CentralizedControl/HandyControl/HandyControl_Shared/Controls/TabControl/TabPanel.cs

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using HandyControl.Data;
using HandyControl.Tools;

namespace HandyControl.Controls;

public class TabPanel : Panel
{
    private int _itemCount;

    /// <summary>
    ///     是否可以更新
    /// </summary>
    internal bool CanUpdate = true;

    /// <summary>
    ///     选项卡字典
    /// </summary>
    internal Dictionary<int, TabItem> ItemDic = new();

    public static readonly DependencyPropertyKey FluidMoveDurationPropertyKey =
        DependencyProperty.RegisterReadOnly("FluidMoveDuration", typeof(Duration), typeof(TabPanel),
            new PropertyMetadata(new Duration(TimeSpan.FromMilliseconds(0))));

    /// <summary>
    ///     流式行为持续时间
    /// </summary>
    public static readonly DependencyProperty FluidMoveDurationProperty =
        FluidMoveDurationPropertyKey.DependencyProperty;

    /// <summary>
    ///     流式行为持续时间
    /// </summary>
    public Duration FluidMoveDuration
    {
        get => (Duration) GetValue(FluidMoveDurationProperty);
        set => SetValue(FluidMoveDurationProperty, value);
    }

    /// <summary>
    ///     是否将标签填充
    /// </summary>
    public static readonly DependencyProperty IsTabFillEnabledProperty = DependencyProperty.Register(
        nameof(IsTabFillEnabled), typeof(bool), typeof(TabPanel), new PropertyMetadata(ValueBoxes.FalseBox));

    /// <summary>
    ///     是否将标签填充
    /// </summary>
    public bool IsTabFillEnabled
    {
        get => (bool) GetValue(IsTabFillEnabledProperty);
        set => SetValue(IsTabFillEnabledProperty, ValueBoxes.BooleanBox(value));
    }

    /// <summary>
    ///     标签宽度
    /// </summary>
    public static readonly DependencyProperty TabItemWidthProperty = DependencyProperty.Register(
        nameof(TabItemWidth), typeof(double), typeof(TabPanel), new PropertyMetadata(200.0));

    /// <summary>
    ///     标签宽度
    /// </summary>
    public double TabItemWidth
    {
        get => (double) GetValue(TabItemWidthProperty);
        set => SetValue(TabItemWidthProperty, value);
    }

    /// <summary>
    ///     标签高度
    /// </summary>
    public static readonly DependencyProperty TabItemHeightProperty = DependencyProperty.Register(
        nameof(TabItemHeight), typeof(double), typeof(TabPanel), new PropertyMetadata(30.0));

    /// <summary>
    ///     标签高度
    /// </summary>
    public double TabItemHeight
    {
        get => (double) GetValue(TabItemHeightProperty);
        set => SetValue(TabItemHeightProperty, value);
    }

    /// <summary>
    ///     是否可以强制更新
    /// </summary>
    internal bool ForceUpdate;

    private Size _oldSize;

    /// <summary>
    ///     是否已经加载
    /// </summary>
    private bool _isLoaded;

    protected override Size MeasureOverride(Size constraint)
    {
        if ((_itemCount == InternalChildren.Count || !CanUpdate) && !ForceUpdate && !IsTabFillEnabled) return _oldSize;
        constraint.Height = TabItemHeight;
        _itemCount = InternalChildren.Count;

        var size = new Size();

        ItemDic.Clear();

        var count = InternalChildren.Count;
        if (count == 0)
        {
            _oldSize = new Size();
            return _oldSize;
        }
        constraint.Width += InternalChildren.Count;

        var itemWidth = .0;
        var arr = new int[count];

        if (!IsTabFillEnabled)
        {
            itemWidth = TabItemWidth;
        }
        else
        {
            if (TemplatedParent is TabControl tabControl)
            {
                arr = ArithmeticHelper.DivideInt2Arr((int) tabControl.ActualWidth + InternalChildren.Count, count);
            }
        }

        for (var index = 0; index < count; index++)
        {
            if (IsTabFillEnabled)
            {
                itemWidth = arr[index];
            }
            if (InternalChildren[index] is TabItem tabItem)
            {
                tabItem.RenderTransform = new TranslateTransform();
                tabItem.MaxWidth = itemWidth;
                var rect = new Rect
                {
                    X = size.Width - tabItem.BorderThickness.Left,
                    Width = itemWidth,
                    Height = TabItemHeight
                };
                tabItem.Arrange(rect);
                tabItem.ItemWidth = itemWidth - tabItem.BorderThickness.Left;
                tabItem.CurrentIndex = index;
                tabItem.TargetOffsetX = 0;
                ItemDic[index] = tabItem;
                size.Width += tabItem.ItemWidth;
            }
        }
        size.Height = constraint.Height;
        _oldSize = size;
        return _oldSize;
    }

    public TabPanel()
    {
        Loaded += (s, e) =>
        {
            if (_isLoaded) return;
            ForceUpdate = true;
            Measure(new Size(DesiredSize.Width, ActualHeight));
            ForceUpdate = false;
            foreach (var item in ItemDic.Values)
            {
                item.TabPanel = this;
            }
            _isLoaded = true;
        };
    }
}