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*
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package javax.accessibility;
/**
* Service Provider Interface (SPI) for Assistive Technology.
* <p>
* This service provider class provides mappings from the platform specific
* accessibility APIs to the Java Accessibility API.
* <p>
* Each service provider implementation is named and can be activated via the
* {@link #activate} method. Service providers can be loaded when the default
* {@link java.awt.Toolkit toolkit} is initialized.
*
* @apiNote There will typically be one provider per platform, such as Windows
* or Linux, to support accessibility for screen readers and
* magnifiers. However, more than one service provider can be
* activated. For example, a test tool which provides visual results
* obtained by interrogating the Java Accessibility API can be
* activated along with the activation of the support for screen
* readers and screen magnifiers.
* @see java.awt.Toolkit#getDefaultToolkit
* @see java.util.ServiceLoader
* @since 9
*/
public abstract class AccessibilityProvider {
/**
* Initializes a new accessibility provider.
*
* @throws SecurityException If a security manager has been installed and it
* denies {@link RuntimePermission} {@code "accessibilityProvider"}
*/
protected AccessibilityProvider() {
// Use a permission check when calling a private constructor to check
// that the proper security permission has been granted before the
// {@code Object} superclass is called. If an exception is thrown before
// the {@code Object} superclass is constructed a finalizer in a
// subclass of this class will not be run. This protects against a
// finalizer vulnerability.
this(checkPermission());
}
/**
* Allows to check a permission before the {@code Object} is called.
*
* @param ignore unused stub to call a {@link #checkPermission()}}
*/
private AccessibilityProvider(Void ignore) { }
/**
* If this code is running with a security manager and if the permission
* {@code "accessibilityProvider"} has not been granted
* {@code SecurityException} will be thrown.
*
* @return {@code null} if {@code SecurityException} was not thrown
* @throws SecurityException If a security manager has been installed and it
* denies {@link RuntimePermission} {@code "accessibilityProvider"}
*/
private static Void checkPermission() {
SecurityManager sm = System.getSecurityManager();
if (sm != null)
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