org.eclipse.jface.preference

Class PreferencePage

java.lang.Object

org.eclipse.jface.dialogs.DialogPage

org.eclipse.jface.preference.PreferencePage

All Implemented Interfaces:

IDialogPage, IMessageProvider, IPreferencePage

Direct Known Subclasses:

ActivitiesPreferencePage, ActivityCategoryPreferencePage, FieldEditorPreferencePage, PropertyPage, RepositoryManipulationPage, RootScopePage, TemplatePreferencePage

public abstract class PreferencePage
extends DialogPage
implements IPreferencePage

Abstract base implementation for all preference page implementations.

Subclasses must implement the createContents framework method to supply the page's main control.

Subclasses should extend the doComputeSize framework method to compute the size of the page's control.

Subclasses may override the performOk, performApply, performDefaults, performCancel, and performHelp framework methods to react to the standard button events.

Subclasses may call the noDefaultAndApplyButton framework method before the page's control has been created to suppress the standard Apply and Defaults buttons.

Field Summary

Fields inherited from interface org.eclipse.jface.dialogs.IMessageProvider

ERROR, INFORMATION, NONE, WARNING

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PreferencePage() Creates a new preference page with an empty title and no image.
protected	PreferencePage(String title) Creates a new preference page with the given title and no image.
protected	PreferencePage(String title, ImageDescriptor image) Creates a new abstract preference page with the given title and image.

Method Summary

Modifier and Type	Method and Description
void	applyData(Object data) Applies the given data to this page.
protected void	applyDialogFont(Composite composite) Apply the dialog font to the composite and it's children if it is set.
Point	computeSize() Computes the size for this page's UI control.
protected void	contributeButtons(Composite parent) Contributes additional buttons to the given composite.
protected abstract Control	createContents(Composite parent) Creates and returns the SWT control for the customized body of this preference page under the given parent composite.
void	createControl(Composite parent) The PreferencePage implementation of this IDialogPage method creates a description label and button bar for the page.
protected Label	createDescriptionLabel(Composite parent) Creates and returns an SWT label under the given composite.
protected Composite	createNoteComposite(Font font, Composite composite, String title, String message) Creates a composite with a highlighted Note entry and a message text.
protected Point	doComputeSize() Computes the size needed by this page's UI control.
protected IPreferenceStore	doGetPreferenceStore() Returns the preference store of this preference page.
protected Button	getApplyButton() Returns the Apply button.
IPreferencePageContainer	getContainer() Returns the container of this page.
protected Button	getDefaultsButton() Returns the Restore Defaults button.
IPreferenceStore	getPreferenceStore() Returns the preference store of this preference page.
boolean	isValid() The preference page implementation of an IPreferencePage method returns whether this preference page is valid.
protected void	noDefaultAndApplyButton() Suppresses creation of the standard Default and Apply buttons for this page.
protected void	noDefaultButton() Suppress creation of the standard Default button for this page.
boolean	okToLeave() The PreferencePage implementation of this IPreferencePage method returns true if the page is valid.
protected void	performApply() Performs special processing when this page's Apply button has been pressed.
boolean	performCancel() The preference page implementation of an IPreferencePage method performs special processing when this page's Cancel button has been pressed.
protected void	performDefaults() Performs special processing when this page's Defaults button has been pressed.
void	performHelp() This default implementation of an IDialogPage method does nothing.
boolean	performOk() Notifies that the OK button of this page's container has been pressed.
void	setContainer(IPreferencePageContainer container) Sets or clears the container of this page.
void	setErrorMessage(String newMessage) Sets or clears the error message for this page.
void	setMessage(String newMessage, int newType) Sets the message for this page with an indication of what type of message it is.
void	setPreferenceStore(IPreferenceStore store) Sets the preference store for this preference page.
void	setSize(Point uiSize) Sets the size of this page's UI component.
void	setTitle(String title) The PreferencePage implementation of this IDialogPage method extends the DialogPage implementation to update the preference page container title.
void	setValid(boolean b) Sets whether this page is valid.
String	toString()
protected void	updateApplyButton() Updates the enabled state of the Apply button to reflect whether this page is valid.

Methods inherited from class org.eclipse.jface.dialogs.DialogPage

convertHeightInCharsToPixels, convertHorizontalDLUsToPixels, convertVerticalDLUsToPixels, convertWidthInCharsToPixels, dispose, getControl, getDescription, getDialogFontName, getErrorMessage, getFont, getImage, getMessage, getMessageType, getShell, getTitle, getToolTipText, initializeDialogUnits, isControlCreated, setButtonLayoutData, setControl, setDescription, setImageDescriptor, setMessage, setVisible

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jface.dialogs.IDialogPage

dispose, getControl, getDescription, getErrorMessage, getImage, getMessage, getTitle, setDescription, setImageDescriptor, setVisible

Constructor Detail

PreferencePage

protected PreferencePage()

Creates a new preference page with an empty title and no image.

PreferencePage

protected PreferencePage(String title)

Creates a new preference page with the given title and no image.

Parameters:

title - the title of this preference page

PreferencePage

protected PreferencePage(String title,
                         ImageDescriptor image)

Creates a new abstract preference page with the given title and image.

Parameters:

title - the title of this preference page

image - the image for this preference page, or null if none

Method Detail

computeSize

public Point computeSize()

Computes the size for this page's UI control.

The default implementation of this IPreferencePage method returns the size set by setSize; if no size has been set, but the page has a UI control, the framework method doComputeSize is called to compute the size.

Specified by:

computeSize in interface IPreferencePage

Returns:

the size of the preference page encoded as new Point(width,height), or (0,0) if the page doesn't currently have any UI component

contributeButtons

protected void contributeButtons(Composite parent)

Contributes additional buttons to the given composite.

The default implementation of this framework hook method does nothing. Subclasses should override this method to contribute buttons to this page's button bar. For each button a subclass contributes, it must also increase the parent's grid layout number of columns by one; that is,

 ((GridLayout) parent.getLayout()).numColumns++);
 

Parameters:

parent - the button bar

createContents

protected abstract Control createContents(Composite parent)

Creates and returns the SWT control for the customized body of this preference page under the given parent composite.

This framework method must be implemented by concrete subclasses. Any subclass returning a Composite object whose Layout has default margins (for example, a GridLayout) are expected to set the margins of this Layout to 0 pixels.

Parameters:

parent - the parent composite

Returns:

the new control

createControl

public void createControl(Composite parent)

The PreferencePage implementation of this IDialogPage method creates a description label and button bar for the page. It calls createContents to create the custom contents of the page.

If a subclass that overrides this method creates a Composite that has a layout with default margins (for example, a GridLayout) it is expected to set the margins of this Layout to 0 pixels.

Specified by:

createControl in interface IDialogPage

Parameters:

parent - the parent composite

See Also:

IDialogPage.createControl(Composite)

applyDialogFont

protected void applyDialogFont(Composite composite)

Apply the dialog font to the composite and it's children if it is set. Subclasses may override if they wish to set the font themselves.

Parameters:

composite -

createDescriptionLabel

protected Label createDescriptionLabel(Composite parent)

Creates and returns an SWT label under the given composite.

Parameters:

parent - the parent composite

Returns:

the new label

doComputeSize

protected Point doComputeSize()

Computes the size needed by this page's UI control.

All pages should override this method and set the appropriate sizes of their widgets, and then call super.doComputeSize.

Returns:

the size of the preference page encoded as new Point(width,height)

doGetPreferenceStore

protected IPreferenceStore doGetPreferenceStore()

Returns the preference store of this preference page.

This is a framework hook method for subclasses to return a page-specific preference store. The default implementation returns null.

Returns:

the preference store, or null if none

getContainer

public IPreferencePageContainer getContainer()

Returns the container of this page.

Returns:

the preference page container, or null if this page has yet to be added to a container

getPreferenceStore

public IPreferenceStore getPreferenceStore()

Returns the preference store of this preference page.

Returns:

the preference store , or null if none

isValid

public boolean isValid()

The preference page implementation of an IPreferencePage method returns whether this preference page is valid. Preference pages are considered valid by default; call setValid(false) to make a page invalid.

Specified by:

isValid in interface IPreferencePage

Returns:

true if the page is in a valid state, and false if invalid

See Also:

IPreferencePage.isValid()

noDefaultAndApplyButton

protected void noDefaultAndApplyButton()

Suppresses creation of the standard Default and Apply buttons for this page.

Subclasses wishing a preference page without these buttons should call this framework method before the page's control has been created.

noDefaultButton

protected void noDefaultButton()

Suppress creation of the standard Default button for this page.

Subclasses wishing a preference page with this button should call this framework method before the page's control has been created.

Since:

3.11

okToLeave

public boolean okToLeave()

The PreferencePage implementation of this IPreferencePage method returns true if the page is valid.

Specified by:

okToLeave in interface IPreferencePage

Returns:

false to abort page flipping and the have the current page remain visible, and true to allow the page flip

See Also:

IPreferencePage.okToLeave()

performApply

protected void performApply()

Performs special processing when this page's Apply button has been pressed.

This is a framework hook method for subclasses to do special things when the Apply button has been pressed. The default implementation of this framework method simply calls performOk to simulate the pressing of the page's OK button.

See Also:

performOk(), performCancel()

performCancel

public boolean performCancel()

The preference page implementation of an IPreferencePage method performs special processing when this page's Cancel button has been pressed.

This is a framework hook method for subclasses to do special things when the Cancel button has been pressed. The default implementation of this framework method does nothing and returns true.

Note that UI guidelines on different platforms disagree on whether Cancel should revert changes that have been applied with the Apply button. Windows wants applied changes to persist on Cancel, whereas Mac and GTK consider Apply a preview that should not be saved on Cancel. Eclipse applications typically adhere to the Windows guidelines and just override performOk() and save preferences there.

Specified by:

performCancel in interface IPreferencePage

Returns:

false to abort the container's cancel procedure and true to allow the cancel to happen

See Also:

IPreferencePage.performCancel()

performDefaults

protected void performDefaults()

Performs special processing when this page's Defaults button has been pressed.

This is a framework hook method for subclasses to do special things when the Defaults button has been pressed. Subclasses may override, but should call super.performDefaults.

performOk

public boolean performOk()

Description copied from interface: IPreferencePage

Notifies that the OK button of this page's container has been pressed.

Specified by:

performOk in interface IPreferencePage

Returns:

false to abort the container's OK processing and true to allow the OK to happen

setContainer

public void setContainer(IPreferencePageContainer container)

Description copied from interface: IPreferencePage

Sets or clears the container of this page.

Specified by:

setContainer in interface IPreferencePage

Parameters:

container - the preference page container, or null

setPreferenceStore

public void setPreferenceStore(IPreferenceStore store)

Sets the preference store for this preference page.

If preferenceStore is set to null, getPreferenceStore will invoke doGetPreferenceStore the next time it is called.

Parameters:

store - the preference store, or null

See Also:

getPreferenceStore()

setSize

public void setSize(Point uiSize)

Description copied from interface: IPreferencePage

Sets the size of this page's UI component.

Specified by:

setSize in interface IPreferencePage

Parameters:

uiSize - the size of the preference page encoded as new Point(width,height)

setTitle

public void setTitle(String title)

The PreferencePage implementation of this IDialogPage method extends the DialogPage implementation to update the preference page container title. Subclasses may extend.

Specified by:

setTitle in interface IDialogPage

Overrides:

setTitle in class DialogPage

Parameters:

title - the title of this dialog page, or null if none

See Also:

IDialogPage.setTitle(String)

setValid

public void setValid(boolean b)

Sets whether this page is valid. The enable state of the container buttons and the apply button is updated when a page's valid state changes.

Parameters:

b - the new valid state

toString

public String toString()

Overrides:

toString in class Object

updateApplyButton

protected void updateApplyButton()

Updates the enabled state of the Apply button to reflect whether this page is valid.

createNoteComposite

protected Composite createNoteComposite(Font font,
                                        Composite composite,
                                        String title,
                                        String message)

Creates a composite with a highlighted Note entry and a message text. This is designed to take up the full width of the page.

Parameters:

font - the font to use

composite - the parent composite

title - the title of the note

message - the message for the note

Returns:

the composite for the note

getApplyButton

protected Button getApplyButton()

Returns the Apply button.

Returns:

the Apply button

getDefaultsButton

protected Button getDefaultsButton()

Returns the Restore Defaults button.

Returns:

the Restore Defaults button

performHelp

public void performHelp()

Description copied from class: DialogPage

This default implementation of an IDialogPage method does nothing. Subclasses should override to take some action in response to a help request.

Specified by:

performHelp in interface IDialogPage

Overrides:

performHelp in class DialogPage

applyData

public void applyData(Object data)

Applies the given data to this page.

It is up to the subclasses to specify the contract and the data format. The contract is not guaranteed if the subclass is in an internal package.

Note: The implementation must silently ignore all unknown data.

The default implementation does nothing.

Parameters:

data - the data as specified by the subclass

Since:

3.1

setErrorMessage

public void setErrorMessage(String newMessage)

Description copied from class: DialogPage

Sets or clears the error message for this page.

Overrides:

setErrorMessage in class DialogPage

Parameters:

newMessage - the message, or null to clear the error message

setMessage

public void setMessage(String newMessage,
                       int newType)

Description copied from class: DialogPage

Sets the message for this page with an indication of what type of message it is.

The valid message types are one of NONE, INFORMATION,WARNING, or ERROR.

Note that for backward compatibility, a message of type ERROR is different than an error message (set using setErrorMessage). An error message overrides the current message until the error message is cleared. This method replaces the current message and does not affect the error message.

Overrides:

setMessage in class DialogPage

Parameters:

newMessage - the message, or null to clear the message

newType - the message type