DllUtil.cpp revision 12677:a4299d47bd00 
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
33DllUtil::~DllUtil()
34{
35    if (module != NULL) {
36        ::FreeLibrary(module);
37        module = NULL;
38    }
39}
40
41HMODULE DllUtil::GetModule()
42{
43    if (!module) {
44        module = JDK_LoadSystemLibrary(name);
45    }
46    return module;
47}
48
49FARPROC DllUtil::GetProcAddress(LPCSTR name)
50{
51    if (GetModule()) {
52        return ::GetProcAddress(GetModule(), name);
53    }
54    throw LibraryUnavailableException();
55}
56
57DwmAPI & DwmAPI::GetInstance()
58{
59    static DwmAPI dll;
60    return dll;
61}
62
63DwmAPI::DwmAPI() :
64    DllUtil("DWMAPI.DLL"),
65    DwmIsCompositionEnabledFunction((DllUtil*)this, "DwmIsCompositionEnabled"),
66    DwmGetWindowAttributeFunction((DllUtil*)this, "DwmGetWindowAttribute")
67{
68}
69
70HRESULT DwmAPI::DwmIsCompositionEnabled(BOOL * pfEnabled)
71{
72    if (GetInstance().DwmIsCompositionEnabledFunction()) {
73        return GetInstance().DwmIsCompositionEnabledFunction()(pfEnabled);
74    }
75    throw FunctionUnavailableException();
76}
77
78HRESULT 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}
87