01: /*
02: * Copyright 2006 Google Inc.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License"); you may not
05: * use this file except in compliance with the License. You may obtain a copy of
06: * the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12: * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13: * License for the specific language governing permissions and limitations under
14: * the License.
15: */
16: package com.google.gwt.user.client.ui;
17:
18: /**
19: * A class that implements this interface receives a preview of keyboard events
20: * before they are passed to the focused widget.
21: *
22: * @see com.google.gwt.user.client.ui.KeyboardListener
23: */
24: public interface HasKeyPreview {
25:
26: /**
27: * Called when a key-down event is received.
28: *
29: * @param key the physical key that was depressed. Constants for this value
30: * are defined in this interface with the KEYCODE prefix.
31: * @param modifiers the modifier keys pressed at when the event occurred. This
32: * value is a combination of the bits defined by
33: * {@link KeyboardListener#MODIFIER_SHIFT},
34: * {@link KeyboardListener#MODIFIER_CTRL}, and
35: * {@link KeyboardListener#MODIFIER_ALT}.
36: */
37: boolean onKeyDownPreview(char key, int modifiers);
38:
39: /**
40: * Called when a key-press event is received.
41: *
42: * @param key the Unicode character that was generated by the keyboard action.
43: * @param modifiers the modifier keys pressed at when the event occurred. This
44: * value is a combination of the bits defined by
45: * {@link KeyboardListener#MODIFIER_SHIFT},
46: * {@link KeyboardListener#MODIFIER_CTRL}, and
47: * {@link KeyboardListener#MODIFIER_ALT}.
48: */
49: boolean onKeyPressPreview(char key, int modifiers);
50:
51: /**
52: * Called when a key-up event is received.
53: *
54: * @param key the physical key that was released. Constants for this value are
55: * defined in this interface with the KEYCODE prefix.
56: * @param modifiers the modifier keys pressed at when the event occurred. This
57: * value is a combination of the bits defined by
58: * {@link KeyboardListener#MODIFIER_SHIFT},
59: * {@link KeyboardListener#MODIFIER_CTRL}, and
60: * {@link KeyboardListener#MODIFIER_ALT}.
61: */
62: boolean onKeyUpPreview(char key, int modifiers);
63: }
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