first steps in printing via libusb

src/gui/CMakeLists.txt

@@ -29,7 +29,7 @@ set(GUI_SOURCES
 
 add_executable(kima2 ${GUI_SOURCES})
 target_include_directories(kima2 PRIVATE ${PROJECT_BINARY_DIR})
-target_link_libraries(kima2 core Qt5::Widgets Qt5::PrintSupport stdc++fs)
+target_link_libraries(kima2 core printer Qt5::Widgets Qt5::PrintSupport stdc++fs)
 if(WIN32)
     set_target_properties(kima2 PROPERTIES LINK_FLAGS "-mwindows")
 endif(WIN32)

src/gui/settingsdialog.cpp

@@ -1,6 +1,7 @@
 #include "settingsdialog.h"
 
 #include <database.h>
+#include <posprinter.h>
 
 #include <QMessageBox>
 #include <QSettings>
@@ -19,6 +20,12 @@ SettingsDialog::SettingsDialog(QWidget* parent, Qt::WindowFlags f) : QDialog(par
     ui_.posPrinterDeviceEdit->setText(posPrinterDevice);
     ui_.feePercentSpinBox->setValue(feeInPercent);
     ui_.maxFeeSpinBox->setValue(maxFeeInEuro);
+
+    connect(ui_.testPosPrinterButton, &QPushButton::clicked, this, [](){
+        //PosPrinter::initialize({0, 0});
+        PosPrinter printer;
+        printer.printTest();
+    });
 }
 
 void SettingsDialog::accept()

src/printer/CMakeLists.txt

@@ -5,5 +5,5 @@ set(PRINTER_SOURCES
 )
 
 add_library(printer STATIC ${PRINTER_SOURCES})
-target_link_libraries(printer ${LibUSB_LIBRARY})
+target_link_libraries(printer ${LIBUSB_1_LIBRARIES})
 target_include_directories(printer PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

src/printer/posprinter.cpp

@@ -2,11 +2,18 @@
 
 #include <exception>
 #include <iostream>
+#include <sstream>
 #include <string>
 
-PosPrinter::PosPrinter() : PosPrinter(std::pair<int, int>{0x0456, 0x0808}) {}
+const std::string PosPrinter::Command::RESET = {0x1b, 0x40};
+const std::string PosPrinter::Command::ENCODING = {'\x1b', '\x74', 16};
+const std::string PosPrinter::Command::CENTERING = {'\x1b', '\x61', '\x01'};
+const std::string PosPrinter::Command::FONT_SIZE_BIG = {'\x1b', '\x21', '\x10'};
+const std::string PosPrinter::Command::FONT_SIZE_NORMAL = {'\x1b', '\x21', '\x00'};
+const std::string PosPrinter::Command::LEFT_ALIGN = {'\x1b', '\x61', '\x00'};
+const std::string PosPrinter::Command::FEED = {0x1b, 0x64, 0x03};
 
-PosPrinter::PosPrinter(std::pair<int, int> vendorModelId)
+PosPrinter::PosPrinter()
 {
     int retValue;
 
@@ -15,17 +22,50 @@ PosPrinter::PosPrinter(std::pair<int, int> vendorModelId)
         throw std::runtime_error("Init error");
     }
 
-    // libusb_set_debug(contextPtr_, 3); // set verbosity level to 3, as suggested in the
+    libusb_device** devList;
-    // documentation
+    int devCount = libusb_get_device_list(contextPtr_, &devList);
+    if (devCount <= 0) {
+        libusb_exit(contextPtr_);
+        throw std::runtime_error("Could not receive device list");
+    }
+    int numDevice = -1;
+    for (int i = 0; i < devCount; ++i) {
+        libusb_device_descriptor desc;
+        libusb_get_device_descriptor(devList[i], &desc);
+        for (const auto& supported : supportedPrinters_.models) {
+            if (desc.idVendor == supported.first && desc.idProduct == supported.second) {
+                numDevice = i;
+                break;
+            }
+        }
+    }
 
-    devicePtr_ =
+    if (numDevice < 0) {
-        libusb_open_device_with_vid_pid(contextPtr_, vendorModelId.first,
+        libusb_exit(contextPtr_);
-                                        vendorModelId.second); // these are vendorID and productID
+        return;
-    if (devicePtr_ == NULL) {
+    }
+
+    retValue = libusb_open(devList[numDevice], &devicePtr_); // these are vendorID and productID
+    if (retValue != 0) {
+        libusb_free_device_list(devList, 1);
+        libusb_exit(contextPtr_);
         throw std::runtime_error("Cannot open printer device");
     }
 
-    // ...
+    if (libusb_kernel_driver_active(devicePtr_, 0) == 1) { // find out if kernel driver is attached
+        std::cout << "Kernel driver active" << std::endl;
+        if (libusb_detach_kernel_driver(devicePtr_, 0) == 0) // detach it
+            std::cout << "Kernel driver detached!" << std::endl;
+    }
+
+    retValue = libusb_claim_interface(
+        devicePtr_, 0); // claim interface 0 (the first) of device (mine had jsut 1)
+    if (retValue < 0) {
+        std::cout << "Cannot claim printer interface" << std::endl;
+        throw std::runtime_error("Cannot claim printer interface");
+    }
+
+    libusb_free_device_list(devList, 1);
 }
 
 PosPrinter::~PosPrinter()
@@ -33,22 +73,47 @@ PosPrinter::~PosPrinter()
     int retValue;
     retValue = libusb_release_interface(devicePtr_, 0); // release the claimed interface
     if (retValue != 0) {
-        std::cout << "Cannot Release Interface" << std::endl;
+        std::cout << "Cannot release printer interface" << std::endl;
     } else {
-        std::cout << "Released Interface" << std::endl;
+        std::cout << "Printer interface released" << std::endl;
     }
 
     libusb_close(devicePtr_); // close the device we opened
     libusb_exit(contextPtr_); // close the session
-
-    delete instance_;
 }
 
-void PosPrinter::initialize(std::pair<int, int> vendorModelId)
+void PosPrinter::write(const std::string& text)
 {
-    if (!instance_) {
+    if (devicePtr_ == NULL)
-        instance_ = new PosPrinter(vendorModelId);
+        return;
-    }
+    int length = text.length();
+    int actual{0};
+    int retValue = libusb_bulk_transfer(devicePtr_, (0x03 | LIBUSB_ENDPOINT_OUT),
+                                        (unsigned char*)text.c_str(), length, &actual, 10000);
+    if (retValue != 0 || actual != length)
+        std::cerr << "Write Error" << std::endl;
 }
 
-PosPrinter* PosPrinter::getInstance() { return instance_; }
+void PosPrinter::printHeader()
+{
+    std::stringstream commandStream;
+
+    commandStream << Command::RESET << Command::ENCODING << Command::CENTERING
+                  << Command::FONT_SIZE_BIG;
+    commandStream << "Kindersachenmarkt\nDettingen\n\n";
+    commandStream << Command::LEFT_ALIGN << Command::Command::FONT_SIZE_NORMAL;
+
+    write(commandStream.str());
+}
+
+void PosPrinter::printTest()
+{
+    using namespace std::string_literals;
+    std::stringstream commandStream;
+    commandStream << Command::ENCODING;
+    commandStream << "Der Drucker kann von KIMA2\nangesprochen werden.\n\n"
+                  << "Beachten Sie, dass nicht\nalle Modelle Strichcodes\nausdrucken können.";
+    commandStream << Command::FEED;
+    printHeader();
+    write(commandStream.str());
+}

src/printer/posprinter.h

@@ -5,18 +5,37 @@
 
 #include <libusb-1.0/libusb.h>
 
+struct SupportedPrinters {
+    std::array<std::pair<int, int>, 2> models{
+        // {Vendor ID, Model ID}
+        std::make_pair(0x0456, 0x0808),
+        std::make_pair(0x0416, 0x5011),
+    };
+};
+
 class PosPrinter
 {
   public:
-    static void initialize(std::pair<int, int> vendorModelIds);
-    static PosPrinter* getInstance();
-  private:
     PosPrinter();
-    PosPrinter(std::pair<int, int> vendorModelId);
     ~PosPrinter();
-    static PosPrinter* instance_;
+    void write(const std::string& text);
+    void printHeader();
+    void printTest();
+
+    struct Command {
+        static const std::string RESET;
+        static const std::string ENCODING;
+        static const std::string CENTERING;
+        static const std::string FONT_SIZE_BIG;
+        static const std::string FONT_SIZE_NORMAL;
+        static const std::string LEFT_ALIGN;
+        static const std::string FEED;
+    };
+
+  private:
     libusb_context* contextPtr_{};
     libusb_device_handle* devicePtr_{};
+    SupportedPrinters supportedPrinters_;
 };
 
 #endif