VerticalContentAlignment を含むバージョン (垂直パネル用):
public class AlignableWrapPanel : Panel {
public AlignableWrapPanel() {
_orientation = Orientation.Horizontal;
}
private static bool IsWidthHeightValid(object value) {
var v = (double)value;
return (double.IsNaN(v)) || (v >= 0.0d && !double.IsPositiveInfinity(v));
}
public static readonly DependencyProperty ItemWidthProperty = DependencyProperty.Register("ItemWidth", typeof(double),
typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure),
IsWidthHeightValid);
[TypeConverter(typeof(LengthConverter))]
public double ItemWidth {
get { return (double)GetValue(ItemWidthProperty); }
set { SetValue(ItemWidthProperty, value); }
}
public static readonly DependencyProperty ItemHeightProperty = DependencyProperty.Register("ItemHeight", typeof(double),
typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure),
IsWidthHeightValid);
[TypeConverter(typeof(LengthConverter))]
public double ItemHeight {
get { return (double)GetValue(ItemHeightProperty); }
set { SetValue(ItemHeightProperty, value); }
}
public static readonly DependencyProperty OrientationProperty = StackPanel.OrientationProperty.AddOwner(typeof(AlignableWrapPanel),
new FrameworkPropertyMetadata(Orientation.Horizontal, FrameworkPropertyMetadataOptions.AffectsMeasure, OnOrientationChanged));
public Orientation Orientation {
get { return _orientation; }
set { SetValue(OrientationProperty, value); }
}
private static void OnOrientationChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
var p = (AlignableWrapPanel)d;
p._orientation = (Orientation)e.NewValue;
}
private Orientation _orientation;
private struct UvSize {
internal UvSize(Orientation orientation, double width, double height) {
U = V = 0d;
_orientation = orientation;
Width = width;
Height = height;
}
internal UvSize(Orientation orientation) {
U = V = 0d;
_orientation = orientation;
}
internal double U;
internal double V;
private readonly Orientation _orientation;
internal double Width {
get { return (_orientation == Orientation.Horizontal ? U : V); }
private set { if (_orientation == Orientation.Horizontal) U = value; else V = value; }
}
internal double Height {
get { return (_orientation == Orientation.Horizontal ? V : U); }
private set { if (_orientation == Orientation.Horizontal) V = value; else U = value; }
}
}
protected override Size MeasureOverride(Size constraint) {
var curLineSize = new UvSize(Orientation);
var panelSize = new UvSize(Orientation);
var uvConstraint = new UvSize(Orientation, constraint.Width, constraint.Height);
var itemWidth = ItemWidth;
var itemHeight = ItemHeight;
var itemWidthSet = !double.IsNaN(itemWidth);
var itemHeightSet = !double.IsNaN(itemHeight);
var childConstraint = new Size(
(itemWidthSet ? itemWidth : constraint.Width),
(itemHeightSet ? itemHeight : constraint.Height));
var children = InternalChildren;
for (int i = 0, count = children.Count; i < count; i++) {
var child = children[i];
if (child == null) continue;
//Flow passes its own constrint to children
child.Measure(childConstraint);
//this is the size of the child in UV space
var sz = new UvSize(
Orientation,
(itemWidthSet ? itemWidth : child.DesiredSize.Width),
(itemHeightSet ? itemHeight : child.DesiredSize.Height));
if (curLineSize.U + sz.U > uvConstraint.U) {
//need to switch to another line
panelSize.U = Math.Max(curLineSize.U, panelSize.U);
panelSize.V += curLineSize.V;
curLineSize = sz;
if (!(sz.U > uvConstraint.U)) continue;
//the element is wider then the constrint - give it a separate line
panelSize.U = Math.Max(sz.U, panelSize.U);
panelSize.V += sz.V;
curLineSize = new UvSize(Orientation);
} else {
//continue to accumulate a line
curLineSize.U += sz.U;
curLineSize.V = Math.Max(sz.V, curLineSize.V);
}
}
//the last line size, if any should be added
panelSize.U = Math.Max(curLineSize.U, panelSize.U);
panelSize.V += curLineSize.V;
//go from UV space to W/H space
return new Size(panelSize.Width, panelSize.Height);
}
protected override Size ArrangeOverride(Size finalSize) {
var firstInLine = 0;
var itemWidth = ItemWidth;
var itemHeight = ItemHeight;
double accumulatedV = 0;
var itemU = (Orientation == Orientation.Horizontal ? itemWidth : itemHeight);
var curLineSize = new UvSize(Orientation);
var uvFinalSize = new UvSize(Orientation, finalSize.Width, finalSize.Height);
var itemWidthSet = !double.IsNaN(itemWidth);
var itemHeightSet = !double.IsNaN(itemHeight);
var useItemU = (Orientation == Orientation.Horizontal ? itemWidthSet : itemHeightSet);
var children = InternalChildren;
for (int i = 0, count = children.Count; i < count; i++) {
var child = children[i];
if (child == null) continue;
var sz = new UvSize(
Orientation,
(itemWidthSet ? itemWidth : child.DesiredSize.Width),
(itemHeightSet ? itemHeight : child.DesiredSize.Height));
if (curLineSize.U + sz.U > uvFinalSize.U) {
//need to switch to another line
ArrangeLine(finalSize, accumulatedV, curLineSize, firstInLine, i, useItemU, itemU);
accumulatedV += curLineSize.V;
curLineSize = sz;
if (sz.U > uvFinalSize.U) {
//the element is wider then the constraint - give it a separate line
//switch to next line which only contain one element
ArrangeLine(finalSize, accumulatedV, sz, i, ++i, useItemU, itemU);
accumulatedV += sz.V;
curLineSize = new UvSize(Orientation);
}
firstInLine = i;
} else {
//continue to accumulate a line
curLineSize.U += sz.U;
curLineSize.V = Math.Max(sz.V, curLineSize.V);
}
}
//arrange the last line, if any
if (firstInLine < children.Count) {
ArrangeLine(finalSize, accumulatedV, curLineSize, firstInLine, children.Count, useItemU, itemU);
}
return finalSize;
}
private void ArrangeLine(Size finalSize, double v, UvSize line, int start, int end, bool useItemU, double itemU) {
double u;
var isHorizontal = Orientation == Orientation.Horizontal;
if (_orientation == Orientation.Vertical) {
switch (VerticalContentAlignment) {
case VerticalAlignment.Center:
u = (finalSize.Height - line.U) / 2;
break;
case VerticalAlignment.Bottom:
u = finalSize.Height - line.U;
break;
default:
u = 0;
break;
}
} else {
switch (HorizontalContentAlignment) {
case HorizontalAlignment.Center:
u = (finalSize.Width - line.U) / 2;
break;
case HorizontalAlignment.Right:
u = finalSize.Width - line.U;
break;
default:
u = 0;
break;
}
}
var children = InternalChildren;
for (var i = start; i < end; i++) {
var child = children[i];
if (child == null) continue;
var childSize = new UvSize(Orientation, child.DesiredSize.Width, child.DesiredSize.Height);
var layoutSlotU = (useItemU ? itemU : childSize.U);
child.Arrange(new Rect(
isHorizontal ? u : v,
isHorizontal ? v : u,
isHorizontal ? layoutSlotU : line.V,
isHorizontal ? line.V : layoutSlotU));
u += layoutSlotU;
}
}
public static readonly DependencyProperty HorizontalContentAlignmentProperty = DependencyProperty.Register(nameof(HorizontalContentAlignment), typeof(HorizontalAlignment),
typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(HorizontalAlignment.Left, FrameworkPropertyMetadataOptions.AffectsArrange));
public HorizontalAlignment HorizontalContentAlignment {
get { return (HorizontalAlignment)GetValue(HorizontalContentAlignmentProperty); }
set { SetValue(HorizontalContentAlignmentProperty, value); }
}
public static readonly DependencyProperty VerticalContentAlignmentProperty = DependencyProperty.Register(nameof(VerticalContentAlignment), typeof(VerticalAlignment),
typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(VerticalAlignment.Top, FrameworkPropertyMetadataOptions.AffectsArrange));
public VerticalAlignment VerticalContentAlignment {
get { return (VerticalAlignment)GetValue(VerticalContentAlignmentProperty); }
set { SetValue(VerticalContentAlignmentProperty, value); }
}
}