Last Updated: 3/4/97
Class NFGraph
Class NFGraph
public class NFGraph extends Panel implements Observer
The NFGraph class is an generic class used for different
kinds of data graphs. It must be sub-classed in order to
generate a graph.
Instance Variables
|
Type |
|
Name |
|
Description |
|
Default |
|
private |
|
NFRegion |
|
|
|
background |
|
Applet |
|
a |
|
the associated Applet |
|
|
|
NFActiveRegion |
|
dwell |
|
If non-null, handles dwell label displaying |
|
null |
|
int |
|
dwellOffset |
|
pixels around a dwell point. |
|
20 |
|
boolean |
|
dwellOn |
|
used to determine if default dwell parameters should be generated. |
|
false |
|
boolean |
|
graphChanged |
|
Set true when the graph has changed and needs to be displayed |
|
false |
|
boolean |
|
incrementalUpdate |
|
Set true when the only the last point should be drawn |
|
false |
|
boolean |
|
layoutChanged |
|
used internally to determine if certain graph items need to be recalculated |
|
false |
|
NFLegend |
|
legend |
|
Legend object |
|
new NFLegend() |
|
boolean |
|
legendChanged |
|
Set true when the legend has changed and needs to be displayed |
|
false |
|
boolean |
|
legendDisplayed |
|
set to true if a legend was actually displayed |
|
false |
|
NFParam |
|
param |
|
Used for parameter parsing |
|
null |
Methods
Color defaultColor (int i)
-
Get a default color for the given index
-
protected void defineParams ()
-
Defines all HTML parameters supported by NFGraph. This method
may be overridden by subclasses to define additional parameters.
In such cases, this method should be executed first.
-
protected void display (Graphics g)
-
Display all graph parts, calling sub-class methods as
necessary.
-
protected void display (boolean forceGraph)
-
If <forceGraph> is true, force a redraw of the graph.
Otherwise, the saved image is redisplayed.
-
protected void display()
-
Display all graph parts, calling sub-class methods as
necessary.
-
protected void drawGraph (Graphics g,
Rectangle r)
-
This method must be overridden by sub-classes in order
to display data sets. It is called by the display() method
after all headers, titles and legends have been displayed.
-
The data displayed should be contained within the given
rectangle, in the given graphics context, in order to
prevent any overwriting of other graph elements.
-
protected void drawGraphLite (Graphics g)
-
This method must be overridden by sub-classes in order
to display data sets. It is called by the display() method
after all headers, titles and legends have been displayed.
-
This drawGraph routine indicates only the last point should be
drawn and no grids or axes need be updated.
-
NFParam getParam()
-
Returns the graphs parameter structure.
-
void initGraph (Applet a)
-
Initialize the NFGraph object
-
protected synchronized void loadParams () throws Exception
-
Loads all HTML parameters supported by NFGraph. This method
may be overridden by subclasses to load additional parameters.
In such cases, this method should be executed first.
-
synchronized final void loadParams (Applet app) throws Exception
-
Loads applet parameters from the HTML file that invoked the
applet. This method may not be overridden by sub-classes.
-
synchronized final void loadParams (String expr) throws Exception
-
Loads application parameters defined by the given parameter
expression. This method may not be overridden by sub-classes.
-
synchronized final void loadParams (String hostname,
int port,
String args) throws Exception
-
Loads application parameters from the NFParamServer designated
by the <host> and <port> arguments. When connected, the <args>
string will be sent to the server, followed by a newline. All
parameters generated by the server will be parsed by a
background thread. See NFParam for further details about
NFParamServer processing.
-
synchronized final void loadParams (URL url) throws Exception
-
Loads application parameters defined by a URL. This method may
not be overridden by sub-classes. See NFUtil.getFileURL() for
a convenient method for getting a URL for a local disk file.
-
boolean mouseDown (Event evt,
int x,
int y)
-
Keeps track of mouse movement over the graph
-
boolean mouseMove (Event evt,
int x,
int y)
-
Keeps track of mouse movement over the graph
-
void paint(Graphics g)
-
handle the paint
-
protected void reset()
-
The reset method may be overridden in order to provide a routine
that computes display parameters without actually displaying
the data.
-
void setBackground (NFRegion region)
-
Set the graph background. By default, no background is displayed.
-
void setFooter (NFLabel footer)
-
Set the graph footer. By default, no footer is displayed.
-
void setHeader (NFLabel header)
-
Set the graph header. By default, no header is displayed.
-
void setLeftTitle (NFLabel title)
-
Set the graph left title. By default, no left title is displayed.
-
void setRightTitle (NFLabel title)
-
Set the graph right title. By default, no right title is displayed.
-