pos printer introduced

src/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_subdirectory("core")
+add_subdirectory("printer")
 add_subdirectory("gui")

src/printer/CMakeLists.txt

@@ -0,0 +1,9 @@
+find_package(LibUSB REQUIRED)
+
+set(PRINTER_SOURCES
+    posprinter.cpp
+)
+
+add_library(printer STATIC ${PRINTER_SOURCES})
+target_link_libraries(printer ${LibUSB_LIBRARY})
+target_include_directories(printer PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

src/printer/posprinter.cpp

@@ -0,0 +1,54 @@
+#include "posprinter.h"
+
+#include <exception>
+#include <iostream>
+#include <string>
+
+PosPrinter::PosPrinter() : PosPrinter(std::pair<int, int>{0x0456, 0x0808}) {}
+
+PosPrinter::PosPrinter(std::pair<int, int> vendorModelId)
+{
+    int retValue;
+
+    retValue = libusb_init(&contextPtr_);
+    if (retValue < 0) {
+        throw std::runtime_error("Init error");
+    }
+
+    // libusb_set_debug(contextPtr_, 3); // set verbosity level to 3, as suggested in the
+    // documentation
+
+    devicePtr_ =
+        libusb_open_device_with_vid_pid(contextPtr_, vendorModelId.first,
+                                        vendorModelId.second); // these are vendorID and productID
+    if (devicePtr_ == NULL) {
+        throw std::runtime_error("Cannot open printer device");
+    }
+
+    // ...
+}
+
+PosPrinter::~PosPrinter()
+{
+    int retValue;
+    retValue = libusb_release_interface(devicePtr_, 0); // release the claimed interface
+    if (retValue != 0) {
+        std::cout << "Cannot Release Interface" << std::endl;
+    } else {
+        std::cout << "Released Interface" << 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)
+{
+    if (!instance_) {
+        instance_ = new PosPrinter(vendorModelId);
+    }
+}
+
+PosPrinter* PosPrinter::getInstance() { return instance_; }

src/printer/posprinter.h

@@ -0,0 +1,22 @@
+#ifndef POS_PRINTER_H
+#define POS_PRINTER_H
+
+#include <memory>
+
+#include <libusb-1.0/libusb.h>
+
+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_;
+    libusb_context* contextPtr_{};
+    libusb_device_handle* devicePtr_{};
+};
+
+#endif