Name

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      TAPEMEASURE__DEFINE

Purpose

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      The purpose of this routine is to provide a tape measure that can be displayed
      in a direct graphics draw widget. Typically, the user drags a line between two
      points in an image and the distance is calculated using the coordinate system
      of the image (which is provided to the TapeMeasure.

Authors

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        FANNING SOFTWARE CONSULTING BURRIDGE COMPUTING
        1645 Sheely Drive 18 The Green South
        Fort Collins Warborough, Oxon
        CO 80526 USA OX10 7DN, ENGLAND
        Phone: 970-221-0438 Phone: +44 (0)1865 858279
        E-mail: davidf@dfanning.com E-mail: davidb@burridgecomputing.co.uk

Category

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      Objects.

Syntax

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      tapeMeasureObject = Obj_New("TAPEMEASURE", X1=0.5, Y1=0.5, X2=0.75, Y2=0.75)
      drawObject -> Add, tapeMeasureObject

Superclasses

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      SELECTABLEOBJECT
      CATDATAATOM
      CATATOM
      CATCONTAINER IDLITCOMPONENT
      IDL_CONTAINER

Class Structure

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  class = { TAPEMEASURE, $
            format: "", $ ; The format of the measured length. Default: '(F8.2)'.
            headsize: 0L, $ ; The tape measure head size in pixels. By default !D.X_Size / 50.
            label: Obj_New(), $ ; A TextLine object for labeling the distance between two points.
            layerObject: Obj_New(), $ ; A CATLAYER object for holding the annotation.
            linestyle: 0L, $ ; The linestyle the tape measure is drawn in.
            midx: 0.0, $ ; The midpoint of the tape measure in X.
            midy: 0.0, $ ; The midpoint of the tape measure in Y.
            moveend: 0L, $ ; Indicates which end of tape measure (1 or 2) you are moving.
            orientation: 0.0, $ ; The orientation of the tape measure
            thickness: 0.0, $ ; The thickness of the tape measure.
            x1: 0.0, $ ; The X location for one end of the tape measure.
            y1: 0.0, $ ; The Y location for one end of the tape measure.
            x2: 0.0, $ ; The X location for the other end of the tape measure.
            y2: 0.0, $ ; The Y location for the other end of the tape measure.
            sx: 0L, $ ; The static end of a moving tape measure.
            sy: 0L, $ ; The static end of a moving tape measure.
            units: "", $ ; A string. Appended to length measurement when displaying. Null by default.
            userCoord: Obj_New(), $ ; A coordinate system provided by the user.
            INHERITS SelectableObject $
          }

Messages

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  TAPEMEASURE_CHANGED: This message is sent whenever SetProperty method is called and the NOMESSAGE
                    keyword is NOT set.

Event Structure

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      This object will add the following fields to the event structure created by an interaction.
      The fields are defined as:
      BOUNDARY_BOX: A 2x5 element array in normalized coordinates giving the boundary box of
                        the object.
      LENGTH: The current length of the tape measure in data coordinates.
      UNITS: A string that is the units of the length. Appended to length, usually.
      XPTS: A two element array giving the X endpoints of the line in data coordinates.
      YPTS: A two element array giving the Y endpoints of the line in data coordinates.

Modification History

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      Written by: David W. Fanning, 25 Jan 2004.