package org.eclipse.jface.preference; | |
/* | |
* (c) Copyright IBM Corp. 2000, 2001. | |
* All Rights Reserved. | |
*/ | |
import org.eclipse.swt.*; | |
import org.eclipse.swt.events.*; | |
import org.eclipse.swt.graphics.*; | |
import org.eclipse.swt.layout.*; | |
import org.eclipse.swt.widgets.*; | |
import org.eclipse.jface.util.*; | |
import org.eclipse.jface.resource.*; | |
/** | |
* Abstract base class for all field editors. | |
* <p> | |
* A field editor presents the value of a preference to the end | |
* user. The value is loaded from a preference store; if | |
* modified by the end user, the value is validated and eventually | |
* stored back to the preference store. A field editor reports | |
* an event when the value, or the validity of the value, changes. | |
* </p> | |
* <p> | |
* Field editors should be used in conjunction with a field | |
* editor preference page (<code>FieldEditorPreferencePage</code>) | |
* which coordinates everything and provides the message line | |
* which display messages emanating from the editor. | |
* </p> | |
* <p> | |
* This package contains ready-to-use field editors for various | |
* types of preferences: | |
* <ul> | |
* <li><code>BooleanFieldEditor</code> - booleans</li> | |
* <li><code>IntegerFieldEditor</code> - integers</li> | |
* <li><code>StringFieldEditor</code> - text strings</li> | |
* <li><code>RadioGroupFieldEditor</code> - enumerations</li> | |
* <li><code>ColorFieldEditor</code> - RGB colors</li> | |
* <li><code>FontFieldEditor</code> - fonts</li> | |
* <li><code>DirectoryFieldEditor</code> - directories</li> | |
* <li><code>FileFieldEditor</code> - files</li> | |
* <li><code>PathEditor</code> - paths</li> | |
* </ul> | |
* </p> | |
*/ | |
public abstract class FieldEditor { | |
/** | |
* Property name constant (value <code>"field_editor_is_valid"</code>) | |
* to signal a change in the validity of the value of this field editor. | |
*/ | |
public static final String IS_VALID = "field_editor_is_valid";//$NON-NLS-1$ | |
/** | |
* Property name constant (value <code>"field_editor_value"</code>) | |
* to signal a change in the value of this field editor. | |
*/ | |
public static final String VALUE = "field_editor_value";//$NON-NLS-1$ | |
/** | |
* Gap between label and control. | |
*/ | |
protected static final int HORIZONTAL_GAP = 8; | |
/** | |
* The preference store, or <code>null</code> if none. | |
*/ | |
private IPreferenceStore preferenceStore = null; | |
/** | |
* The name of the preference displayed in this field editor. | |
*/ | |
private String preferenceName; | |
/** | |
* Indicates whether the default value is currently displayed, | |
* initially <code>false</code>. | |
*/ | |
private boolean isDefaultPresented = false; | |
/** | |
* The label's text. | |
*/ | |
private String labelText; | |
/** | |
* The label control. | |
*/ | |
private Label label; | |
/** | |
* Listener, or <code>null</code> if none | |
*/ | |
private IPropertyChangeListener propertyChangeListener; | |
/** | |
* The page containing this field editor | |
*/ | |
private PreferencePage page; | |
/** | |
* Creates a new field editor. | |
*/ | |
protected FieldEditor() { | |
} | |
/** | |
* Creates a new field editor. | |
* | |
* @param name the name of the preference this field editor works on | |
* @param labelText the label text of the field editor | |
* @param parent the parent of the field editor's control | |
*/ | |
protected FieldEditor(String name, String labelText, Composite parent) { | |
init(name, labelText); | |
createControl(parent); | |
} | |
/** | |
* Adjusts the horizontal span of this field editor's basic controls | |
* <p> | |
* Subclasses must implement this method to adjust the horizontal span | |
* of controls so they appear correct in the given number of columns. | |
* </p> | |
* <p> | |
* The number of columns will always be equal to or greater than the | |
* value returned by this editor's <code>getNumberOfControls</code> method. | |
* | |
* @param numColumns the number of columns | |
*/ | |
protected abstract void adjustForNumColumns(int numColumns); | |
/** | |
* Applies a font. | |
* <p> | |
* The default implementation of this framework method | |
* does nothing. Subclasses should override this method | |
* if they want to change the font of the SWT control to | |
* a value different than the standard dialog font. | |
* </p> | |
*/ | |
protected void applyFont() { | |
} | |
/** | |
* Checks if the given parent is the current parent of the | |
* supplied control; throws an (unchecked) exception if they | |
* are not correctly related. | |
* | |
* @param control the control | |
* @param parent the parent control | |
*/ | |
protected void checkParent(Control control, Composite parent) { | |
Assert.isTrue(control.getParent() == parent, "Different parents");//$NON-NLS-1$ | |
} | |
/** | |
* Clears the error message from the message line. | |
*/ | |
protected void clearErrorMessage() { | |
if (page != null) | |
page.setErrorMessage(null); | |
} | |
/** | |
* Clears the normal message from the message line. | |
*/ | |
protected void clearMessage() { | |
if (page != null) | |
page.setMessage(null); | |
} | |
/** | |
* Returns the number of pixels corresponding to the | |
* given number of horizontal dialog units. | |
* <p> | |
* Clients may call this framework method, but should not override it. | |
* </p> | |
* | |
* @param control the control being sized | |
* @param dlus the number of horizontal dialog units | |
* @return the number of pixels | |
*/ | |
protected int convertHorizontalDLUsToPixels(Control control, int dlus) { | |
GC gc= new GC(control); | |
gc.setFont(control.getFont()); | |
int averageWidth= gc.getFontMetrics().getAverageCharWidth(); | |
gc.dispose(); | |
double horizontalDialogUnitSize = averageWidth * 0.25; | |
return (int)Math.round(dlus * horizontalDialogUnitSize); | |
} | |
/** | |
* Returns the number of pixels corresponding to the | |
* given number of vertical dialog units. | |
* <p> | |
* Clients may call this framework method, but should not override it. | |
* </p> | |
* | |
* @param control the control being sized | |
* @param dlus the number of vertical dialog units | |
* @return the number of pixels | |
*/ | |
protected int convertVerticalDLUsToPixels(Control control, int dlus) { | |
GC gc= new GC(control); | |
gc.setFont(control.getFont()); | |
int height = gc.getFontMetrics().getHeight(); | |
gc.dispose(); | |
double verticalDialogUnitSize = height * 0.125; | |
return (int)Math.round(dlus * verticalDialogUnitSize); | |
} | |
/** | |
* Creates this field editor's main control containing all of its | |
* basic controls. | |
* | |
* @param parent the parent control | |
*/ | |
protected void createControl(Composite parent) { | |
GridLayout layout = new GridLayout(); | |
layout.numColumns = getNumberOfControls(); | |
layout.marginWidth = 0; | |
layout.marginHeight = 0; | |
layout.horizontalSpacing = HORIZONTAL_GAP; | |
parent.setLayout(layout); | |
doFillIntoGrid(parent, layout.numColumns); | |
} | |
/** | |
* Disposes the SWT resources used by this field editor. | |
*/ | |
public void dispose() { | |
// nothing to dispose | |
} | |
/** | |
* Fills this field editor's basic controls into the given parent. | |
* <p> | |
* Subclasses must implement this method to create the controls | |
* for this field editor. | |
* </p> | |
* | |
* @param parent the composite used as a parent for the basic controls; | |
* the parent's layout must be a <code>GridLayout</code> | |
* @param numColumns the number of columns | |
*/ | |
protected abstract void doFillIntoGrid(Composite parent, int numColumns); | |
/** | |
* Initializes this field editor with the preference value from | |
* the preference store. | |
* <p> | |
* Subclasses must implement this method to properly initialize | |
* the field editor. | |
* </p> | |
*/ | |
protected abstract void doLoad(); | |
/** | |
* Initializes this field editor with the default preference value from | |
* the preference store. | |
* <p> | |
* Subclasses must implement this method to properly initialize | |
* the field editor. | |
* </p> | |
*/ | |
protected abstract void doLoadDefault(); | |
/** | |
* Stores the preference value from this field editor into | |
* the preference store. | |
* <p> | |
* Subclasses must implement this method to save the entered value | |
* into the preference store. | |
* </p> | |
*/ | |
protected abstract void doStore(); | |
/** | |
* Fills this field editor's basic controls into the given parent. | |
* | |
* @param parent the composite used as a parent for the basic controls; | |
* the parent's layout must be a <code>GridLayout</code> | |
* @param numColumns the number of columns | |
*/ | |
public void fillIntoGrid(Composite parent, int numColumns) { | |
Assert.isTrue(numColumns >= getNumberOfControls()); | |
Assert.isTrue(parent.getLayout() instanceof GridLayout); | |
doFillIntoGrid(parent, numColumns); | |
} | |
/** | |
* Informs this field editor's listener, if it has one, about a change to | |
* one of this field editor's boolean-valued properties. Does nothing | |
* if the old and new values are the same. | |
* | |
* @param property the field editor property name, | |
* such as <code>VALUE</code> or <code>IS_VALID</code> | |
* @param oldValue the old value | |
* @param newValue the new value | |
*/ | |
protected void fireStateChanged(String property, boolean oldValue, boolean newValue) { | |
if (oldValue == newValue) | |
return; | |
fireValueChanged(property, new Boolean(oldValue), new Boolean(newValue)); | |
} | |
/** | |
* Informs this field editor's listener, if it has one, about a change to | |
* one of this field editor's properties. | |
* | |
* @param property the field editor property name, | |
* such as <code>VALUE</code> or <code>IS_VALID</code> | |
* @param oldValue the old value object, or <code>null</code> | |
* @param newValue the new value, or <code>null</code> | |
*/ | |
protected void fireValueChanged(String property, Object oldValue, Object newValue) { | |
if (propertyChangeListener == null) | |
return; | |
propertyChangeListener.propertyChange(new PropertyChangeEvent(this, property, oldValue, newValue)); | |
} | |
/** | |
* Returns the symbolic font name used by this field editor. | |
* | |
* @return the symbolic font name | |
*/ | |
public String getFieldEditorFontName() { | |
return JFaceResources.DIALOG_FONT; | |
} | |
/** | |
* Returns the label control. | |
* | |
* @return the label control, or <code>null</code> | |
* if no label control has been created | |
*/ | |
protected Label getLabelControl() { | |
return label; | |
} | |
/** | |
* Returns this field editor's label component. | |
* <p> | |
* The label is created if it does not already exist | |
* </p> | |
* | |
* @param parent the parent | |
* @return the label control | |
*/ | |
public Label getLabelControl(Composite parent) { | |
if (label == null) { | |
label = new Label(parent, SWT.LEFT); | |
String text = getLabelText(); | |
if (text != null) | |
label.setText(text); | |
label.addDisposeListener(new DisposeListener() { | |
public void widgetDisposed(DisposeEvent event) { | |
label = null; | |
} | |
}); | |
} else { | |
checkParent(label, parent); | |
} | |
return label; | |
} | |
/** | |
* Returns this field editor's label text. | |
* | |
* @return the label text | |
*/ | |
public String getLabelText() { | |
return labelText; | |
} | |
/** | |
* Returns the number of basic controls this field editor consists of. | |
* | |
* @return the number of controls | |
*/ | |
public abstract int getNumberOfControls(); | |
/** | |
* Returns the name of the preference this field editor operates on. | |
* | |
* @return the name of the preference | |
*/ | |
public String getPreferenceName() { | |
return preferenceName; | |
} | |
/** | |
* Returns the preference page in which this field editor | |
* appears. | |
* | |
* @returns the preference page, or <code>null</code> if none | |
*/ | |
protected PreferencePage getPreferencePage() { | |
return page; | |
} | |
/** | |
* Returns the preference store used by this field editor. | |
* | |
* @return the preference store, or <code>null</code> if none | |
* @see #setPreferenceStore | |
*/ | |
public IPreferenceStore getPreferenceStore() { | |
return preferenceStore; | |
} | |
/** | |
* Initialize the field editor with the given preference name and label. | |
* | |
* @param name the name of the preference this field editor works on | |
* @param labelText the label text of the field editor | |
*/ | |
protected void init(String name, String labelText) { | |
Assert.isNotNull(name); | |
Assert.isNotNull(labelText); | |
preferenceName = name; | |
this.labelText = labelText; | |
} | |
/** | |
* Returns whether this field editor contains a valid value. | |
* <p> | |
* The default implementation of this framework method | |
* returns <code>true</code>. Subclasses wishing to perform | |
* validation should override both this method and | |
* <code>refreshValidState</code>. | |
* </p> | |
* | |
* @return <code>true</code> if the field value is valid, | |
* and <code>false</code> if invalid | |
* @see #refreshValidState | |
*/ | |
public boolean isValid() { | |
return true; | |
} | |
/** | |
* Initializes this field editor with the preference value from | |
* the preference store. | |
*/ | |
public void load() { | |
if (preferenceStore != null) { | |
isDefaultPresented = false; | |
doLoad(); | |
refreshValidState(); | |
} | |
} | |
/** | |
* Initializes this field editor with the default preference value | |
* from the preference store. | |
*/ | |
public void loadDefault() { | |
if (preferenceStore != null) { | |
isDefaultPresented = true; | |
doLoadDefault(); | |
refreshValidState(); | |
} | |
} | |
/** | |
* Returns whether this field editor currently presents the | |
* default value for its preference. | |
* | |
* @return <code>true</code> if the default value is presented, | |
* and <code>false</code> otherwise | |
*/ | |
public boolean presentsDefaultValue() { | |
return isDefaultPresented; | |
} | |
/** | |
* Refreshes this field editor's valid state after a value change | |
* and fires an <code>IS_VALID</code> property change event if | |
* warranted. | |
* <p> | |
* The default implementation of this framework method does | |
* nothing. Subclasses wishing to perform validation should override | |
* both this method and <code>isValid</code>. | |
* </p> | |
* | |
* @see #isValid | |
*/ | |
protected void refreshValidState() { | |
} | |
/** | |
* Sets the focus to this field editor. | |
* <p> | |
* The default implementation of this framework method | |
* does nothing. Subclasses may reimplement. | |
* </p> | |
*/ | |
public void setFocus() { | |
// do nothing; | |
} | |
/** | |
* Sets this field editor's label text. | |
* The label is typically presented to the left of the entry field. | |
* | |
* @param text the label text | |
*/ | |
public void setLabelText(String text) { | |
Assert.isNotNull(text); | |
labelText = text; | |
if (label != null) | |
label.setText(text); | |
} | |
/** | |
* Sets the name of the preference this field editor operates on. | |
* <p> | |
* The ability to change this allows the same field editor object | |
* to be reused for different preferences. | |
* </p> | |
* <p> | |
* For example: <p> | |
* <pre> | |
* ... | |
* editor.setPreferenceName("font"); | |
* editor.load(); | |
* </pre> | |
* </p> | |
* | |
* @param name the name of the preference | |
*/ | |
public void setPreferenceName(String name) { | |
preferenceName = name; | |
} | |
/** | |
* Sets the preference page in which this field editor | |
* appears. | |
* | |
* @param preferencePage the preference page, or <code>null</code> if none | |
*/ | |
public void setPreferencePage(PreferencePage preferencePage) { | |
page = preferencePage; | |
} | |
/** | |
* Sets the preference store used by this field editor. | |
* | |
* @param store the preference store, or <code>null</code> if none | |
* @see #getPreferenceStore | |
*/ | |
public void setPreferenceStore(IPreferenceStore store) { | |
preferenceStore = store; | |
} | |
/** | |
* Sets whether this field editor is presenting the default value. | |
* | |
* @return <code>true</code> if the default value is being presented, | |
* and <code>false</code> otherwise | |
*/ | |
protected void setPresentsDefaultValue(boolean b) { | |
isDefaultPresented = b; | |
} | |
/** | |
* Sets or removes the property change listener for this field editor. | |
* <p> | |
* Note that field editors can support only a single listener. | |
* </p> | |
* | |
* @param listener a property change listener, or <code>null</code> | |
* to remove | |
*/ | |
public void setPropertyChangeListener(IPropertyChangeListener listener) { | |
propertyChangeListener = listener; | |
} | |
/** | |
* Shows the given error message in the page for this | |
* field editor if it has one. | |
* | |
* @param msg the error message | |
*/ | |
protected void showErrorMessage(String msg) { | |
if (page != null) | |
page.setErrorMessage(msg); | |
} | |
/** | |
* Shows the given message in the page for this | |
* field editor if it has one. | |
* | |
* @param msg the message | |
*/ | |
protected void showMessage(String msg) { | |
if (page != null) | |
page.setErrorMessage(msg); | |
} | |
/** | |
* Stores this field editor's value back into the preference store. | |
*/ | |
public void store() { | |
if (preferenceStore == null) | |
return; | |
if (isDefaultPresented) { | |
preferenceStore.setToDefault(preferenceName); | |
} else { | |
doStore(); | |
} | |
} | |
} |