Generate labels with pangocairo (#8)

Goal of this PR is to have some basic labels generated with pangocairo
- size of the canvas should be matching the input text and grow/shrink accordingly
- basic formatting options like fontsize and align should be working

Reviewed-on: moritz/ptouch-prnt#8

src/graphics/interface/ILabel.hpp

@@ -0,0 +1,80 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2024-2025  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <vector>
+
+constexpr const char* DEFAULT_FONT_FAMILY = "sans";
+constexpr const double DEFAULT_FONT_SIZE  = 32.0;
+
+enum class HAlignPosition {
+    UNKNOWN = 0,
+    LEFT    = 1,
+    CENTER  = 2,
+    RIGHT   = 3,
+    JUSTIFY = 4,
+};
+const std::map<std::string, HAlignPosition> HALignPositionMap{{"", HAlignPosition::UNKNOWN},
+                                                              {"left", HAlignPosition::LEFT},
+                                                              {"center", HAlignPosition::CENTER},
+                                                              {"right", HAlignPosition::RIGHT},
+                                                              {"justify", HAlignPosition::JUSTIFY}};
+
+enum class VAlignPosition {
+    UNKNOWN = 0,
+    TOP     = 1,
+    MIDDLE  = 2,
+    BOTTOM  = 3,
+};
+
+const std::map<std::string, VAlignPosition> VALignPositionMap{{"", VAlignPosition::UNKNOWN},
+                                                              {"top", VAlignPosition::TOP},
+                                                              {"middle", VAlignPosition::MIDDLE},
+                                                              {"bottom", VAlignPosition::BOTTOM}};
+
+struct PrintableText {
+    std::string text{""};
+    std::string fontFamily{DEFAULT_FONT_FAMILY};
+    double fontSize{DEFAULT_FONT_SIZE};
+    HAlignPosition hAlign{HAlignPosition::LEFT};
+    VAlignPosition vAlign{VAlignPosition::MIDDLE};
+};
+
+namespace ptprnt::graphics {
+class ILabel {
+   public:
+    virtual ~ILabel() = default;
+
+    virtual bool create(PrintableText printableText)  = 0;
+    virtual bool create(const std::string& labelText) = 0;
+    virtual std::vector<uint8_t> getRaw()             = 0;
+    virtual int getWidth()                            = 0;
+    virtual int getHeight()                           = 0;
+
+    virtual void setText(const std::string& text)             = 0;
+    virtual void setFontSize(const double fontSize)           = 0;
+    virtual void setFontFamily(const std::string& fontFamily) = 0;
+    virtual void setHAlign(HAlignPosition hpos)               = 0;
+    virtual void setVAlign(VAlignPosition vpos)               = 0;
+};
+}  // namespace ptprnt::graphics