package org.eclipse.jface.preference; | |
/* | |
* (c) Copyright IBM Corp. 2000, 2001. | |
* All Rights Reserved. | |
*/ | |
import org.eclipse.jface.resource.JFaceResources; | |
import org.eclipse.jface.util.Assert; | |
import org.eclipse.swt.*; | |
import org.eclipse.swt.events.*; | |
import org.eclipse.swt.graphics.*; | |
import org.eclipse.swt.layout.*; | |
import org.eclipse.swt.widgets.*; | |
/** | |
* A field editor for a string type preference. | |
* <p> | |
* This class may be used as is, or subclassed as required. | |
* </p> | |
*/ | |
public class StringFieldEditor extends FieldEditor { | |
/** | |
* Validation strategy constant (value <code>0</code>) indicating that | |
* the editor should perform validation after every key stroke. | |
* | |
* @see #setValidateStrategy | |
*/ | |
public static final int VALIDATE_ON_KEY_STROKE = 0; | |
/** | |
* Validation strategy constant (value <code>1</code>) indicating that | |
* the editor should perform validation only when the text widget | |
* loses focus. | |
* | |
* @see #setValidateStrategy | |
*/ | |
public static final int VALIDATE_ON_FOCUS_LOST = 1; | |
/** | |
* Text limit constant (value <code>-1</code>) indicating unlimited | |
* text limit and width. | |
*/ | |
public static int UNLIMITED = -1; | |
/** | |
* Cached valid state. | |
*/ | |
private boolean isValid; | |
/** | |
* Old text value. | |
*/ | |
private String oldValue; | |
/** | |
* The text field, or <code>null</code> if none. | |
*/ | |
private Text textField; | |
/** | |
* Width of text field in characters; initially unlimited. | |
*/ | |
private int widthInChars = UNLIMITED; | |
/** | |
* Text limit of text field in characters; initially unlimited. | |
*/ | |
private int textLimit = UNLIMITED; | |
/** | |
* The error message, or <code>null</code> if none. | |
*/ | |
private String errorMessage; | |
/** | |
* Indicates whether the empty string is legal; | |
* <code>true</code> by default. | |
*/ | |
private boolean emptyStringAllowed = true; | |
/** | |
* The validation strategy; | |
* <code>VALIDATE_ON_KEY_STROKE</code> by default. | |
*/ | |
private int validateStrategy= VALIDATE_ON_KEY_STROKE; | |
/** | |
* Creates a new string field editor | |
*/ | |
protected StringFieldEditor() { | |
} | |
/** | |
* Creates a string field editor. | |
* Use the method <code>setTextLimit</code> to limit the text. | |
* | |
* @param name the name of the preference this field editor works on | |
* @param labelText the label text of the field editor | |
* @param width the width of the text input field in characters, | |
* or <code>UNLIMITED</code> for no limit | |
* @param parent the parent of the field editor's control | |
*/ | |
public StringFieldEditor(String name, String labelText, int width, Composite parent) { | |
init(name, labelText); | |
widthInChars = width; | |
isValid = false; | |
errorMessage = JFaceResources.getString("StringFieldEditor.errorMessage");//$NON-NLS-1$ | |
createControl(parent); | |
} | |
/** | |
* Creates a string field editor of unlimited width. | |
* Use the method <code>setTextLimit</code> to limit the text. | |
* | |
* @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 | |
*/ | |
public StringFieldEditor(String name, String labelText, Composite parent) { | |
this(name, labelText, UNLIMITED, parent); | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
protected void adjustForNumColumns(int numColumns) { | |
GridData gd = (GridData)textField.getLayoutData(); | |
gd.horizontalSpan = numColumns - 1; | |
// We only grab excess space if we have to | |
// If another field editor has more columns then | |
// we assume it is setting the width. | |
gd.grabExcessHorizontalSpace = gd.horizontalSpan == 1; | |
} | |
/** | |
* Checks whether the text input field contains a valid value or not. | |
* | |
* @return <code>true</code> if the field value is valid, | |
* and <code>false</code> if invalid | |
*/ | |
protected boolean checkState() { | |
boolean result = false; | |
if (emptyStringAllowed) | |
result = true; | |
if (textField == null) | |
result = false; | |
String txt = textField.getText(); | |
if (txt == null) | |
result = false; | |
result = (txt.trim().length() > 0) || emptyStringAllowed; | |
// call hook for subclasses | |
result = result && doCheckState(); | |
if (result) | |
clearErrorMessage(); | |
else | |
showErrorMessage(errorMessage); | |
return result; | |
} | |
/** | |
* Hook for subclasses to do specific state checks. | |
* <p> | |
* The default implementation of this framework method does | |
* nothing and returns <code>true</code>. Subclasses should | |
* override this method to specific state checks. | |
* </p> | |
* | |
* @return <code>true</code> if the field value is valid, | |
* and <code>false</code> if invalid | |
*/ | |
protected boolean doCheckState() { | |
return true; | |
} | |
/** | |
* Fills this field editor's basic controls into the given parent. | |
* <p> | |
* The string field implementation of this <code>FieldEditor</code> | |
* framework method contributes the text field. Subclasses may override | |
* but must call <code>super.doFillIntoGrid</code>. | |
* </p> | |
*/ | |
protected void doFillIntoGrid(Composite parent, int numColumns) { | |
getLabelControl(parent); | |
textField = getTextControl(parent); | |
GridData gd = new GridData(); | |
gd.horizontalSpan = numColumns - 1; | |
if (widthInChars != UNLIMITED) { | |
GC gc = new GC(textField); | |
try { | |
Point extent = gc.textExtent("X");//$NON-NLS-1$ | |
gd.widthHint = widthInChars * extent.x; | |
} finally { | |
gc.dispose(); | |
} | |
} else { | |
gd.horizontalAlignment = gd.FILL; | |
gd.grabExcessHorizontalSpace = true; | |
} | |
textField.setLayoutData(gd); | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
protected void doLoad() { | |
if (textField != null) { | |
String value = getPreferenceStore().getString(getPreferenceName()); | |
textField.setText(value); | |
oldValue = value; | |
} | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
protected void doLoadDefault() { | |
if (textField != null) { | |
String value = getPreferenceStore().getDefaultString(getPreferenceName()); | |
textField.setText(value); | |
} | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
protected void doStore() { | |
getPreferenceStore().setValue(getPreferenceName(), textField.getText()); | |
} | |
/** | |
* Returns the error message that will be displayed when and if | |
* an error occurs. | |
* | |
* @return the error message, or <code>null</code> if none | |
*/ | |
public String getErrorMessage() { | |
return errorMessage; | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
public int getNumberOfControls() { | |
return 2; | |
} | |
/** | |
* Returns the field editor's value. | |
* | |
* @return the current value | |
*/ | |
public String getStringValue() { | |
if (textField != null) | |
return textField.getText(); | |
else | |
return getPreferenceStore().getString(getPreferenceName()); | |
} | |
/** | |
* Returns this field editor's text control. | |
* | |
* @param parent the parent | |
* @return the text control, or <code>null</code> if no | |
* text field is created yet | |
*/ | |
protected Text getTextControl() { | |
return textField; | |
} | |
/** | |
* Returns this field editor's text control. | |
* <p> | |
* The control is created if it does not yet exist | |
* </p> | |
* | |
* @param parent the parent | |
* @return the text control | |
*/ | |
public Text getTextControl(Composite parent) { | |
if (textField == null) { | |
textField = new Text(parent, SWT.SINGLE | SWT.BORDER); | |
switch (validateStrategy) { | |
case VALIDATE_ON_KEY_STROKE : | |
textField.addKeyListener(new KeyAdapter() { | |
public void keyPressed(KeyEvent e) { | |
valueChanged(); | |
} | |
}); | |
textField.addFocusListener(new FocusAdapter() { | |
public void focusGained(FocusEvent e) { | |
refreshValidState(); | |
} | |
public void focusLost(FocusEvent e) { | |
clearErrorMessage(); | |
} | |
}); | |
break; | |
case VALIDATE_ON_FOCUS_LOST : | |
textField.addKeyListener(new KeyAdapter() { | |
public void keyPressed(KeyEvent e) { | |
clearErrorMessage(); | |
} | |
}); | |
textField.addFocusListener(new FocusAdapter() { | |
public void focusGained(FocusEvent e) { | |
refreshValidState(); | |
} | |
public void focusLost(FocusEvent e) { | |
valueChanged(); | |
clearErrorMessage(); | |
} | |
}); | |
break; | |
default : | |
Assert.isTrue(false, "Unknown validate strategy");//$NON-NLS-1$ | |
} | |
textField.addDisposeListener(new DisposeListener() { | |
public void widgetDisposed(DisposeEvent event) { | |
textField = null; | |
} | |
}); | |
if(textLimit > 0){//Only set limits above 0 - see SWT spec | |
textField.setTextLimit(textLimit); | |
} | |
} else { | |
checkParent(textField, parent); | |
} | |
return textField; | |
} | |
/** | |
* Returns whether an empty string is a valid value. | |
* | |
* @return <code>true</code> if an empty string is a valid value, and | |
* <code>false</code> if an empty string is invalid | |
* @see #setEmptyStringAllowed | |
*/ | |
public boolean isEmptyStringAllowed() { | |
return emptyStringAllowed; | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
public boolean isValid() { | |
return isValid; | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
protected void refreshValidState() { | |
isValid = checkState(); | |
} | |
/** | |
* Sets whether the empty string is a valid value or not. | |
* | |
* @param b <code>true</code> if the empty string is allowed, | |
* and <code>false</code> if it is considered invalid | |
*/ | |
public void setEmptyStringAllowed(boolean b) { | |
emptyStringAllowed = b; | |
} | |
/** | |
* Sets the error message that will be displayed when and if | |
* an error occurs. | |
* | |
* @param message the error message | |
*/ | |
public void setErrorMessage(String message) { | |
errorMessage = message; | |
} | |
/* (non-Javadoc) | |
* Method declared on FieldEditor. | |
*/ | |
public void setFocus() { | |
if (textField != null) { | |
textField.setFocus(); | |
} | |
} | |
/** | |
* Sets this field editor's value. | |
* | |
* @param value the new value, or <code>null</code> meaning the empty string | |
*/ | |
public void setStringValue(String value) { | |
if (textField != null) { | |
if (value == null) | |
value = "";//$NON-NLS-1$ | |
oldValue = textField.getText(); | |
if (!oldValue.equals(value)) { | |
textField.setText(value); | |
valueChanged(); | |
} | |
} | |
} | |
/** | |
* Sets this text field's text limit. | |
* | |
* @param limit the limit on the number of character in the text | |
* input field, or <code>UNLIMITED</code> for no limit | |
*/ | |
public void setTextLimit(int limit) { | |
textLimit = limit; | |
if (textField != null) | |
textField.setTextLimit(limit); | |
} | |
/** | |
* Sets the strategy for validating the text. | |
* | |
* @param value either <code>VALIDATE_ON_KEY_STROKE</code> to perform | |
* on the fly checking (the default), or <code>VALIDATE_ON_FOCUS_LOST</code> to | |
* perform validation only after the text has been typed in | |
*/ | |
public void setValidateStrategy(int value) { | |
Assert.isTrue(value == VALIDATE_ON_FOCUS_LOST || value == VALIDATE_ON_KEY_STROKE); | |
validateStrategy = value; | |
} | |
/** | |
* Shows the error message set via <code>setErrorMessage</code>. | |
*/ | |
public void showErrorMessage() { | |
showErrorMessage(errorMessage); | |
} | |
/** | |
* Informs this field editor's listener, if it has one, about a change | |
* to the value (<code>VALUE</code> property) provided that the old and | |
* new values are different. | |
* <p> | |
* This hook is <em>not</em> called when the text is initialized | |
* (or reset to the default value) from the preference store. | |
* </p> | |
*/ | |
protected void valueChanged() { | |
setPresentsDefaultValue(false); | |
boolean oldState = isValid; | |
refreshValidState(); | |
if (isValid != oldState) | |
fireStateChanged(IS_VALID, oldState, isValid); | |
String newValue = textField.getText(); | |
if (!newValue.equals(oldValue)) { | |
fireValueChanged(VALUE, oldValue, newValue); | |
oldValue = newValue; | |
} | |
} | |
} |