com.jgoodies.forms.util

Class DefaultUnitConverter

public final class DefaultUnitConverter extends AbstractUnitConverter

This is the default implementation of the {@link 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: 1.5 $

Author: Karsten Lentzsch

See Also: UnitConverter Size Sizes

Method Summary
voidaddPropertyChangeListener(PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list.
voidaddPropertyChangeListener(String propertyName, PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list for a specific property.
StringgetAverageCharacterWidthTestString()
Returns the string used to compute the average character width.
FontgetDefaultDialogFont()
Returns the dialog font that is used to compute the dialog base units.
protected doublegetDialogBaseUnitsX(Component component)
Returns the cached or computed horizontal dialog base units.
protected doublegetDialogBaseUnitsY(Component component)
Returns the cached or computed vertical dialog base units for the given component.
static DefaultUnitConvertergetInstance()
Lazily instantiates and returns the sole instance.
voidremovePropertyChangeListener(PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list.
voidremovePropertyChangeListener(String propertyName, PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list for a specific property.
voidsetAverageCharacterWidthTestString(String newTestString)
Sets a string that will be used to compute the average character width.
voidsetDefaultDialogFont(Font newFont)
Sets a dialog font that will be used to compute the dialog base units.

Method Detail

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

See Also: removePropertyChangeListener DefaultUnitConverter DefaultUnitConverter

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: DefaultUnitConverter DefaultUnitConverter

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()
Returns the dialog font that is used to compute the dialog base units. If a default dialog font has been set using {@link #setDefaultDialogFont(Font)}, this font will be returned. Otherwise a cached fallback will be lazily created.

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.

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.

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

See Also: addPropertyChangeListener DefaultUnitConverter DefaultUnitConverter

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: DefaultUnitConverter removePropertyChangeListener

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:

Parameters: newTestString the test string to be used

Throws: IllegalArgumentException if the test string is empty NullPointerException if the test string is null

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 © 2002-2007 JGoodies Karsten Lentzsch. All Rights Reserved.