/*
* @(#)InputMethod.java 1.31 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.awt.im.spi;
import java.util.Locale;
import java.awt.AWTEvent;
import java.awt.Rectangle;
import java.lang.Character.Subset;
/**
* Defines the interface for an input method that supports complex text input.
* Input methods traditionally support text input for languages that have
* more characters than can be represented on a standard-size keyboard,
* such as Chinese, Japanese, and Korean. However, they may also be used to
* support phonetic text input for English or character reordering for Thai.
* <p>
* Subclasses of InputMethod can be loaded by the input method framework; they
* can then be selected either through the API
* ({@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod})
* or the user interface (the input method selection menu).
*
* @since 1.3
*
* @version 1.31, 11/17/05
* @author JavaSoft International
*/
public interface InputMethod {
/**
* Sets the input method context, which is used to dispatch input method
* events to the client component and to request information from
* the client component.
* <p>
* This method is called once immediately after instantiating this input
* method.
*
* @param context the input method context for this input method
* @exception NullPointerException if <code>context</code> is null
*/
public void setInputMethodContext(InputMethodContext context);
/**
* Attempts to set the input locale. If the input method supports the
* desired locale, it changes its behavior to support input for the locale
* and returns true.
* Otherwise, it returns false and does not change its behavior.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod},
* <li>when switching to this input method through the user interface if the user
* specified a locale or if the previously selected input method's
* {@link java.awt.im.spi.InputMethod#getLocale getLocale} method
* returns a non-null value.
* </ul>
*
* @param locale locale to input
* @return whether the specified locale is supported
* @exception NullPointerException if <code>locale</code> is null
*/
public boolean setLocale(Locale locale);
/**
* Returns the current input locale. Might return null in exceptional cases.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#getLocale InputContext.getLocale} and
* <li>when switching from this input method to a different one through the
* user interface.
* </ul>
*
* @return the current input locale, or null
*/
public Locale getLocale();
/**
* Sets the subsets of the Unicode character set that this input method
* is allowed to input. Null may be passed in to indicate that all
* characters are allowed.
* <p>
* This method is called
* <ul>
* <li>immediately after instantiating this input method,
* <li>when switching to this input method from a different one, and
* <li>by {@link java.awt.im.InputContext#setCharacterSubsets InputContext.setCharacterSubsets}.
* </ul>
*
* @param subsets the subsets of the Unicode character set from which
* characters may be input
*/
public void setCharacterSubsets(Subset[] subsets);
/**
* Enables or disables this input method for composition,
* depending on the value of the parameter <code>enable</code>.
* <p>
* An input method that is enabled for composition interprets incoming
* events for both composition and control purposes, while a
* disabled input method does not interpret events for composition.
* Note however that events are passed on to the input method regardless
* whether it is enabled or not, and that an input method that is disabled
* for composition may still interpret events for control purposes,
* including to enable or disable itself for composition.
* <p>
* For input methods provided by host operating systems, it is not always possible to
* determine whether this operation is supported. For example, an input method may enable
* composition only for some locales, and do nothing for other locales. For such input
* methods, it is possible that this method does not throw
* {@link java.lang.UnsupportedOperationException UnsupportedOperationException},
* but also does not affect whether composition is enabled.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#setCompositionEnabled InputContext.setCompositionEnabled},
* <li>when switching to this input method from a different one using the
* user interface or
* {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod},
* if the previously selected input method's
* {@link java.awt.im.spi.InputMethod#isCompositionEnabled isCompositionEnabled}
* method returns without throwing an exception.
* </ul>
*
* @param enable whether to enable the input method for composition
* @throws UnsupportedOperationException if this input method does not
* support the enabling/disabling operation
* @see #isCompositionEnabled
*/
public void setCompositionEnabled(boolean enable);
/**
* Determines whether this input method is enabled.
* An input method that is enabled for composition interprets incoming
* events for both composition and control purposes, while a
* disabled input method does not interpret events for composition.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#isCompositionEnabled InputContext.isCompositionEnabled} and
* <li>when switching from this input method to a different one using the
* user interface or
* {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod}.
* </ul>
*
* @return <code>true</code> if this input method is enabled for
* composition; <code>false</code> otherwise.
* @throws UnsupportedOperationException if this input method does not
* support checking whether it is enabled for composition
* @see #setCompositionEnabled
*/
public boolean isCompositionEnabled();
/**
* Starts the reconversion operation. The input method obtains the
* text to be reconverted from the current client component using the
* {@link java.awt.im.InputMethodRequests#getSelectedText InputMethodRequests.getSelectedText}
* method. It can use other <code>InputMethodRequests</code>
* methods to request additional information required for the
* reconversion operation. The composed and committed text
* produced by the operation is sent to the client component as a
* sequence of <code>InputMethodEvent</code>s. If the given text
* cannot be reconverted, the same text should be sent to the
* client component as committed text.
* <p>
* This method is called by
* {@link java.awt.im.InputContext#reconvert() InputContext.reconvert}.
*
* @throws UnsupportedOperationException if the input method does not
* support the reconversion operation.
*/
public void reconvert();
/**
* Dispatches the event to the input method. If input method support is
* enabled for the focussed component, incoming events of certain types
* are dispatched to the current input method for this component before
* they are dispatched to the component's methods or event listeners.
* The input method decides whether it needs to handle the event. If it
* does, it also calls the event's <code>consume</code> method; this
* causes the event to not get dispatched to the component's event
* processing methods or event listeners.
* <p>
* Events are dispatched if they are instances of InputEvent or its
* subclasses.
* This includes instances of the AWT classes KeyEvent and MouseEvent.
* <p>
* This method is called by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}.
*
* @param event the event being dispatched to the input method
* @exception NullPointerException if <code>event</code> is null
*/
public void dispatchEvent(AWTEvent event);
/**
* Notifies this input method of changes in the client window
* location or state. This method is called while this input
* method is the current input method of its input context and
* notifications for it are enabled (see {@link
* InputMethodContext#enableClientWindowNotification
* InputMethodContext.enableClientWindowNotification}). Calls
* to this method are temporarily suspended if the input context's
* {@link java.awt.im.InputContext#removeNotify removeNotify}
* method is called, and resume when the input method is activated
* for a new client component. It is called in the following
* situations:
* <ul>
* <li>
* when the window containing the current client component changes
* in location, size, visibility, iconification state, or when the
* window is closed.</li>
* <li>
* from <code> enableClientWindowNotification(inputMethod,
* true)</code> if the current client component exists,</li>
* <li>
* when activating the input method for the first time after it
* called
* <code>enableClientWindowNotification(inputMethod,
* true)</code> if during the call no current client component was
* available,</li>
* <li>
* when activating the input method for a new client component
* after the input context's removeNotify method has been
* called.</li>
* </ul>
* @param bounds client window's {@link
* java.awt.Component#getBounds bounds} on the screen; or null if
* the client window is iconified or invisible
*/
public void notifyClientWindowChange(Rectangle bounds);
/**
* Activates the input method for immediate input processing.
* <p>
* If an input method provides its own windows, it should make sure
* at this point that all necessary windows are open and visible.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}
* when a client component receives a FOCUS_GAINED event,
* <li>when switching to this input method from a different one using the
* user interface or
* {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod}.
* </ul>
* The method is only called when the input method is inactive.
* A newly instantiated input method is assumed to be inactive.
*/
public void activate();
/**
* Deactivates the input method.
* The isTemporary argument has the same meaning as in
* {@link java.awt.event.FocusEvent#isTemporary FocusEvent.isTemporary}.
* <p>
* If an input method provides its own windows, only windows that relate
* to the current composition (such as a lookup choice window) should be
* closed at this point.
* It is possible that the input method will be immediately activated again
* for a different client component, and closing and reopening more
* persistent windows (such as a control panel) would create unnecessary
* screen flicker.
* Before an instance of a different input method class is activated,
* {@link #hideWindows} is called on the current input method.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}
* when a client component receives a FOCUS_LOST event,
* <li>when switching from this input method to a different one using the
* user interface or
* {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod},
* <li>before {@link #removeNotify removeNotify} if the current client component is
* removed.
* </ul>
* The method is only called when the input method is active.
*
* @param isTemporary whether the focus change is temporary
*/
public void deactivate(boolean isTemporary);
/**
* Closes or hides all windows opened by this input method instance or
* its class.
* <p>
* This method is called
* <ul>
* <li>before calling {@link #activate activate} on an instance of a different input
* method class,
* <li>before calling {@link #dispose dispose} on this input method.
* </ul>
* The method is only called when the input method is inactive.
*/
public void hideWindows();
/**
* Notifies the input method that a client component has been
* removed from its containment hierarchy, or that input method
* support has been disabled for the component.
* <p>
* This method is called by {@link java.awt.im.InputContext#removeNotify InputContext.removeNotify}.
* <p>
* The method is only called when the input method is inactive.
*/
public void removeNotify();
/**
* Ends any input composition that may currently be going on in this
* context. Depending on the platform and possibly user preferences,
* this may commit or delete uncommitted text. Any changes to the text
* are communicated to the active component using an input method event.
*
* <p>
* A text editing component may call this in a variety of situations,
* for example, when the user moves the insertion point within the text
* (but outside the composed text), or when the component's text is
* saved to a file or copied to the clipboard.
* <p>
* This method is called
* <ul>
* <li>by {@link java.awt.im.InputContext#endComposition InputContext.endComposition},
* <li>by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}
* when switching to a different client component
* <li>when switching from this input method to a different one using the
* user interface or
* {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod}.
* </ul>
*/
public void endComposition();
/**
* Releases the resources used by this input method.
* In particular, the input method should dispose windows and close files that are no
* longer needed.
* <p>
* This method is called by {@link java.awt.im.InputContext#dispose InputContext.dispose}.
* <p>
* The method is only called when the input method is inactive.
* No method of this interface is called on this instance after dispose.
*/
public void dispose();
/**
* Returns a control object from this input method, or null. A
* control object provides methods that control the behavior of the
* input method or obtain information from the input method. The type
* of the object is an input method specific class. Clients have to
* compare the result against known input method control object
* classes and cast to the appropriate class to invoke the methods
* provided.
* <p>
* This method is called by
* {@link java.awt.im.InputContext#getInputMethodControlObject InputContext.getInputMethodControlObject}.
*
* @return a control object from this input method, or null
*/
public Object getControlObject();
}