demos/objects/objects-community.c

   1 #include "cll1.h"
   2
   3 /* This is example of advanced C<<1 object oriented features... */
   4
   5 def_interface(Shape, Interface)
   6 {
   7  void method(draw) (Shape self);
   8  void method(move) (Shape self, int x, int y);
   9  str method(desc) (Shape self);
  10  void method(rename) (Shape self, str name);
  11  void method(reset) (Shape self, int x1, int y1, int x2, int y2, int x3, int y3);
  12  float method(area) (Shape self);
  13  int count;
  14 };
  15
  16 /* We intentionaly define heterogenous objects, which share only the interface
  17    binding. Not only we can use different order of variables, and different
  18    names - but we can even store these data on remote systems, etc.  */
  19
  20 def_mem(Tri)
  21 {
  22  interface(Interface);
  23  int x1, y1, x2, y2, x3, y3;
  24  str name;
  25 };
  26
  27 def_mem(Rect)
  28 {
  29  interface(Interface);
  30  str desc;
  31  int x1, y1, x2, y2;
  32 };
  33
  34 def_mem(Circ)
  35 {
  36  interface(Interface);
  37  int x1, y1;
  38  str comment;
  39  int r;
  40 };
  41
  42 def_community(Shape, Interface);
  43
  44 /* Note: interface(Interface); has to be at first position in all objects asociated in community */
  45
  46 def_mem(Object_list)
  47 {
  48  Shape object;
  49  list(Object_list);
  50 };
  51
  52
  53 /* implementation of methods */
  54
  55 void drawTri(Shape community)
  56 {
  57  I_am(self, Tri);
  58
  59  printf("Drawing %s: %d,%d - %d,%d - %d,%d .\n",
  60         self->name, self->x1, self->y1, self->x2, self->y2, self->x3, self->y3);
  61 };
  62
  63 void drawRect(Shape community)
  64 {
  65  I_am(self, Rect);
  66
  67  printf("Drawing %s: %d,%d - %d,%d .\n",
  68         self->desc, self->x1, self->y1, self->x2, self->y2);
  69 };
  70
  71 void drawCirc(Shape community)
  72 {
  73  I_am(self, Circ);
  74
  75  printf("Drawing %s: %d,%d - r=%d .\n",
  76         self->comment, self->x1, self->y1, self->r);
  77 };
  78
  79 void moveTri(Shape community, int x, int y)
  80 {
  81  I_am(self, Tri);
  82
  83  self->x1 += x;
  84  self->y1 += y;
  85  self->x2 += x;
  86  self->y2 += y;
  87  self->x3 += x;
  88  self->y3 += y;
  89 };
  90
  91 void moveRect(Shape community, int x, int y)
  92 {
  93  I_am(self, Rect);
  94
  95  self->x1 += x;
  96  self->y1 += y;
  97  self->x2 += x;
  98  self->y2 += y;
  99 };
 100
 101 void moveCirc(Shape community, int x, int y)
 102 {
 103  I_am(self, Circ);
 104
 105  self->x1 += x;
 106  self->y1 += y;
 107 };
 108
 109 str descTri(Shape community)
 110 {
 111  I_am(self, Tri);
 112
 113  return self->name;
 114 }
 115
 116 str descRect(Shape community)
 117 {
 118  I_am(self, Rect);
 119
 120  return self->desc;
 121 }
 122
 123 str descCirc(Shape community)
 124 {
 125  I_am(self, Circ);
 126
 127  return self->comment;
 128 }
 129
 130 float calcAreaTri(Shape community)
 131 {
 132  I_am(self, Tri);
 133
 134  return 0;
 135 }
 136
 137 float calcAreaRect(Shape community)
 138 {
 139  I_am(self, Rect);
 140
 141  return (self->x2 - self->x1)*(self->y2 - self->y1);
 142 }
 143
 144 float calcAreaCirc(Shape community)
 145 {
 146  I_am(self, Circ);
 147
 148  return PI * self->r * self->r;
 149 }
 150
 151 void setTri(Shape community, int x1, int y1, int x2, int y2, int x3, int y3)
 152 {
 153  I_am(self, Tri);
 154
 155  self->x1 = x1;
 156  self->y1 = y1;
 157  self->x2 = x2;
 158  self->y2 = y2;
 159  self->x3 = x3;
 160  self->y3 = y3;
 161 }
 162
 163 void setRect(Shape community, int x1, int y1, int x2, int y2, int dummy1, int dummy2)
 164 {
 165  I_am(self, Rect);
 166
 167  self->x1 = x1;
 168  self->y1 = y1;
 169  self->x2 = x2;
 170  self->y2 = y2;
 171 }
 172
 173 void setCirc(Shape community, int x1, int y1, int r, int dummy1, int dummy2, int dummy3)
 174 {
 175  I_am(self, Circ);
 176
 177  self->x1 = x1;
 178  self->y1 = y1;
 179  self->r = r;
 180 }
 181
 182 void nameRect(Shape community, str name)
 183 {
 184  I_am(self, Rect);
 185
 186  self->desc = name;
 187 }
 188
 189 /* Example of using object interface methods from inside constructor methods */
 190
 191 construct(Tri,Interface) (Tri self, int x1, int y1, int x2, int y2, int x3, int y3)
 192 {
 193  self->name = "TRIANGLE";
 194  interface_of(self)->count++;
 195  _(reset, self, x1, y1, x2, y2, x3, y3);
 196
 197  return self;
 198 }
 199
 200 construct(Rect,Interface) (Rect self, int x1, int y1, int x2, int y2)
 201 {
 202  self->desc = "rectangle";
 203  interface_of(self)->count++;
 204  _(reset, self, x1, y1, x2, y2, 0, 0);
 205
 206  return self;
 207 }
 208
 209 construct(Circ,Interface) (Circ self, int x1, int y1, int r)
 210 {
 211  self->comment = "Circle";
 212  interface_of(self)->count++;
 213  _(reset, self, x1, y1, r, 0, 0, 0);
 214
 215  return self;
 216 }
 217
 218 /* registration of implemented methods to three interfaces of the same type */
 219
 220 Interface triInterface(void)
 221 {
 222  Get_mem(this, Interface);
 223
 224  this->draw = drawTri;
 225  this->move = moveTri;
 226  this->desc = descTri;
 227  this->rename = NULL;
 228  this->reset = setTri;
 229  this->area = calcAreaTri;
 230  this->count = 0;
 231
 232  return this;
 233 }
 234
 235 Interface rectInterface(void)
 236 {
 237  Get_mem(this, Interface);
 238
 239  this->draw = drawRect;
 240  this->move = moveRect;
 241  this->desc = descRect;
 242  this->rename = nameRect;
 243  this->reset = setRect;
 244  this->area = calcAreaRect;
 245  this->count = 0;
 246
 247  return this;
 248 }
 249
 250 Interface circInterface(void)
 251 {
 252  Get_mem(this, Interface);
 253
 254  this->draw = drawCirc;
 255  this->move = moveCirc;
 256  this->desc = descCirc;
 257  this->rename = NULL;
 258  this->reset = setCirc;
 259  this->area = calcAreaCirc;
 260  this->count = 0;
 261
 262  return this;
 263 }
 264
 265 /* usage of object community inside C<<1 program */
 266
 267 program
 268 {
 269  Interface triangles = triInterface();
 270  Interface rectangles = rectInterface();
 271  Interface circles = circInterface();
 272  Object_list all = NULL, one;
 273
 274  one = get_mem(Object_list);
 275  one->object = get_obj_as(Shape, Rect, rectangles, 0, 10, 1, 11);
 276  append(one, all);
 277
 278  one = get_mem(Object_list);
 279  one->object = get_obj_as(Shape, Tri, triangles, 0, 0, 0, 4, 3, 0);
 280  append(one, all);
 281
 282  one = get_mem(Object_list);
 283  one->object = get_obj_as(Shape, Rect, rectangles, 10, 0, 11, 1);
 284  append(one, all);
 285
 286  one = get_mem(Object_list);
 287  one->object = get_obj_as(Shape, Circ, circles, 0, 10, 1);
 288  append(one, all);
 289
 290  printf("We have created %d triangles, %d rectangles and %d circles:\n",
 291         triangles->count, rectangles->count, circles->count);
 292
 293  for_each(one, all)
 294  {
 295   _(draw, one->object);
 296   printf("Area of this %s is %f (square pixels).\n", _(desc, one->object), _(area, one->object));
 297   printf("We have created %d instances of this type of object.\n", interface_of(one->object)->count);
 298
 299   if(interface_of(one->object) == rectangles)
 300   {
 301    _(reset, one->object, 0, 0, 1, 1, 0, 0);
 302    _(rename, one->object, "Renamed rectangle");
 303   }
 304   else
 305   {
 306    _(move, one->object, 10, 10);
 307   }
 308  }
 309
 310  print("Rectangles were reset to new size and renamed, other objects were moved:");
 311  for_each(one, all)
 312  {
 313   _(draw, one->object);
 314  }
 315 }