Method: function(Object)

1: /*
2: * *********************************************************************************************************************
3: *
4: * TheseFoolishThings: Miscellaneous utilities
5: * http://tidalwave.it/projects/thesefoolishthings
6: *
7: * Copyright (C) 2009 - 2023 by Tidalwave s.a.s. (http://tidalwave.it)
8: *
9: * *********************************************************************************************************************
10: *
11: * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
12: * the License. You may obtain a copy of the License at
13: *
14: * http://www.apache.org/licenses/LICENSE-2.0
15: *
16: * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
17: * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
18: * specific language governing permissions and limitations under the License.
19: *
20: * *********************************************************************************************************************
21: *
22: * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
23: * git clone https://github.com/tidalwave-it/thesefoolishthings-src
24: *
25: * *********************************************************************************************************************
26: */
27: package it.tidalwave.role.ui.function;
28:
29: import javax.annotation.Nonnull;
30: import it.tidalwave.role.ui.Changeable;
31: import it.tidalwave.role.ui.ChangingSource;
32: import lombok.extern.slf4j.Slf4j;
33:
34: /***********************************************************************************************************************
35: *
36: * Changes the destination only at a certain condition in function of the target.
37: *
38: * @author Fabrizio Giudici
39: *
40: **********************************************************************************************************************/
41: @Slf4j
42: public abstract class WeakCopyFunctionSupport<T> extends UnaryBoundFunctionSupport<T, T> implements Changeable<T>
43: {
44: @Nonnull
45: protected T targetValue;
46:
47: public WeakCopyFunctionSupport (@Nonnull final ChangingSource<T> source)
48: {
49: super(source);
50: }
51:
52: @Override
53: protected void onSourceChange (@Nonnull final T oldSourceValue, @Nonnull final T newSourceValue)
54: {
55: final T oldValue = function(oldSourceValue);
56: final T newValue = function(newSourceValue);
57:
58: if (shouldChange(oldValue, newValue))
59: {
60: value = newValue;
61: fireValueChanged(oldValue, newValue);
62: }
63: }
64:
65: @Override
66: public void set (final T value)
67: {
68: this.targetValue = value;
69: }
70:
71: protected abstract boolean shouldChange (T oldValue, T newValue);
72:
73: @Override @Nonnull
74: protected T function (@Nonnull final T value)
75: {
76: return value;
77: }
78: }