Managing duplicates in the TreeView controls

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Managing duplicates in the TreeView controls

Associating an image with the elements of a TreeView control

Collapsing/Expanding a treeview by programming

Collapsing/Expanding a treeview by programming (object syntax)

Events associated with TreeView controls

Handling a TreeView control at run time

Handling a TreeView control by programming

Handling a TreeView control by programming (object syntax)

Handling an element found in a TreeView control by programming (object syntax)

Handling an element of a TreeView control by programming

How to fill a TreeView control from a data file? (object syntax)

How to fill a Treeview control from a data file?

Managing duplicates in the TreeView controls

Managing duplicates in the TreeView controls (object syntax)

Properties associated with the TreeView control

Properties associated with the rows of a TreeView control

The TreeView control

TreeView control linked to a data file

Overview
Principle
Implementation
Defining an identifier for managing the duplicates
Handling an element via its identifier
Finding out the identifier of an element

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Managing duplicates in the TreeView controls

Overview

WINDEV, WINDEV Mobile and WEBDEV allow you to add duplicates into the elements of a TreeView control. The mechanism for managing the duplicates in the TreeView controls allows you to easily handle these duplicates.

Principle

The management of duplicates in the TreeView controls is based on the management of the identifiers for each treeview element.

Indeed, when adding, inserting or modifying an element in a TreeView control, you have the ability to specify an identifier for the element used. This identifier (defined by the developer) will be used to identify the duplicate handled by the user.

The principle is straightforward: all you have to do is use a different identifier for each duplicate. This identifier will be retrieved by the functions for treeview management and it will be used to identify the duplicated handled.

Implementation

Defining an identifier for managing the duplicates

The definition of an identifier is performed when adding or modifying an element to a Treeview control.

To associate an identifier with an element found in a TreeView control, this identifier must be specified in the following programming functions:


TreeAdd	Adds a "leaf" element (and all necessary nodes) into a TreeView control.
TreeInsert	Inserts a leaf into a TreeView control at a specific position.
TreeModify	Modifies an element (node or leaf) in a TreeView control.

Example:

ResultTreeView is boolean
ResultTreeView = TreeAdd(TREE_TreeView1, "Root" + TAB + "Node" + TAB + "Leaf", ...
tvDefault, tvDefault, "Leaf ID")
ResultTreeView = TreeAdd(TREE_TreeView1, "Root" + TAB + "Node" + TAB + "Leaf", ...
tvDefault, tvDefault, "ID of Leaf 2", tvAcceptDuplicate)

Handling an element via its identifier

To handle a duplicate element, its identifier must be known and specified.

to handle an element whose path is known, each path element must be filled (if necessary) by its identifier via TreeID.

Example: To add a leaf to the "Root"+TAB+"Node"+TAB+"Leaf" element, whose identifier is "Leaf ID", use the following syntax:

ResultTreeView = TreeAdd(TREE_TreeView1, "Root" + TAB + "Node" + TAB + "Leaf" + ...
TreeID("Leaf ID") + TAB + "My Element", tvDefault, tvDefault, "My Element 1")

TreeID can also be used with the following syntax: <TreeView Name> [ <Element Path>].

For example:

TREE_TreeView1["Root" + TAB + "Node" + TAB + "Leaf" + TreeID("Leaf ID") + ...
TAB + "My Element"]..Color = LightRed

Finding out the identifier of an element

To find out the identifier of a treeview element, all you have to do is use TreeIdentifier.

When managing the duplicates, the identifier is an integral part of the path as it is used to identify the selected element.

Therefore, the WLanguage functions returning the path of an element (when selecting an element for example) can return:

the path of the element while ignoring the identifier.
the path of the element by including (if necessary) the identifier of each element found in the path.

The affected functions are as follows:


TreeListItem	Lists the "children" of a node and the "child" elements of these "children" in a TreeView control.
TreePosition	Displays a TreeView control from a specified element (node or leaf) or returns the name of the first element displayed in a TreeView control.
TreeSelect	Returns the full path of selected element in a TreeView control.

Related Examples:

Unit examples (WINDEV): The TreeView control

[ + ] Using the TreeView control via the WLanguage Tree functions.