Files
yoga/csharp/Xamarin.iOS/Facebook.YogaKit.iOS/YogaKit.cs
2016-12-16 14:09:39 +00:00

396 lines
10 KiB
C#

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using CoreGraphics;
using Facebook.Yoga;
using Foundation;
using UIKit;
namespace Facebook.YogaKit.iOS
{
class YGNodeBridge : NSObject
{
bool disposed;
internal WeakReference<UIView> viewRef;
internal YogaNode node;
public YGNodeBridge()
{
node = new YogaNode();
}
public void SetContext(UIView view)
{
viewRef = new WeakReference<UIView>(view);
YogaKit.Bridges.Add(node, this);
}
protected override void Dispose(bool disposing)
{
if (disposing && !disposed)
{
disposed = true;
YogaKit.Bridges.Remove(node);
viewRef = null;
node = null;
}
base.Dispose(disposing);
}
}
public static class YogaKit
{
internal static Dictionary<YogaNode, YGNodeBridge> Bridges = new Dictionary<YogaNode, YGNodeBridge>();
static NSString YogaNodeKey = new NSString(nameof(GetYogaNode));
static NSString UsesYogaKey = new NSString(nameof(UsesYoga));
static NSString IncludeYogaKey = new NSString(nameof(UsesYoga));
public static void UsesYoga(this UIView view, bool usesYoga)
{
var value = NSNumber.FromBoolean(usesYoga);
objc_setAssociatedObject(view.Handle, UsesYogaKey.Handle, value.Handle, AssociationPolicy.RETAIN_NONATOMIC);
}
public static bool GetUsesYoga(this UIView view)
{
var value = ObjCRuntime.Runtime.GetNSObject(objc_getAssociatedObject(view.Handle, UsesYogaKey.Handle)) as NSNumber;
return value == null ? false : value.BoolValue;
}
public static void IncludeYogaLayout(this UIView view, bool includeInLayout)
{
var value = NSNumber.FromBoolean(includeInLayout);
objc_setAssociatedObject(view.Handle, IncludeYogaKey.Handle, value.Handle, AssociationPolicy.RETAIN_NONATOMIC);
}
public static bool GetIncludeYogaLayout(this UIView view)
{
var value = ObjCRuntime.Runtime.GetNSObject(objc_getAssociatedObject(view.Handle, IncludeYogaKey.Handle)) as NSNumber;
return value == null ? true : value.BoolValue;
}
public static void YogaWidth(this UIView view, nfloat width)
{
var node = GetYogaNode(view);
node.Width = (float)width;
}
public static void YogaHeight(this UIView view, nfloat height)
{
var node = GetYogaNode(view);
node.Height = (float)height;
}
public static void YogaMinWidth(this UIView view, float minWidth)
{
var node = GetYogaNode(view);
node.MinWidth = minWidth;
}
public static void YogaMinHeight(this UIView view, float minHeight)
{
var node = GetYogaNode(view);
node.MinHeight = minHeight;
}
public static void YogaMaxWidth(this UIView view, float maxWidth)
{
var node = GetYogaNode(view);
node.MaxWidth = maxWidth;
}
public static void YogaMaxHeight(this UIView view, float maxHeight)
{
var node = GetYogaNode(view);
node.MaxHeight = maxHeight;
}
public static void YogaAlignItems(this UIView view, Yoga.YogaAlign align)
{
var node = GetYogaNode(view);
node.AlignItems = align;
}
public static void YogaJustify(this UIView view, Yoga.YogaJustify justify)
{
var node = GetYogaNode(view);
node.JustifyContent = justify;
}
public static void YogaAlign(this UIView view, Yoga.YogaAlign align)
{
var node = GetYogaNode(view);
node.AlignContent = align;
}
public static void YogaAlignSelf(this UIView view, Yoga.YogaAlign align)
{
var node = GetYogaNode(view);
node.AlignSelf = align;
}
public static void YogaDirection(this UIView view, Yoga.YogaDirection direction)
{
var node = GetYogaNode(view);
node.StyleDirection = direction;
}
public static void YogaFlexDirection(this UIView view, Yoga.YogaFlexDirection direction)
{
var node = GetYogaNode(view);
node.FlexDirection = direction;
}
public static void YogaPositionType(this UIView view, Yoga.YogaPositionType position)
{
var node = GetYogaNode(view);
node.PositionType = position;
}
public static void YogaFlexWrap(this UIView view, Yoga.YogaWrap wrap)
{
var node = GetYogaNode(view);
node.Wrap = wrap;
}
public static void YogaFlexShrink(this UIView view, float shrink)
{
var node = GetYogaNode(view);
node.FlexShrink = shrink;
}
public static void YogaFlexGrow(this UIView view, float grow)
{
var node = GetYogaNode(view);
node.FlexGrow = grow;
}
public static void YogaFlexBasis(this UIView view, float basis)
{
var node = GetYogaNode(view);
node.FlexBasis = basis;
}
public static void YogaPositionForEdge(this UIView view, float position, YogaEdge edge)
{
var node = GetYogaNode(view);
node.SetPosition(edge, position);
}
public static void YogaMarginForEdge(this UIView view, float margin, YogaEdge edge)
{
var node = GetYogaNode(view);
node.SetMargin(edge, margin);
}
public static void YogaPaddingForEdge(this UIView view, float padding, YogaEdge edge)
{
var node = GetYogaNode(view);
node.SetPadding(edge, padding);
}
public static void YogaAspectRation(this UIView view, float ratio)
{
var node = GetYogaNode(view);
node.StyleAspectRatio = ratio;
}
#region Layout and Sizing
public static void YogaApplyLayout(this UIView view)
{
CalculateLayoutWithSize(view, view.Bounds.Size);
ApplyLayoutToViewHierarchy(view);
}
public static CGSize YogaIntrinsicSize(this UIView view)
{
var constrainedSize = new CGSize
{
Width = float.NaN,
Height = float.NaN
};
return CalculateLayoutWithSize(view, constrainedSize);
}
public static YogaDirection YogaResolvedDirection(this UIView view)
{
var node = GetYogaNode(view);
return node.LayoutDirection;
}
#endregion
static CGSize CalculateLayoutWithSize(UIView view, CGSize size)
{
if (!view.GetUsesYoga())
{
System.Diagnostics.Debug.WriteLine("Doesn't use Yoga");
}
AttachNodesFromViewHierachy(view);
var node = GetYogaNode(view);
node.Width = (float)size.Width;
node.Height = (float)size.Height;
node.CalculateLayout();
return new CGSize { Width = node.LayoutWidth, Height = node.LayoutHeight };
}
static long MeasureView(YogaNode node, float width, YogaMeasureMode widthMode, float height, YogaMeasureMode heightMode)
{
var constrainedWidth = (widthMode == YogaMeasureMode.Undefined) ? nfloat.MaxValue : width;
var constrainedHeight = (heightMode == YogaMeasureMode.Undefined) ? nfloat.MaxValue : height;
UIView view = null;
if (Bridges.ContainsKey(node))
Bridges[node].viewRef.TryGetTarget(out view);
var sizeThatFits = view.SizeThatFits(new CGSize(constrainedWidth, constrainedHeight));
var finalWidth = SanitizeMeasurement(constrainedWidth, sizeThatFits.Width, widthMode);
var finalHeight = SanitizeMeasurement(constrainedHeight, sizeThatFits.Height, heightMode);
return MeasureOutput.Make(finalWidth, finalHeight);
}
static float SanitizeMeasurement(nfloat constrainedSize, nfloat measuredSize, YogaMeasureMode measureMode)
{
float result;
if (measureMode == YogaMeasureMode.Exactly)
{
result = (float)constrainedSize;
}
else if (measureMode == YogaMeasureMode.AtMost)
{
result = (float)Math.Min(constrainedSize, measuredSize);
}
else {
result = (float)measuredSize;
}
return result;
}
static void ApplyLayoutToViewHierarchy(UIView view)
{
if (!view.GetIncludeYogaLayout())
return;
var node = GetYogaNode(view);
CGPoint topLeft = new CGPoint(node.LayoutX, node.LayoutY);
CGPoint bottomRight = new CGPoint(topLeft.X + node.LayoutWidth, topLeft.Y + node.LayoutHeight);
view.Frame = new CGRect(RoundPixelValue(topLeft.X), RoundPixelValue(topLeft.Y), RoundPixelValue(bottomRight.X) - RoundPixelValue(topLeft.X), RoundPixelValue(bottomRight.Y) - RoundPixelValue(topLeft.Y));
bool isLeaf = !view.GetUsesYoga() || view.Subviews.Length == 0;
if (!isLeaf)
{
for (int i = 0; i < view.Subviews.Length; i++)
{
ApplyLayoutToViewHierarchy(view.Subviews[i]);
}
}
}
static double RoundPixelValue(nfloat value)
{
nfloat scale = UIScreen.MainScreen.Scale;
return Math.Round(value * scale) / scale;
}
static void AttachNodesFromViewHierachy(UIView view)
{
var node = GetYogaNode(view);
// Only leaf nodes should have a measure function
if (!view.GetUsesYoga() || view.Subviews.Length == 0)
{
node.SetMeasureFunction(MeasureView);
RemoveAllChildren(node);
}
else
{
node.SetMeasureFunction(null);
// Create a list of all the subviews that we are going to use for layout.
var subviewsToInclude = new List<UIView>();
foreach (var subview in view.Subviews)
{
if (subview.GetIncludeYogaLayout())
{
subviewsToInclude.Add(subview);
}
}
var shouldReconstructChildList = false;
if (node.Count != subviewsToInclude.Count)
{
shouldReconstructChildList = true;
}
else
{
for (int i = 0; i < subviewsToInclude.Count; i++)
{
if (node[i] != GetYogaNode(subviewsToInclude[i]))
{
shouldReconstructChildList = true;
break;
}
}
}
if (shouldReconstructChildList)
{
RemoveAllChildren(node);
for (int i = 0; i < subviewsToInclude.Count; i++)
{
var subView = subviewsToInclude[i];
node.Insert(i, subView.GetYogaNode());
AttachNodesFromViewHierachy(subView);
}
}
}
}
static void RemoveAllChildren(YogaNode node)
{
if (node == null)
return;
while (node.Count > 0)
{
node.Clear();
}
}
static YogaNode GetYogaNode(this UIView view)
{
var value = ObjCRuntime.Runtime.GetNSObject(objc_getAssociatedObject(view.Handle, YogaNodeKey.Handle)) as YGNodeBridge;
if (value == null)
{
value = new YGNodeBridge();
value.SetContext(view);
objc_setAssociatedObject(view.Handle, YogaNodeKey.Handle, value.Handle, AssociationPolicy.RETAIN_NONATOMIC);
}
return value.node;
}
[DllImport("/usr/lib/libobjc.dylib")]
static extern void objc_setAssociatedObject(IntPtr @object, IntPtr key, IntPtr value, AssociationPolicy policy);
[DllImport("/usr/lib/libobjc.dylib")]
static extern IntPtr objc_getAssociatedObject(IntPtr @object, IntPtr key);
enum AssociationPolicy
{
ASSIGN = 0,
RETAIN_NONATOMIC = 1,
COPY_NONATOMIC = 3,
RETAIN = 01401,
COPY = 01403,
}
}
}