Android带有undo,redo功能的EditText

没别的，只有代码自己看。。。

package zwp.mycalendar.widget;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.widget.EditText;

/**
 * 自定义EditText
 * @author 周文鹏
 * @date 2015-6-23
 */
public class ZPEditText extends EditText {
    private List<EditHistory> undoHistories; // 撤销文字
    private List<EditHistory> redoHistories; // 重做文字
    private boolean activate = false; // 是否激活redo
    private boolean clear = true; // 是否清空redo
    private OnTextChangeListener listener; // 文字改变监听器

    public ZPEditText(Context context) {
        this(context, null);
    }

    public ZPEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public ZPEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    /**
     * 初始化
     */
    private void init() {
        undoHistories = new ArrayList<EditHistory>();
        redoHistories = new ArrayList<EditHistory>();
        addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                if (listener != null) {
                    listener.onTextChange(ZPEditText.this, s);
                }
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
                if (activate) {
                    redoHistories.add(new EditHistory(s.toString(), start, count, after));
                    activate = false;
                } else {
                    undoHistories.add(new EditHistory(s.toString(), start, count, after));
                    if (clear) {
                        redoHistories.clear();
                    }
                    clear = true;
                }
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        });
    }

    /**
     * 撤销
     */
    public void undo() {
        if (canUndo()) {
            activate = true;
            Editable editable = getEditableText();
            EditHistory history = undoHistories.remove(undoHistories.size() - 1);
            if (history.count > 0) {
                editable.append(history.text.subSequence(history.start, history.start + history.count));
            }
            if (history.after > 0) {
                editable.delete(history.start, history.start + history.after);
            }
        }
    }

    /**
     * 重做
     */
    public void redo() {
        if (canRedo()) {
            clear = false;
            Editable editable = getEditableText();
            EditHistory history = redoHistories.remove(redoHistories.size() - 1);
            if (history.count > 0) {
                editable.append(history.text.subSequence(history.start, history.start + history.count));
            }
            if (history.after > 0) {
                editable.delete(history.start, history.start + history.after);
            }
        }
    }

    /**
     * 是否可以撤销
     */
    public boolean canUndo() {
        if (undoHistories.size() > 0) {
            return true;
        }
        return false;
    }

    /**
     * 是否可以重做
     */
    public boolean canRedo() {
        if (redoHistories.size() > 0) {
            return true;
        }
        return false;
    }

    /**
     * 获取文字改变监听器
     * @return
     */
    public OnTextChangeListener getOnTextChangeListener() {
        return listener;
    }

    /**
     * 设置文字改变监听器
     * @param listener
     */
    public void setOnTextChangeListener(OnTextChangeListener listener) {
        this.listener = listener;
    }

    /**
     * 存储Edit操作
     * @author 周文鹏
     * @date 2015-6-24
     */
    private class EditHistory {
        public CharSequence text;
        public int start;
        public int count;
        public int after;

        public EditHistory(CharSequence text, int start, int count, int after) {
            this.text = text;
            this.start = start;
            this.count = count;
            this.after = after;
        }

        @Override
        public String toString() {
            return "EditHistory [text=" + text + ", start=" + start
                    + ", count=" + count + ", after=" + after + "]";
        }
    }

    /**
     * 文字改变监听器
     * @author 周文鹏
     * @date 2015-6-24
     */
    public interface OnTextChangeListener {
        void onTextChange(ZPEditText editText, CharSequence text);
    }
}