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Home ChartPack RChart Class TRChart Methods FindNearestItemAlongAxis
See also: FindNearestItemScreen, GetItemParams, SetItemParams, FindNearestItemReal 

FindNearestItemAlongAxis

Unit:SDL_rchart
Class: TRChart
Declaration: [1] function FindNearestItemAlongAxis (pos: double; Axis: TAxis; ItemID: TrcItem; ClassNumber: byte; var dist: double): longint;
[2] function FindNearestItemAlongAxis (pos: double; Axis: TAxis; ItemID: TrcItem; ClassNumber: byte; VisLayersOnly: boolean; var dist: double): longint;

The function FindNearestItemAlongAxis searches for the item which is closest to the positon pos along the axis specified by the parameter Axis, and which belongs to the item type ItemID, and has a class number of ClassNumber. In order to search through all items in the data container, ItemID should be set to tkEverything and ClassNumber must be 255.

There are two overloaded versions: version [2] provides the option to restrict the search to visible layers only by setting the parameter VisLayersOnly to TRUE.

The function returns the index of the closest item, which can be used to access the found item by means of GetItemParams, and SetItemParams. A value of -1 indicates that no element has been found. In addition, the variable parameter Dist contains the distance of the nearest item.

The distances between the reference position pos and the items of the chart are calculated using screen coordinates (pixels).


Last Update: 2023-Dec-13