wpftoolkit/ExtendedWPFToolkitSolution/Src/Xceed.Wpf.AvalonDock/Controls/LayoutDocumentFloatingWindowControl.cs

/*************************************************************************************
   
   Toolkit for WPF

   Copyright (C) 2007-2022 Xceed Software Inc.

   This program is provided to you under the terms of the XCEED SOFTWARE, INC.
   COMMUNITY LICENSE AGREEMENT (for non-commercial use) as published at 
   https://github.com/xceedsoftware/wpftoolkit/blob/master/license.md 

   For more features, controls, and fast professional support,
   pick up the Plus Edition at https://xceed.com/xceed-toolkit-plus-for-wpf/

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  ***********************************************************************************/

using Microsoft.Windows.Shell;
using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls.Primitives;
using Xceed.Wpf.AvalonDock.Layout;

namespace Xceed.Wpf.AvalonDock.Controls
{
  public class LayoutDocumentFloatingWindowControl : LayoutFloatingWindowControl
  {
    #region Members

    private LayoutDocumentFloatingWindow _model;

    #endregion

    #region Constructors

    static LayoutDocumentFloatingWindowControl()
    {
      DefaultStyleKeyProperty.OverrideMetadata( typeof( LayoutDocumentFloatingWindowControl ), new FrameworkPropertyMetadata( typeof( LayoutDocumentFloatingWindowControl ) ) );
    }

    internal LayoutDocumentFloatingWindowControl( LayoutDocumentFloatingWindow model, bool isContentImmutable )
       : base( model, isContentImmutable )
    {
      _model = model;
      UpdateThemeResources();
    }

    internal LayoutDocumentFloatingWindowControl( LayoutDocumentFloatingWindow model )
        : this( model, false )
    {
    }

    #endregion

    #region Properties

    public LayoutItem RootDocumentLayoutItem
    {
      get
      {
        if( ( _model == null ) || ( _model.Root == null ) || ( _model.Root.Manager == null ) )
          return null;

        return _model.Root.Manager.GetLayoutItemFromModel( _model.RootDocument );
      }
    }

    #endregion

    #region Overrides

    public override ILayoutElement Model
    {
      get
      {
        return _model;
      }
    }

    protected override void OnInitialized( EventArgs e )
    {
      base.OnInitialized( e );

      if( _model.RootDocument == null )
      {
        InternalClose();
      }
      else
      {
        var manager = _model.Root.Manager;

        Content = manager.CreateUIElementForModel( _model.RootDocument );

        _model.RootDocumentChanged += new EventHandler( _model_RootDocumentChanged );
      }
    }

    protected override IntPtr FilterMessage( IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled )
    {
      switch( msg )
      {
        case Win32Helper.WM_NCLBUTTONDOWN: //Left button down on title -> start dragging over docking manager
          if( wParam.ToInt32() == Win32Helper.HT_CAPTION )
          {
            if( _model.RootDocument != null )
              _model.RootDocument.IsActive = true;
          }
          break;
        case Win32Helper.WM_NCRBUTTONUP:
          if( wParam.ToInt32() == Win32Helper.HT_CAPTION )
          {
            if( OpenContextMenu() )
              handled = true;
            if( _model.Root.Manager.ShowSystemMenu )
              WindowChrome.GetWindowChrome( this ).ShowSystemMenu = !handled;
            else
              WindowChrome.GetWindowChrome( this ).ShowSystemMenu = false;
          }
          break;

      }

      return base.FilterMessage( hwnd, msg, wParam, lParam, ref handled );
    }

    protected override void OnClosed( EventArgs e )
    {
      base.OnClosed( e );

      _model.RootDocumentChanged -= new EventHandler( _model_RootDocumentChanged );
    }

    protected override bool CanClose( object parameter = null )
    {
      if( this.Model == null )
        return false;

      var root = this.Model.Root;
      if( root == null )
        return false;

      var manager = root.Manager;
      if( manager == null )
        return false;

      foreach( var document in this.Model.Descendents().OfType<LayoutDocument>().ToArray() )
      {
        if( !document.CanClose )
        {
          return false;
        }

        var documentLayoutItem = manager.GetLayoutItemFromModel( document ) as LayoutDocumentItem;
        if( documentLayoutItem == null ||
            documentLayoutItem.CloseCommand == null ||
            !documentLayoutItem.CloseCommand.CanExecute( parameter ) )
        {
          return false;
        }
      }

      return true;
    }

    #endregion

    #region Private Methods

    private void _model_RootDocumentChanged( object sender, EventArgs e )
    {
      if( _model.RootDocument == null )
      {
        InternalClose();
      }
    }

    private bool OpenContextMenu()
    {
      var ctxMenu = _model.Root.Manager.DocumentContextMenu;
      if( ctxMenu != null && RootDocumentLayoutItem != null )
      {
        ctxMenu.PlacementTarget = null;
        ctxMenu.Placement = PlacementMode.MousePoint;
        ctxMenu.DataContext = RootDocumentLayoutItem;
        ctxMenu.IsOpen = true;
        return true;
      }

      return false;
    }

    #endregion
  }
}