contrib/jwrapper/src/code_generator.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Copyright 2014 Frédéric Vachon <fredvac@gmail.com>
   4 # Copyright 2015 Alexis Laferrière <alexis.laf@xymus.net>
   5 #
   6 # Licensed under the Apache License, Version 2.0 (the "License");
   7 # you may not use this file except in compliance with the License.
   8 # You may obtain a copy of the License at
   9 #
  10 #     http://www.apache.org/licenses/LICENSE-2.0
  11 #
  12 # Unless required by applicable law or agreed to in writing, software
  13 # distributed under the License is distributed on an "AS IS" BASIS,
  14 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15 # See the License for the specific language governing permissions and
  16 # limitations under the License.
  17
  18 # Services to generate extern class `in "Java"`
  19 module code_generator
  20
  21 intrude import model
  22
  23 class CodeGenerator
  24
  25         # Path to the output file
  26         var file_name: String
  27
  28         # Model of Java class being wrapped
  29         var model: JavaModel
  30
  31         # Comment out methods with unknown (unwrapped) types
  32         var comment_unknown_types: Bool
  33
  34         # Generate stub classes for unknown types used in the generated module
  35         var stub_for_unknown_types: Bool
  36
  37         # Output file
  38         var file_out: Writer = new FileWriter.open(file_name) is lazy, writable
  39
  40         # Name of the Nit module to generate
  41         var module_name: nullable String is lazy do
  42                 if file_name.file_extension == "nit" then
  43                         # Output file ends with .nit, we expect it to be a valid name
  44                         return file_name.basename(".nit")
  45                 else return null
  46         end
  47
  48         # Generate the Nit module into `file_out`
  49         fun generate
  50         do
  51                 # License
  52                 file_out.write license
  53
  54                 # Module declaration
  55                 var module_name = module_name
  56                 if module_name != null then file_out.write "module {module_name}\n"
  57                 file_out.write "\n"
  58
  59                 # All importations
  60                 var imports = new HashSet[String]
  61                 imports.add "import mnit_android\n"
  62                 for jclass in model.classes do
  63                         for import_ in jclass.imports do imports.add "import android::{import_}\n"
  64                 end
  65                 file_out.write imports.join("\n")
  66
  67                 for jclass in model.classes do
  68
  69                         file_out.write gen_class_header(jclass.class_type)
  70
  71                         for id, signatures in jclass.methods do
  72                                 var c = 0
  73                                 for signature in signatures do
  74                                         var nid = id
  75                                         if c > 0 then nid += c.to_s
  76                                         c += 1
  77
  78                                         file_out.write gen_method(jclass, id, nid, signature.return_type, signature.params)
  79                                         file_out.write "\n"
  80                                 end
  81                         end
  82                         file_out.write "end\n\n"
  83                 end
  84
  85                 if stub_for_unknown_types then
  86                         for jtype in model.unknown_types do
  87                                 file_out.write gen_unknown_class_header(jtype)
  88                                 file_out.write "\n"
  89                         end
  90                 end
  91         end
  92
  93         # License for the header of the generated Nit module
  94         var license = """
  95 # This file is part of NIT (http://www.nitlanguage.org).
  96 #
  97 # Licensed under the Apache License, Version 2.0 (the "License");
  98 # you may not use this file except in compliance with the License.
  99 # You may obtain a copy of the License at
 100 #
 101 #     http://www.apache.org/licenses/LICENSE-2.0
 102 #
 103 # Unless required by applicable law or agreed to in writing, software
 104 # distributed under the License is distributed on an "AS IS" BASIS,
 105 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 106 # See the License for the specific language governing permissions and
 107 # limitations under the License.
 108
 109 # This code has been generated using `jwrapper`
 110 """ is writable
 111
 112         fun gen_class_header(jtype: JavaType): String
 113         do
 114                 var temp = new Array[String]
 115                 temp.add("extern class Native{jtype.id} in \"Java\" `\{ {jtype} `\}\n")
 116                 temp.add("\tsuper JavaObject\n\n")
 117
 118                 return temp.join
 119         end
 120
 121         fun gen_unknown_class_header(jtype: JavaType): String
 122         do
 123                 var nit_type: NitType
 124                 if jtype.extern_name.has_generic_params then
 125                         nit_type = jtype.extern_name.generic_params.first
 126                 else
 127                         nit_type = jtype.extern_name
 128                 end
 129
 130                 var temp = new Array[String]
 131                 temp.add("extern class {nit_type} in \"Java\" `\{ {jtype.to_package_name} `\}\n")
 132                 temp.add("\tsuper JavaObject\n\nend\n")
 133
 134                 return temp.join
 135         end
 136
 137         fun gen_method(java_class: JavaClass, jmethod_id, nmethod_id: String, jreturn_type: JavaType, jparam_list: Array[JavaType]): String
 138         do
 139                 var java_params = ""
 140                 var nit_params  = ""
 141                 var nit_id = "arg"
 142                 var nit_id_no = 0
 143                 var nit_types = new Array[NitType]
 144                 var comment = ""
 145
 146                 # Parameters
 147                 for i in [0..jparam_list.length[ do
 148                         var jparam = jparam_list[i]
 149                         var nit_type = jparam.to_nit_type
 150
 151                         if not nit_type.is_complete then
 152                                 if jparam.is_wrapped then
 153                                         java_class.imports.add nit_type.mod.as(not null)
 154                                 else
 155                                         model.unknown_types.add jparam
 156                                         if comment_unknown_types then
 157                                                 comment = "#"
 158                                         else
 159                                                 nit_type = jparam.extern_name
 160                                         end
 161                                 end
 162                         end
 163
 164                         var cast = ""
 165
 166                         if not jparam.is_collection then cast = jparam.param_cast
 167
 168                         nit_types.add(nit_type)
 169                         nit_type.arg_id = "{nit_id}{nit_id_no}"
 170
 171                         if i == jparam_list.length - 1 then
 172                                 java_params += "{cast}{nit_id}{nit_id_no}"
 173                                 nit_params  += "{nit_id}{nit_id_no}: {nit_type}"
 174                         else
 175                                 java_params += "{cast}{nit_id}{nit_id_no}" + ", "
 176                                 nit_params  += "{nit_id}{nit_id_no}: {nit_type}, "
 177                         end
 178
 179                         nit_id_no += 1
 180                 end
 181
 182                 # Method identifier
 183                 var method_id = nmethod_id.to_nit_method_name
 184                 var nit_signature = new Array[String]
 185
 186                 nit_signature.add "\tfun {method_id}"
 187
 188                 if not jparam_list.is_empty then
 189                         nit_signature.add "({nit_params})"
 190                 end
 191
 192                 var return_type = null
 193
 194                 if not jreturn_type.is_void then
 195                         return_type = jreturn_type.to_nit_type
 196
 197                         if not return_type.is_complete then
 198                                 if jreturn_type.is_wrapped then
 199                                         java_class.imports.add return_type.mod.as(not null)
 200                                 else
 201                                         model.unknown_types.add jreturn_type
 202                                         if comment_unknown_types then
 203                                                 comment = "#"
 204                                         else
 205                                                 return_type = jreturn_type.extern_name
 206                                         end
 207                                 end
 208                         end
 209
 210                         nit_signature.add ": {return_type} "
 211                 end
 212
 213                 var temp = new Array[String]
 214
 215                 temp.add(comment + nit_signature.join)
 216
 217                 # FIXME : This huge `if` block is only necessary to copy primitive arrays as long as there's no better way to do it
 218                 if comment == "#" then
 219                         temp.add(" in \"Java\" `\{\n{comment}\t\tself.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 220                 # Methods with return type
 221                 else if return_type != null then
 222                         temp.add(" in \"Java\" `\{\n{comment}\t\treturn {jreturn_type.return_cast}self.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 223                 # Methods without return type
 224                 else if jreturn_type.is_void then
 225                         temp.add(" in \"Java\" `\{\n{comment}\t\tself.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 226                 # No copy
 227                 else
 228                         temp.add(" in \"Java\" `\{\n{comment}\t\tself.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 229                 end
 230
 231                 return temp.join
 232         end
 233 end
 234
 235 redef class String
 236         # Convert the Java method name `self` to the Nit style
 237         #
 238         # * Converts to snake case
 239         # * Strips `Get` and `Set`
 240         # * Add suffix `=` to setters
 241         fun to_nit_method_name: String
 242         do
 243                 var name = self.to_snake_case
 244                 if name.has_prefix("get_") then
 245                         name = name.substring_from(4)
 246                 else if name.has_prefix("set_") then
 247                         name = name.substring_from(4) + "="
 248                 end
 249
 250                 return name
 251         end
 252 end