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Diffstat (limited to 'libjava/classpath/java/awt/DefaultFocusTraversalPolicy.java')
-rw-r--r-- | libjava/classpath/java/awt/DefaultFocusTraversalPolicy.java | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/libjava/classpath/java/awt/DefaultFocusTraversalPolicy.java b/libjava/classpath/java/awt/DefaultFocusTraversalPolicy.java new file mode 100644 index 000000000..3f017c5a5 --- /dev/null +++ b/libjava/classpath/java/awt/DefaultFocusTraversalPolicy.java @@ -0,0 +1,111 @@ +/* DefaultFocusTraversalPolicy.java -- + Copyright (C) 2002, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.awt; + +/** + * DefaultFocusTraversalPolicy is the default focus traversal policy + * used by Containers. + * + * This policy sharpens ContainerOrderFocusTraversalPolicy's + * acceptance criteria, to reject those Components that have + * unfocusable peers. Despite this extra strictness, this policy will + * always accept a Component that has explicitly been set focusable by + * any means. + * + * This AWT implementation assumes that the peers of the following + * Components are not focusable: Canvas, Panel, Label, ScrollPane, + * Scrollbar, Window, and any lightweight Component. + * + * A Component's focusability is independent of the focusability of + * its peer. + * + * @author Thomas Fitzsimmons (fitzsim@redhat.com) + * @since 1.4 + */ +public class DefaultFocusTraversalPolicy + extends ContainerOrderFocusTraversalPolicy +{ + private static final long serialVersionUID = 8876966522510157497L; + + /** + * Construct a default focus traversal policy. + */ + public DefaultFocusTraversalPolicy () + { + } + + /** + * Check whether a given Component would be acceptable as a focus + * owner. The Component must be displayable, visible and enabled to + * be acceptable. If the Component's focus traversability has been + * overridden, by overriding Component.isFocusTraversable or + * Component.isFocusable, or by calling Component.setFocusable, then + * the Component will be accepted if it is focusable. If the + * Component uses the default focus traversable behaviour, then + * <code>comp</code> will always be rejected if it is a Canvas, + * Panel, Label, ScrollPane, Scrollbar, Window or lightweight + * Component. + * + * @param comp the Component to check + * + * @return true if the Component is an acceptable target for + * keyboard input focus, false otherwise + */ + protected boolean accept (Component comp) + { + if (comp.visible + && comp.isDisplayable () + && comp.enabled) + { + if (comp.isFocusTraversableOverridden != 0 + && (comp.isFocusTraversable () || comp.isFocusable())) + return true; + + if (!(comp instanceof Canvas + || comp instanceof Panel + || comp instanceof Label + || comp instanceof ScrollPane + || comp instanceof Scrollbar + || comp instanceof Window + || comp.isLightweight ())) + return true; + } + return false; + } +} |