java.lang.Object java.awt.im.InputContext
Provides methods to control text input facilities such as input methods and keyboard layouts. Two methods handle both input methods and keyboard layouts: selectInputMethod lets a client component select an input method or keyboard layout by locale, getLocale lets a client component obtain the locale of the current input method or keyboard layout. The other methods more specifically support interaction with input methods: They let client components control the behavior of input methods, and dispatch events from the client component to the input method.
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 2 platform supports input methods that have been developed in the Java programming language, using the interfaces in the java.awt.im.spi package, and installed into a Java 2 runtime environment as extensions. 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 2 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.
Constructor Summary | |
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protected |
InputContext
() Constructs an InputContext. |
Method Summary | |
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void |
dispatchEvent
(
AWTEvent
event) Dispatches an event to the active input method. |
void |
dispose
() Disposes of the input context and release the resources used by it. |
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
(
Component
client) 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
(
Locale
locale) 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
(
Character.Subset
[] subsets) Sets the subsets of the Unicode character set that input methods of this input context should be allowed to input. |
void |
setCompositionEnabled
(boolean enable) Enables or disables the current input method for composition, depending on the value of the parameter enable. |
Methods inherited from class java.lang. Object |
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clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Constructor Detail |
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protected InputContext()
Method Detail |
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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.
public Locale getLocale()
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)
public void setCompositionEnabled(boolean 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.
public boolean isCompositionEnabled()
public void reconvert()
public void dispatchEvent(AWTEvent event)
public void removeNotify(Component client)
public 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.