DropTree

(System Library)

Description: Draws a control similar to a Droplist, but rather than a flat list, a tree of possible selections is displayed.
Returns: Object reference.
Usage: Script Only.
Function Groups: System
Related to: Bevel | CheckBox | ColorSelect | DropList | Edit | GridList | HScrollbar | Listbox | RadioButtons | SpinBox | SplitList | TextBox | ToolBar | VScrollbar | TreeControl
Format: System.DropTree(Left, Bottom, Right, Top, TreeData, Title, SelectedKey, FocusID, FTrigger[, DrawBevel, AlignTitle, DlgRoot, Trigger, BGcolor])
Parameters:  
Left
Any numeric expression for the left coordinate of the tool.
Bottom
Any numeric expression for the bottom coordinate of the tool.
Right
Any numeric expression for the right coordinate of the tool.
Top
Any numeric expression for the top coordinate of the tool.
TreeData
The data to display, in Node array format. The format is the same as for a call to TreeControl
Title
Any text expression to be used as a title.
SelectedKey
The key of the selected item. Must be a variable, and may specify initial selection.
FocusID
Any numeric expression from 0 to 32767 for the FocusID.
FTrigger
The Focus Trigger of the DropTree.
DrawBevel
Optional Boolean. If TRUE (non-0) a bevel is drawn. Defaults to FALSE.
AlignTitle
An optional parameter that is any logical expression. If TRUE (non-0) the title is included in the calculation for vertical alignment. The default is FALSE.
DlgRoot
Optional. The object value of the root dialog. Used for alignment of the DropTree.
Defaults to the caller if not specified.
Trigger
An optional numeric expression. Initially set to zero (0) when the DropTree opens.
If the user presses the Escape key or closes the extended window, then Trigger becomes 1.
BGColor
Optional background color of the control.
Comments:

This function allows the use of disabled options - grayed in appearance and unselectable.
The following set of helper functions is available. These may be added to the caller of DropTree to add special handling of certain events.

  • OnLeftClick(NodeArray)

- Subroutine: The left mouse button was released over a tree node.

  • OnRightClick(NodeArray, X, Y)

- Subroutine: The right mouse button was released over a node. X and Y are the coordinates of the mouse.

  • OnDoubleClick(NodeArray, X, Y)

- Subroutine: The left mouse button was double-clicked over a node. X and Y are the coordinates of the mouse.

  • CreateSubTree(NodeKey)

-

  • ExpandTreeToNode(NodeKey)

- Recursive Subroutine: Used for SetSelected call, expands to given node

  • Collapse()

- Will traverse the whole tree starting from the leaves, working towards the root, calling CollapseNodes() on each node.