SftTree/OCX 7.5 - ActiveX Tree Control

HorizontalExtent Property, SftTreeItems Object

Defines the current horizontal scrolling extent.

Syntax

Get

Put

object

A SftTreeItems object.

Extent

Defines the current horizontal scrolling extent. If this value is 0 (or less than the width of the tree control), horizontal scrolling is disabled. The units used depend on the container (Visual Basic, Visual C++, etc.) and the coordinate system used.

Comments

The HorizontalExtent property defines the current horizontal scrolling extent.

The HorizontalExtent and Items.HorizontalExtentPix methods are synonyms, but may use different coordinate systems.

A tree control's displayable area can be wider than the tree control's window width. If the displayable area is wider, the tree control can be scrolled horizontally if it has a horizontal scroll bar (see Scrollbars property). The width of the displayable area can be set by the application using the Items.RecalcHorizontalExtent method or the Items.HorizontalExtent property. For performance reasons, the optimal width is not automatically calculated when adding items to a tree control.

The width Extent set using this property must be equal to or greater than the combined column widths plus the width returned by the ColumnsObj.OverheadWidth property.

The HorizontalExtent property defines the horizontal extent of the displayable area (or the left pane of a split tree control).

The Items.HorizontalExtent2 property defines the horizontal extent of the displayable area in the right pane of a split tree control. The Items.HorizontalExtent2 property can only be used with a split tree control.

If the width set is smaller than the actual window width, the control cannot be scrolled horizontally. The horizontal scroll bar will be disabled or hidden, based on the Scrollbars property.

By default, a tree control does not handle horizontal scrolling, even if the Scrollbars property defines scroll bars to be available. To start horizontal scrolling, an application has to use the Items.RecalcHorizontalExtent method or the Items.HorizontalExtent property. They indicate to the tree control that horizontal scrolling support is desired and allows it to determine the horizontal scrolling extent.

The tree control doesn't automatically update the horizontal extent when items are added or deleted or other methods or properties are used, which may invalidate the horizontal extent. The Items.RecalcHorizontalExtent method or Items.HorizontalExtent property have to be used again to recalculate or redefine the extent.

Examples

VB.NET

            AxSftTree1.BulkUpdate = False
        End If

        ' make horizontal extent and width of column 0 wider than previous
        ' setting, but never smaller
        AxSftTree1.ColumnsObj.MakeOptimal()
        AxSftTree1.Items.RecalcHorizontalExtent()

        If horzExtent > AxSftTree1.Items.HorizontalExtent Then
            AxSftTree1.Items.HorizontalExtent = horzExtent
        End If
        If firstColumnWidth > AxSftTree1.get_Column(0).WidthPix Then
            AxSftTree1.get_Column(0).WidthPix = firstColumnWidth
        End If
    End Sub

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VB6

Private Sub SftTree1_OLEDragDrop(Data As SftTreeLib75.DataObject, Effect As Long, Button As Integer, Shift As Integer, x As Single, y As Single)
    Dim insertAt As Integer
    Dim str As String
    Dim lvl As Integer, newItem As Integer
    Dim horzExtent As Single, col0Width As Single

    ' get horizontal extent and width of column 0
    horzExtent = SftTree1.Items.HorizontalExtent
    col0Width = SftTree1.Column(0).Width

    insertAt = SftTree1.Items.DropHighlight
    If insertAt < 0 Then Exit Sub

    If Data.GetFormat(vbCFText) Then
        lvl = SftTree1.Item(insertAt).Level
        str = Data.GetData(vbCFText)

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C#

                axSftTree1.BulkUpdate = false;
            }

            // make horizontal extent and width of column 0 wider than previous
            // setting, but never smaller
            axSftTree1.ColumnsObj.MakeOptimal();
            axSftTree1.Items.RecalcHorizontalExtent();

            if (horzExtent > axSftTree1.Items.HorizontalExtent)
                axSftTree1.Items.HorizontalExtent = horzExtent;
            if (firstColumnWidth > axSftTree1.get_Column(0).WidthPix)
                axSftTree1.get_Column(0).WidthPix = firstColumnWidth;
        }

        private void Picture1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) {
            System.Windows.Forms.DataObject data = new System.Windows.Forms.DataObject();

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See Also SftTreeItems Object | Object Hierarchy