android/email/Utility.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * 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 com.android.email;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Date;

import com.android.email.codec.binary.Base64;

import android.text.Editable;
import android.widget.TextView;

public class Utility {
    public final static String readInputStream(InputStream in, String encoding) throws IOException {
        InputStreamReader reader = new InputStreamReader(in, encoding);
        StringBuffer sb = new StringBuffer();
        int count;
        char[] buf = new char[512];
        while ((count = reader.read(buf)) != -1) {
            sb.append(buf, 0, count);
        }
        return sb.toString();
    }

    public final static boolean arrayContains(Object[] a, Object o) {
        for (int i = 0, count = a.length; i < count; i++) {
            if (a[i].equals(o)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Combines the given array of Objects into a single string using the
     * seperator character and each Object's toString() method. between each
     * part.
     *
     * @param parts
     * @param seperator
     * @return
     */
    public static String combine(Object[] parts, char seperator) {
        if (parts == null) {
            return null;
        }
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < parts.length; i++) {
            sb.append(parts[i].toString());
            if (i < parts.length - 1) {
                sb.append(seperator);
            }
        }
        return sb.toString();
    }

    public static String base64Decode(String encoded) {
        if (encoded == null) {
            return null;
        }
        byte[] decoded = new Base64().decode(encoded.getBytes());
        return new String(decoded);
    }

    public static String base64Encode(String s) {
        if (s == null) {
            return s;
        }
        byte[] encoded = new Base64().encode(s.getBytes());
        return new String(encoded);
    }

    public static boolean requiredFieldValid(TextView view) {
        return view.getText() != null && view.getText().length() > 0;
    }

    public static boolean requiredFieldValid(Editable s) {
        return s != null && s.length() > 0;
    }

    /**
     * Ensures that the given string starts and ends with the double quote character. The string is not modified in any way except to add the
     * double quote character to start and end if it's not already there.
     *
     * TODO: Rename this, because "quoteString()" can mean so many different things.
     *
     * sample -> "sample"
     * "sample" -> "sample"
     * ""sample"" -> "sample"
     * "sample"" -> "sample"
     * sa"mp"le -> "sa"mp"le"
     * "sa"mp"le" -> "sa"mp"le"
     * (empty string) -> ""
     * " -> ""
     * @param s
     * @return
     */
    public static String quoteString(String s) {
        if (s == null) {
            return null;
        }
        if (!s.matches("^\".*\"$")) {
            return "\"" + s + "\"";
        }
        else {
            return s;
        }
    }

    /**
     * Apply quoting rules per IMAP RFC,
     * quoted          = DQUOTE *QUOTED-CHAR DQUOTE
     * QUOTED-CHAR     = <any TEXT-CHAR except quoted-specials> / "\" quoted-specials
     * quoted-specials = DQUOTE / "\"
     *
     * This is used primarily for IMAP login, but might be useful elsewhere.
     *
     * NOTE:  Not very efficient - you may wish to preflight this, or perhaps it should check
     * for trouble chars before calling the replace functions.
     *
     * @param s The string to be quoted.
     * @return A copy of the string, having undergone quoting as described above
     */
    public static String imapQuoted(String s) {

        // First, quote any backslashes by replacing \ with \\
        // regex Pattern:  \\    (Java string const = \\\\)
        // Substitute:     \\\\  (Java string const = \\\\\\\\)
        String result = s.replaceAll("\\\\", "\\\\\\\\");

        // Then, quote any double-quotes by replacing " with \"
        // regex Pattern:  "    (Java string const = \")
        // Substitute:     \\"  (Java string const = \\\\\")
        result = result.replaceAll("\"", "\\\\\"");

        // return string with quotes around it
        return "\"" + result + "\"";
    }

    /**
     * A fast version of  URLDecoder.decode() that works only with UTF-8 and does only two
     * allocations. This version is around 3x as fast as the standard one and I'm using it
     * hundreds of times in places that slow down the UI, so it helps.
     */
    public static String fastUrlDecode(String s) {
        try {
            byte[] bytes = s.getBytes("UTF-8");
            byte ch;
            int length = 0;
            for (int i = 0, count = bytes.length; i < count; i++) {
                ch = bytes[i];
                if (ch == '%') {
                    int h = (bytes[i + 1] - '0');
                    int l = (bytes[i + 2] - '0');
                    if (h > 9) {
                        h -= 7;
                    }
                    if (l > 9) {
                        l -= 7;
                    }
                    bytes[length] = (byte) ((h << 4) | l);
                    i += 2;
                }
                else if (ch == '+') {
                    bytes[length] = ' ';
                }
                else {
                    bytes[length] = bytes[i];
                }
                length++;
            }
            return new String(bytes, 0, length, "UTF-8");
        }
        catch (UnsupportedEncodingException uee) {
            return null;
        }
    }

    /**
     * Returns true if the specified date is within today. Returns false otherwise.
     * @param date
     * @return
     */
    public static boolean isDateToday(Date date) {
        // TODO But Calendar is so slowwwwwww....
        Date today = new Date();
        if (date.getYear() == today.getYear() &&
                date.getMonth() == today.getMonth() &&
                date.getDate() == today.getDate()) {
            return true;
        }
        return false;
    }

    /*
     * TODO disabled this method globally. It is used in all the settings screens but I just
     * noticed that an unrelated icon was dimmed. Android must share drawables internally.
     */
    public static void setCompoundDrawablesAlpha(TextView view, int alpha) {
//        Drawable[] drawables = view.getCompoundDrawables();
//        for (Drawable drawable : drawables) {
//            if (drawable != null) {
//                drawable.setAlpha(alpha);
//            }
//        }
    }
}