public class InputContext extends Object
By default, one InputContext instance is created per Window instance, and this input context is shared by all components within the window's container hierarchy. However, this means that only one text input operation is possible at any one time within a window, and that the text needs to be committed when moving the focus from one text component to another. If this is not desired, text components can create their own input context instances.
The Java Platform supports input methods that have been developed in the Java programming language, using the interfaces in the java.awt.im.spi
package, which can be made available by adding them to the application's class path. Implementations may also support using the native input methods of the platforms they run on; however, not all platforms and locales provide input methods. Keyboard layouts are provided by the host platform.
Input methods are unavailable if (a) no input method written in the Java programming language has been installed and (b) the Java Platform implementation or the underlying platform does not support native input methods. In this case, input contexts can still be created and used; their behavior is specified with the individual methods below.
Modifier | Constructor | Description |
---|---|---|
protected |
Constructs an InputContext. |
Modifier and Type | Method | Description |
---|---|---|
void |
dispatchEvent |
Dispatches an event to the active input method. |
void |
dispose() |
Releases the resources used by this input context. |
void |
endComposition() |
Ends any input composition that may currently be going on in this context. |
Object |
getInputMethodControlObject() |
Returns a control object from the current input method, or null. |
static InputContext |
getInstance() |
Returns a new InputContext instance. |
Locale |
getLocale() |
Returns the current locale of the current input method or keyboard layout. |
boolean |
isCompositionEnabled() |
Determines whether the current input method is enabled for composition. |
void |
reconvert() |
Asks the current input method to reconvert text from the current client component. |
void |
removeNotify |
Notifies the input context that a client component has been removed from its containment hierarchy, or that input method support has been disabled for the component. |
boolean |
selectInputMethod |
Attempts to select an input method or keyboard layout that supports the given locale, and returns a value indicating whether such an input method or keyboard layout has been successfully selected. |
void |
setCharacterSubsets |
Sets the subsets of the Unicode character set that input methods of this input context should be allowed to input. |
void |
setCompositionEnabled |
Enables or disables the current input method for composition, depending on the value of the parameter enable . |
protected InputContext()
getInstance()
.public static InputContext getInstance()
public boolean selectInputMethod(Locale locale)
Not all host operating systems provide API to determine the locale of the currently selected native input method or keyboard layout, and to select a native input method or keyboard layout by locale. For host operating systems that don't provide such API, selectInputMethod
assumes that native input methods or keyboard layouts provided by the host operating system support only the system's default locale.
A text editing component may call this method, for example, when the user changes the insertion point, so that the user can immediately continue typing in the language of the surrounding text.
locale
- The desired new locale.NullPointerException
- if locale
is nullpublic Locale getLocale()
InputMethod.getLocale()
method returns null. Not all host operating systems provide API to determine the locale of the currently selected native input method or keyboard layout. For host operating systems that don't provide such API, getLocale
assumes that the current locale of all native input methods or keyboard layouts provided by the host operating system is the system's default locale.
public void setCharacterSubsets(Character.Subset[] subsets)
subsets
- The subsets of the Unicode character set from which characters may be inputpublic void setCompositionEnabled(boolean enable)
enable
. 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.
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 UnsupportedOperationException
, but also does not affect whether composition is enabled.
enable
- whether to enable the current input method for compositionUnsupportedOperationException
- if there is no current input method available or the current input method does not support the enabling/disabling operationpublic boolean isCompositionEnabled()
true
if the current input method is enabled for composition; false
otherwiseUnsupportedOperationException
- if there is no current input method available or the current input method does not support checking whether it is enabled for compositionpublic void reconvert()
InputMethodRequests.getSelectedText
method. The other InputMethodRequests
methods must be prepared to deal with further information requests by the input method. The composed and/or committed text will be sent to the client component as a sequence of InputMethodEvent
s. If the input method cannot reconvert the given text, the text is returned as committed text in an InputMethodEvent
.UnsupportedOperationException
- if there is no current input method available or the current input method does not support the reconversion operation.public void dispatchEvent(AWTEvent event)
event
- The eventNullPointerException
- if event
is nullpublic void removeNotify(Component client)
Component.removeNotify
method. Potentially pending input from input methods for this component is discarded. If no input methods are available, then this method has no effect.client
- Client componentNullPointerException
- if client
is nullpublic void endComposition()
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.
public void dispose()
public Object getInputMethodControlObject()
If no input methods are available or the current input method does not provide an input method control object, then null is returned.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/java/awt/im/InputContext.html