pdfMerge.cpp

//Built statically with cmake under VS Community 2019
//https://github.com/kiyolee/zlib-win-build
//http://download.savannah.gnu.org/releases/freetype/freetype-2.10.2.tar.gz
//
//https://sourceforge.net/projects/podofo/files/latest/download
//cmake .. -DZLIB_INCLUDE_DIR=C:\Temp\podofo-static\build\zlib -DZLIB_LIBRARY_RELEASE=C:\Temp\zlib-win-build-main\zlib-win-build-main\build-VS2019\Release\libz.lib -A Win32 -DPODOFO_BUILD_STATIC:BOOL=TRUE -DCMAKE_BUILD_TYPE=Release -DFREETYPE_INCLUDE_DIR=C:\Temp\podofo-static\build\freetype\include -DFREETYPE_LIBRARY_RELEASE=C:\Temp\podofo-static\build\freetype\objs\Win32\Release Static\freetype.lib -DPODOFO_BUILD_SHARED=FALSE
//
//Own PDF Merge App VS configuration :
//Include :
//C:\Temp\podofo-static\src
//WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)
//Link:
//C:\Temp\podofo-static;C:\Temp\zlib-win-build-main\zlib-win-build-main\build-VS2019\Release;C:\Temp\podofo-static\build\freetype\objs\Win32\Release Static
//podofo.lib;freetype.lib;libz.lib;%(AdditionalDependencies)
//Windows (/SUBSYSTEM:WINDOWS)
///libpath:C:/Temp/podofo-static/podofo.lib /libpath:C:\Temp\zlib-win-build-main\zlib-win-build-main\build-VS2019\Release\libz.lib /libpath:C:\Temp\podofo-static\build\freetype\objs\freetype.lib



#include <windows.h>
#include <string>
#pragma comment(lib, "Ws2_32.lib")
#include <podofo/podofo.h>
#include "resource.h"
using namespace std;

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
HANDLE hwndButton;

void CenterWindow(HWND);
LPWSTR stringToLPWSTR(const string& instr);
void mergePDF(vector<char*> inputfiles, char* outputfile);
vector<string> split(string s, string delimiter);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow)
{
    MSG msg;
    WNDCLASSW wc = { 0 };
    wc.lpszClassName = L"MPDF";
    wc.hInstance = hInstance;
    wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
    wc.lpfnWndProc = WndProc;
    wc.hCursor = LoadCursor(0, IDC_ARROW);
    wc.hIcon = LoadIcon(GetModuleHandle(NULL), MAKEINTRESOURCE(IDI_MYICON));
    RegisterClassW(&wc);
    CreateWindowW(wc.lpszClassName, L"MPDF", WS_SYSMENU | WS_CAPTION | WS_MINIMIZEBOX | WS_VISIBLE, 260, 134, 220, 220, 0, 0, hInstance, 0);
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_KEYDOWN:
        if (wParam == VK_ESCAPE) {
            int ret = MessageBoxW(hwnd, L"Are you sure you want to quit?",
                L"Message", MB_OKCANCEL);
            if (ret == IDOK) {
                SendMessage(hwnd, WM_CLOSE, 0, 0);
            }
        }
        break;
    case WM_CREATE:
        CenterWindow(hwnd);
        hwndButton = CreateWindowW(L"Button", L"Click to Merge PDFs", WS_VISIBLE | WS_CHILD, 0, 0, 210, 190, hwnd, (HMENU)ID_BUTTON, NULL, NULL);
        break;
    case WM_COMMAND:
        if (LOWORD(wParam) == ID_BUTTON)
        {
            string path(MAX_PATH, '\0');
            OPENFILENAME ofn;
            TCHAR szFile[MAX_PATH];
            ZeroMemory(&ofn, sizeof(ofn));
            ofn.lStructSize = sizeof(ofn);
            ofn.lpstrFile = (LPWSTR)&path[0];
            ofn.lpstrFile[0] = '\0';
            ofn.hwndOwner = NULL;
            ofn.nMaxFile = sizeof(szFile);
            ofn.lpstrFilter = TEXT("Pdf Files\0*.pdf\0Any File\0*.*\0");
            ofn.nFilterIndex = 1;
            ofn.lpstrTitle = TEXT("Select PDF files");
            ofn.lpstrInitialDir = L"";
            ofn.Flags = OFN_DONTADDTORECENT | OFN_FILEMUSTEXIST | OFN_ALLOWMULTISELECT;
            if (GetOpenFileName(&ofn))
            {
                OutputDebugString(ofn.lpstrFile);
                int cSize = WideCharToMultiByte(CP_ACP, 0, ofn.lpstrFile, wcslen(ofn.lpstrFile), NULL, 0, NULL, NULL);
                string output(static_cast<size_t>(cSize), '\0');
                WideCharToMultiByte(CP_ACP, 0, ofn.lpstrFile, wcslen(ofn.lpstrFile), reinterpret_cast<char*>(&output[0]), cSize, NULL, NULL);
                string delimiter = " ";
                vector<string> v = split(output, delimiter);
                vector<char*> inputfiles;
                for (unsigned int i = 1; i < v.size();i++) {
                    string output = v[0] + v[i];
                    char* theFilePath = new char[100];
                    strcpy(theFilePath, output.c_str());
                    inputfiles.emplace_back(theFilePath);
                }
                PoDoFo::PdfError::EnableDebug(false);
                char* outputfile = new char[100];
                WCHAR path[MAX_PATH];
                GetCurrentDirectory(MAX_PATH, path);
                std::wstring fileName;
                fileName = L"\\output.pdf";
                wcscat(path, fileName.c_str());

                sprintf(outputfile, "%ws", path);
                try {
                    mergePDF(inputfiles, outputfile);
                }
                catch (const PoDoFo::PdfError& e) {
                    OutputDebugStringA("Error occured during pdf merge!");
                    e.PrintErrorMsg();
                    return e.GetError();
                }
                OutputDebugString(ofn.lpstrFile);
            }
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    }
    return DefWindowProcW(hwnd, msg, wParam, lParam);
}

void CenterWindow(HWND hwnd)
{
    RECT rc = { 0 };
    GetWindowRect(hwnd, &rc);
    int win_w = rc.right - rc.left;
    int win_h = rc.bottom - rc.top;
    int screen_w = GetSystemMetrics(SM_CXSCREEN);
    int screen_h = GetSystemMetrics(SM_CYSCREEN);
    SetWindowPos(hwnd, HWND_TOP, (screen_w - win_w) / 2, (screen_h - win_h) / 2, 0, 0, SWP_NOSIZE);
}

LPWSTR stringToLPWSTR(const string& instr)
{
    int bufferlen = ::MultiByteToWideChar(CP_ACP, 0, instr.c_str(), instr.size(), NULL, 0);
    LPWSTR widestr = new WCHAR[bufferlen + 1];
    ::MultiByteToWideChar(CP_ACP, 0, instr.c_str(), instr.size(), widestr, bufferlen);
    widestr[bufferlen] = 0;
    return widestr;
}

void mergePDF(vector<char*> inputfiles, char* outputfile) {
    try {
        PoDoFo::PdfMemDocument firstDoc;
        firstDoc.Load(inputfiles[0]);
        for (int k = 1; k < inputfiles.size(); k++) {
            PoDoFo::PdfMemDocument doc;
            doc.Load(inputfiles[k]);
            firstDoc.Append(doc);
        }
         firstDoc.Write(outputfile);
    }
    catch (const PoDoFo::PdfError& e) {
        throw e;
    }
}

vector<string> split(string s, string delimiter) {
    size_t pos_start = 0, pos_end, delim_len = delimiter.length();
    string token;
    vector<string> res;

    while ((pos_end = s.find(delimiter, pos_start)) != string::npos) {
        token = s.substr(pos_start, pos_end - pos_start);
        pos_start = pos_end + delim_len;
        res.push_back(token);
    }

    res.push_back(s.substr(pos_start));
    return res;
}