ParcelableGen.py

"""
Copyright (C) 2013 initialxy and other contributors
http://code.google.com/p/parcelable-generator/

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

"""
A utility to generate Java codes in order to make a class Parcelable. Run this
script with
>> python ParcelableGen.py
Copy and paste your Java class into stdin, signify end of file (ctrl+z on
windows or ctrl+d on *nix), then press enter. Java codes will be printed to
stdout. Copy and paste generated code into your Java file. You probably want to
press shift+ctrl+o then shift+ctrl+f in Eclipse afterwards. It could make
mistakes, so sometimes manual editing is required. For one, it cannot correctly
detect enums (it's not that smart). It detects enums by checking if type name
ends with "Type". If it gets wrong, you might want to temporarily change type
name (either add or remove "Type" from its end), generate, then manually
correct type name. But it still makes your life much easier.
"""

import sys
import re
import abc

VERSION = "1.2"

CLASS_REGEX = re.compile(r"^\s*public (static |)(abstract |)class\s+(\S+)\s+.*")
MEMBER_REGEX = re.compile(r"^\s*(public|private)\s+(\S+)\s+(\S+)\;.*")

PREFERRED_LIST_TYPE = "ArrayList"

ENUM_TYPE_NAMING_SCHEME = re.compile(r".+Type")

# Template for Parcelable code block. Use Mustash-like syntax
# eg. if ({{key}}) { return; }, instead of str.format() compatible syntax
# eg. if ({key}) {{ return; }} for better Java readability.
TEMPLATE = """
    /**************************************************************************
     * Code to make this class Parcelable. Generated by ParcelableGen.py
     */

    public static final Parcelable.Creator<{{className}}> CREATOR = new Creator();

    /**
     * Default constructor, needed for Jackson. Remove if necessary.
     */
    public {{className}}() {
    }

    /**
     * Reconstruct from Parcel
     */
    public {{className}}(Parcel in) {
{{read}}
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
{{write}}
    }

    @Override
    public int describeContents() {
        return 0;
    }

    private static class Creator implements Parcelable.Creator<{{className}}> {
        public {{className}} createFromParcel(Parcel source) {
            return new {{className}}(source);
        }

        public {{className}}[] newArray(int size) {
            return new {{className}}[size];
        }
    }

    /**************************************************************************
     * Parcelable codes end
     */
    """

class Generator(object):
    def __init__(self):
        self.template = ""
        self.indentation = ""
        self.tab = ""
        self.className = ""
        self.members = []
        self.adapters = []
        self.defaultAdapter = None;

    def setTemplate(self, template, indentation, tab):
        self.template = template;
        self.indentation = indentation;
        self.tab = tab;

    def setClassName(self, className):
        self.className = className;

    def addMember(self, dataType, name):
        self.members.append((dataType, name))

    def addAdapter(self, adapter):
        self.adapters.append(adapter)

    def setDefaultAdapter(self, adapter):
        self.defaultAdapter = adapter

    def gen(self):
        # To be used as string builders.
        read = []
        write = []

        for m in self.members:
            isAdapterFound = False
            for a in self.adapters:
                n = a.getSupportedType().match(m[0])
                if n:
                    isAdapterFound = True
                    read += a.genRead(m[0], m[1]).split("\n")
                    write += a.genWrite(m[0], m[1]).split("\n")
                    break

            if not isAdapterFound:
                if self.defaultAdapter is not None:
                    # If none of the registered adapters are suitable, use
                    # default.
                    read.append(self.defaultAdapter.genRead(m[0], m[1]))
                    write.append(self.defaultAdapter.genWrite(m[0], m[1]))
                else :
                    sys.stderr.write(m[0] + " " + m[1] \
                            + " is ignored, because no suitable adapter " \
                            + "is found.\n")

        # Add indentation.
        read = self.__formatIndentation(read)
        write = self.__formatIndentation(write)

        out = self.template.replace("{{className}}", self.className)
        out = out.replace("{{read}}", "\n".join(read))
        out = out.replace("{{write}}", "\n".join(write))

        print out

    def __formatIndentation(self, lines):
        """Responsible for making corrections for indentation"""
        additionalTabs = 0

        for i in range(len(lines)):
            # Strip first
            lines[i] = lines[i].strip()

            curAdditionalTabs = additionalTabs

            openingBracketNum = 0
            closingBracketNum = 0

            # We need to count the number of closing brackets before opening
            # brackets and delete that many number of tabs for current line.
            # While at it also count the number of opening brackets and
            # closing brackets. We will use one iteration for this.
            for c in lines[i]:
                if c == "{":
                    openingBracketNum += 1
                if c == "}":
                    closingBracketNum += 1
                    if openingBracketNum <= 0:
                        curAdditionalTabs -= 1

            if curAdditionalTabs < 0:
                curAdditionalTabs = 0;

            additionalTabs += openingBracketNum
            additionalTabs -= closingBracketNum

            lines[i] = self.indentation + (self.tab * curAdditionalTabs) \
                    + lines[i]

        return lines

class ConfiguredGenerator(Generator):
    """Sets up all of the adapters in constructor"""

    NATIVE_TYPES = ["byte", "double", "float", "int", "long", "String",
            "java.lang.String", "boolean[]", "byte[]", "char[]", "double[]", 
            "float[]", "int[]", "long[]", "String[]"]

    NATIVE_TYPES_METHOD_NAMES = ["Byte", "Double", "Float", "Int", "Long",
            "String", "String", "BooleanArray", "ByteArray", "CharArray",
            "DoubleArray", "FloatArray", "IntArray", "longArray", "StringArray"]

    VALUE_OF_TYPES = ["Byte", "Short", "Integer", "Long", "Float", "Double",
            "Boolean", "Char"]

    CONSTRUCTOR_TYPES = ["BigDecimal", "BigInteger"]

    def __init__(self):
        super(ConfiguredGenerator, self).__init__()
        self.setTemplate(TEMPLATE, " " * 8, " " * 4)

        self.setDefaultAdapter(ParcelableAdapter())

        for i in range(len(self.NATIVE_TYPES)):
            self.addAdapter(NativeTypeAdapter(self.NATIVE_TYPES[i],
                    self.NATIVE_TYPES_METHOD_NAMES[i]))

        self.addAdapter(PrimitiveBooleanAdapter())
        self.addAdapter(ListAdapter(PREFERRED_LIST_TYPE))
        self.addAdapter(EnumAdapter(ENUM_TYPE_NAMING_SCHEME))
        self.addAdapter(CalendarAdapter())
        self.addAdapter(GregorianCalendarAdapter())
        self.addAdapter(XMLGregorianCalendarAdapter())

        for t in self.VALUE_OF_TYPES:
            self.addAdapter(ValueOfAdapter(t))

        for t in self.CONSTRUCTOR_TYPES:
            self.addAdapter(StringConstructorAdapter(t))

class Adapter(object):
    @abc.abstractmethod
    def getSupportedType(self):
        "Returns supported dataType as a compiled regex."
        return

    @abc.abstractmethod
    def genRead(self, dataType, name):
        """Given dataType and name, generate Parcelable read codes
        (in.read.*) as a string, don't worry about indentation."""
        return

    @abc.abstractmethod
    def genWrite(self, dataType, name):
        """Given dataType and name, generate Parcelable write codes
        (out.write.*). don't worry about indentation."""
        return

class TemplateAdapter(Adapter):
    """Extend this adapter for anything that simply needs to put dataType and
    name into a template. We use replace() instead of str.format() for
    templating because the output source code we are dealing with is Java,
    which contains open and closing brackets ({}) by itself. If we were going
    to use str.format(), then all of the Java brackets need to be doubled up.
    eg. if ({key}) {{ return; }} instead of if ({{key}}) { return; }. This makes
    the template less readable as Java and more likely to cause problems. So we
    are gonna stick with Mustash-like template syntax on this one."""

    @abc.abstractmethod
    def getReadTemplate(self):
        """Return read code template."""
        return

    @abc.abstractmethod
    def getWriteTemplate(self):
        """Return write code template."""
        return

    def genRead(self, dataType, name):
        return self.getReadTemplate() \
                .replace("{{dataType}}", dataType).replace("{{name}}", name)

    def genWrite(self, dataType, name):
        return self.getWriteTemplate() \
                .replace("{{dataType}}", dataType).replace("{{name}}", name)

class NativeTypeAdapter(Adapter):
    """Use this adapter for any of the primitive types that's natively
    supported by Parcel."""

    def __init__(self, supportedTypeStr, typeMethodNameSuffix):
        """supportedTypeStr is expected to a string."""
        self.supportedType = re.compile(
                supportedTypeStr.replace("[", "\\[").replace("]", "\\]"))
        self.typeMethodNameSuffix = typeMethodNameSuffix

    def getSupportedType(self):
        return self.supportedType

    def genRead(self, dataType, name):
        return name + " = in.read" + self.typeMethodNameSuffix + "();"

    def genWrite(self, dataType, name):
        return "out.write" + self.typeMethodNameSuffix + "(" + name + ");"

class ParcelableAdapter(TemplateAdapter):
    """Use this adapter for Parcelable type. This adapter really should be
    used as default adapter."""

    SUPPORTED_TYPE = re.compile(r".*Parcelable")

    def getSupportedType(self):
        return self.SUPPORTED_TYPE

    def getReadTemplate(self):
        return """{{name}} = in.readParcelable({{dataType}}.class.getClassLoader());"""

    def getWriteTemplate(self):
        return """out.writeParcelable({{name}}, 0);"""

class PrimitiveBooleanAdapter(TemplateAdapter):
    """Use this adapter for primitive boolean type."""

    SUPPORTED_TYPE = re.compile(r"boolean")

    def getSupportedType(self):
        return self.SUPPORTED_TYPE

    def getReadTemplate(self):
        return """boolean[] {{name}}Array = new boolean[1];
                in.readBooleanArray({{name}}Array);
                {{name}} = {{name}}Array[0];"""

    def getWriteTemplate(self):
        return """out.writeBooleanArray(new boolean[] { {{name}} });"""

class ListAdapter(TemplateAdapter):
    """Use this adapter for any of the List types."""

    SUPPORTED_TYPE = re.compile(r".*List")

    GENERICS_REGEX = re.compile(r"\s*(\S+)\<(.+)\>.*")

    READ_TEMPLATE = """{{name}} = new {{listType}}<{{genericType}}>();
            in.readList({{name}}, {{genericType}}.class.getClassLoader());"""

    def __init__(self, preferredListType):
        self.preferredListType = preferredListType

    def getSupportedType(self):
        return self.SUPPORTED_TYPE

    def genRead(self, dataType, name):
        genericType = ""
        listType = ""

        m = self.GENERICS_REGEX.match(dataType)
        if m:
            genericType = m.group(2)
            listType = m.group(1)
        else:
            listType = dataType

        if listType == "" or listType == "List" or listType == "java.util.List":
            listType = self.preferredListType

        return self.READ_TEMPLATE.replace("{{name}}", name) \
                .replace("{{listType}}", listType) \
                .replace("{{genericType}}", genericType)

    def getReadTemplate(self):
        """This implementation is useless, because genRead() is implemeted. I
        just want to override all of the abstract methods, because that makes
        me happy as a Java guy."""
        return ""

    def getWriteTemplate(self):
        return """out.writeList({{name}});"""

class EnumAdapter(TemplateAdapter):
    """Use this adapter for primitive enum type. Note that it depends on a
    consistent enum type naming scheme to identify enums."""

    def __init__(self, enumTypeNamingScheme):
        """enumTypeNamingScheme is expected to be a compiled regex."""
        self.enumTypeNamingScheme = enumTypeNamingScheme

    def getSupportedType(self):
        return self.enumTypeNamingScheme

    def getReadTemplate(self):
        return """String {{name}}Str = in.readString();
                if ({{name}}Str != null) {
                    {{name}} = {{dataType}}.valueOf({{name}}Str);
                } else {
                    {{name}} = null;
                }"""

    def getWriteTemplate(self):
        return """out.writeString({{name}} != null ? {{name}}.name() : null);"""

class SimpleTypeNameAdapter(TemplateAdapter):
    """Extend this adapter for anything that doesn't need complicated type
    matching regex. It will help matching against package name too. eg. If you
    pass in Calendar, it will match against Calendar as well as
    java.util.Calendar"""

    def __init__(self, supportedTypeStr):
        """supportedTypeStr is expected to be a string."""
        self.supportedType = re.compile( \
                r"(.+\.|)({supportedTypeStr})" \
                .format(supportedTypeStr = supportedTypeStr))

    def getSupportedType(self):
        return self.supportedType

class CalendarAdapter(SimpleTypeNameAdapter):
    """Use this adapter for Calendar type."""

    def __init__(self, supportedTypeStr = "Calendar"):
        super(CalendarAdapter, self).__init__(supportedTypeStr)

    def getReadTemplate(self):
        return """String {{name}}TimeZoneStr = in.readString();
                if ({{name}}TimeZoneStr != null) {
                    {{name}} = {{dataType}}.getInstance();
                    {{name}}.setTimeZone(TimeZone.getTimeZone({{name}}TimeZoneStr));
                    {{name}}.setTimeInMillis(in.readLong());
                } else {
                    {{name}} = null;
                }"""

    def getWriteTemplate(self):
        return """if ({{name}} != null) {
                    out.writeString({{name}}.getTimeZone().getID());
                    out.writeLong({{name}}.getTimeInMillis());
                } else {
                    out.writeString(null);
                }"""

class GregorianCalendarAdapter(CalendarAdapter):
    """Use this adapter for GregorianCalenar type."""

    def __init__(self, supportedTypeStr = "GregorianCalendar"):
        super(GregorianCalendarAdapter, self).__init__(supportedTypeStr)

    def getReadTemplate(self):
        return """String {{name}}TimeZoneStr = in.readString();
                if ({{name}}TimeZoneStr != null) {
                    {{name}} = new {{dataType}}(TimeZone.getTimeZone({{name}}TimeZoneStr));
                    {{name}}.setTimeInMillis(in.readLong());
                } else {
                    {{name}} = null;
                }"""

class StringSerializableTypeAdapter(TemplateAdapter):
    """Extend this abstract adapter for anything that can be serialized with
    its own toString() method."""

    def getWriteTemplate(self):
        return """out.writeString({{name}} != null ? {{name}}.toString() : null);"""

class XMLGregorianCalendarAdapter(SimpleTypeNameAdapter, StringSerializableTypeAdapter):
    """Use this adapter for XMLGregorianCalenar type."""

    def __init__(self, supportedTypeStr = "XMLGregorianCalendar"):
        super(XMLGregorianCalendarAdapter, self).__init__(supportedTypeStr)

    def getReadTemplate(self):
        return """String {{name}}Str = in.readString();
                if ({{name}}Str != null) {
                    try {
                        {{name}} = javax.xml.datatype.DatatypeFactory.newInstance().newXMLGregorianCalendar({{name}}Str);
                    } catch (DatatypeConfigurationException dce) {}
                } else {
                    {{name}} = null;
                }"""

class StringConstructorAdapter(SimpleTypeNameAdapter,
        StringSerializableTypeAdapter):
    """Use this adapter for anyting that can be deserialized from String by
    using its constructor."""

    def getReadTemplate(self):
        return """String {{name}}Str = in.readString();
                if ({{name}}Str != null) {
                    {{name}} = new {{dataType}}({{name}}Str);
                } else {
                    {{name}} = null;
                }"""

class ValueOfAdapter(SimpleTypeNameAdapter,
        StringSerializableTypeAdapter):
    """Use this adapter for anyting that can be deserialized from String by
    using its valueOf() method."""

    def getReadTemplate(self):
        return """String {{name}}Str = in.readString();
                if ({{name}}Str != null) {
                    {{name}} = {{dataType}}.valueOf({{name}}Str);
                } else {
                    {{name}} = null;
                }"""

def main():
    lines = sys.stdin.readlines()
    gen = ConfiguredGenerator()

    for line in lines:
        m = MEMBER_REGEX.match(line)

        if m:
            gen.addMember(m.group(2), m.group(3))
            continue;

        m = CLASS_REGEX.match(line)
        
        if m:
            gen.setClassName(m.group(3))
            continue

    gen.gen()

main()