Multilabel support & Label refactoring (#17)

Reviewed-on: moritz/ptouch-prnt#17

src/printers/FakePrinter.cpp

@@ -39,27 +39,30 @@ const PrinterInfo FakePrinter::mInfo = {.driverName = "FakePrinter",
                                         .usbId{0x0000, 0x0000},  // No USB ID - virtual printer created explicitly
                                         .pixelLines = 128};
 
-const std::string_view FakePrinter::getDriverName() {
+std::string_view FakePrinter::getDriverName() {
     return mInfo.driverName;
 }
 
-const std::string_view FakePrinter::getName() {
+std::string_view FakePrinter::getName() {
     return mInfo.name;
 }
 
-const std::string_view FakePrinter::getVersion() {
+std::string_view FakePrinter::getVersion() {
     return mInfo.version;
 }
 
-const PrinterInfo FakePrinter::getPrinterInfo() {
+PrinterInfo FakePrinter::getPrinterInfo() {
     return mInfo;
 }
 
-const PrinterStatus FakePrinter::getPrinterStatus() {
+PrinterStatus FakePrinter::getPrinterStatus() {
+    if (!mHasAttachedDevice) {
+        return {};
+    }
     return mStatus;
 }
 
-const libusbwrap::usbId FakePrinter::getUsbId() {
+libusbwrap::usbId FakePrinter::getUsbId() {
     return mInfo.usbId;
 }
 
@@ -86,6 +89,9 @@ bool FakePrinter::printBitmap(const graphics::Bitmap<graphics::ALPHA8>& bitmap)
 }
 
 bool FakePrinter::printMonochromeData(const graphics::MonochromeData& data) {
+    if (!mHasAttachedDevice) {
+        return false;
+    }
     spdlog::debug("FakePrinter: Simulating printing of {}x{} bitmap", data.width, data.height);
 
     // Simulate the printing process by reconstructing the bitmap
@@ -125,6 +131,9 @@ bool FakePrinter::printLabel(const std::unique_ptr<graphics::ILabel> label) {
 }
 
 bool FakePrinter::print() {
+    if (!mHasAttachedDevice) {
+        return false;
+    }
     spdlog::debug("FakePrinter: Print command (no-op for virtual printer)");
     return true;
 }