factory.c

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