Collapsing/Expanding a treeview by programming

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Example

Associating an image with the elements of a TreeView control

Collapsing/Expanding a treeview by programming

Collapsing/Expanding a treeview by programming (prefixed 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 (prefixed syntax)

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

Handling an element of a TreeView control by programming

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

How to fill a Treeview control from a data file?

Managing duplicates in the TreeView controls

Managing duplicates in the TreeView controls (prefixed 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

Collapsing/Expanding a treeview by programming
Example

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Collapsing/Expanding a treeview by programming

To collapse a treeview by programming, all you have to do is use TreeCollapse.
To expand a treeview by programming, all you have to do is use TreeListItem combined with a specific local procedure.

Versions 19 and later

Note: To optimize the filling of a TreeView control, you have the ability to use ..AddChildDelayed on the rows of the TreeView control. This property is used to define the procedure that will be run to fill the level to expand. The search for children and the fill of children are performed only when the user wants to see them.

New in version 19

Example

The following codes are used to:

initialize a TreeView control.
expand part of the TreeView control.
collapse the TreeView control.

Initialize the TreeView control by programming:

TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert", "CAKE-.BMP", "CAKE-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Ice cream")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Ice cream" + ...
TAB + "Vanilla", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Ice cream" + ...
TAB + "Strawberry", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Ice cream" + ...
TAB + "Chocolate", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Cup")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Cup" + ...
TAB + "Banana Split", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Cup" + ...
TAB + "Cherry Garcia", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Cup" + ...
TAB + "Colonel", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Apple pie")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Apple pie" + ...
TAB + "with whipped cream", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Apple pie" + ...
TAB + "with apple brandy", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Crème brûlée", "NEXT5-.BMP")
TreeAdd(TREE_RecipeTV, "Recipe" + TAB + "Dessert" + TAB + "Meringue with cream", "NEXT5-.BMP")
Expand all the elements: The "ExpandAll" procedure is called for each "child" element found. This procedure expands all the collapsed "child" nodes of the "Dessert" node.

// Lists the "children" of "Desserts" node in "TREE_RecipeTV" treeview
// The "ExpandAll" procedure is called
// for each "child" of "Desserts" node found
Res = TreeListItem(TREE_RecipeTV, "Recipe" + TAB + "Dessert", "ExpandAll")

// Local procedure named "ExpandAll"
// This procedure expands all the collapsed "child" nodes of the "Desserts" node
PROCEDURE ExpandAll(TREE_RecipeTV, ChildPath, ChildFound, Level, Pointer)
// Is the element found a leaf?
IF TreeTypeItem(TREE_RecipeTV, ChildPath + ChildFound) = tvLeaf THEN
        RETURN // Back to TreeListItem
ELSE
        // Is the element found collapsed?
        IF TreeStatus(TREE_RecipeTV, ChildPath + ChildFound) = tvCollapse THEN
                TreeExpand(TREE_RecipeTV, ChildPath + ChildFound)
        END
END
Collapse the "Dessert" node.

// Collapses the "Desserts" node in "TREE_RecipeTV"
Res = TreeCollapse(TREE_RecipeTV, "Recipe" + TAB + "Dessert")