From 2b6fdc153148c2687e41cb1fd4256d5011db3b16 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Wies=C5=82aw=20=C5=A0olt=C3=A9s?= Date: Thu, 30 May 2019 20:49:39 +0200 Subject: [PATCH] Initial port of WPF WrapPanel --- src/Avalonia.Controls/WrapPanel.cs | 195 ++++++++++++++--------------- 1 file changed, 93 insertions(+), 102 deletions(-) diff --git a/src/Avalonia.Controls/WrapPanel.cs b/src/Avalonia.Controls/WrapPanel.cs index 597734d400..b6215a28cc 100644 --- a/src/Avalonia.Controls/WrapPanel.cs +++ b/src/Avalonia.Controls/WrapPanel.cs @@ -92,109 +92,127 @@ namespace Avalonia.Controls } } - private UVSize CreateUVSize(Size size) => new UVSize(Orientation, size); - - private UVSize CreateUVSize() => new UVSize(Orientation); - /// - protected override Size MeasureOverride(Size availableSize) + protected override Size MeasureOverride(Size constraint) { - var desiredSize = CreateUVSize(); - var lineSize = CreateUVSize(); - var uvAvailableSize = CreateUVSize(availableSize); + var curLineSize = new UVSize(Orientation); + var panelSize = new UVSize(Orientation); + var uvConstraint = new UVSize(Orientation, constraint.Width, constraint.Height); - foreach (var child in Children) + var childConstraint = new Size(constraint.Width, constraint.Height); + + for (int i = 0, count = Children.Count; i < count; i++) { - child.Measure(availableSize); - var childSize = CreateUVSize(child.DesiredSize); - if (lineSize.U + childSize.U <= uvAvailableSize.U) // same line + 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, child.DesiredSize.Width, child.DesiredSize.Height); + + if ((curLineSize.U + sz.U) > uvConstraint.U) //need to switch to another line { - lineSize.U += childSize.U; - lineSize.V = Max(lineSize.V, childSize.V); + panelSize.U = Max(curLineSize.U, panelSize.U); + panelSize.V += curLineSize.V; + curLineSize = sz; + + if (sz.U > uvConstraint.U) //the element is wider then the constrint - give it a separate line + { + panelSize.U = Max(sz.U, panelSize.U); + panelSize.V += sz.V; + curLineSize = new UVSize(Orientation); + } } - else // moving to next line + else //continue to accumulate a line { - desiredSize.U = Max(lineSize.U, uvAvailableSize.U); - desiredSize.V += lineSize.V; - lineSize = childSize; + curLineSize.U += sz.U; + curLineSize.V = Max(sz.V, curLineSize.V); } } - // last element - desiredSize.U = Max(lineSize.U, desiredSize.U); - desiredSize.V += lineSize.V; - return desiredSize.ToSize(); + //the last line size, if any should be added + panelSize.U = 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) { + int firstInLine = 0; double accumulatedV = 0; - var uvFinalSize = CreateUVSize(finalSize); - var lineSize = CreateUVSize(); - int firstChildInLineIndex = 0; - for (int index = 0; index < Children.Count; index++) + UVSize curLineSize = new UVSize(Orientation); + UVSize uvFinalSize = new UVSize(Orientation, finalSize.Width, finalSize.Height); + + for (int i = 0; i < Children.Count; i++) { - var child = Children[index]; - var childSize = CreateUVSize(child.DesiredSize); - if (lineSize.U + childSize.U <= uvFinalSize.U) // same line + var child = Children[i]; + if (child == null) continue; + + var sz = new UVSize(Orientation, child.DesiredSize.Width, child.DesiredSize.Height); + + if ((curLineSize.U + sz.U) > uvFinalSize.U) //need to switch to another line { - lineSize.U += childSize.U; - lineSize.V = Max(lineSize.V, childSize.V); + arrangeLine(accumulatedV, curLineSize.V, firstInLine, i); + + 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(accumulatedV, sz.V, i, ++i); + + accumulatedV += sz.V; + curLineSize = new UVSize(Orientation); + } + firstInLine = i; } - else // moving to next line + else //continue to accumulate a line { - var controlsInLine = GetControlsBetween(firstChildInLineIndex, index); - ArrangeLine(accumulatedV, lineSize.V, controlsInLine); - accumulatedV += lineSize.V; - lineSize = childSize; - firstChildInLineIndex = index; + curLineSize.U += sz.U; + curLineSize.V = Max(sz.V, curLineSize.V); } } - if (firstChildInLineIndex < Children.Count) + //arrange the last line, if any + if (firstInLine < Children.Count) { - var controlsInLine = GetControlsBetween(firstChildInLineIndex, Children.Count); - ArrangeLine(accumulatedV, lineSize.V, controlsInLine); + arrangeLine(accumulatedV, curLineSize.V, firstInLine, Children.Count); } - return finalSize; - } - private IEnumerable GetControlsBetween(int first, int last) - { - return Children.Skip(first).Take(last - first); + return finalSize; } - private void ArrangeLine(double v, double lineV, IEnumerable controls) + private void arrangeLine(double v, double lineV, int start, int end) { double u = 0; bool isHorizontal = (Orientation == Orientation.Horizontal); - foreach (var child in controls) + + for (int i = 0, count = Children.Count; i < count; i++) { - var childSize = CreateUVSize(child.DesiredSize); - var x = isHorizontal ? u : v; - var y = isHorizontal ? v : u; - var width = isHorizontal ? childSize.U : lineV; - var height = isHorizontal ? lineV : childSize.U; - child.Arrange(new Rect(x, y, width, height)); - u += childSize.U; + var child = Children[i]; + if (child != null) + { + UVSize childSize = new UVSize(Orientation, child.DesiredSize.Width, child.DesiredSize.Height); + double layoutSlotU = childSize.U; + child.Arrange(new Rect( + (isHorizontal ? u : v), + (isHorizontal ? v : u), + (isHorizontal ? layoutSlotU : lineV), + (isHorizontal ? lineV : layoutSlotU))); + u += layoutSlotU; + } } } - /// - /// Used to not not write separate code for horizontal and vertical orientation. - /// U is direction in line. (x if orientation is horizontal) - /// V is direction of lines. (y if orientation is horizontal) - /// - [DebuggerDisplay("U = {U} V = {V}")] + private struct UVSize { - private readonly Orientation _orientation; - - internal double U; - - internal double V; - - private UVSize(Orientation orientation, double width, double height) + internal UVSize(Orientation orientation, double width, double height) { U = V = 0d; _orientation = orientation; @@ -202,52 +220,25 @@ namespace Avalonia.Controls Height = height; } - internal UVSize(Orientation orientation, Size size) - : this(orientation, size.Width, size.Height) - { - } - internal UVSize(Orientation orientation) { U = V = 0d; _orientation = orientation; } - private double Width + internal double U; + internal double V; + private Orientation _orientation; + + internal double Width { get { return (_orientation == Orientation.Horizontal ? U : V); } - set - { - if (_orientation == Orientation.Horizontal) - { - U = value; - } - else - { - V = value; - } - } + set { if (_orientation == Orientation.Horizontal) U = value; else V = value; } } - - private double Height + internal double Height { get { return (_orientation == Orientation.Horizontal ? V : U); } - set - { - if (_orientation == Orientation.Horizontal) - { - V = value; - } - else - { - U = value; - } - } - } - - public Size ToSize() - { - return new Size(Width, Height); + set { if (_orientation == Orientation.Horizontal) V = value; else U = value; } } } }