FXGXY/java/net/micode/notes/ui/NoteEditText.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * 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.
 */

package net.micode.notes.ui;

import android.content.Context;
import android.graphics.Rect;
import android.text.Layout;
import android.text.Selection;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.style.URLSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.view.ContextMenu;
import android.view.KeyEvent;
import android.view.MenuItem;
import android.view.MenuItem.OnMenuItemClickListener;
import android.view.MotionEvent;
import android.widget.EditText;

import net.micode.notes.R;

import java.util.HashMap;
import java.util.Map;
/**
 * 自定义EditText，用于笔记编辑界面
 * 扩展功能包括：支持链接识别、回车换行处理、删除空行处理等
 */
public class NoteEditText extends EditText {
    private static final String TAG = "NoteEditText";
    private int mIndex;// 当前EditText在列表中的索引位置
    private int mSelectionStartBeforeDelete;// 删除操作前的光标起始位置
    // 链接协议常量
    private static final String SCHEME_TEL = "tel:" ;
    private static final String SCHEME_HTTP = "http:" ;
    private static final String SCHEME_EMAIL = "mailto:" ;
    // 链接协议与对应菜单资源ID的映射
    private static final Map<String, Integer> sSchemaActionResMap = new HashMap<String, Integer>();
    static {
        sSchemaActionResMap.put(SCHEME_TEL, R.string.note_link_tel);
        sSchemaActionResMap.put(SCHEME_HTTP, R.string.note_link_web);
        sSchemaActionResMap.put(SCHEME_EMAIL, R.string.note_link_email);
    }

    /**
     * Call by the {@link NoteEditActivity} to delete or add edit text
     */
    public interface OnTextViewChangeListener {
        /**
         * Delete current edit text when {@link KeyEvent#KEYCODE_DEL} happens
         * and the text is null
         */
        void onEditTextDelete(int index, String text);

        /**
         * Add edit text after current edit text when {@link KeyEvent#KEYCODE_ENTER}
         * happen
         */
        void onEditTextEnter(int index, String text);

        /**
         * Hide or show item option when text change
         */
        void onTextChange(int index, boolean hasText);
    }

    private OnTextViewChangeListener mOnTextViewChangeListener;
    //构造方法
    public NoteEditText(Context context) {
        super(context, null);
        mIndex = 0;
    }
    // 设置当前EditText索引
    public void setIndex(int index) {
        mIndex = index;
    }
    // 设置文本变化监听器
    public void setOnTextViewChangeListener(OnTextViewChangeListener listener) {
        mOnTextViewChangeListener = listener;
    }

    public NoteEditText(Context context, AttributeSet attrs) {
        super(context, attrs, android.R.attr.editTextStyle);
    }

    public NoteEditText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // 处理触摸事件，精确定位光标位置
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                // 计算触摸点坐标（考虑padding和滚动偏移）
                int x = (int) event.getX();
                int y = (int) event.getY();
                x -= getTotalPaddingLeft();
                y -= getTotalPaddingTop();
                x += getScrollX();
                y += getScrollY();
                
                // 获取触摸点对应的文本位置
                Layout layout = getLayout();
                int line = layout.getLineForVertical(y);
                int off = layout.getOffsetForHorizontal(line, x);
                Selection.setSelection(getText(), off);// 设置光标位置
                break;
        }

        return super.onTouchEvent(event);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // 按键按下事件处理
        switch (keyCode) {
            case KeyEvent.KEYCODE_ENTER://回车键
                if (mOnTextViewChangeListener != null) {
                    return false;// 交给onKeyUp处理
                }
                break;
            case KeyEvent.KEYCODE_DEL://删除键
                mSelectionStartBeforeDelete = getSelectionStart();// 记录删除前光标位置
                break;
            default:
                break;
        }
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        // 按键释放事件处理
        switch(keyCode) {
            case KeyEvent.KEYCODE_DEL://删除键
                if (mOnTextViewChangeListener != null) {
                     // 如果光标在开头且不是第一个EditText，则删除当前EditText
                    if (0 == mSelectionStartBeforeDelete && mIndex != 0) {
                        mOnTextViewChangeListener.onEditTextDelete(mIndex, getText().toString());
                        return true;// 已处理，不继续传递
                    }
                } else {
                    Log.d(TAG, "OnTextViewChangeListener was not seted");
                }
                break;
            case KeyEvent.KEYCODE_ENTER:// 回车键
                if (mOnTextViewChangeListener != null) {
                     // 从光标处分割文本，后半部分放入新EditText
                    int selectionStart = getSelectionStart();
                    String text = getText().subSequence(selectionStart, length()).toString();
                    setText(getText().subSequence(0, selectionStart));// 保留前半部分
                    mOnTextViewChangeListener.onEditTextEnter(mIndex + 1, text);// 创建新EditText
                } else {
                    Log.d(TAG, "OnTextViewChangeListener was not seted");
                }
                break;
            default:
                break;
        }
        return super.onKeyUp(keyCode, event);
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        // 焦点变化时通知监听器
        if (mOnTextViewChangeListener != null) {
            if (!focused && TextUtils.isEmpty(getText())) {
                mOnTextViewChangeListener.onTextChange(mIndex, false); // 无文本
            } else {
                mOnTextViewChangeListener.onTextChange(mIndex, true); // 有文本
            }
        }
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
    }

    @Override
    protected void onCreateContextMenu(ContextMenu menu) {
        // 创建上下文菜单（长按弹出）
        if (getText() instanceof Spanned) {
            int selStart = getSelectionStart();
            int selEnd = getSelectionEnd();
            // 获取选中范围的URL链接
            int min = Math.min(selStart, selEnd);
            int max = Math.max(selStart, selEnd);

            final URLSpan[] urls = ((Spanned) getText()).getSpans(min, max, URLSpan.class);
            if (urls.length == 1) {
                // 根据URL类型添加对应的菜单项
                int defaultResId = 0;
                for(String schema: sSchemaActionResMap.keySet()) {
                    if(urls[0].getURL().indexOf(schema) >= 0) {
                        defaultResId = sSchemaActionResMap.get(schema);
                        break;
                    }
                }

                if (defaultResId == 0) {
                    defaultResId = R.string.note_link_other; // 默认菜单项
                }
                // 添加菜单项并设置点击事件
                menu.add(0, 0, 0, defaultResId).setOnMenuItemClickListener(
                        new OnMenuItemClickListener() {
                            public boolean onMenuItemClick(MenuItem item) {
                                // goto a new intent
                                urls[0].onClick(NoteEditText.this);
                                return true;
                            }
                        });
            }
        }
        super.onCreateContextMenu(menu);
    }
}