https://github.com/noties/lazy

Utility to postpone initialisation of a value
https://github.com/noties/lazy

android lazy

Last synced: 2 months ago
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Utility to postpone initialisation of a value

• Host: GitHub
• URL: https://github.com/noties/lazy
• Owner: noties
• License: apache-2.0
• Created: 2017-01-10T12:29:06.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2018-03-31T08:41:08.000Z (almost 7 years ago)
• Last Synced: 2023-07-07T14:17:25.895Z (over 1 year ago)
• Topics: android, lazy
• Language: Java
• Homepage:
• Size: 97.7 KB
• Stars: 2
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Lazy

Utility to postpone initialisation of a value

[![listeners](https://img.shields.io/maven-central/v/ru.noties/lazy.svg?label=lazy)](http://search.maven.org/#search|ga|1|g%3A%22ru.noties%22%20AND%20a%3A%22lazy%22)

```gradle

implementation 'ru.noties:lazy:1.1.0'

```

---

```java

final Lazy lazy = Lazy.of(() -> "I'm so lazy!");

```

```java

final Lazy lazy = Lazy.of(Calendar::getInstance);

final Calendar calendar = lazy.get();

```

```java

final Lazy lazy = Lazy.ofSynchronized(this::query);

```

```java

final Lazy lazy = Lazy.of(() -> 42);

final Lazy sync = Lazy.ofSynchronized(lazy);

```

## Hide

Starting with `1.1.0` Lazy provides a way to _hide_ wrapped type:

```java

final CharSequence cs = Lazy.ofHidden(CharSequence.class, () -> "Yeah, it's me");

// or

final CharSequence cs = Lazy.of(() -> "We are the lazy!").hide(CharSequence.class);

```

**NB** This works _ONLY_ for interface types as internally `java.lang.reflect.Proxy` is used.

---

With some lifecycle notification (using [lifebus](https://github.com/noties/Lifebus)):

```java

public class MainActivity extends Activity {

    

    private Lifebus lifebus;

    

    private CharSequence hiddenLazy;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        

        lifebus = ActivityLifebus.create(this);

        

        hiddenLazy = Lazy.of(() -> "Really resource consuming thing here")

                .accept(lazy -> lifebus.on(ActivityEvent.DESTROY, () -> {

                    if (lazy.hasValue()) {

                        // release it here

                        lazy.get();

                    }

                }))

                .hide(CharSequence.class);

    }

}

```

```

  Copyright 2018 Dimitry Ivanov ([email protected])

  Licensed under the Apache License, Version 2.0 (the "License");

  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  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 CONDITIONS OF ANY KIND, either express or implied.

  See the License for the specific language governing permissions and

  limitations under the License.

```