Package com.storedobject.svg

Class Node<N extends Node<N>>

java.lang.Object

com.storedobject.svg.Node<N>

Type Parameters:

N - Type of the node.

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

Chart, Element

public abstract class Node<N extends Node<N>>
extends Object
implements Serializable

Base class for all SVG objects. This represents a single visual unit or part of an SVG document. It has got its own size and origin, and can be independently translated and scaled. Many such node objects can be combined to form larger visual compositions.

Note: The coordinates system used has the origin (0, 0) in the top left corner.

Author:

Syam

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static int	NUMERIC_PRECISION	The numeric precision used for formatting double values in the SVG output.
protected double	x1	Current x and y coordinates of this node.
protected double	x2	Current x and y coordinates of this node.
protected double	y1	Current x and y coordinates of this node.
protected double	y2	Current x and y coordinates of this node.

Constructor Summary

Constructors

Constructor	Description
Node()	Default constructor for the Node class.

Method Summary

Modifier and Type	Method	Description
protected String	attributes()	Retrieves a string representation of the node's attributes.
protected void	compute()	This method is invoked to perform any necessary computations just before the SVG content is generated.
N	copy()	Create a copy of this node instance.
final Document	createDocument()	Creates a new Document instance associated with the current Node.
final boolean	equals(Object obj)	Compares this node with another object for equality.
static String	escapeXml(String text)	Escape XML special characters in a string.
protected String	extraContent()	Provides additional content specific to the node.
final N	flipHorizontally()	Flips the node horizontally.
final N	flipHorizontallyAroundOrigin()	Flips the node horizontally around the origin (0, 0).
Node<N>	flipVertically()	Flips the node vertically.
final N	flipVerticallyAroundOrigin()	Flips the node vertically around the origin (0, 0).
Coordinates	getCoordinates()	Retrieves the coordinates associated with this Node.
final long	getId()	Retrieves the unique identifier of the node.
Margin	getMargin()	Retrieves the margin associated with this node.
final String	getSvg()	Retrieves the SVG representation of the current Node.
final int	hashCode()	Returns a hash code for this node based on its unique ID.
protected long	id()	Retrieves the unique identifier of the node.
static String	ID(long id)	Generates a unique string identifier for the given numerical ID.
static long	IDValue()	Generates a globally unique identifier in a thread-safe manner.
protected String	innerContent()	Retrieves the inner content of the node.
final N	moveTo(double x, double y)	Moves the node to a specified (x, y) coordinate.
final N	moveTo(Point point)	Moves the node to a specified Point.
final N	rotate(double angle)	Rotates the node by a given angle around its origin.
final N	rotateAround(double angle, double x, double y)	Rotates the node by a given angle around a specified point (x, y).
final N	rotateAround(double angle, Point point)	Rotates the node by a given angle around a specified Point.
final N	rotateAroundCenter(double angle)	Rotates the node by a given angle around its center.
final N	scale(double scale)	Scales the node uniformly by a given factor.
final N	scale(double sx, double sy)	Scales the node by given factors sx and sy.
final N	scaleHeightTo(double toHeight)	Scales the height of the node to a specified value.
final N	scaleTo(double toWidth, double toHeight)	Scales the node to a specified width and height.
final N	scaleWidthTo(double toWidth)	Scales the width of the node to a specified value.
protected String	styles()	Retrieves the styles associated with this node.
protected String	tag()	Retrieves the tag associated with this node.
final String	toString()
static String	toString(double v)	Converts the given double value to a string representation with specified numeric precision.
final TransformMatrix<N>	transform()	Retrieves the transformation matrix associated with this node.
final N	translate(double dx, double dy)	Translates the node by a given offset (dx, dy).
final N	translate(Point point)	Translates the node by a given offset specified as a Point.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

NUMERIC_PRECISION

public static int NUMERIC_PRECISION

The numeric precision used for formatting double values in the SVG output. The default value is 4.

x1

protected double x1

Current x and y coordinates of this node. These values should be maintained by the subclasses, and these values determine the position, width, and height of the node. If the width and height ae zero, then no output is generated.

Note: Computation of these values should not take care of any transformations applied to the node. Changes to the coordinates due to transformation are automatically handled.

y1

protected double y1

Current x and y coordinates of this node. These values should be maintained by the subclasses, and these values determine the position, width, and height of the node. If the width and height ae zero, then no output is generated.

Note: Computation of these values should not take care of any transformations applied to the node. Changes to the coordinates due to transformation are automatically handled.

x2

protected double x2

Current x and y coordinates of this node. These values should be maintained by the subclasses, and these values determine the position, width, and height of the node. If the width and height ae zero, then no output is generated.

Note: Computation of these values should not take care of any transformations applied to the node. Changes to the coordinates due to transformation are automatically handled.

y2

protected double y2

Current x and y coordinates of this node. These values should be maintained by the subclasses, and these values determine the position, width, and height of the node. If the width and height ae zero, then no output is generated.

Note: Computation of these values should not take care of any transformations applied to the node. Changes to the coordinates due to transformation are automatically handled.

Constructor Details

Node

public Node()

Default constructor for the Node class. Initializes a new instance of the node object with default properties.

Method Details

tag

protected String tag()

Retrieves the tag associated with this node. This tag is typically used to denote the type or category of the node in contexts such as SVG generation or XML representation.

Note: If null is returned, it indicates that the node does not have a specific tag and may be treated as a generic group. In such cases, only inner content and extra content are considered.

Returns:

A string representing the tag of the node. The default implementation returns "g".

id

protected long id()

Retrieves the unique identifier of the node.

Returns:

The unique identifier as a long value.

attributes

protected String attributes()

Retrieves a string representation of the node's attributes. This method is typically overridden by subclasses to provide specific attributes corresponding to the node's state or properties. By default, this method returns null if no attributes are defined.

Returns:

A string representing the attributes of the node, or null if no attributes are defined.

innerContent

protected String innerContent()

Retrieves the inner content of the node. This method is typically implemented or overridden by subclasses to provide specific content representing the inner state or structure of the node.

Returns:

A string containing the inner content of the node, or null if no content is defined.

extraContent

protected String extraContent()

Provides additional content specific to the node. This method is intended to be overridden by subclasses to define custom extra content specific to their implementation. By default, it returns null if no additional content is defined.

Note: The extra content should be formatted as per SVG standards with appropriate tags. No validation is performed on the extra content.

Returns:

A string representing the extra content of the node, or null if no extra content is defined.

styles

protected String styles()

Retrieves the styles associated with this node. This method is typically overridden by subclasses to provide specific styling information related to the node's state or properties.

Returns:

A string representing the styles of the node, or null if no styles are defined.

getId

public final long getId()

Retrieves the unique identifier of the node.

Returns:

The unique identifier as a long value.

transform

public final TransformMatrix<N> transform()

Retrieves the transformation matrix associated with this node. If the transformation matrix is not already initialized, this method creates a new TransformMatrix instance and returns it.

Returns:

The TransformMatrix object associated with this node.

flipVertically

public Node<N> flipVertically()

Flips the node vertically.

Returns:

The node itself after flipping.

flipVerticallyAroundOrigin

public final N flipVerticallyAroundOrigin()

Flips the node vertically around the origin (0, 0).

Returns:

The node itself after flipping.

flipHorizontally

public final N flipHorizontally()

Flips the node horizontally.

Returns:

The node itself after flipping.

flipHorizontallyAroundOrigin

public final N flipHorizontallyAroundOrigin()

Flips the node horizontally around the origin (0, 0).

Returns:

The node itself after flipping.

rotate

public final N rotate(double angle)

Rotates the node by a given angle around its origin.

Parameters:

angle - The clockwise angle of rotation in degrees.

Returns:

The node itself after rotation.

rotateAroundCenter

public final N rotateAroundCenter(double angle)

Rotates the node by a given angle around its center.

Parameters:

angle - The clockwise angle of rotation in degrees.

Returns:

The node itself after rotation.

rotateAround

public final N rotateAround(double angle,
 double x,
 double y)

Rotates the node by a given angle around a specified point (x, y).

Parameters:

angle - The clockwise angle of rotation in degrees.

x - The x-coordinate of the rotation center.

y - The y-coordinate of the rotation center.

Returns:

The node itself after rotation.

rotateAround

public final N rotateAround(double angle,
 Point point)

Rotates the node by a given angle around a specified Point.

Parameters:

angle - The clockwise angle of rotation in degrees.

point - The point around which to rotate.

Returns:

The node itself after rotation.

translate

public final N translate(double dx,
 double dy)

Translates the node by a given offset (dx, dy).

Parameters:

dx - The distance to translate along the x-axis.

dy - The distance to translate along the y-axis.

Returns:

The node itself after translation.

translate

public final N translate(Point point)

Translates the node by a given offset specified as a Point.

Parameters:

point - The offset point for translation.

Returns:

The node itself after translation.

moveTo

public final N moveTo(Point point)

Moves the node to a specified Point.

Parameters:

point - The destination point.

Returns:

The node itself after moving.

moveTo

public final N moveTo(double x,
 double y)

Moves the node to a specified (x, y) coordinate.

Parameters:

x - The destination x-coordinate.

y - The destination y-coordinate.

Returns:

The node itself after moving.

scale

public final N scale(double scale)

Scales the node uniformly by a given factor.

Parameters:

scale - The scaling factor.

Returns:

The node itself after scaling.

scaleWidthTo

public final N scaleWidthTo(double toWidth)

Scales the width of the node to a specified value.

Parameters:

toWidth - The target width.

Returns:

The node itself after scaling.

scaleHeightTo

public final N scaleHeightTo(double toHeight)

Scales the height of the node to a specified value.

Parameters:

toHeight - The target height.

Returns:

The node itself after scaling.

scale

public final N scale(double sx,
 double sy)

Scales the node by given factors sx and sy.

Parameters:

sx - The scaling factor along the x-axis.

sy - The scaling factor along the y-axis.

Returns:

The node itself after scaling.

scaleTo

public final N scaleTo(double toWidth,
 double toHeight)

Scales the node to a specified width and height.

Parameters:

toWidth - The target width.

toHeight - The target height.

Returns:

The node itself after scaling.

equals

public final boolean equals(Object obj)

Compares this node with another object for equality. Two nodes are considered equal if they have the same unique ID.

Overrides:

equals in class Object

Parameters:

obj - The object to compare with.

Returns:

true if the objects are equal, false otherwise.

hashCode

public final int hashCode()

Returns a hash code for this node based on its unique ID.

Overrides:

hashCode in class Object

Returns:

A hash code value for this node.

copy

public N copy()

Create a copy of this node instance.

Returns:

a new instance that is a copy of this node but with a new unique ID.

toString

public static String toString(double v)

Converts the given double value to a string representation with specified numeric precision.

Parameters:

v - the double value to be converted to a string

Returns:

the string representation of the given double value with the applied numeric precision

escapeXml

public static String escapeXml(String text)

Escape XML special characters in a string.

Parameters:

text - Text to escape.

Returns:

Escaped string.

IDValue

public static long IDValue()

Generates a globally unique identifier in a thread-safe manner. The method increments the current ID value atomically. If the ID value reaches Long.MAX_VALUE, it resets to 0 before incrementing.

Returns:

A unique identifier as a long value.

ID

public static String ID(long id)

Generates a unique string identifier for the given numerical ID.

Parameters:

id - The numerical ID to be converted into a string identifier.

Returns:

A string in the format "so-svg-" followed by the numerical ID.

getCoordinates

public Coordinates getCoordinates()

Retrieves the coordinates associated with this Node.

Note: This method returns the bounding coordinates of the node's content, and it does not include any margin and/or transforms applied to the node.

Returns:

A Coordinates object representing the bounding coordinates with properties (x1, y1, x2, y2).

getMargin

public Margin getMargin()

Retrieves the margin associated with this node. If the margin is not yet initialized, a new Margin instance is created and returned.

Returns:

The margin object associated with this node.

createDocument

public final Document createDocument()

Creates a new Document instance associated with the current Node. This method initializes and returns a Document object for the node.

Returns:

A new Document instance associated with the current Node.

getSvg

public final String getSvg()

Retrieves the SVG representation of the current Node. This method internally uses a Document instance to generate the SVG output.

Returns:

A string containing the SVG representation of the current Node.

compute

protected void compute()

This method is invoked to perform any necessary computations just before the SVG content is generated.

Note: At least coordinates values should be set here properly.

toString

public final String toString()

Overrides:

toString in class Object