factory.c

   1 #include <shlobj.h>
   2 #include "menuengine.h"
   3 #include "factory.h"
   4 #include "ext.h"
   5 #include "menu.h"
   6 #include "columns.h"
   7
   8 /*
   9  * Since COM objects cannot be constructed like your traditional object (i.e.
  10  * with a proper constructor), they have to be constructed by another object,
  11  * the class factory.
  12  *
  13  * The class factory is an object which exists exactly once, and it cannot
  14  * be constructed or destroyed.  Its sole purpose is to construct objects
  15  * given an interface.
  16  */
  17
  18 STDMETHODIMP class_factory_query_interface(IClassFactory *this,
  19                                            REFIID guid, void **pointer)
  20 {
  21         if (!IsEqualIID(guid, &IID_IUnknown) &&
  22                         !IsEqualIID(guid, &IID_IClassFactory)) {
  23                 *pointer = 0;
  24                 return E_NOINTERFACE;
  25         }
  26
  27         *pointer = this;
  28         return NOERROR;
  29 }
  30
  31 static ULONG STDMETHODCALLTYPE return_one(IClassFactory *this)
  32 {
  33         return(1);
  34 }
  35
  36 static STDMETHODIMP create_instance(IClassFactory *this_,
  37                 IUnknown *outer, REFIID guid, void **pointer)
  38 {
  39         HRESULT result;
  40         struct git_data *data;
  41
  42         *pointer = 0;
  43
  44         if (outer)
  45                 return CLASS_E_NOAGGREGATION;
  46
  47         if (!(data = GlobalAlloc(GMEM_FIXED, sizeof(struct git_data))))
  48                 return E_OUTOFMEMORY;
  49         memset(data, 0, sizeof(struct git_data));
  50
  51         data->shell_ext.virtual_table = &git_shell_ext_virtual_table;
  52         data->menu.virtual_table = &git_menu_virtual_table;
  53         data->columns.virtual_table = &git_columns_virtual_table;
  54         data->shell_ext.git_data = data->menu.git_data =
  55                 data->columns.git_data = data;
  56
  57         result = query_interface_git_data(data, guid, pointer);
  58         if (!result)
  59                 InterlockedIncrement(&object_count);
  60         return result;
  61 }
  62
  63 static STDMETHODIMP lock_server(IClassFactory *this, BOOL lock)
  64 {
  65         if (lock)
  66                 InterlockedIncrement(&lock_count);
  67         else
  68                 InterlockedDecrement(&lock_count);
  69
  70         return NOERROR;
  71 }
  72
  73 IClassFactoryVtbl factory_virtual_table = {
  74         class_factory_query_interface,
  75         return_one,
  76         return_one,
  77         create_instance,
  78         lock_server
  79 };
  80
  81 IClassFactory factory = {
  82         &factory_virtual_table
  83 };