widget/windows/WindowsEMF.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "WindowsEMF.h"
   7
   8 namespace mozilla {
   9 namespace widget {
  10
  11 WindowsEMF::WindowsEMF() : mEmf(nullptr), mDC(nullptr) {}
  12
  13 WindowsEMF::~WindowsEMF() { ReleaseAllResource(); }
  14
  15 bool WindowsEMF::InitForDrawing(const wchar_t* aMetafilePath /* = nullptr */) {
  16   ReleaseAllResource();
  17
  18   mDC = ::CreateEnhMetaFile(nullptr, aMetafilePath, nullptr, nullptr);
  19   return !!mDC;
  20 }
  21
  22 bool WindowsEMF::InitFromFileContents(const wchar_t* aMetafilePath) {
  23   MOZ_ASSERT(aMetafilePath);
  24   ReleaseAllResource();
  25
  26   mEmf = ::GetEnhMetaFileW(aMetafilePath);
  27   return !!mEmf;
  28 }
  29
  30 bool WindowsEMF::InitFromFileContents(LPBYTE aBytes, UINT aSize) {
  31   MOZ_ASSERT(aBytes && aSize != 0);
  32   ReleaseAllResource();
  33
  34   mEmf = SetEnhMetaFileBits(aSize, aBytes);
  35
  36   return !!mEmf;
  37 }
  38
  39 bool WindowsEMF::FinishDocument() {
  40   if (mDC) {
  41     mEmf = ::CloseEnhMetaFile(mDC);
  42     mDC = nullptr;
  43   }
  44   return !!mEmf;
  45 }
  46
  47 void WindowsEMF::ReleaseEMFHandle() {
  48   if (mEmf) {
  49     ::DeleteEnhMetaFile(mEmf);
  50     mEmf = nullptr;
  51   }
  52 }
  53
  54 void WindowsEMF::ReleaseAllResource() {
  55   FinishDocument();
  56   ReleaseEMFHandle();
  57 }
  58
  59 bool WindowsEMF::Playback(HDC aDeviceContext, const RECT& aRect) {
  60   DebugOnly<bool> result = FinishDocument();
  61   MOZ_ASSERT(result, "This function should be used after InitXXX.");
  62
  63   return ::PlayEnhMetaFile(aDeviceContext, mEmf, &aRect) != 0;
  64 }
  65
  66 bool WindowsEMF::SaveToFile() {
  67   DebugOnly<bool> result = FinishDocument();
  68   MOZ_ASSERT(result, "This function should be used after InitXXX.");
  69
  70   ReleaseEMFHandle();
  71   return true;
  72 }
  73
  74 UINT WindowsEMF::GetEMFContentSize() {
  75   DebugOnly<bool> result = FinishDocument();
  76   MOZ_ASSERT(result, "This function should be used after InitXXX.");
  77
  78   return GetEnhMetaFileBits(mEmf, 0, NULL);
  79 }
  80
  81 bool WindowsEMF::GetEMFContentBits(LPBYTE aBytes) {
  82   DebugOnly<bool> result = FinishDocument();
  83   MOZ_ASSERT(result, "This function should be used after InitXXX.");
  84
  85   UINT emfSize = GetEMFContentSize();
  86   if (GetEnhMetaFileBits(mEmf, emfSize, aBytes) != emfSize) {
  87     return false;
  88   }
  89
  90   return true;
  91 }
  92
  93 }  // namespace widget
  94 }  // namespace mozilla