finder/plugin.c

   1 /* plugin.c
   2  *
   3  * Implementation of a finder menu plugin for git-cheetah
   4  *
   5  * This implements the COM interface for the finder plugin
   6  *
   7  * Copyright (C) Heiko Voigt, 2009
   8  *
   9  * inspired by an example from Brent Simmons
  10  * brent@ranchero.com, http://macte.ch/kmyXM
  11  *
  12  */
  13
  14 #include "../common/git-compat-util.h"
  15 #include "../common/strbuf.h"
  16 #include "../common/debug.h"
  17 #include "../common/menuengine.h"
  18 #include "../common/cheetahmenu.h"
  19 #include "util.h"
  20 #include "menu.h"
  21 #include "plugin.h"
  22
  23 void *create_instance(CFAllocatorRef a, CFUUIDRef id);
  24 static HRESULT query_interface(void *me, REFIID id, LPVOID *ret);
  25 static ULONG retain(void *me);
  26 static ULONG release(void *me);
  27
  28 static ContextualMenuInterfaceStruct plugin_virtual_table = {
  29         NULL,
  30         /* Standard COM */
  31         query_interface,
  32         retain,
  33         release,
  34         /* Context Menu Interface */
  35         query_context_menu,
  36         invoke_command,
  37         cleanup_context_menu
  38 };
  39
  40 void *create_instance(CFAllocatorRef a, CFUUIDRef id)
  41 {
  42         struct plugin_data *me;
  43
  44         if (!CFEqual(id, kContextualMenuTypeID))
  45                 return NULL;
  46
  47         CFPlugInAddInstanceForFactory(myUUID);
  48
  49         me = (struct plugin_data *) malloc(sizeof(struct plugin_data));
  50         memset(me, 0, sizeof(struct plugin_data));
  51
  52         me->virtual_table = &plugin_virtual_table;
  53         me->id = CFRetain(myUUID);
  54         me->num_ref = 1;
  55
  56         return me;
  57 }
  58
  59 static HRESULT query_interface(void *_me, REFIID id, LPVOID *ret)
  60 {
  61         struct plugin_data *me = _me;
  62         Boolean interface_supported = false;
  63         CFUUIDRef query_id = CFUUIDCreateFromUUIDBytes(NULL, id);
  64
  65         if (CFEqual(query_id, kContextualMenuInterfaceID))
  66                 interface_supported = true;
  67
  68         if (CFEqual(query_id, IUnknownUUID))
  69                 interface_supported = true;
  70
  71         CFRelease(query_id);
  72
  73         if (!interface_supported) {
  74                 *ret = NULL;
  75                 return E_NOINTERFACE;
  76         }
  77
  78         retain(me);
  79         *ret = me;
  80
  81         return S_OK;
  82 }
  83
  84 static ULONG retain(void *_me)
  85 {
  86         struct plugin_data *me = _me;
  87         return ++(me->num_ref);
  88 }
  89
  90 static ULONG release(void *_me)
  91 {
  92         struct plugin_data *me = _me;
  93         me->num_ref--;
  94
  95         if (me->num_ref > 0)
  96                 return me->num_ref;
  97
  98         if (me->id) {
  99                 CFPlugInRemoveInstanceForFactory(me->id);
 100                 CFRelease(me->id);
 101         }
 102
 103         free(me);
 104         return 0;
 105 }