Package org.eclipse.jface.preference

Class StringFieldEditor

java.lang.Object

org.eclipse.jface.preference.FieldEditor

org.eclipse.jface.preference.StringFieldEditor

Direct Known Subclasses:

IntegerFieldEditor, StringButtonFieldEditor

public class StringFieldEditor
extends FieldEditor

A field editor for a string type preference.

This class may be used as is, or subclassed as required.

Field Summary

Fields

Modifier and Type	Field	Description
protected String	oldValue	Old text value.
static int	UNLIMITED	Text limit constant (value -1) indicating unlimited text limit and width.
static int	VALIDATE_ON_FOCUS_LOST	Validation strategy constant (value 1) indicating that the editor should perform validation only when the text widget loses focus.
static int	VALIDATE_ON_KEY_STROKE	Validation strategy constant (value 0) indicating that the editor should perform validation after every key stroke.

Fields inherited from class org.eclipse.jface.preference.FieldEditor

HORIZONTAL_GAP, IS_VALID, VALUE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StringFieldEditor()	Creates a new string field editor
	StringFieldEditor(String name, String labelText, int widthInChars, int heigthInChars, int strategy, Composite parent)	Creates a string field editor.
	StringFieldEditor(String name, String labelText, int width, int strategy, Composite parent)	Creates a string field editor.
	StringFieldEditor(String name, String labelText, int width, Composite parent)	Creates a string field editor.
	StringFieldEditor(String name, String labelText, Composite parent)	Creates a string field editor of unlimited width.

Method Summary

Modifier and Type	Method	Description
protected void	adjustForNumColumns(int numColumns)	Adjusts the horizontal span of this field editor's basic controls.
protected boolean	checkState()	Checks whether the text input field contains a valid value or not.
protected Text	createTextWidget(Composite parent)	Create the text widget.
protected boolean	doCheckState()	Hook for subclasses to do specific state checks.
protected void	doFillIntoGrid(Composite parent, int numColumns)	Fills this field editor's basic controls into the given parent.
protected void	doLoad()	Initializes this field editor with the preference value from the preference store.
protected void	doLoadDefault()	Initializes this field editor with the default preference value from the preference store.
protected void	doStore()	Stores the preference value from this field editor into the preference store.
String	getErrorMessage()	Returns the error message that will be displayed when and if an error occurs.
int	getNumberOfControls()	Returns the number of basic controls this field editor consists of.
String	getStringValue()	Returns the field editor's value.
protected Text	getTextControl()	Returns this field editor's text control.
Text	getTextControl(Composite parent)	Returns this field editor's text control.
boolean	isEmptyStringAllowed()	Returns whether an empty string is a valid value.
boolean	isValid()	Returns whether this field editor contains a valid value.
protected void	refreshValidState()	Refreshes this field editor's valid state after a value change and fires an IS_VALID property change event if warranted.
void	setEmptyStringAllowed(boolean b)	Sets whether the empty string is a valid value or not.
void	setEnabled(boolean enabled, Composite parent)	Set whether or not the controls in the field editor are enabled.
void	setErrorMessage(String message)	Sets the error message that will be displayed when and if an error occurs.
void	setFocus()	Sets the focus to this field editor.
void	setStringValue(String value)	Sets this field editor's value.
void	setTextLimit(int limit)	Sets this text field's text limit.
void	setValidateStrategy(int value)	Sets the strategy for validating the text.
void	showErrorMessage()	Shows the error message set via setErrorMessage.
protected void	valueChanged()	Informs this field editor's listener, if it has one, about a change to the value (VALUE property) provided that the old and new values are different.

Methods inherited from class org.eclipse.jface.preference.FieldEditor

applyFont, checkParent, clearErrorMessage, clearMessage, convertHorizontalDLUsToPixels, convertVerticalDLUsToPixels, createControl, dispose, fillIntoGrid, fireStateChanged, fireValueChanged, getFieldEditorFontName, getLabelControl, getLabelControl, getLabelText, getPage, getPreferenceName, getPreferencePage, getPreferenceStore, init, load, loadDefault, presentsDefaultValue, setButtonLayoutData, setLabelText, setPage, setPreferenceName, setPreferencePage, setPreferenceStore, setPresentsDefaultValue, setPropertyChangeListener, showErrorMessage, showMessage, store

Methods inherited from class java.lang.Object

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

Field Detail

VALIDATE_ON_KEY_STROKE

public static final int VALIDATE_ON_KEY_STROKE

Validation strategy constant (value 0) indicating that the editor should perform validation after every key stroke.

See Also:

setValidateStrategy(int), Constant Field Values

VALIDATE_ON_FOCUS_LOST

public static final int VALIDATE_ON_FOCUS_LOST

Validation strategy constant (value 1) indicating that the editor should perform validation only when the text widget loses focus.

See Also:

setValidateStrategy(int), Constant Field Values

UNLIMITED

public static int UNLIMITED

Text limit constant (value -1) indicating unlimited text limit and width.

oldValue

protected String oldValue

Old text value.

Since:

3.4 this field is protected.

Constructor Detail

StringFieldEditor

protected StringFieldEditor()

Creates a new string field editor

StringFieldEditor

public StringFieldEditor(String name,
                         String labelText,
                         int widthInChars,
                         int heigthInChars,
                         int strategy,
                         Composite parent)

Creates a string field editor. Use the method setTextLimit to limit the text.

Parameters:

name - the name of the preference this field editor works on

labelText - the label text of the field editor

widthInChars - the width of the text input field in characters, or UNLIMITED for no limit

heigthInChars - the height of the text input field in characters.

strategy - either VALIDATE_ON_KEY_STROKE to perform on the fly checking (the default), or VALIDATE_ON_FOCUS_LOST to perform validation only after the text has been typed in

parent - the parent of the field editor's control

Since:

3.17

StringFieldEditor

public StringFieldEditor(String name,
                         String labelText,
                         int width,
                         int strategy,
                         Composite parent)

Creates a string field editor. Use the method setTextLimit to limit the text.

Parameters:

name - the name of the preference this field editor works on

labelText - the label text of the field editor

width - the width of the text input field in characters, or UNLIMITED for no limit

strategy - either VALIDATE_ON_KEY_STROKE to perform on the fly checking (the default), or VALIDATE_ON_FOCUS_LOST to perform validation only after the text has been typed in

parent - the parent of the field editor's control

Since:

2.0

StringFieldEditor

public StringFieldEditor(String name,
                         String labelText,
                         int width,
                         Composite parent)

Creates a string field editor. Use the method setTextLimit to limit the text.

Parameters:

name - the name of the preference this field editor works on

labelText - the label text of the field editor

width - the width of the text input field in characters, or UNLIMITED for no limit

parent - the parent of the field editor's control

StringFieldEditor

public StringFieldEditor(String name,
                         String labelText,
                         Composite parent)

Creates a string field editor of unlimited width. Use the method setTextLimit to limit the text.

Parameters:

name - the name of the preference this field editor works on

labelText - the label text of the field editor

parent - the parent of the field editor's control

Method Detail

adjustForNumColumns

protected void adjustForNumColumns(int numColumns)

Description copied from class: FieldEditor

Adjusts the horizontal span of this field editor's basic controls.

Subclasses must implement this method to adjust the horizontal span of controls so they appear correct in the given number of columns.

The number of columns will always be equal to or greater than the value returned by this editor's getNumberOfControls method.

Specified by:

adjustForNumColumns in class FieldEditor

Parameters:

numColumns - the number of columns

checkState

protected boolean checkState()

Checks whether the text input field contains a valid value or not.

Returns:

true if the field value is valid, and false if invalid

doCheckState

protected boolean doCheckState()

Hook for subclasses to do specific state checks.

The default implementation of this framework method does nothing and returns true. Subclasses should override this method to specific state checks.

Returns:

true if the field value is valid, and false if invalid

doFillIntoGrid

protected void doFillIntoGrid(Composite parent,
                              int numColumns)

Fills this field editor's basic controls into the given parent.

The string field implementation of this FieldEditor framework method contributes the text field. Subclasses may override but must call super.doFillIntoGrid.

Specified by:

doFillIntoGrid in class FieldEditor

Parameters:

parent - the composite used as a parent for the basic controls; the parent's layout must be a GridLayout

numColumns - the number of columns

doLoad

protected void doLoad()

Description copied from class: FieldEditor

Initializes this field editor with the preference value from the preference store.

Subclasses must implement this method to properly initialize the field editor.

Specified by:

doLoad in class FieldEditor

doLoadDefault

protected void doLoadDefault()

Description copied from class: FieldEditor

Initializes this field editor with the default preference value from the preference store.

Subclasses must implement this method to properly initialize the field editor.

Specified by:

doLoadDefault in class FieldEditor

doStore

protected void doStore()

Description copied from class: FieldEditor

Stores the preference value from this field editor into the preference store.

Subclasses must implement this method to save the entered value into the preference store.

Specified by:

doStore in class FieldEditor

getErrorMessage

public String getErrorMessage()

Returns the error message that will be displayed when and if an error occurs.

Returns:

the error message, or null if none

getNumberOfControls

public int getNumberOfControls()

Description copied from class: FieldEditor

Returns the number of basic controls this field editor consists of.

Specified by:

getNumberOfControls in class FieldEditor

Returns:

the number of controls

getStringValue

public String getStringValue()

Returns the field editor's value.

Returns:

the current value

getTextControl

protected Text getTextControl()

Returns this field editor's text control.

Returns:

the text control, or null if no text field is created yet

getTextControl

public Text getTextControl(Composite parent)

Returns this field editor's text control.

The control is created if it does not yet exist

Parameters:

parent - the parent

Returns:

the text control

createTextWidget

protected Text createTextWidget(Composite parent)

Create the text widget.

Parameters:

parent - the parent composite

Returns:

The widget

Since:

3.17

isEmptyStringAllowed

public boolean isEmptyStringAllowed()

Returns whether an empty string is a valid value.

Returns:

true if an empty string is a valid value, and false if an empty string is invalid

See Also:

setEmptyStringAllowed(boolean)

isValid

public boolean isValid()

Description copied from class: FieldEditor

Returns whether this field editor contains a valid value.

The default implementation of this framework method returns true. Subclasses wishing to perform validation should override both this method and refreshValidState.

Overrides:

isValid in class FieldEditor

Returns:

true if the field value is valid, and false if invalid

See Also:

FieldEditor.refreshValidState()

refreshValidState

protected void refreshValidState()

Description copied from class: FieldEditor

Refreshes this field editor's valid state after a value change and fires an IS_VALID property change event if warranted.

The default implementation of this framework method does nothing. Subclasses wishing to perform validation should override both this method and isValid.

Overrides:

refreshValidState in class FieldEditor

See Also:

FieldEditor.isValid()

setEmptyStringAllowed

public void setEmptyStringAllowed(boolean b)

Sets whether the empty string is a valid value or not.

Parameters:

b - true if the empty string is allowed, and false if it is considered invalid

setErrorMessage

public void setErrorMessage(String message)

Sets the error message that will be displayed when and if an error occurs.

Parameters:

message - the error message

setFocus

public void setFocus()

Description copied from class: FieldEditor

Sets the focus to this field editor.

The default implementation of this framework method does nothing. Subclasses may reimplement.

Overrides:

setFocus in class FieldEditor

setStringValue

public void setStringValue(String value)

Sets this field editor's value.

Parameters:

value - the new value, or null meaning the empty string

setTextLimit

public void setTextLimit(int limit)

Sets this text field's text limit.

Parameters:

limit - the limit on the number of character in the text input field, or UNLIMITED for no limit

setValidateStrategy

public void setValidateStrategy(int value)

Sets the strategy for validating the text.

Calling this method has no effect after createPartControl is called. Thus this method is really only useful for subclasses to call in their constructor. However, it has public visibility for backward compatibility.

Parameters:

value - either VALIDATE_ON_KEY_STROKE to perform on the fly checking (the default), or VALIDATE_ON_FOCUS_LOST to perform validation only after the text has been typed in

showErrorMessage

public void showErrorMessage()

Shows the error message set via setErrorMessage.

valueChanged

protected void valueChanged()

Informs this field editor's listener, if it has one, about a change to the value (VALUE property) provided that the old and new values are different.

This hook is not called when the text is initialized (or reset to the default value) from the preference store.

setEnabled

public void setEnabled(boolean enabled,
                       Composite parent)

Description copied from class: FieldEditor

Set whether or not the controls in the field editor are enabled.

Overrides:

setEnabled in class FieldEditor

Parameters:

enabled - The enabled state.

parent - The parent of the controls in the group. Used to create the controls if required.