Regret is an Android library for apps that wants to implement an undo/redo feature. The library is simple to use and works with all primitive types and objects and is especially suitable for drawing, text and photo editing apps.

Regret is based on the UndoRedoList

Usage

1) Instantiate Regret and add key-value data to it

   Regret regret = new Regret(context, this);
   regret.add(KEY_TEXT, editText.getText().toString());
   regret.add(KEY_TEXT_COLOR, Color.BLACK);

2) Call regret.undo() or regret.redo(). The key-value data will be returned via the listener

  @Override
    public void onDo(String key, Object value) {
        switch (key) {
            case KEY_TEXT:
                editText.setText((CharSequence) value);
                break;
            case KEY_TEXT_COLOR:
                editText.setTextColor((Integer) value);
                break;
        }
    }

3) Update UI related buttons such as Undo/Redo buttons with the following listener

    @Override
    public void onCanDo(boolean canUndo, boolean canRedo) {
        btnUndo.setAlpha(canUndo ? 1 : 0.4f);
        btnRedo.setAlpha(canRedo ? 1 : 0.4f);
        btnUndo.setEnabled(canUndo);
        btnRedo.setEnabled(canRedo);
    }

Installation

Add the dependency in your build.gradle

dependencies {
    implementation 'io.github.muddz:regret:1.4.0'  
}

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License

Copyright 2018 Muddi Walid

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.