Diagrams(3tk)							    Tk Diagrams 						     Diagrams(3tk)

__________________________________________________________________________________________________________________________________________________

NAME

       Diagrams - User documentation of the Diagrams package

SYNOPSIS

       package require Tcl  8.4

       package require Tk  8.4

       package require Diagrams  0.2

       ::Diagrams::drawin canvas

       ::Diagrams::saveps filename

       ::Diagrams::direction newdir

       ::Diagrams::currentpos pos

       ::Diagrams::getpos anchor obj

       ::Diagrams::position xcoord ycoord

       ::Diagrams::box text width height

       ::Diagrams::plaintext text width height

       ::Diagrams::circle text radius

       ::Diagrams::slanted text width height angle

       ::Diagrams::diamond text width height

       ::Diagrams::drum text width height

       ::Diagrams::arrow text length heads

       ::Diagrams::line args

       ::Diagrams::attach anchor

       ::Diagrams::color name

       ::Diagrams::fillcolor name

       ::Diagrams::textcolor name

       ::Diagrams::usegap use

       ::Diagrams::xgap value

       ::Diagrams::ygap value

       ::Diagrams::textfont name

       ::Diagrams::linewidth pixels

       ::Diagrams::linestyle style

       ::Diagrams::pushstate

       ::Diagrams::popstate

       ::Diagrams::computepos

       ::Diagrams::boxcoords x1 y1 x2 y2

       ::Diagrams::moveobject obj

_________________________________________________________________

DESCRIPTION

       The Diagrams package is meant to help drawing diagrams, like flowcharts. The philosophy is that you should be concentrating on the contents
       of the diagram, rather than the exact positioning and sizing of all items within it. The Diagrams package uses a few simple rules to layout
       the items:

       o      Each item (or object) in the diagram has a number of "anchors" - places where arrows and lines can be connected to.

       o      You can draw an arrow or a line from an object in a preset direction

       o      Sizing  and  positioning	should	be  done as automatic as possible: this is achieved for instance by drawing boxes and circles with
	      text, rather than first drawing a rectangle and then drawing the text inside it or vice versa.

       The commands within this package can be split up in several categories. Each category is described in a separate section.

GENERAL COMMANDS FOR POSITIONING AND SETUP

       ::Diagrams::drawin canvas
	      Set the canvas widget in which to draw

	      widget canvas
		     Widget to draw in

       ::Diagrams::saveps filename
	      Save the drawing in a PostScript file

	      filename string
		     Name of the file to save the drawing in

       ::Diagrams::direction newdir
	      Set the direction for moving the current position.  The direction is one of: north  northeast  east southeast  south southwest  west
	      northwest  N	 NE	    E	 SE	    S	  SW	    W	 NW up	   up-right   left down-right down  down-left left up-left
	      centre center	C

	      newdir string
		     New direction

       ::Diagrams::currentpos pos
	      Set the current position explicitly (argument must be a position "object")

	      pos list
		     New position (retrieve via getpos for instance)

       ::Diagrams::getpos anchor obj
	      Get the position of a particular "anchor" point of an object anchor should be one of the direction strings

	      anchor string
		     Name of the anchor (one of the directions - see the direction command

	      obj list
		     The object in question

       ::Diagrams::position xcoord ycoord
	      Create a position "object"

	      xcoord float
		     X-coordinate of the position

	      ycoord float
		     Y-coordinate of the position

DRAWING OBJECTS

       ::Diagrams::box text width height
	      Draw a box from the current position (width and height are both optional; if not given, the text determines the width and height)

	      string text
		     Text to be shown inside the box

	      float width
		     Width (if any) of the box in pixels

	      float height
		     Height (if any) of the box in pixels

       ::Diagrams::plaintext text width height
	      Draw plain text from the current position (width and height are both optional; if not given,  the  text  determines  the	width  and
	      height)

	      string text
		     Text to be shown

	      float width
		     Width (if any) of the (invisible) box in which to position the text

	      float height
		     Height (if any) of the box

       ::Diagrams::circle text radius
	      Draw a circle from the current position (the radius is optional)

	      string text
		     Text to be shown inside the circle

	      float radius
		     Radius (if any) of the circle in pixels

       ::Diagrams::slanted text width height angle
	      Draw a slanted box from the current position (width, height and angle are optional)

	      string text
		     Text to be shown inside the box

	      float width
		     Width (if any) of the box in pixels

	      float height
		     Height (if any) of the box in pixels

	      float angle
		     Angle of the slanted box

       ::Diagrams::diamond text width height
	      Draw a diamond-shaped box from the current position (width and height are both optional; if not given, the text determines the width
	      and height)

	      string text
		     Text to be shown inside the diamond

	      float width
		     Width (if any) of the diamond in pixels

	      float height
		     Height (if any) of the diamond in pixels

       ::Diagrams::drum text width height
	      Draw a drumshaped item from th ecurrent position (width and height are both optional; if not given, the text  determines	the  width
	      and height)

	      string text
		     Text to be shown inside the drum

	      float width
		     Width (if any) of the drum in pixels

	      float height
		     Height (if any) of the drum in pixels

       ::Diagrams::arrow text length heads
	      Draw  an	arrow  from the current position to the next.  The text is drawn next to the arrow, the length (in pixels) is optional. If
	      not given the gap parameters are used.

	      string text
		     Text to be shown along the arrow

	      float length
		     Length of the arrow in pixels

	      float heads
		     Which arrow heads to draw (first, last or both - defaults to last)

       ::Diagrams::line args
	      Draw a line specified via positions or via line segments The arguments are either position or length-angle pairs

	      list args
		     List of positions or of length-angle pairs

ATTRIBUTES

       (Note: attributes are persistent)

       ::Diagrams::attach anchor
	      Set the anchor point for attaching arrows to

	      string anchor
		     Any one of the valid anchor (e.g. N or North)

       ::Diagrams::color name
	      Set the color for the outline of a box etc.

	      color name
		     Name of the colour to be used

       ::Diagrams::fillcolor name
	      Set the color to fill the objects

	      color name
		     Name of the colour to be used

       ::Diagrams::textcolor name
	      Set the color to draw the text in

	      color name
		     Name of the colour to be used

       ::Diagrams::usegap use
	      Turn the gap on(1) or off(0). Note: usually a small gap is used when positioning objects.

	      boolean use
		     Use the gap to compute the position of the next object or not

       ::Diagrams::xgap value
	      Size of the gap in horizontal direction (in pixels)

	      integer value
		     Gap width in pixels

       ::Diagrams::ygap value
	      Size of the gap in vertical direction (in pixels)

	      integer value
		     Gap height in pixels

       ::Diagrams::textfont name
	      Set the name of the font to use

	      string name
		     Name of a text font

       ::Diagrams::linewidth pixels
	      Set the width of the lines (in line objects and arrows and the outline of boxes and other objects)

	      integer pixels
		     Number of pixels the lines are wide

       ::Diagrams::linestyle style
	      Set the style of the lines and arrows and of the outline of boxes and other objects. The predefined line	styles	are:  solid,  dot,
	      dash,  dash-dot,	dash-dot-dot  (these are the distinguishable line styles on Windows). You can also use the style patterns from the
	      canvas directly.

	      string style
		     Name of a valid line style

COMMANDS FOR IMPLEMENTING NEW OBJECTS

       Note: it is best to study how for instance box objects are implemented first.

       ::Diagrams::pushstate
	      Save the current global settings Used when defining an object that is composed of other objects

       ::Diagrams::popstate
	      Restore the previously saved global settings

       ::Diagrams::computepos
	      Compute the current position

       ::Diagrams::boxcoords x1 y1 x2 y2
	      Compute the anchor coordinates for a box-like object (this is merely a convenience routine. In general, you will have to compute the
	      list of coordinates yourself - see for instance the diamond object)

	      float x1
		     X coordinate of upper-left corner

	      float y1
		     Y coordinate of upper-left corner

	      float x2
		     X coordinate of lower-right corner

	      float y2
		     Y coordinate of lower-right corner

       ::Diagrams::moveobject obj
	      Move the object to the right position and return the new information

	      list obj
		     List of data representing the object

KEYWORDS

       diagrams, drawing

diagrams								0.2							     Diagrams(3tk)