Add a printer factory to simplify construction of printer drivers (#11)

Co-authored-by: Moritz Martinius <mm@cloudprinters.de>
Reviewed-on: #11

tests/meson.build

@@ -1,14 +1,38 @@
-tests = [['bitmap_test', 'bitmap_test_exe', ptprnt_srcs + ['bitmap_test/bitmap_test.cpp']],
-         ['image_test', 'image_test_exe', ptprnt_srcs +['image_test/image_test.cpp']],
-         ['monochrome_test', 'monochrome_test_exe', ptprnt_srcs +['monochrome_test/monochrome_test.cpp']]
-        ]
+tests = [
+    [
+        'bitmap_test',
+        'bitmap_test_exe',
+        ['../src/graphics/Bitmap.cpp', 'bitmap_test/bitmap_test.cpp'],
+    ],
+    [
+        'image_test',
+        'image_test_exe',
+        ['../src/graphics/Image.cpp', 'image_test/image_test.cpp'],
+    ],
+    [
+        'monochrome_test',
+        'monochrome_test_exe',
+        [
+            '../src/graphics/Monochrome.cpp',
+            'monochrome_test/monochrome_test.cpp',
+        ],
+    ],
+]
 
 foreach test : tests
-    test(test.get(0),
-         executable(test.get(1),
-                    sources: test.get(2),
-                    include_directories: incdir,
-                    dependencies: [gtest_dep, usb_dep, log_dep, pangocairo_dep, cli11_dep]
-         )
+    test(
+        test.get(0),
+        executable(
+            test.get(1),
+            sources: test.get(2),
+            include_directories: incdir,
+            dependencies: [
+                gtest_dep,
+                usb_dep,
+                log_dep,
+                pangocairo_dep,
+                cli11_dep,
+            ],
+        ),
     )
-endforeach
+endforeach