eXontrol Software - ExplorerBar ActiveX, NET Control

Use the LayoutChanged event to notify your application that the control's content is changed. The LayoutChanged event is called if the control is resized, if a group is expanded or collapsed, if the control is scrolled, and so on. The Left, Top, Width and Height properties determine the location of the group's list in client coordinates.

C++ The following tutorial shows the steps that are required to insert an ActiveX control inside the control. Shortly, the idea is to insert child windows to the control, and to move the windows when the control fires the LayoutChanged event. The following sample shows how to add a SysTreeView32 window to the control. The following sample contains all code you need to handle ActiveX inside the control.

Insert an ExplorerBar control ( IDC_EXPLORERBAR1 ), to the dialog (form)
Add a variable member m_explorerBar, using the Class wizard
Add a Tree control ( IDC_TREE1 ) to the dialog ( form )
Add a variable member m_tree, using the Class wizard
Locate the OnInitDialog member of the dialog

Call the initialization functions to the OnInitDialog function like follows:

BOOL OnInitDialog()
{
	....
	initTree();
	initExplorerBar();
	...	
	return TRUE;  
}

Implement the initTree function. For instance, the following sample adds few items to the tree control

void initTree()
{
	HTREEITEM h = m_tree.InsertItem( _T("Root") );
	HTREEITEM hChild1 =m_tree.InsertItem( _T("Child1"), h );
	m_tree.InsertItem( _T("SubChild1"), hChild1 );
	m_tree.InsertItem( _T("SubChild2"), hChild1 );
	HTREEITEM hChild2 =m_tree.InsertItem( _T("Child2"), h );
	m_tree.Expand( h, TVE_EXPAND );
	m_tree.Expand( hChild1, TVE_EXPAND );
}

Implement the initExplorerBar function like follows:

void initExplorerBar()
{
	COleVariant vtMissing; V_VT( &vtMissing ) = VT_ERROR;
	m_explorerBar.BeginUpdate();
		// Adds a group that hosts a tree control 
		CGroups groups = m_explorerBar.GetGroups();
		CGroup group = groups.Add( _T("Tree inside") );
		group.SetItemHeight( 84 );
		group.AddItem( _T(""), vtMissing );
		group.SetExpanded( TRUE );
		initHost( m_tree.m_hWnd, m_explorerBar, group.GetIndex() );
	m_explorerBar.EndUpdate();
}

The initExplorerBar function adds a group, and a single item to the group. The ItemHeight property of the Group object is called, to specifies the height of the item, but in our case it will specify the height of the hosted window. The initHost function changes the parent window of the host window, and holds the window's handle to the group's user data.

Implement the initHost function like follows:

void initHost( HWND hWnd, CExplorerBar&amp; explorerBar, long nGroupIndex )
{
	CGroup group = explorerBar.GetGroups().GetItem( COleVariant( nGroupIndex ) );
	if ( hWnd )
	{
		::SetClassLong( hWnd, GCL_STYLE, CS_HREDRAW | CS_VREDRAW );
		::SetWindowPos( explorerBar.m_hWnd, hWnd , 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_FRAMECHANGED );
		::SetParent( hWnd, explorerBar.m_hWnd );
		
		// Stores the handle to the inside window to the group's user data.
		group.SetUserData( COleVariant( (long)hWnd ) );
		moveHost( hWnd, explorerBar, nGroupIndex );
	}
}

The initHost function changes the Z order of the window, change the parent window, holds the window's handle to the group's user data, and moves the window to the new position.

Implement the moveHost function like follows:

void moveHost( HWND hWnd, CExplorerBar&amp; explorerBar, long nGroupIndex )
{
	if ( ::IsWindow( hWnd ) )
	{
		CGroup group = explorerBar.GetGroups().GetItem( COleVariant( nGroupIndex ) );
		CRect rtGroup;
		rtGroup.left = group.GetLeft();
		rtGroup.right = rtGroup.left + group.GetWidth();
		rtGroup.top = group.GetTop();
		rtGroup.bottom = rtGroup.top + group.GetHeight();
/*
		::SetWindowPos( hWnd, NULL, rtGroup.left, rtGroup.top, rtGroup.Width(), rtGroup.Height(), SWP_FRAMECHANGED | SWP_NOZORDER | SWP_HIDEWINDOW | SWP_NOREDRAW);
		::SetWindowPos( hWnd, NULL, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOZORDER | SWP_NOSIZE | SWP_NOMOVE | ( group.GetExpanded() ? SWP_SHOWWINDOW : SWP_HIDEWINDOW ) );
*/
		::SetWindowPos( hWnd, NULL, rtGroup.left, rtGroup.top, rtGroup.Width(), rtGroup.Height(), SWP_NOZORDER | ( group.GetExpanded() ? SWP_SHOWWINDOW : SWP_HIDEWINDOW ) );
	}
}

The moveHost function moves the window to the coordinates specified by Left, Top, Width and Height properties of the Group object.

Handle the LayoutChanged event of the ExplorerBar control like follows:

void OnLayoutChangedExplorerbar1() 
{
	if ( IsWindow( m_explorerBar.m_hWnd ) )
	{
		CGroups groups = m_explorerBar.GetGroups();
		for ( long i = 0; i < groups.GetCount(); i++ )
			moveHost( m_explorerBar, i );
	}
}

VB The following tutorial shows the steps that are required to insert an ActiveX control inside the control. Shortly, the idea is to insert child windows to the control, and to move the windows when the control fires the LayoutChanged event. The following sample shows how to add a ListBox control to the ExplorerBar control. The following sample contains all code you need to handle ActiveX inside the control.

Insert an ExplorerBar control ( ExplorerBar1 ) to the form
Add a ListBox control ( List1 ) to the form

Call initialization functions in the Form_Load event like follows:

Private Sub Form_Load()
    ...
    initList
    initExplorerBar
    ...
End Sub

Implement the initList function. For instance, the following sample adds few items to the ListBox control

Private Sub initList()
    With List1
        .AddItem "Item 1"
        .AddItem "Item 2"
        .AddItem "Item 3"
        .AddItem "Item 4"
    End With
End Sub

Implement the initExplorerBar function like follows:
```
Private Sub initExplorerBar()
    With ExplorerBar1
        .BeginUpdate
            With .Groups.Add("List")
                .ItemHeight = 84
                .AddItem ""
                initHost List1, ExplorerBar1, .Index
                .Expanded = True
            End With
        .EndUpdate
    End With
End Sub
```
The initExplorerBar function adds a group, and a single item to the group. The ItemHeight property of the Group object is called, to specify the height of the item, but in our case it will specify the height of the hosted window. The initHost function changes the parent window of the host window, and holds the control's reference to the group's user data.

Implement the initHost function like follows:

Private Sub initHost(ByVal c As Object, ByVal e As EXPLORERBARLibCtl.ExplorerBar, ByVal i As Long)
    Dim g As EXPLORERBARLibCtl.Group
    Set g = e.Groups(i)
    If Not c Is Nothing Then
        SetParent c.hwnd, e.hwnd
        g.UserData = c
        moveHost e, i
    End If
End Sub

The initHost function change the parent window, holds the control to the group's user data, and moves the control to the new position.

Implement the moveHost function like follows:

Private Sub moveHost(ByVal e As EXPLORERBARLibCtl.ExplorerBar, ByVal i As Long)
On Error Resume Next
    Dim g As EXPLORERBARLibCtl.Group
    Set g = e.Groups(i)
    Dim c As Object
    Set c = g.UserData
    If Not c Is Nothing Then
        If Not (g.Expanded) Then
            c.Visible = False
        End If
        c.Left = g.Left * Screen.TwipsPerPixelX
        c.Top = g.Top * Screen.TwipsPerPixelY
        c.Width = g.Width * Screen.TwipsPerPixelX
        c.Height = g.Height * Screen.TwipsPerPixelY
        If (g.Expanded) Then
            c.Visible = True
        End If
    End If
End Sub

The moveHost function moves the control to the coordinates specified by Left, Top, Width and Height properties of the Group object.

Handle the LayoutChanged event of the ExplorerBar control like follows:

Private Sub ExplorerBar1_LayoutChanged()
    Dim g As EXPLORERBARLibCtl.Group
    For Each g In ExplorerBar1.Groups
        moveHost ExplorerBar1, g.Index
    Next
End Sub

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