com.jgoodies.forms.util

Class DefaultUnitConverter

java.lang.Object

com.jgoodies.forms.util.AbstractUnitConverter

com.jgoodies.forms.util.DefaultUnitConverter

All 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 custom computation. More information how to use dialog units in screen design can be found in Microsoft's Design Specifications and Guidelines.

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

Version:

$Revision: 1.23 $

Author:

Karsten Lentzsch

See Also:

UnitConverter, Size, Sizes

Field Summary

Fields

Modifier and Type	Field and Description
static String	BALANCED_AVERAGE_CHARACTER_TEST_STRING
static String	MODERN_AVERAGE_CHARACTER_TEST_STRING
static String	PROPERTY_AVERAGE_CHARACTER_WIDTH_TEST_STRING
static String	PROPERTY_DEFAULT_DIALOG_FONT

Method Summary

Methods

Modifier and Type	Method and Description
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() Returns the dialog font that is 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, getScreenResolution, inchAsPixel, inchAsPixel, millimeterAsPixel, millimeterAsPixel, pointAsPixel, pointAsPixel

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_AVERAGE_CHARACTER_WIDTH_TEST_STRING

public static final String PROPERTY_AVERAGE_CHARACTER_WIDTH_TEST_STRING

See Also:

Constant Field Values

PROPERTY_DEFAULT_DIALOG_FONT

public static final String PROPERTY_DEFAULT_DIALOG_FONT

See Also:

Constant Field Values

MODERN_AVERAGE_CHARACTER_TEST_STRING

public static final String MODERN_AVERAGE_CHARACTER_TEST_STRING

Since:

1.4

See Also:

Constant Field Values

BALANCED_AVERAGE_CHARACTER_TEST_STRING

public static final String BALANCED_AVERAGE_CHARACTER_TEST_STRING

Since:

1.4

See Also:

Constant Field Values

Method Detail

getInstance

public static DefaultUnitConverter getInstance()

Lazily instantiates and returns the sole instance.

Returns:

the lazily instantiated sole instance

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

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

Throws:

NullPointerException - if newTestString is null

IllegalArgumentException - if newTestString is empty or whitespace

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 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

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

getDialogBaseUnitsX

protected double getDialogBaseUnitsX(Component component)

Returns the cached or computed horizontal dialog base units.

Specified by:

getDialogBaseUnitsX in class 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.

Specified by:

getDialogBaseUnitsY in class AbstractUnitConverter

Parameters:

component - a Component that provides the font and graphics

Returns:

the vertical dialog base units

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(PropertyChangeListener), removePropertyChangeListener(String, PropertyChangeListener), addPropertyChangeListener(String, PropertyChangeListener)

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(PropertyChangeListener), addPropertyChangeListener(String, PropertyChangeListener), removePropertyChangeListener(String, PropertyChangeListener)

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)

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)