first steps in printing via libusb

src/gui/settingsdialog.cpp

@@ -24,6 +24,7 @@ SettingsDialog::SettingsDialog(QWidget* parent, Qt::WindowFlags f) : QDialog(par
     connect(ui_.testPosPrinterButton, &QPushButton::clicked, this, [](){
         //PosPrinter::initialize({0, 0});
         PosPrinter printer;
+        printer.printTest();
     });
 }
 

src/printer/posprinter.cpp

@@ -2,8 +2,17 @@
 
 #include <exception>
 #include <iostream>
+#include <sstream>
 #include <string>
 
+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()
 {
     int retValue;
@@ -72,3 +81,39 @@ PosPrinter::~PosPrinter()
     libusb_close(devicePtr_); // close the device we opened
     libusb_exit(contextPtr_); // close the session
 }
+
+void PosPrinter::write(const std::string& text)
+{
+    if (devicePtr_ == NULL)
+        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;
+}
+
+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

@@ -18,6 +18,19 @@ class PosPrinter
   public:
     PosPrinter();
     ~PosPrinter();
+    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_{};