gecko-dev/widget/gtk/nsPSPrinters.cpp

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ex: set tabstop=8 softtabstop=4 shiftwidth=4 expandtab: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nscore.h"
#include "nsCUPSShim.h"
#include "nsIServiceManager.h"
#include "nsPSPrinters.h"
#include "nsReadableUtils.h"        // StringBeginsWith()
#include "nsCUPSShim.h"
#include "mozilla/Preferences.h"

#include "prlink.h"
#include "prenv.h"
#include "plstr.h"

using namespace mozilla;

#define NS_CUPS_PRINTER "CUPS/"
#define NS_CUPS_PRINTER_LEN (sizeof(NS_CUPS_PRINTER) - 1)

/* dummy printer name for the gfx/src/ps driver */
#define NS_POSTSCRIPT_DRIVER_NAME "PostScript/"

nsCUPSShim gCupsShim;

nsPSPrinterList::nsPSPrinterList()
{
    // Should we try cups?
    if (Preferences::GetBool("print.postscript.cups.enabled", true) &&
        !gCupsShim.IsInitialized()) {
        gCupsShim.Init();
    }
}


/* Check whether the PostScript module has been disabled at runtime */
bool
nsPSPrinterList::Enabled()
{
    const char *val = PR_GetEnv("MOZILLA_POSTSCRIPT_ENABLED");
    if (val && (val[0] == '0' || !PL_strcasecmp(val, "false")))
        return false;

    // is the PS module enabled?
    return Preferences::GetBool("print.postscript.enabled", true);
}


/* Fetch a list of printers handled by the PostsScript module */
void
nsPSPrinterList::GetPrinterList(nsTArray<nsCString>& aList)
{
    aList.Clear();

    // Query CUPS for a printer list. The default printer goes to the
    // head of the output list; others are appended.
    if (gCupsShim.IsInitialized()) {
        cups_dest_t *dests;

        int num_dests = (gCupsShim.mCupsGetDests)(&dests);
        if (num_dests) {
            for (int i = 0; i < num_dests; i++) {
                nsAutoCString fullName(NS_CUPS_PRINTER);
                fullName.Append(dests[i].name);
                if (dests[i].instance != nullptr) {
                    fullName.Append('/');
                    fullName.Append(dests[i].instance);
                }
                if (dests[i].is_default)
                    aList.InsertElementAt(0, fullName);
                else
                    aList.AppendElement(fullName);
            }
        }
        (gCupsShim.mCupsFreeDests)(num_dests, dests);
    }

    // Build the "classic" list of printers -- those accessed by running
    // an opaque command. This list always contains a printer named "default".
    // In addition, we look for either an environment variable
    // MOZILLA_POSTSCRIPT_PRINTER_LIST or a preference setting
    // print.printer_list, which contains a space-separated list of printer
    // names.
    aList.AppendElement(
            NS_LITERAL_CSTRING(NS_POSTSCRIPT_DRIVER_NAME "default"));

    nsAutoCString list(PR_GetEnv("MOZILLA_POSTSCRIPT_PRINTER_LIST"));
    if (list.IsEmpty()) {
        list = Preferences::GetCString("print.printer_list");
    }
    if (!list.IsEmpty()) {
        // For each printer (except "default" which was already added),
        // construct a string "PostScript/<name>" and append it to the list.
        char *state;

        for (char *name = PL_strtok_r(list.BeginWriting(), " ", &state);
                nullptr != name;
                name = PL_strtok_r(nullptr, " ", &state)
        ) {
            if (0 != strcmp(name, "default")) {
                nsAutoCString fullName(NS_POSTSCRIPT_DRIVER_NAME);
                fullName.Append(name);
                aList.AppendElement(fullName);
            }
        }
    }
}


/* Identify the printer type */
nsPSPrinterList::PrinterType
nsPSPrinterList::GetPrinterType(const nsACString& aName)
{
    if (StringBeginsWith(aName, NS_LITERAL_CSTRING(NS_POSTSCRIPT_DRIVER_NAME)))
        return kTypePS;
    else if (StringBeginsWith(aName, NS_LITERAL_CSTRING(NS_CUPS_PRINTER)))
        return kTypeCUPS;
    else
        return kTypeUnknown;
}