Files
Wino-Mail/Wino.Calendar/Controls/WinoCalendarPanel.cs

262 lines
10 KiB
C#

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Wino.Calendar.Models;
using Wino.Calendar.ViewModels.Data;
using Wino.Core.Domain.Interfaces;
namespace Wino.Calendar.Controls
{
public class WinoCalendarPanel : Panel
{
private const double LastItemRightExtraMargin = 12d;
// Store each ICalendarItem measurements by their Id.
private readonly Dictionary<Guid, CalendarItemMeasurement> _measurements = new Dictionary<Guid, CalendarItemMeasurement>();
public static readonly DependencyProperty EventItemMarginProperty = DependencyProperty.Register(nameof(EventItemMargin), typeof(Thickness), typeof(WinoCalendarPanel), new PropertyMetadata(new Thickness(0, 0, 0, 0)));
// public static readonly DependencyProperty RepresentingDateProperty = DependencyProperty.Register(nameof(RepresentingDate), typeof(DateTime), typeof(WinoCalendarControl), new PropertyMetadata(DateTime.MinValue));
public static readonly DependencyProperty HourHeightProperty = DependencyProperty.Register(nameof(HourHeight), typeof(double), typeof(WinoCalendarPanel), new PropertyMetadata(0d));
public double HourHeight
{
get { return (double)GetValue(HourHeightProperty); }
set { SetValue(HourHeightProperty, value); }
}
public Thickness EventItemMargin
{
get { return (Thickness)GetValue(EventItemMarginProperty); }
set { SetValue(EventItemMarginProperty, value); }
}
//private static void OnDayChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
//{
// if (d is WinoCalendarPanel control)
// {
// // We need to listen for new events being added or removed from the collection to reset measurements.
// if (e.OldValue is CalendarDayModel oldDayModel)
// {
// control.DetachCollection(oldDayModel.EventsCollection.RegularEvents);
// }
// if (e.NewValue is CalendarDayModel newDayModel)
// {
// control.AttachCollection(newDayModel.EventsCollection.RegularEvents);
// }
// control.ResetMeasurements();
// control.UpdateLayout();
// }
//}
//private void AttachCollection(IEnumerable<ICalendarItem> events)
//{
// if (events is INotifyCollectionChanged collection)
// {
// // var t = new Grid();
// collection.CollectionChanged += EventCollectionChanged;
// }
//}
//private void DetachCollection(IEnumerable<ICalendarItem> events)
//{
// if (events is INotifyCollectionChanged collection)
// {
// collection.CollectionChanged -= EventCollectionChanged;
// }
//}
private void ResetMeasurements() => _measurements.Clear();
// No need to handle actions. Each action requires a full measurement update.
private void EventCollectionChanged(object sender, NotifyCollectionChangedEventArgs e) => ResetMeasurements();
private double GetChildTopMargin(ICalendarItem calendarItemViewModel, double availableHeight)
{
var childStart = calendarItemViewModel.StartTime;
double totalMinutes = 1440;
double minutesFromStart = (childStart - childStart.DateTime.Date).TotalMinutes;
return (minutesFromStart / totalMinutes) * availableHeight;
}
private double GetChildWidth(CalendarItemMeasurement calendarItemMeasurement, double availableWidth)
{
return (calendarItemMeasurement.Right - calendarItemMeasurement.Left) * availableWidth;
}
private double GetChildLeftMargin(CalendarItemMeasurement calendarItemMeasurement, double availableWidth)
=> availableWidth * calendarItemMeasurement.Left;
private double GetChildHeight(DateTimeOffset childStart, DateTimeOffset childEnd)
{
double totalMinutes = 1440;
double availableHeight = HourHeight * 24;
double childDuration = (childEnd - childStart).TotalMinutes;
return (childDuration / totalMinutes) * availableHeight;
}
protected override Size ArrangeOverride(Size finalSize)
{
// Measure/arrange each child height and width.
// This is a vertical calendar. Therefore the height of each child is the duration of the event.
// Children weights for left and right will be saved if they don't exist.
// This is important because we don't want to measure the weights again.
// They don't change until new event is added or removed.
// Width of the each child may depend on the rectangle packing algorithm.
// Children are first categorized into columns. Then each column is shifted to the left until
// no overlap occurs. The width of each child is calculated based on the number of columns it spans.
double availableHeight = finalSize.Height;
double availableWidth = finalSize.Width;
var calendarControls = Children.Cast<ContentPresenter>();
if (!calendarControls.Any()) return base.ArrangeOverride(finalSize);
if (_measurements.Count == 0 && calendarControls.Any())
{
// We keep track of this collection when event is added/removed/reset etc.
// So if the collection is empty, we must fill it up again for proper calculations.
var events = calendarControls.Select(a => a.Content as CalendarItemViewModel);
LayoutEvents(events);
}
foreach (var control in calendarControls)
{
// We can't arrange this child. It doesn't have a valid ICalendarItem or measurement.
if (!(control.Content is ICalendarItem child) || !_measurements.ContainsKey(child.Id)) continue;
var childMeasurement = _measurements[child.Id];
double childHeight = Math.Max(0, GetChildHeight(child.StartTime, child.StartTime.AddMinutes(child.DurationInMinutes)));
double childWidth = Math.Max(0, GetChildWidth(childMeasurement, finalSize.Width));
double childTop = Math.Max(0, GetChildTopMargin(child, availableHeight));
double childLeft = Math.Max(0, GetChildLeftMargin(childMeasurement, availableWidth));
bool isHorizontallyLastItem = childMeasurement.Right == 1;
// Add additional right margin to items that falls on the right edge of the panel.
// Max of 5% of the width or 20px max.
var extraRightMargin = isHorizontallyLastItem ? Math.Max(LastItemRightExtraMargin, finalSize.Width * 5 / 100) : 0;
if (childWidth < 0) childWidth = 1;
control.Measure(new Size(childWidth, childHeight));
var arrangementRect = new Rect(childLeft + EventItemMargin.Left, childTop + EventItemMargin.Top, Math.Max(childWidth - extraRightMargin, 1), childHeight);
control.Arrange(arrangementRect);
}
return finalSize;
}
#region ColumSpanning and Packing Algorithm
private void AddOrUpdateMeasurement(ICalendarItem calendarItem, CalendarItemMeasurement measurement)
{
if (_measurements.ContainsKey(calendarItem.Id))
{
_measurements[calendarItem.Id] = measurement;
}
else
{
_measurements.Add(calendarItem.Id, measurement);
}
}
// Pick the left and right positions of each event, such that there are no overlap.
private void LayoutEvents(IEnumerable<ICalendarItem> events)
{
var columns = new List<List<ICalendarItem>>();
DateTime? lastEventEnding = null;
foreach (var ev in events.OrderBy(ev => ev.Period.Start).ThenBy(ev => ev.Period.End))
{
if (ev.Period.Start >= lastEventEnding)
{
PackEvents(columns);
columns.Clear();
lastEventEnding = null;
}
bool placed = false;
foreach (var col in columns)
{
if (!col.Last().Period.OverlapsWith(ev.Period))
{
col.Add(ev);
placed = true;
break;
}
}
if (!placed)
{
columns.Add(new List<ICalendarItem> { ev });
}
if (lastEventEnding == null || ev.Period.End > lastEventEnding.Value)
{
lastEventEnding = ev.Period.End;
}
}
if (columns.Count > 0)
{
PackEvents(columns);
}
}
// Set the left and right positions for each event in the connected group.
private void PackEvents(List<List<ICalendarItem>> columns)
{
float numColumns = columns.Count;
int iColumn = 0;
foreach (var col in columns)
{
foreach (var ev in col)
{
int colSpan = ExpandEvent(ev, iColumn, columns);
var leftWeight = iColumn / numColumns;
var rightWeight = (iColumn + colSpan) / numColumns;
AddOrUpdateMeasurement(ev, new CalendarItemMeasurement(leftWeight, rightWeight));
}
iColumn++;
}
}
// Checks how many columns the event can expand into, without colliding with other events.
private int ExpandEvent(ICalendarItem ev, int iColumn, List<List<ICalendarItem>> columns)
{
int colSpan = 1;
foreach (var col in columns.Skip(iColumn + 1))
{
foreach (var ev1 in col)
{
if (ev1.Period.OverlapsWith(ev.Period)) return colSpan;
}
colSpan++;
}
return colSpan;
}
#endregion
}
}