Diagrams(n) 0.3 "Tk Diagrams"

Name

Diagrams - User documentation of the Diagrams package

Table Of Contents

• Table Of Contents
• Synopsis
• Description
• GENERAL COMMANDS FOR POSITIONING AND SETUP
• DRAWING OBJECTS
• ATTRIBUTES
• COMMANDS FOR IMPLEMENTING NEW OBJECTS
• Keywords

Synopsis

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:

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

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

• 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

::Diagrams::bracket dir dist begin end

Draw an arrow consisting of three lines from one item to another. The first argument gives the direction in which the arrow "bulges" away from the items, the second argument gives the distance over which it bulges.

string dir

Direction of "bulging" - one of north, south, east or west.

float dist

Length of the two end pieces of the arrow

list begin

Description of the item where the arrow begins as (returned by one of the item creation procedures, box, circle ...)

list end

Ditto for the item where the arrow points to

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