VObject::Detect

Section: ET++ method description (n)
Updated: automatically Mon Apr 8 20:17:57 1991
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NAME

VObject::Detect - instance method

TEMPLATE

foundItem = VObject * Detect(BoolFun compareFunction, void * compareFunctionArg)

SPECIFIERS

public virtual

DESCRIPTION

Detect searches a certain VObject in the VObject Tree starting at this.
Detect walks down the VObject tree, applies compareFunction to each VObject and returns the first one where the compareFunction returns TRUE.
Detect is never called directly. The interface to this method are the method FindItem and the method FindItemPtr which call Detect with different compare functions. For example, it is possible to look for a VObject with a certain id.
Detect should be overridden if the subclass contains one or more "child" VObjects to forward Detect also to its childs. The default implementation applies the compareFunction only to this.
For example, the method CompositeVObject::Detect first applies the compareFunction to every VObject in its list and at last to itself. This way of searching a tree is generally called depth-first search because it first tries to walk down the tree as deep as possible.
Another good example is the method Menu::Detect. Method is sometimes overridden.

ARGUMENTS

BoolFun compareFunction: This function is called with the following arguments (item, item, compareFunctionArg) whereby item contains the VObject currently visited in the VObject tree.
This function has to compare the item with the compareFunctionArg and return whether they are equal.
void * compareFunctionArg: is passed to the compareFunction as third argument. See compareFunction.

RETURN ARGUMENT

VObject * foundItem: contains the first VObject where compareFunction returns TRUE. It is NULL if compareFunction never returns TRUE.

FIRST DEFINITION

class VObject

FILES

implementation:: VObject.C

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Time: 00:40:22 GMT, March 30, 2022