JDK14/Java14源码在线阅读
/*
* Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.awt;
import java.awt.peer.TextFieldPeer;
import java.awt.event.*;
import java.util.EventListener;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import javax.accessibility.*;
/**
* A {@code TextField} object is a text component
* that allows for the editing of a single line of text.
* <p>
* For example, the following image depicts a frame with four
* text fields of varying widths. Two of these text fields
* display the predefined text {@code "Hello"}.
* <p>
* <img src="doc-files/TextField-1.gif" alt="The preceding text describes this
* image." style="margin: 7px 10px;">
* <p>
* Here is the code that produces these four text fields:
*
* <hr><blockquote><pre>
* TextField tf1, tf2, tf3, tf4;
* // a blank text field
* tf1 = new TextField();
* // blank field of 20 columns
* tf2 = new TextField("", 20);
* // predefined text displayed
* tf3 = new TextField("Hello!");
* // predefined text in 30 columns
* tf4 = new TextField("Hello", 30);
* </pre></blockquote><hr>
* <p>
* Every time the user types a key in the text field, one or
* more key events are sent to the text field. A {@code KeyEvent}
* may be one of three types: keyPressed, keyReleased, or keyTyped.
* The properties of a key event indicate which of these types
* it is, as well as additional information about the event,
* such as what modifiers are applied to the key event and the
* time at which the event occurred.
* <p>
* The key event is passed to every {@code KeyListener}
* or {@code KeyAdapter} object which registered to receive such
* events using the component's {@code addKeyListener} method.
* ({@code KeyAdapter} objects implement the
* {@code KeyListener} interface.)
* <p>
* It is also possible to fire an {@code ActionEvent}.
* If action events are enabled for the text field, they may
* be fired by pressing the {@code Return} key.
* <p>
* The {@code TextField} class's {@code processEvent}
* method examines the action event and passes it along to
* {@code processActionEvent}. The latter method redirects the
* event to any {@code ActionListener} objects that have
* registered to receive action events generated by this
* text field.
*
* @author Sami Shaio
* @see java.awt.event.KeyEvent
* @see java.awt.event.KeyAdapter
* @see java.awt.event.KeyListener
* @see java.awt.event.ActionEvent
* @see java.awt.Component#addKeyListener
* @see java.awt.TextField#processEvent
* @see java.awt.TextField#processActionEvent
* @see java.awt.TextField#addActionListener
* @since 1.0
*/
public class TextField extends TextComponent {
/**
* The number of columns in the text field.
* A column is an approximate average character
* width that is platform-dependent.
* Guaranteed to be non-negative.
*
* @serial
* @see #setColumns(int)
* @see #getColumns()
*/
int columns;
/**
* The echo character, which is used when
* the user wishes to disguise the characters
* typed into the text field.
* The disguises are removed if echoChar = {@code 0}.
*
* @serial
* @see #getEchoChar()
* @see #setEchoChar(char)
* @see #echoCharIsSet()
*/
char echoChar;
transient ActionListener actionListener;
private static final String base = "textfield";
private static int nameCounter = 0;
/*
* JDK 1.1 serialVersionUID
*/
private static final long serialVersionUID = -2966288784432217853L;
/**
* Initialize JNI field and method ids
*/
private static native void initIDs();
static {
/* ensure that the necessary native libraries are loaded */
Toolkit.loadLibraries();
if (!GraphicsEnvironment.isHeadless()) {
initIDs();
}
}
/**
* Constructs a new text field.
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true.
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public TextField() throws HeadlessException {
this("", 0);
}
/**
* Constructs a new text field initialized with the specified text.
* @param text the text to be displayed. If
* {@code text} is {@code null}, the empty
* string {@code ""} will be displayed.
* If {@code text} contains EOL and/or LF characters, then
* each will be replaced by space character.
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true.
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public TextField(String text) throws HeadlessException {
this(text, (text != null) ? text.length() : 0);
}
/**
* Constructs a new empty text field with the specified number
* of columns. A column is an approximate average character
* width that is platform-dependent.
* @param columns the number of columns. If
* {@code columns} is less than {@code 0},
* {@code columns} is set to {@code 0}.
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true.
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public TextField(int columns) throws HeadlessException {
this("", columns);
}
/**
* Constructs a new text field initialized with the specified text
* to be displayed, and wide enough to hold the specified
* number of columns. A column is an approximate average character
* width that is platform-dependent.
* @param text the text to be displayed. If
* {@code text} is {@code null}, the empty
* string {@code ""} will be displayed.
* If {@code text} contains EOL and/or LF characters, then
* each will be replaced by space character.
* @param columns the number of columns. If
* {@code columns} is less than {@code 0},
* {@code columns} is set to {@code 0}.
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true.
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public TextField(String text, int columns) throws HeadlessException {
super(replaceEOL(text));
this.columns = (columns >= 0) ? columns : 0;
}
/**
* Construct a name for this component. Called by getName() when the
* name is null.
*/
String constructComponentName() {
synchronized (TextField.class) {
return base + nameCounter++;
}
}
/**
* Creates the TextField's peer. The peer allows us to modify the
* appearance of the TextField without changing its functionality.
*/
public void addNotify() {
synchronized (getTreeLock()) {
if (peer == null)
peer = getComponentFactory().createTextField(this);
super.addNotify();
}
}
/**
* Gets the character that is to be used for echoing.
* <p>
* An echo character is useful for text fields where
* user input should not be echoed to the screen, as in
* the case of a text field for entering a password.
* If {@code echoChar} = {@code 0}, user
* input is echoed to the screen unchanged.
* <p>
* A Java platform implementation may support only a limited,
* non-empty set of echo characters. This function returns the
* echo character originally requested via setEchoChar(). The echo
* character actually used by the TextField implementation might be
* different.
* @return the echo character for this text field.
* @see java.awt.TextField#echoCharIsSet
* @see java.awt.TextField#setEchoChar
*/
public char getEchoChar() {
return echoChar;
}
/**
* Sets the echo character for this text field.
* <p>
* An echo character is useful for text fields where
* user input should not be echoed to the screen, as in
* the case of a text field for entering a password.
* Setting {@code echoChar} = {@code 0} allows
* user input to be echoed to the screen again.
* <p>
* A Java platform implementation may support only a limited,
* non-empty set of echo characters. Attempts to set an
* unsupported echo character will cause the default echo
* character to be used instead. Subsequent calls to getEchoChar()
* will return the echo character originally requested. This might
* or might not be identical to the echo character actually
* used by the TextField implementation.
* @param c the echo character for this text field.
* @see java.awt.TextField#echoCharIsSet
* @see java.awt.TextField#getEchoChar
* @since 1.1
*/
public void setEchoChar(char c) {
setEchoCharacter(c);
}
/**
* Sets the character to be echoed when protected input is displayed.
*
* @param c the echo character for this text field
*
* @deprecated As of JDK version 1.1,
* replaced by {@code setEchoChar(char)}.
*/
@Deprecated
public synchronized void setEchoCharacter(char c) {
if (echoChar != c) {
echoChar = c;
TextFieldPeer peer = (TextFieldPeer)this.peer;
if (peer != null) {
peer.setEchoChar(c);
}
}
}
/**
* Sets the text that is presented by this
* text component to be the specified text.
* @param t the new text. If
* {@code t} is {@code null}, the empty
* string {@code ""} will be displayed.
* If {@code t} contains EOL and/or LF characters, then
* each will be replaced by space character.
* @see java.awt.TextComponent#getText
*/
public void setText(String t) {
super.setText(replaceEOL(t));
// This could change the preferred size of the Component.
invalidateIfValid();
}
/**
* Replaces EOL characters from the text variable with a space character.
* @param text the new text.
* @return Returns text after replacing EOL characters.
*/
private static String replaceEOL(String text) {
if (text == null) {
return text;
}
String[] strEOLs = {System.lineSeparator(), "\n"};
for (String eol : strEOLs) {
if (text.contains(eol)) {
text = text.replace(eol, " ");
}
}
return text;
}
/**
* Indicates whether or not this text field has a
* character set for echoing.
* <p>
* An echo character is useful for text fields where
* user input should not be echoed to the screen, as in
* the case of a text field for entering a password.
* @return {@code true} if this text field has
* a character set for echoing;
* {@code false} otherwise.
* @see java.awt.TextField#setEchoChar
* @see java.awt.TextField#getEchoChar
*/
public boolean echoCharIsSet() {
return echoChar != 0;
}
/**
* Gets the number of columns in this text field. A column is an
* approximate average character width that is platform-dependent.
* @return the number of columns.
* @see java.awt.TextField#setColumns
* @since 1.1
*/
public int getColumns() {
return columns;
}
/**
* Sets the number of columns in this text field. A column is an
* approximate average character width that is platform-dependent.
* @param columns the number of columns.
* @see java.awt.TextField#getColumns
* @exception IllegalArgumentException if the value
* supplied for {@code columns}
* is less than {@code 0}.
* @since 1.1
*/
public void setColumns(int columns) {
int oldVal;
synchronized (this) {
oldVal = this.columns;
if (columns < 0) {
throw new IllegalArgumentException("columns less than zero.");
}
if (columns != oldVal) {
this.columns = columns;
}
}
if (columns != oldVal) {
invalidate();
}
}
/**
* Gets the preferred size of this text field
* with the specified number of columns.
* @param columns the number of columns
* in this text field.
* @return the preferred dimensions for
* displaying this text field.
* @since 1.1
*/
public Dimension getPreferredSize(int columns) {
return preferredSize(columns);
}
/**
* Returns the preferred size for this text field
* with the specified number of columns.
*
* @param columns the number of columns
* @return the preferred size for the text field
*
* @deprecated As of JDK version 1.1,
* replaced by {@code getPreferredSize(int)}.
*/
@Deprecated
public Dimension preferredSize(int columns) {
synchronized (getTreeLock()) {
TextFieldPeer peer = (TextFieldPeer)this.peer;
return (peer != null) ?
peer.getPreferredSize(columns) :
super.preferredSize();
}
}
/**
* Gets the preferred size of this text field.
* @return the preferred dimensions for
* displaying this text field.
* @since 1.1
*/
public Dimension getPreferredSize() {
return preferredSize();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by {@code getPreferredSize()}.
*/
@Deprecated
public Dimension preferredSize() {
synchronized (getTreeLock()) {
return (columns > 0) ?
preferredSize(columns) :
super.preferredSize();
}
}
/**
* Gets the minimum dimensions for a text field with
* the specified number of columns.
* @param columns the number of columns in
* this text field.
* @return the minimum size for this text field
* @since 1.1
*/
public Dimension getMinimumSize(int columns) {
return minimumSize(columns);
}
/**
* Returns the minimum dimensions for a text field with
* the specified number of columns.
*
* @param columns the number of columns
* @return the minimum size for this text field
* @deprecated As of JDK version 1.1,
* replaced by {@code getMinimumSize(int)}.
*/
@Deprecated
public Dimension minimumSize(int columns) {
synchronized (getTreeLock()) {
TextFieldPeer peer = (TextFieldPeer)this.peer;
return (peer != null) ?
peer.getMinimumSize(columns) :
super.minimumSize();
}
}
/**
* Gets the minimum dimensions for this text field.
* @return the minimum dimensions for
* displaying this text field.
* @since 1.1
*/
public Dimension getMinimumSize() {
return minimumSize();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by {@code getMinimumSize()}.
*/
@Deprecated
public Dimension minimumSize() {
synchronized (getTreeLock()) {
return (columns > 0) ?
minimumSize(columns) :
super.minimumSize();
}
}
/**
* Adds the specified action listener to receive
* action events from this text field.
* If l is null, no exception is thrown and no action is performed.
* <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
* >AWT Threading Issues</a> for details on AWT's threading model.
*
* @param l the action listener.
* @see #removeActionListener
* @see #getActionListeners
* @see java.awt.event.ActionListener
* @since 1.1
*/
public synchronized void addActionListener(ActionListener l) {
if (l == null) {
return;
}
actionListener = AWTEventMulticaster.add(actionListener, l);
newEventsOnly = true;
}
/**
* Removes the specified action listener so that it no longer
* receives action events from this text field.
* If l is null, no exception is thrown and no action is performed.
* <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
* >AWT Threading Issues</a> for details on AWT's threading model.
*
* @param l the action listener.
* @see #addActionListener
* @see #getActionListeners
* @see java.awt.event.ActionListener
* @since 1.1
*/
public synchronized void removeActionListener(ActionListener l) {
if (l == null) {
return;
}
actionListener = AWTEventMulticaster.remove(actionListener, l);
}
/**
* Returns an array of all the action listeners
* registered on this textfield.
*
* @return all of this textfield's {@code ActionListener}s
* or an empty array if no action
* listeners are currently registered
*
* @see #addActionListener
* @see #removeActionListener
* @see java.awt.event.ActionListener
* @since 1.4
*/
public synchronized ActionListener[] getActionListeners() {
return getListeners(ActionListener.class);
}
/**
* Returns an array of all the objects currently registered
* as <code><em>Foo</em>Listener</code>s
* upon this {@code TextField}.
* <code><em>Foo</em>Listener</code>s are registered using the
* <code>add<em>Foo</em>Listener</code> method.
*
* <p>
* You can specify the {@code listenerType} argument
* with a class literal, such as
* <code><em>Foo</em>Listener.class</code>.
* For example, you can query a
* {@code TextField t}
* for its action listeners with the following code:
*
* <pre>ActionListener[] als = (ActionListener[])(t.getListeners(ActionListener.class));</pre>
*
* If no such listeners exist, this method returns an empty array.
*
* @param listenerType the type of listeners requested; this parameter
* should specify an interface that descends from
* {@code java.util.EventListener}
* @return an array of all objects registered as
* <code><em>Foo</em>Listener</code>s on this textfield,
* or an empty array if no such
* listeners have been added
* @exception ClassCastException if {@code listenerType}
* doesn't specify a class or interface that implements
* {@code java.util.EventListener}
*
* @see #getActionListeners
* @since 1.3
*/
public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
EventListener l = null;
if (listenerType == ActionListener.class) {
l = actionListener;
} else {
return super.getListeners(listenerType);
}
return AWTEventMulticaster.getListeners(l, listenerType);
}
// REMIND: remove when filtering is done at lower level
boolean eventEnabled(AWTEvent e) {
if (e.id == ActionEvent.ACTION_PERFORMED) {
if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 ||
actionListener != null) {
return true;
}
return false;
}
return super.eventEnabled(e);
}
/**
* Processes events on this text field. If the event
* is an instance of {@code ActionEvent},
* it invokes the {@code processActionEvent}
* method. Otherwise, it invokes {@code processEvent}
* on the superclass.
* <p>Note that if the event parameter is {@code null}
* the behavior is unspecified and may result in an
* exception.
*
* @param e the event
* @see java.awt.event.ActionEvent
* @see java.awt.TextField#processActionEvent
* @since 1.1
*/
protected void processEvent(AWTEvent e) {
if (e instanceof ActionEvent) {
processActionEvent((ActionEvent)e);
return;
}
super.processEvent(e);
}
/**
* Processes action events occurring on this text field by
* dispatching them to any registered
* {@code ActionListener} objects.
* <p>
* This method is not called unless action events are
* enabled for this component. Action events are enabled
* when one of the following occurs:
* <ul>
* <li>An {@code ActionListener} object is registered
* via {@code addActionListener}.
* <li>Action events are enabled via {@code enableEvents}.
* </ul>
* <p>Note that if the event parameter is {@code null}
* the behavior is unspecified and may result in an
* exception.
*
* @param e the action event
* @see java.awt.event.ActionListener
* @see java.awt.TextField#addActionListener
* @see java.awt.Component#enableEvents
* @since 1.1
*/
protected void processActionEvent(ActionEvent e) {
ActionListener listener = actionListener;
if (listener != null) {
listener.actionPerformed(e);
}
}
/**
* Returns a string representing the state of this {@code TextField}.
* This method is intended to be used only for debugging purposes, and the
* content and format of the returned string may vary between
* implementations. The returned string may be empty but may not be
* {@code null}.
*
* @return the parameter string of this text field
*/
protected String paramString() {
String str = super.paramString();
if (echoChar != 0) {
str += ",echo=" + echoChar;
}
return str;
}
/*
* Serialization support.
*/
/**
* The textField Serialized Data Version.
*
* @serial
*/
private int textFieldSerializedDataVersion = 1;
/**
* Writes default serializable fields to stream. Writes
* a list of serializable ActionListener(s) as optional data.
* The non-serializable ActionListener(s) are detected and
* no attempt is made to serialize them.
*
* @serialData Null terminated sequence of zero or more pairs.
* A pair consists of a String and Object.
* The String indicates the type of object and
* is one of the following :
* ActionListenerK indicating and ActionListener object.
*
* @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener)
* @see java.awt.Component#actionListenerK
*/
private void writeObject(ObjectOutputStream s)
throws IOException
{
s.defaultWriteObject();
AWTEventMulticaster.save(s, actionListenerK, actionListener);
s.writeObject(null);
}
/**
* Read the ObjectInputStream and if it isn't null,
/**代码未完, 请加载全部代码(NowJava.com).**/
关注时代Java
关注时代Java