android源码追踪学习 RecipientsEditor

RecipientsEditor 新建短信时输入收接者的editor，

public class RecipientsEditor extends MultiAutoCompleteTextView {
    private int mLongPressedPosition = -1;
    private final RecipientsEditorTokenizer mTokenizer;
    private char mLastSeparator = ',';

    public RecipientsEditor(Context context, AttributeSet attrs) {
        super(context, attrs, android.R.attr.autoCompleteTextViewStyle);
        mTokenizer = new RecipientsEditorTokenizer(context, this);
        setTokenizer(mTokenizer);
        // For the focus to move to the message body when soft Next is pressed
        setImeOptions(EditorInfo.IME_ACTION_NEXT);
        // Set threshold as 1 CharSequence.
        setThreshold(1);
        addTextChangedListener(new TextWatcher() {
            private Annotation[] mAffected;

            public void beforeTextChanged(CharSequence s, int start,
                    int count, int after) {
                mAffected = ((Spanned) s).getSpans(start, start + count,
                        Annotation.class);
            }

            public void onTextChanged(CharSequence s, int start,
                    int before, int after) {
                if (before == 0 && after == 1) {    // inserting a character
                    char c = s.charAt(start);
                    if (c == ',' || c == ';') {
                        // Remember the delimiter the user typed to end this recipient. We'll
                        // need it shortly in terminateToken().
                        mLastSeparator = c;
                    }
                }
            }

            public void afterTextChanged(Editable s) {
                if (mAffected != null) {
                    for (Annotation a : mAffected) {
                        s.removeSpan(a);
                    }
                }

                mAffected = null;
            }
        });
    }

RecipientsEditor 继承于 MultiAutoCompleteTextView

可支持输入多个手机号码，每个手机号码用用分隔符分开，有自动完成功能，预置匹配的数据为联系人；

其中RecipientsEditorTokenizer为了找出输入字符串中的分隔符","和“，”

private class RecipientsEditorTokenizer
            implements MultiAutoCompleteTextView.Tokenizer {
        private final MultiAutoCompleteTextView mList;
        private final Context mContext;

        RecipientsEditorTokenizer(Context context, MultiAutoCompleteTextView list) {
            mList = list;
            mContext = context;
        }

        public int findTokenStart(CharSequence text, int cursor) {
            int i = cursor;
            char c;

            while (i > 0 && (c = text.charAt(i - 1)) != ',' && c != ';') {
                i--;
            }
            while (i < cursor && text.charAt(i) == ' ') {
                i++;
            }

            return i;
        }

        public int findTokenEnd(CharSequence text, int cursor) {
            int i = cursor;
            int len = text.length();
            char c;

            while (i < len) {
                if ((c = text.charAt(i)) == ',' || c == ';') {
                    return i;
                } else {
                    i++;
                }
            }

            return len;
        }

        public CharSequence terminateToken(CharSequence text) {
            int i = text.length();

            while (i > 0 && text.charAt(i - 1) == ' ') {
                i--;
            }

            char c;
            if (i > 0 && ((c = text.charAt(i - 1)) == ',' || c == ';')) {
                return text;
            } else {
                // Use the same delimiter the user just typed.
                // This lets them have a mixture of commas and semicolons in their list.
                String separator = mLastSeparator + " ";
                if (text instanceof Spanned) {
                    SpannableString sp = new SpannableString(text + separator);
                    TextUtils.copySpansFrom((Spanned) text, 0, text.length(),
                                            Object.class, sp, 0);
                    return sp;
                } else {
                    return text + separator;
                }
            }
        }

setImeOptions(EditorInfo.IME_ACTION_NEXT);//设置软键盘右下角的button的功能为下一个，即切换到下一个输入框，如果设置成EditorInfo.IME_ACTION_DONE，则表示输入完成，关掉软键盘，还有很多其他的选项可供设置的

setThreshold(1);// Threshold门槛的意思，此处设置只要输入一个字符就开始匹配，若设置为“2”则表示要输入两个字符才是匹配。

addTextChangedListener(TextWatcher);//添加一个TextView监听器

TextWatcher里有三个回调方法，当有输入框里的字符有变化时会自动依次调用以下三个方法：

beforeTextChanged(CharSequence s, int start,int count, int after) ；

//此处已输入为例解释上面各变量的意思，s 是输入以前的字符串，start光标所在的位置， count为要改变的字符个数，即选中的个数，after为要插入的个数

onTextChanged(CharSequence s, int start, int before, int after)

//s为改变后的字符串，start和上面的start一样， before和上面的count一样，after与上面的after一样

afterTextChanged(Editable s)// s为改变后的字符串

预制匹配数据为联系人的方法是通过设置适配器：

 mRecipientsEditor.setAdapter(new RecipientsAdapter(this));

RecipientsAdapter 是extends ResourceCursorAdapter的

在适配器里面通过Phone.CONTENT_FILTER_URI，获取电话本里的信息。