The mouse DLL now loads Interception.

MainApp/MouseDll.cs

@@ -5,12 +5,14 @@ namespace MouseInterception
 {
     class MouseDll
     {
+        // NOTE: The first place DLL's are loaded from are the application directory.
+        private const string DLL_NAME = "mouse.dll" ;
 
-        [DllImport( @"mouse.dll" , CallingConvention=CallingConvention.Cdecl )]
+        [DllImport( @DLL_NAME , CallingConvention=CallingConvention.Cdecl )]
         [return: MarshalAs(UnmanagedType.BStr)]
         private static extern string open_api() ;
 
-        [DllImport( @"mouse.dll" , CallingConvention=CallingConvention.Cdecl )]
+        [DllImport( @DLL_NAME , CallingConvention=CallingConvention.Cdecl )]
         [return: MarshalAs(UnmanagedType.BStr)]
         private static extern string close_api() ;
 

MouseDll/main.cpp

@@ -1,21 +1,39 @@
+#include <windows.h>
 #include <stdexcept>
+#include <cassert>
 #include "main.hpp"
+#include "utils.hpp"
 
 using namespace std ;
 
 // --- LOCAL DATA ------------------------------------------------------
 
-static bool gIsOpen = false ;
+static HMODULE ghInterceptionDll = NULL ;
 
 // ---------------------------------------------------------------------
 
 void
 openApi()
 {
-    // open the API
-    if ( gIsOpen )
+    // check if we are open
+    if ( ghInterceptionDll != NULL )
         throw runtime_error( "API is already open." ) ;
-    gIsOpen = true ;
+
+    // load Interception
+    wchar_t buf[ _MAX_PATH+1 ] ;
+    GetModuleFileName( NULL , buf , ARRAY_SIZE(buf) ) ;
+    wchar_t drive[_MAX_DIR+1] , dir[_MAX_DIR+1] , fname[_MAX_FNAME+1] , extn[_MAX_EXT+1] ;
+    errno_t rc = _wsplitpath_s( buf , drive , ARRAY_SIZE(drive) , dir , ARRAY_SIZE(dir) , fname , ARRAY_SIZE(fname) , extn , ARRAY_SIZE(extn) ) ;
+    if ( rc == 0 )
+        _wmakepath_s( buf , ARRAY_SIZE(buf) , drive , dir , L"interception" , L".dll" ) ;
+    else
+    {
+        assert( false ) ;
+        wcscpy_s( buf , ARRAY_SIZE(buf) , L"interception.dll" ) ;
+    }
+    ghInterceptionDll = LoadLibrary( buf ) ;
+    if ( ghInterceptionDll == NULL )
+        throw runtime_error( MAKE_STRING( "Can't load Interception: " << getLastErrorString() ) ) ;
 }
 
 // ---------------------------------------------------------------------
@@ -23,8 +41,11 @@ openApi()
 void
 closeApi()
 {
-    // close the API
-    if ( ! gIsOpen )
+    // check if we are open
+    if ( ghInterceptionDll == NULL )
         throw runtime_error( "API is not open." ) ;
-    gIsOpen = false ;
+
+    // close Interception
+    FreeLibrary( ghInterceptionDll ) ;
+    ghInterceptionDll = NULL ;
 }

MouseDll/utils.cpp

@@ -6,6 +6,34 @@ using namespace std ;
 
 // ---------------------------------------------------------------------
 
+string
+getErrorString( int errorCode )
+{
+    // get the WIN32 error message
+    char buf[ 4*1024 ] = "" ;
+    if ( errorCode != 0 )
+    {
+        DWORD nBytes = FormatMessageA(
+            FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_MAX_WIDTH_MASK ,
+            NULL ,
+            errorCode ,
+            MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT) ,
+            buf , sizeof(buf) ,
+            NULL
+        ) ;
+    }
+    if ( buf[0] != '\0' )
+        return buf ;
+
+    // just return the WIN32 error code
+    sprintf_s( buf , sizeof(buf) , "WIN32 ERROR: %08lX" , errorCode ) ;
+    return buf ;
+}
+
+string getLastErrorString() { return getErrorString( GetLastError() ) ; }
+
+// ---------------------------------------------------------------------
+
 wstring 
 fromUtf8( const char* pStr , int len )
 {

MouseDll/utils.hpp

@@ -6,12 +6,19 @@
 
 // ---------------------------------------------------------------------
 
+extern std::string getLastErrorString() ;
+extern std::string getErrorString( int errorCode ) ;
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 extern std::wstring fromUtf8( const char* pStr , int len=-1 ) ;
 inline std::wstring fromUtf8( const std::string& str ) { return fromUtf8(str.c_str(),str.length()) ; }
 
+#define MAKE_STRING( msg ) ( ((std::ostringstream&)((std::ostream&)std::ostringstream() << msg)).str() )
+
 // ---------------------------------------------------------------------
 
-#define MAKE_STRING( msg ) ( ((std::ostringstream&)((std::ostream&)std::ostringstream() << msg)).str() )
+#define ARRAY_SIZE( arr ) ( sizeof(arr) / sizeof((arr)[0]) )
 
 // ---------------------------------------------------------------------