- /*
- * @(#)IIOParamController.java 1.12 03/12/19
- *
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package javax.imageio;
-
- /**
- * An interface to be implemented by objects that can determine the
- * settings of an <code>IIOParam</code> object, either by putting up a
- * GUI to obtain values from a user, or by other means. This
- * interface merely specifies a generic <code>activate</code> method
- * that invokes the controller, without regard for how the controller
- * obtains values (<i>i.e.</i>, whether the controller puts up a GUI
- * or merely computes a set of values is irrelevant to this
- * interface).
- *
- * <p> Within the <code>activate</code> method, a controller obtains
- * initial values by querying the <code>IIOParam</code> object's
- * <code>get</code> methods, modifies values by whatever means, then
- * invokes the <code>IIOParam</code> object's <code>set</code> methods
- * to modify the appropriate settings. Normally, these
- * <code>set</code> methods will be invoked all at once at a final
- * commit in order that a cancel operation not disturb existing
- * values. In general, applications may expect that when the
- * <code>activate</code> method returns <code>true</code>, the
- * <code>IIOParam</code> object is ready for use in a read or write
- * operation.
- *
- * <p> Vendors may choose to provide GUIs for the
- * <code>IIOParam</code> subclasses they define for a particular
- * plug-in. These can be set up as default controllers in the
- * corresponding <code>IIOParam</code> subclasses.
- *
- * <p> Applications may override any default GUIs and provide their
- * own controllers embedded in their own framework. All that is
- * required is that the<code>activate</code> method behave modally
- * (not returning until either cancelled or committed), though it need
- * not put up an explicitly modal dialog. Such a non-modal GUI
- * component would be coded roughly as follows:
- *
- * <br>
- * <pre>
- * class MyGUI extends SomeComponent implements IIOParamController {
- *
- * public MyGUI() {
- * // ...
- * setEnabled(false);
- * }
- *
- * public boolean activate(IIOParam param) {
- * // disable other components if desired
- * setEnabled(true);
- * // go to sleep until either cancelled or committed
- * boolean ret = false;
- * if (!cancelled) {
- * // set values on param
- * ret = true;
- * }
- * setEnabled(false);
- * // enable any components disabled above
- * return ret;
- * }
- * </pre>
- *
- * <p> Alternatively, an algorithmic process such as a database lookup
- * or the parsing of a command line could be used as a controller, in
- * which case the <code>activate</code> method would simply look up or
- * compute the settings, call the <code>IIOParam.setXXX</code>
- * methods, and return <code>true</code>.
- *
- * @see IIOParam#setController
- * @see IIOParam#getController
- * @see IIOParam#getDefaultController
- * @see IIOParam#hasController
- * @see IIOParam#activateController
- *
- * @version 0.5
- */
- public interface IIOParamController {
-
- /**
- * Activates the controller. If <code>true</code> is returned,
- * all settings in the <code>IIOParam</code> object should be
- * ready for use in a read or write operation. If
- * <code>false</code> is returned, no settings in the
- * <code>IIOParam</code> object will be disturbed (<i>i.e.</i>,
- * the user canceled the operation).
- *
- * @param param the <code>IIOParam</code> object to be modified.
- *
- * @return <code>true</code> if the <code>IIOParam</code> has been
- * modified, <code>false</code> otherwise.
- *
- * @exception IllegalArgumentException if <code>param</code> is
- * <code>null</code> or is not an instance of the correct class.
- */
- boolean activate(IIOParam param);
- }