Method: WeakCopyFunctionSupport(ChangingSource)

1: /*
2: * *************************************************************************************************************************************************************
3: *
4: * TheseFoolishThings: Miscellaneous utilities
5: * http://tidalwave.it/projects/thesefoolishthings
6: *
7: * Copyright (C) 2009 - 2024 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 the License.
12: * 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 an "AS IS" BASIS, WITHOUT WARRANTIES OR
17: * CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
18: *
19: * *************************************************************************************************************************************************************
20: *
21: * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
22: * git clone https://github.com/tidalwave-it/thesefoolishthings-src
23: *
24: * *************************************************************************************************************************************************************
25: */
26: package it.tidalwave.role.ui.function;
27:
28: import javax.annotation.Nonnull;
29: import it.tidalwave.role.ui.Changeable;
30: import it.tidalwave.role.ui.ChangingSource;
31: import lombok.extern.slf4j.Slf4j;
32:
33: /***************************************************************************************************************************************************************
34: *
35: * Changes the destination only at a certain condition in function of the target.
36: *
37: * @author Fabrizio Giudici
38: *
39: **************************************************************************************************************************************************************/
40: @Slf4j
41: public abstract class WeakCopyFunctionSupport<T> extends UnaryBoundFunctionSupport<T, T> implements Changeable<T>
42: {
43: @Nonnull
44: protected T targetValue;
45:
46: public WeakCopyFunctionSupport (@Nonnull final ChangingSource<T> source)
47: {
48: super(source);
49: }
50:
51: @Override
52: protected void onSourceChange (@Nonnull final T oldSourceValue, @Nonnull final T newSourceValue)
53: {
54: final var oldValue = function(oldSourceValue);
55: final var newValue = function(newSourceValue);
56:
57: if (shouldChange(oldValue, newValue))
58: {
59: value = newValue;
60: fireValueChanged(oldValue, newValue);
61: }
62: }
63:
64: @Override
65: public void set (final T value)
66: {
67: this.targetValue = value;
68: }
69:
70: protected abstract boolean shouldChange (T oldValue, T newValue);
71:
72: @Override @Nonnull
73: protected T function (@Nonnull final T value)
74: {
75: return value;
76: }
77: }