ilog.views.sdm.renderer

Class IlvHalfZoomingRenderer

java.lang.Object

ilog.views.sdm.renderer.IlvSDMRenderer

ilog.views.sdm.renderer.IlvFilterSDMRenderer

ilog.views.sdm.renderer.IlvHalfZoomingRenderer

public class IlvHalfZoomingRenderer
extends IlvFilterSDMRenderer

The class IlvHalfZoomingRenderer is a filtering renderer that prevents the nodes of the graph to zoom in and/or out beyond given limits.

The half-zooming renderer wraps each graphic node created by the filtered renderer in an IlvHalfZoomingGraphic.

The minimum zoom, maximum zoom, initial zoom and rotatable flag are fetched from the style sheet using the rendering properties MinZoom, MaxZoom, InitialZoom, and Rotatable.

When the view is zoomed in and the zoom level becomes greater than the maximum zoom, the nodes keep a fixed size.

When the view is zoomed out and the zoom level becomes smaller than the minimum zoom, the nodes are replaced by gray boxes. The gray boxes keep getting smaller as the view is zoomed out.

If the minimum zoom is 0, the objects are zoomed out normally, as if the half-zooming renderer was not present. Similarly, if the maximum zoom is 0, the objects always get bigger when the view is zoomed in, as if the half-zooming renderer was not present.

For example, with the following CSS rule, the nodes will no longer grow as soon as the zoom level becomes larger than 4, and they are grayed out when the zoom becomes smaller than 0.25:

  SDM {
    HalfZooming : "true";
  }
  node {
    MaxZoom : "4";
    MinZoom : "0.25";
  }
  

The zoom thresholds can also be set globally for all the nodes by setting the minZoom and maxZoom directly on the renderer, as follows:

  SDM {
    HalfZooming : "true";
  }
  HalfZooming {
    maxZoom : "4";
    minZoom : "0.25";
  }
  

The half zooming renderer supports node alpha transparency. Use this feature to add transparency to specific nodes without changing the individual foreground, background and stroke colors for the node.

For any node, the alpha transparency value must be between 0 and 1. The following CSS rule specifies that certain nodes must appear transparent with an alpha value of 0.3:

  SDM {
    HalfZooming : "true";
  }
  node.MyType {
    MaxZoom : "4";
    MinZoom : "0.25";
    Alpha: "0.3";
  }
  

The following CSS rule sets the default alpha transparency for all nodes:

  SDM {
    HalfZooming : "true";
  }
  HalfZooming {
    alpha : "0.4";
  }
  

CSS example:

ilvHalfZoomingRenderer {
class : "ilog.views.sdm.renderer.IlvHalfZoomingRenderer";
alias : "<value>";
alpha : "2.0";
grayedWhenUnzoomed : "false";
initialZoom : "3.0";
maxZoom : "3.0";
minZoom : "3.0";
parameter : "<value>";
rotatable : "false";
unzoomedBackground : "green";
unzoomedForeground : "green";
}

Property Summary

Properties

Modifier and Type	Property and Description
java.lang.String	alias Sets the alias of this renderer.
float	alpha Changes the alpha transparency value for the objects.
java.lang.String	class Default constructor.
boolean	grayedWhenUnzoomed Specifies whether half-zooming objects are drawn as gray boxes when the zoom level is less than the minimum zoom, or if they are drawn at their minimum size.
double	initialZoom Changes the initial zoom level.
double	maxZoom Changes the maximum zoom level above which the objects stop zooming.
double	minZoom Changes the minimum zoom level below which the objects are replaced by gray boxes.
java.lang.String	parameter This method gives access to a privileged parameter of the renderer, and allows this parameter to be specified quickly in the main option rule of the style sheet.
boolean	rotatable Sets whether the objects support rotation.
java.awt.Color	unzoomedBackground Sets the background color used to fill the nodes below the minimum zoom level.
java.awt.Color	unzoomedForeground Sets the foreground color used to draw the outline of the nodes below the minimum zoom level.

Method Summary

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Property Detail

class

public java.lang.String class

Default constructor.

CSS example: class : "ilog.views.sdm.renderer.IlvHalfZoomingRenderer";

alias

public java.lang.String alias

Sets the alias of this renderer. The alias is the symbolic name used to designate the renderer in the SDM style sheet, for example SubGraph or GraphLayout.

CSS example: alias : "<value>";

alpha

public float alpha

Changes the alpha transparency value for the objects. The alpha value is used to render the transparency level of the wrapped object. The value must be in the range of [0.0, 1.0]. Setting the alpha value to 1 means that the object is totally transparent.

This global alpha transparency value is used as a default when the Alpha property has not been set in the CSS rules for the nodes.

CSS example: alpha : "2.0";

grayedWhenUnzoomed

public boolean grayedWhenUnzoomed

Specifies whether half-zooming objects are drawn as gray boxes when the zoom level is less than the minimum zoom, or if they are drawn at their minimum size.

The default value of true.

CSS example: grayedWhenUnzoomed : "false";

initialZoom

public double initialZoom

Changes the initial zoom level.

This global initial zoom level is used as a default when no InitialZoom property has been set in the CSS rules for the nodes.

CSS example: initialZoom : "3.0";

maxZoom

public double maxZoom

Changes the maximum zoom level above which the objects stop zooming.

This global maximum zoom level is used as a default when no MaxZoom property has been set in the CSS rules for the nodes.

CSS example: maxZoom : "3.0";

minZoom

public double minZoom

Changes the minimum zoom level below which the objects are replaced by gray boxes.

This global minimum zoom level is used as a default when no MinZoom property has been set in the CSS rules for the nodes.

CSS example: minZoom : "3.0";

parameter

public java.lang.String parameter

This method gives access to a privileged parameter of the renderer, and allows this parameter to be specified quickly in the main option rule of the style sheet.

For example, the main parameter of the ilog.views.sdm.renderer.maps.IlvMapRenderer is the name of the map file. You can specify that you want to display a map of the USA by the single declaration:

    SDM {
      Map : "usa.ivl";
    }
  

The default implementation does nothing. Subclasses should override this method to give access to their main parameter.

CSS example: parameter : "<value>";

rotatable

public boolean rotatable

Sets whether the objects support rotation.

The rotation setting is not delegated to the wrapped object:

• If rotation support is disabled, the objects always stay in the upright position. This is true even if a wrapped object supports rotation.
• If rotation support is enabled, and the wrapped object also supports rotation, it will rotate normally. If the wrapped object does not support rotation, it will remain static.

CSS example: rotatable : "false";

unzoomedBackground

public java.awt.Color unzoomedBackground

Sets the background color used to fill the nodes below the minimum zoom level.

CSS example: unzoomedBackground : "green";

A color can either be a string representing a color or else an octal or hexadecimal string that starts with the character "#" or else a comma separated "RGB" value where the integer values are in the range 0..255.

unzoomedForeground

public java.awt.Color unzoomedForeground

Sets the foreground color used to draw the outline of the nodes below the minimum zoom level.

CSS example: unzoomedForeground : "green";

A color can either be a string representing a color or else an octal or hexadecimal string that starts with the character "#" or else a comma separated "RGB" value where the integer values are in the range 0..255.