INTERFACEThis is a vbt class for displaying graphs (in the graph theory sense, not the Cartesian sense). A graph is specified as a collection of nodes, connected by a collection of links. Geometry of the display is entirely client-specified, in terms of real-number world coordinates. The client establishes aGraphVBT ;
relevant rectangle of world coordinate space;
the VBT automatically maintains the transformation so that this
rectangle is always shown in the VBT, regardless of its size and shape.
These graphs allow more than one distinct link between the same pair of nodes, so links are always specified in terms of (node number, link number) rather than node pair. Thus there are two names for every link, depending on which end it is viewed from. When creating links it is allowable but not necessary to create a link from both ends.
IMPORT GraphData, VBT;
IMPORT Point, RealPoint, Rect, Text;
IMPORT PaintOp, Pixmap, Font;
CONST
MaxLink = GraphData.MaxEdge;
TYPE
T <: VBT.Leaf;
NodeIndex = CARDINAL;
LinkIndex = [0..MaxLink];
PointArray = GraphData.PointArray;
Coord = REAL;
ErrorKind = {NoSuchNode, NoSuchLink, NoSuchPoint, InvalidColor,
TooManySizes, ShapeNotProvided};
LinkHalf = {Top, Bottom};
FocusDevice = {Mouse, Keyboard};
EXCEPTION
Error(ErrorKind);
********************************************************************
PROCEDURE New(): T;***************************** Corodinate system ******************** Client coordinates are given as real numbers. The rectangle specified in SetWC is the active rectangle; as the window is resized and reshaped, world coordinates will be scaled to screen coordinates in such a way that the active rectangle is always visible. Default active rectangle is [-100..100] in both dimensions. Aspect ratio of world coordinates depends on the setting of the
square parameter. If it is true, the aspect
ratio is unchangeably set to 1:1 - a square as specified in world
coordinates will always appear as a square on the screen. If
the aspect ratio of the window does not match that of the active
rectangle, there will be empty white space in the dimension in
which the window is excessive. If square is false, the aspect
ratio will vary with the shape of the window, and world coordinate
space will fill the window in both dimensions.
It is ok to make n > s or s > n, to get a right-handed or left-handed coordinate system as desired.
TYPE
FisheyeMapType = {Cartesian, Polar};
FisheyeType = {Graphical, Semantic};
PROCEDURE SetFisheyeFocus(v: T; focus: RealPoint.T);
PROCEDURE GetFisheyeFocus(v: T): RealPoint.T;
PROCEDURE SetFisheyeDistortion(v: T; distortion: REAL);
PROCEDURE GetFisheyeDistortion(v: T): REAL;
PROCEDURE SetFisheyeFocusDevice(v: T; device: FocusDevice);
PROCEDURE GetFisheyeFocusDevice(v: T): FocusDevice;
PROCEDURE GetFisheyeFocusSize(v: T): INTEGER;
PROCEDURE SetFisheyeSizeFactor(v: T; sizeFactor: REAL);
PROCEDURE GetFisheyeSizeFactor(v: T): REAL;
PROCEDURE SetFisheye(v: T; READONLY val: BOOLEAN);
PROCEDURE GetFisheye(v: T): BOOLEAN;
PROCEDURE SetCageSize(v: T; READONLY val: INTEGER);
PROCEDURE GetCageSize(v: T): INTEGER;
PROCEDURE SetFisheyeText(v:T; READONLY val: BOOLEAN);
PROCEDURE GetFisheyeText(v: T): BOOLEAN;
PROCEDURE SetFisheyeVWThreshold(v: T; READONLY val: REAL);
PROCEDURE GetFisheyeVWThreshold(v: T): REAL;
PROCEDURE SetFisheyeSizeAPICoeff(v: T; READONLY val: REAL);
PROCEDURE GetFisheyeSizeAPICoeff(v: T): REAL;
PROCEDURE SetFisheyeSizeAPIPower(v:T; READONLY val: REAL);
PROCEDURE GetFisheyeSizeAPIPower(v: T): REAL;
PROCEDURE SetShape (v: T; shape: Shape);
PROCEDURE SetStyle (v: T; style: Style);
PROCEDURE SetFisheyeType(v: T; fisheye_type: FisheyeType);
PROCEDURE SetFisheyeMapType(v: T; fisheye_map_type: FisheyeMapType);
PROCEDURE SetSemanticColor(v: T; useColor: BOOLEAN);
PROCEDURE SetNodeColor(v: T; color: Color);
PROCEDURE SetFocusColor(v: T; color: Color);
PROCEDURE SetLinkColor(v: T; color: Color);
PROCEDURE SetLabelColor(v: T; color: Color);
PROCEDURE SetLinkThickness(v: T; thickness: INTEGER);
PROCEDURE SetNodeInteriorColor(v: T; color: Color);
Establish a margin around the visible part of coordinates.
The margin will be m times the default node size. Should be called
before SetWC; modifies the effect of all SetWC calls thereafter.
PROCEDURE SetMarginSize(v : T; m: REAL);Set the world coordinate rectangle. If the SetMarginSize feature is used, this should take place after the margin size and the default node size are established.
PROCEDURE SetWC(v : T; n, w, s, e : REAL; square: BOOLEAN := TRUE); PROCEDURE GetWC(v: T; VAR (*out*) n, w, s, e: REAL);Convert a point from world coordinates to screen coordinates. These are virtual screen coordinates; there is no checking to see that the point is in fact visible on the screen.
PROCEDURE WtoS(v: T; rp: RealPoint.T): Point.T;Convert a point from screen coordinates to world coordinates.
PROCEDURE StoW(v: T; p: Point.T): RealPoint.T;**************** Other global parameters ******************
PROCEDURE SetMaxNodes(v: T; max: CARDINAL);
(* Establish a maximum number of nodes supported in this view. Calling this
procedure wipes out the entire graph previously defined, if any. It
also establishes the acceptable range of NodeIndex parameters as
[0..max-1]. If this procedure has never been called on v, then the
maximum is 100. *)
PROCEDURE SetBg(v: T; tint: PaintOp.T);
(* Background tint of the vbt. Default PaintOp.Bg. *)
PROCEDURE SetFont(v: T; font: Font.T);
(* Font used in node labels. Default VT6x13. *)
********************************************************************
TYPE
Color = [-3..253];
CONST
Black = -2;
White = -1;
DefaultColor = -3;
CONST
Red = 0;
Orange = 1;
Yellow = 2;
Green = 3;
Blue = 4;
Purple = 5;
Maroon = 6;
Sky = 7;
TYPE
ColorCount = [0..253];
PROCEDURE SetNColors(v: T; n: ColorCount);
(* Set the size of the color space (not including Black and White). This
wipes out any previous color setup, so should be done only during
initialization. *)
PROCEDURE SetColorFromTint(v: T; color: Color; tint: PaintOp.T);
(* Define the mapping from GraphVBT color space to an arbitrary tint. *)
PROCEDURE GetColorFromName(name: Text.T): Color;
***************** Miscellaneous node properties ******************
TYPE
Style = {Filled, Border};
LabelStyle = {NoLabel, Left, Center, Right};
************************** Shapes *****************************
A shape is defined by a collection of bitmaps for various sizes
of the two styles Filled and Border. NameWithin is a variant of
Border, so it takes to part in shape definition. Several shapes
are predefined; clients may add others.
CONST MaxShape = 10; TYPE Shape = [0..MaxShape]; CONST (* predefined shapes *) Circle = 0; Rectangle = 1; Diamond = 2; InvTriangle = 3; Triangle = 4; Pentagon = 5; Hexagon = 6; Octagon = 8; Ellipse = 9;To define a shape, one begins by specifying the maximum number of sizes that will be supported for it.
PROCEDURE InitShape(shape: Shape; nSizes: CARDINAL);The rest of the job is to provide bitmaps for the various sizes and styles.
PROCEDURE ProvideShapeCircle(
shape: Shape; (* must be already Inited *)
size: CARDINAL; (* "radius" in pixels *)
style: Style;
box: Rect.T;
pixmap: Pixmap.T) RAISES {Error};
PROCEDURE ProvideShapeRectangle(
shape: Shape; (* must be already Inited *)
size: CARDINAL; (* "radius" in pixels *)
style: Style;
box: Rect.T) RAISES {Error};
********************** Graph creation *********************
PROCEDURE NewNode(
v: T;
n: NodeIndex;
x, y: Coord;
api: REAL;
label: Text.T := NIL) RAISES {Error};
NewLink: create a link from node a, slot aIndex, to node b, slot
bIndex. Order of a and b is unimportant, and it is ok to make
duplicate calls, one from each end, provided they agree.
Segmented links, i.e. those that are drawn in more than one piece, are permitted, and are specified by providing a non-NIL segPoints, which is an array of intermediate vertices, in order from a to b. These vertices should be roughly evenly spaced if arrows are to be used.
PROCEDURE NewLink(
v: T;
a, b: NodeIndex;
aIndex, bIndex: LinkIndex;
segPoints: GraphData.PointArray := NIL) RAISES {Error};
A GraphData.T is a linked data structure that can describe an entire
graph. Setup loads the contents of a GraphVBT from such a structure,
creating nodes and links with default properties. Node labels
come from the names of nodes as given in g. Setup calls SetMaxNodes
if necessary, and will reserve extraNodes node slots beyond (numbered
higher than) those filled by g.
If ComputeWC is true, Setup will also establish world coordinates based upon the bounding box of the coordinates of nodes in g. The world coordinate box will be that bounding box, expanded by a margin equal to <margin> fraction of its greater dimension. Thus in the default case, a margin of 1/10 of the greater dimension of the bounding box will be used.
PROCEDURE Setup(
v: T;
g: GraphData.T;
allowSegmented: BOOLEAN := TRUE;
extraNodes: CARDINAL := 0;
computeWC: BOOLEAN := TRUE;
margin: REAL := 0.1);
PROCEDURE Redraw(v: T; force: BOOLEAN := TRUE);
END GraphVBT.