1 /*
   2  * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 
  27 #include "DllUtil.h"
  28 #include <jdk_util.h>
  29 
  30 // Disable warning about using this in the initializer list.
  31 #pragma warning( disable : 4355)
  32 
  33 DllUtil::~DllUtil()
  34 {
  35     if (module != NULL) {
  36         ::FreeLibrary(module);
  37         module = NULL;
  38     }
  39 }
  40 
  41 HMODULE DllUtil::GetModule()
  42 {
  43     if (!module) {
  44         module = JDK_LoadSystemLibrary(name);
  45     }
  46     return module;
  47 }
  48 
  49 FARPROC DllUtil::GetProcAddress(LPCSTR name)
  50 {
  51     if (GetModule()) {
  52         return ::GetProcAddress(GetModule(), name);
  53     }
  54     throw LibraryUnavailableException();
  55 }
  56 
  57 DwmAPI & DwmAPI::GetInstance()
  58 {
  59     static DwmAPI dll;
  60     return dll;
  61 }
  62 
  63 DwmAPI::DwmAPI() :
  64     DllUtil("DWMAPI.DLL"),
  65     DwmIsCompositionEnabledFunction((DllUtil*)this, "DwmIsCompositionEnabled"),
  66     DwmGetWindowAttributeFunction((DllUtil*)this, "DwmGetWindowAttribute")
  67 {
  68 }
  69 
  70 HRESULT DwmAPI::DwmIsCompositionEnabled(BOOL * pfEnabled)
  71 {
  72     if (GetInstance().DwmIsCompositionEnabledFunction()) {
  73         return GetInstance().DwmIsCompositionEnabledFunction()(pfEnabled);
  74     }
  75     throw FunctionUnavailableException();
  76 }
  77 
  78 HRESULT DwmAPI::DwmGetWindowAttribute(HWND hwnd, DWORD dwAttribute,
  79         PVOID pvAttribute, DWORD cbAttribute)
  80 {
  81     if (GetInstance().DwmGetWindowAttributeFunction()) {
  82         return GetInstance().DwmGetWindowAttributeFunction()(hwnd, dwAttribute,
  83                 pvAttribute, cbAttribute);
  84     }
  85     throw FunctionUnavailableException();
  86 }