com.jgoodies.forms.util

Class DefaultUnitConverter

Implemented Interfaces:
UnitConverter

public final class DefaultUnitConverter
extends AbstractUnitConverter

This is the default implementation of the UnitConverter interface. It converts horizontal and vertical dialog base units to pixels.

The horizontal base unit is equal to the average width, in pixels, of the characters in the system font; the vertical base unit is equal to the height, in pixels, of the font. Each horizontal base unit is equal to 4 horizontal dialog units; each vertical base unit is equal to 8 vertical dialog units.

The DefaultUnitConverter computes dialog base units using a default font and a test string for the average character width. You can configure the font and the test string via the bound Bean properties defaultDialogFont and averageCharacterWidthTestString. See also Microsoft's suggestion for a custom computation here.

Since the Forms 1.1 this converter logs font information at the CONFIG level.

Version:
$Revision: 1.3 $
Author:
Karsten Lentzsch
See Also:
UnitConverter, Size, Sizes

Method Summary

void
addPropertyChangeListener(PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list.
void
addPropertyChangeListener(String propertyName, PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list for a specific property.
String
getAverageCharacterWidthTestString()
Returns the string used to compute the average character width.
Font
getDefaultDialogFont()
Lazily creates and returns the dialog font used to compute the dialog base units.
protected double
getDialogBaseUnitsX(Component component)
Returns the cached or computed horizontal dialog base units.
protected double
getDialogBaseUnitsY(Component component)
Returns the cached or computed vertical dialog base units for the given component.
static DefaultUnitConverter
getInstance()
Lazily instantiates and returns the sole instance.
void
removePropertyChangeListener(PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list.
void
removePropertyChangeListener(String propertyName, PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list for a specific property.
void
setAverageCharacterWidthTestString(String newTestString)
Sets a string that will be used to compute the average character width.
void
setDefaultDialogFont(Font newFont)
Sets a dialog font that will be used to compute the dialog base units.

Methods inherited from class com.jgoodies.forms.util.AbstractUnitConverter

centimeterAsPixel, centimeterAsPixel, computeAverageCharWidth, dialogUnitXAsPixel, dialogUnitXAsPixel, dialogUnitYAsPixel, dialogUnitYAsPixel, getDefaultScreenResolution, getDialogBaseUnitsX, getDialogBaseUnitsY, getScreenResolution, inchAsPixel, inchAsPixel, millimeterAsPixel, millimeterAsPixel, pointAsPixel, pointAsPixel

Method Details

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list. The listener is registered for all bound properties of this class.

If listener is null, no exception is thrown and no action is performed.

Parameters:
listener - the PropertyChangeListener to be added

addPropertyChangeListener

public void addPropertyChangeListener(String propertyName,
                                      PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list for a specific property. The specified property may be user-defined.

Note that if this Model is inheriting a bound property, then no event will be fired in response to a change in the inherited property.

If listener is null, no exception is thrown and no action is performed.

Parameters:
propertyName - one of the property names listed above
listener - the PropertyChangeListener to be added
See Also:
removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener), addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)

getAverageCharacterWidthTestString

public String getAverageCharacterWidthTestString()
Returns the string used to compute the average character width. By default it is initialized to "X".
Returns:
the test string used to compute the average character width

getDefaultDialogFont

public Font getDefaultDialogFont()
Lazily creates and returns the dialog font used to compute the dialog base units.
Returns:
the font used to compute the dialog base units

getDialogBaseUnitsX

protected double getDialogBaseUnitsX(Component component)
Returns the cached or computed horizontal dialog base units.
Overrides:
getDialogBaseUnitsX in interface AbstractUnitConverter
Parameters:
component - a Component that provides the font and graphics
Returns:
the horizontal dialog base units

getDialogBaseUnitsY

protected double getDialogBaseUnitsY(Component component)
Returns the cached or computed vertical dialog base units for the given component.
Overrides:
getDialogBaseUnitsY in interface AbstractUnitConverter
Parameters:
component - a Component that provides the font and graphics
Returns:
the vertical dialog base units

getInstance

public static DefaultUnitConverter getInstance()
Lazily instantiates and returns the sole instance.
Returns:
the lazily instantiated sole instance

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list. This method should be used to remove PropertyChangeListeners that were registered for all bound properties of this class.

If listener is null, no exception is thrown and no action is performed.

Parameters:
listener - the PropertyChangeListener to be removed

removePropertyChangeListener

public void removePropertyChangeListener(String propertyName,
                                         PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list for a specific property. This method should be used to remove PropertyChangeListeners that were registered for a specific bound property.

If listener is null, no exception is thrown and no action is performed.

Parameters:
propertyName - a valid property name
listener - the PropertyChangeListener to be removed
See Also:
addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener), removePropertyChangeListener(java.beans.PropertyChangeListener)

setAverageCharacterWidthTestString

public void setAverageCharacterWidthTestString(String newTestString)
Sets a string that will be used to compute the average character width. By default it is initialized to "X". You can provide other test strings, for example:
  • "Xximeee"
  • "ABCEDEFHIJKLMNOPQRSTUVWXYZ"
  • "abcdefghijklmnopqrstuvwxyz"
Parameters:
newTestString - the test string to be used

setDefaultDialogFont

public void setDefaultDialogFont(Font newFont)
Sets a dialog font that will be used to compute the dialog base units.
Parameters:
newFont - the default dialog font to be set

Copyright © 2002-2006 JGoodies Karsten Lentzsch. All Rights Reserved.