof(Alignment));
428 Interop.FlexLayout.FlexLayout_SetFlexAlignment(swigCPtr, (int)value);
434 /// Gets/Sets the alignment of the layout items.
435 /// Items alignment describes how to align children along the cross axis of their container.<br/>
436 /// Align items is very similar to <see cref="Justification"/> but instead of applying to the main axis, align items applies to the cross axis.
438 /// <exception cref="InvalidEnumArgumentException">Thrown when using invalid arguments that are enumerators.</exception>
439 /// <since_tizen> 6 </since_tizen>
440 public AlignmentType ItemsAlignment
442 get => GetFlexItemsAlignment();
445 if (value < AlignmentType.Auto || value > AlignmentType.Stretch)
446 throw new InvalidEnumArgumentException(nameof(ItemsAlignment));
448 Interop.FlexLayout.FlexLayout_SetFlexItemsAlignment(swigCPtr, (int)value);
454 /// Enumeration for the direction of the main axis in the flex container.
455 /// This determines the direction that flex items are laid out in the flex container.
457 /// <since_tizen> 6 </since_tizen>
458 public enum FlexDirection
461 /// The flexible items are displayed vertically as a column
465 /// The flexible items are displayed vertically as a column, but in reverse order
469 /// The flexible items are displayed horizontally as a row
473 /// The flexible items are displayed horizontally as a row, but in reverse order
479 /// Enumeration for the alignment of the flex items when the items do not use all available space on the main-axis.
481 /// <since_tizen> 6 </since_tizen>
482 public enum FlexJustification
485 /// Items are positioned at the beginning of the container.
489 /// Items are positioned at the center of the container.
493 /// Items are positioned at the end of the container.
497 /// Items are positioned with equal space between the lines.
501 /// Items are positioned with equal space before, between, and after the lines.<br/>
502 /// Compared to <see cref="FlexJustification.SpaceBetween"/> using <see cref="FlexJustification.SpaceAround"/>
503 /// will result in space being distributed to the beginning of the first child and end of the last child.
509 /// Enumeration for the wrap type of the flex container when there is no enough room for all the items on one flex line.
511 /// <since_tizen> 6 </since_tizen>
512 public enum FlexWrapType
515 /// Flex items laid out in single line (shrunk to fit the flex container along the main axis)
519 /// Flex items laid out in multiple lines if needed
525 /// 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.
527 /// <since_tizen> 6 </since_tizen>
528 public enum AlignmentType
531 /// Inherits the same alignment from the parent
535 /// At the beginning of the container
539 /// At the center of the container
543 /// At the end of the container
547 /// Stretch to fit the container
553 /// Enumeration for the position type of the flex item how it is positioned within its parent.
555 /// <since_tizen> 8 </since_tizen>
556 public enum PositionType
559 /// Flex items laid out relatively.
563 /// Flex items laid out absolutely.
568 private void measureChild(global::System.IntPtr childPtr, float width, int measureModeWidth, float height, int measureModeHeight, out MeasuredSize measureSize)
570 // We need to measure child layout
571 View child = Registry.GetManagedBaseHandleFromNativePtr(childPtr) as View;
574 measureSize.width = 0;
575 measureSize.height = 0;
579 LayoutItem childLayout = child.Layout;
581 MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
582 new MeasureSpecification(
583 new LayoutLength(parentMeasureSpecificationWidth.Size - (child.Margin.Start + child.Margin.End)),
584 parentMeasureSpecificationWidth.Mode),
585 new LayoutLength(Padding.Start + Padding.End),
586 new LayoutLength(child.WidthSpecification));
588 MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
589 new MeasureSpecification(
590 new LayoutLength(parentMeasureSpecificationHeight.Size - (child.Margin.Top + child.Margin.Bottom)),
591 parentMeasureSpecificationHeight.Mode),
592 new LayoutLength(Padding.Top + Padding.Bottom),
593 new LayoutLength(child.HeightSpecification));
595 childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
597 measureSize.width = childLayout.MeasuredWidth.Size.AsRoundedValue();
598 measureSize.height = childLayout.MeasuredHeight.Size.AsRoundedValue();
601 void InsertChild(LayoutItem child)
603 // Store created node for child
604 IntPtr childPtr = Interop.FlexLayout.FlexLayout_AddChildWithMargin(swigCPtr, View.getCPtr(child.Owner), Extents.getCPtr(child.Owner.Margin), measureChildDelegate, LayoutChildren.Count - 1);
605 HandleRef childHandleRef = new HandleRef(child.Owner, childPtr);
606 SetAttachedValue(child.Owner, FlexItemProperty, childHandleRef);
610 /// Callback when child is added to container.<br />
611 /// Derived classes can use this to set their own child properties on the child layout's owner.<br />
613 /// <param name="child">The Layout child.</param>
614 /// <since_tizen> 6 </since_tizen>
615 protected override void OnChildAdd(LayoutItem child)
621 /// Callback when child is removed from container.<br />
623 /// <param name="child">The Layout child.</param>
624 /// <since_tizen> 6 </since_tizen>
625 protected override void OnChildRemove(LayoutItem child)
627 // When child View is removed from it's parent View (that is a Layout) then remove it from the layout too.
628 // FlexLayout refers to the child as a View not LayoutItem.
629 Interop.FlexLayout.FlexLayout_RemoveChild(swigCPtr, child);
633 /// Measure the layout and its content to determine the measured width and the measured height.<br />
635 /// <param name="widthMeasureSpec">horizontal space requirements as imposed by the parent.</param>
636 /// <param name="heightMeasureSpec">vertical space requirements as imposed by the parent.</param>
637 /// <since_tizen> 6 </since_tizen>
638 protected override void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
640 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
641 Extents padding = Owner.Padding;
642 Extents margin = Owner.Margin;
644 Interop.FlexLayout.FlexLayout_SetMargin(swigCPtr, Extents.getCPtr(margin));
645 Interop.FlexLayout.FlexLayout_SetPadding(swigCPtr, Extents.getCPtr(padding));
647 float width = FlexUndefined; // Behaves as WrapContent (Flex Auto)
648 float height = FlexUndefined; // Behaves as WrapContent (Flex Auto)
650 if (widthMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || widthMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
652 width = widthMeasureSpec.Size.AsDecimal();
655 if (heightMeasureSpec.Mode == MeasureSpecification.ModeType.Exactly || heightMeasureSpec.Mode == MeasureSpecification.ModeType.AtMost)
657 height = heightMeasureSpec.Size.AsDecimal();
660 // Save measureSpec to measure children.
661 // In other Layout, we can pass it as parameter to measuring child but in FlexLayout we can't
662 // because measurChild function is called by native callback.
663 parentMeasureSpecificationWidth = widthMeasureSpec;
664 parentMeasureSpecificationHeight = heightMeasureSpec;
666 // Assign child properties
667 for (int i = 0; i < LayoutChildren.Count; i++)
669 LayoutItem layoutItem = LayoutChildren[i];
670 View Child = layoutItem?.Owner;
671 HandleRef childHandleRef = (HandleRef)Child.GetValue(FlexItemProperty);
672 if (childHandleRef.Handle == IntPtr.Zero || Child == null)
675 if (!layoutItem.Owner.ExcludeLayouting)
677 SetFlexPositionType(Child, PositionType.Absolute);
678 Interop.FlexLayout.FlexLayout_SetFlexPositionType(childHandleRef, (int)PositionType.Absolute);
679 MeasureChildWithoutPadding(layoutItem, widthMeasureSpec, heightMeasureSpec);
684 SetFlexPositionType(Child, PositionType.Relative);
685 Interop.FlexLayout.FlexLayout_SetFlexPositionType(childHandleRef, (int)PositionType.Relative);
688 AlignmentType flexAlignemnt = GetFlexAlignmentSelf(Child);
689 float flexAspectRatio = GetFlexAspectRatio(Child);
690 float flexBasis = GetFlexBasis(Child);
691 float flexShrink = GetFlexShrink(Child);
692 float flexGrow = GetFlexGrow(Child);
694 Interop.FlexLayout.FlexLayout_SetFlexAlignmentSelf(childHandleRef, (int)flexAlignemnt);
695 Interop.FlexLayout.FlexLayout_SetFlexAspectRatio(childHandleRef, flexAspectRatio);
696 Interop.FlexLayout.FlexLayout_SetFlexBasis(childHandleRef, flexBasis);
697 Interop.FlexLayout.FlexLayout_SetFlexShrink(childHandleRef, flexShrink);
698 Interop.FlexLayout.FlexLayout_SetFlexGrow(childHandleRef, flexGrow);
701 Interop.FlexLayout.FlexLayout_CalculateLayout(swigCPtr, width, height, isLayoutRtl);
703 LayoutLength flexLayoutWidth = new LayoutLength(Interop.FlexLayout.FlexLayout_GetWidth(swigCPtr));
704 LayoutLength flexLayoutHeight = new LayoutLength(Interop.FlexLayout.FlexLayout_GetHeight(swigCPtr));
706 Debug.WriteLineIf(LayoutDebugFlex, "FlexLayout OnMeasure width:" + flexLayoutWidth.AsRoundedValue()
707 + " height:" + flexLayoutHeight.AsRoundedValue());
709 SetMeasuredDimensions(GetDefaultSize(flexLayoutWidth, widthMeasureSpec),
710 GetDefaultSize(flexLayoutHeight, heightMeasureSpec));
714 /// Assign a size and position to each of its children.<br />
716 /// <param name="changed">This is a new size or position for this layout.</param>
717 /// <param name="left">Left position, relative to parent.</param>
718 /// <param name="top"> Top position, relative to parent.</param>
719 /// <param name="right">Right position, relative to parent.</param>
720 /// <param name="bottom">Bottom position, relative to parent.</param>
721 /// <since_tizen> 6 </since_tizen>
722 protected override void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)
725 bool isLayoutRtl = Owner.LayoutDirection == ViewLayoutDirectionType.RTL;
726 LayoutLength width = right - left;
727 LayoutLength height = bottom - top;
729 // Call to FlexLayout implementation to calculate layout values for later retrieval.
730 Interop.FlexLayout.FlexLayout_CalculateLayout(swigCPtr, width.AsDecimal(), height.AsDecimal(), isLayoutRtl);
732 int count = LayoutChildren.Count;
733 for (int childIndex = 0; childIndex < count; childIndex++)
735 LayoutItem childLayout = LayoutChildren[childIndex];
736 if (childLayout != null)
738 if (childLayout.Owner.ExcludeLayouting)
740 // Get the frame for the child, start, top, end, bottom.
741 Vector4 frame = new Vector4(Interop.FlexLayout.FlexLayout_GetNodeFrame(swigCPtr, childIndex), true);
742 childLayout.Layout(new LayoutLength(frame.X), new LayoutLength(frame.Y), new LayoutLength(frame.Z), new LayoutLength(frame.W));
746 LayoutForIndependentChild();
749 } // namesspace Tizen.NUI