Reintroduce newlines via multiple text flags

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/PtouchPrint.cpp

@@ -37,7 +37,7 @@
 
 #include "CLI/Option.hpp"
 #include "PrinterDriverFactory.hpp"
-#include "graphics/Label.hpp"
+#include "graphics/LabelBuilder.hpp"
 #include "graphics/interface/ILabel.hpp"
 #include "libusbwrap/UsbDeviceFactory.hpp"
 
@@ -162,25 +162,21 @@ int PtouchPrint::run() {
         return 0;
     }
 
-    auto label = std::make_unique<graphics::Label>(printer->getPrinterInfo().pixelLines);
+    // Use LabelBuilder to construct the label
-    std::string labelText{};
+    graphics::LabelBuilder labelBuilder(printer->getPrinterInfo().pixelLines);
-    // TODO: refactor
+
     for (const auto& [cmd, value] : mCommands) {
         switch (cmd) {
             case CliCmdType::Text:
-                if (labelText.empty()) {
+                labelBuilder.addText(value);
-                    labelText = value;
-                } else {
-                    labelText = labelText + '\n' + value;
-                }
                 break;
             case CliCmdType::Font:
                 spdlog::debug("Setting font to {}", value);
-                label->setFontFamily(value);
+                labelBuilder.setFontFamily(value);
                 break;
             case CliCmdType::FontSize:
                 spdlog::debug("Setting font size to {}", std::stod(value));
-                label->setFontSize(std::stod(value));
+                labelBuilder.setFontSize(std::stod(value));
                 break;
             case CliCmdType::HAlign:
                 spdlog::debug("Setting text horizontal alignment to {}", value);
@@ -188,9 +184,9 @@ int PtouchPrint::run() {
                     auto hPos = HALignPositionMap.find(value);
                     if (hPos == HALignPositionMap.end()) {
                         spdlog::warn("Invalid horizontal alignment specified!");
-                        label->setHAlign(HAlignPosition::UNKNOWN);
+                        labelBuilder.setHAlign(HAlignPosition::UNKNOWN);
                     } else {
-                        label->setHAlign(hPos->second);
+                        labelBuilder.setHAlign(hPos->second);
                     }
                 }
                 break;
@@ -199,10 +195,10 @@ int PtouchPrint::run() {
                 {
                     auto vPos = VALignPositionMap.find(value);
                     if (vPos == VALignPositionMap.end()) {
-                        spdlog::warn("Invalid verical alignment specified!");
+                        spdlog::warn("Invalid vertical alignment specified!");
-                        label->setVAlign(VAlignPosition::UNKNOWN);
+                        labelBuilder.setVAlign(VAlignPosition::UNKNOWN);
                     } else {
-                        label->setVAlign(vPos->second);
+                        labelBuilder.setVAlign(vPos->second);
                     }
                 }
                 break;
@@ -213,8 +209,8 @@ int PtouchPrint::run() {
                 break;
         }
     }
-    label->create(labelText);
+
-    label->writeToPng("./testlabel.png");
+    auto label = labelBuilder.build();
     if (!printer->printLabel(std::move(label))) {
         spdlog::error("An error occured while printing");
         return -1;

src/graphics/LabelBuilder.cpp

@@ -0,0 +1,95 @@
+/*
+    ptrnt - print labels on linux
+    Copyright (C) 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/>.
+
+ */
+
+#include "LabelBuilder.hpp"
+
+#include <spdlog/spdlog.h>
+
+#include "Label.hpp"
+
+namespace ptprnt::graphics {
+
+LabelBuilder::LabelBuilder(int printerHeight) : mPrinterHeight(printerHeight) {
+    reset();
+}
+
+ILabelBuilder& LabelBuilder::addText(const std::string& text) {
+    if (!text.empty()) {
+        if (!mAccumulatedText.empty()) {
+            // Add a newline if the label already has some text accumulated
+            mAccumulatedText += '\n';
+        }
+        mAccumulatedText += text;
+        spdlog::debug("LabelBuilder: Added text '{}', total length: {}", text, mAccumulatedText.length());
+    }
+    return *this;
+}
+
+ILabelBuilder& LabelBuilder::setFontFamily(const std::string& fontFamily) {
+    mCurrentFontFamily = fontFamily;
+    spdlog::debug("LabelBuilder: Set font family to '{}'", fontFamily);
+    return *this;
+}
+
+ILabelBuilder& LabelBuilder::setFontSize(double fontSize) {
+    mCurrentFontSize = fontSize;
+    spdlog::debug("LabelBuilder: Set font size to {}", fontSize);
+    return *this;
+}
+
+ILabelBuilder& LabelBuilder::setHAlign(HAlignPosition hAlign) {
+    mCurrentHAlign = hAlign;
+    spdlog::debug("LabelBuilder: Set horizontal alignment to {}", static_cast<int>(hAlign));
+    return *this;
+}
+
+ILabelBuilder& LabelBuilder::setVAlign(VAlignPosition vAlign) {
+    mCurrentVAlign = vAlign;
+    spdlog::debug("LabelBuilder: Set vertical alignment to {}", static_cast<int>(vAlign));
+    return *this;
+}
+
+std::unique_ptr<ILabel> LabelBuilder::build() {
+    spdlog::debug("LabelBuilder: Building label with text: '{}'", mAccumulatedText);
+
+    auto label = std::make_unique<Label>(mPrinterHeight);
+
+    // Apply current formatting settings
+    label->setFontFamily(mCurrentFontFamily);
+    label->setFontSize(mCurrentFontSize);
+    label->setHAlign(mCurrentHAlign);
+    label->setVAlign(mCurrentVAlign);
+
+    // Create the label with accumulated text
+    label->create(mAccumulatedText);
+
+    return label;
+}
+
+ILabelBuilder& LabelBuilder::reset() {
+    mAccumulatedText.clear();
+    mCurrentFontFamily = DEFAULT_FONT_FAMILY;
+    mCurrentFontSize   = DEFAULT_FONT_SIZE;
+    mCurrentHAlign     = HAlignPosition::LEFT;
+    mCurrentVAlign     = VAlignPosition::MIDDLE;
+    spdlog::debug("LabelBuilder: Reset to default state");
+    return *this;
+}
+
+}  // namespace ptprnt::graphics

src/graphics/LabelBuilder.hpp

@@ -0,0 +1,64 @@
+/*
+    ptrnt - print labels on linux
+    Copyright (C) 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 <memory>
+#include <string>
+#include <vector>
+
+#include "interface/ILabel.hpp"
+#include "interface/ILabelBuilder.hpp"
+
+namespace ptprnt::graphics {
+
+/**
+ * @brief Concrete implementation of ILabelBuilder
+ *
+ * Builds labels by accumulating text segments with formatting options,
+ * then creates a Label instance with all the collected content.
+ */
+class LabelBuilder : public ILabelBuilder {
+   public:
+    /**
+     * @brief Construct a LabelBuilder for a specific printer height
+     * @param printerHeight Height of the printer in pixels (tape width)
+     */
+    explicit LabelBuilder(int printerHeight);
+
+    ~LabelBuilder() override = default;
+
+    ILabelBuilder& addText(const std::string& text) override;
+    ILabelBuilder& setFontFamily(const std::string& fontFamily) override;
+    ILabelBuilder& setFontSize(double fontSize) override;
+    ILabelBuilder& setHAlign(HAlignPosition hAlign) override;
+    ILabelBuilder& setVAlign(VAlignPosition vAlign) override;
+    std::unique_ptr<ILabel> build() override;
+    ILabelBuilder& reset() override;
+
+   private:
+    int mPrinterHeight;
+    std::string mAccumulatedText;
+    std::string mCurrentFontFamily{DEFAULT_FONT_FAMILY};
+    double mCurrentFontSize{DEFAULT_FONT_SIZE};
+    HAlignPosition mCurrentHAlign{HAlignPosition::LEFT};
+    VAlignPosition mCurrentVAlign{VAlignPosition::MIDDLE};
+};
+
+}  // namespace ptprnt::graphics

src/graphics/interface/ILabelBuilder.hpp

@@ -0,0 +1,88 @@
+/*
+    ptrnt - print labels on linux
+    Copyright (C) 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 <memory>
+#include <string>
+
+#include "ILabel.hpp"
+
+namespace ptprnt::graphics {
+
+/**
+ * @brief Builder interface for creating labels with text and formatting options
+ *
+ * The LabelBuilder provides a fluent API for constructing labels with various
+ * text elements, fonts, sizes, and alignment options. It separates the construction
+ * logic from the label rendering logic, making it easier to test and maintain.
+ */
+class ILabelBuilder {
+   public:
+    virtual ~ILabelBuilder() = default;
+
+    /**
+     * @brief Add text to the label with current formatting settings
+     * @param text The text to add
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& addText(const std::string& text) = 0;
+
+    /**
+     * @brief Set the font family for subsequent text additions
+     * @param fontFamily Font family name (e.g., "sans", "serif", "monospace")
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& setFontFamily(const std::string& fontFamily) = 0;
+
+    /**
+     * @brief Set the font size for subsequent text additions
+     * @param fontSize Font size in points
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& setFontSize(double fontSize) = 0;
+
+    /**
+     * @brief Set horizontal alignment for subsequent text additions
+     * @param hAlign Horizontal alignment position
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& setHAlign(HAlignPosition hAlign) = 0;
+
+    /**
+     * @brief Set vertical alignment for subsequent text additions
+     * @param vAlign Vertical alignment position
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& setVAlign(VAlignPosition vAlign) = 0;
+
+    /**
+     * @brief Build and return the label with all added content
+     * @return Unique pointer to the constructed label
+     */
+    virtual std::unique_ptr<ILabel> build() = 0;
+
+    /**
+     * @brief Reset the builder to initial state
+     * @return Reference to this builder for method chaining
+     */
+    virtual ILabelBuilder& reset() = 0;
+};
+
+}  // namespace ptprnt::graphics

src/meson.build

@@ -12,6 +12,7 @@ ptprnt_hpps = files (
     'PrinterDriverFactory.hpp',
     'graphics/Bitmap.hpp',
     'graphics/Label.hpp',
+    'graphics/LabelBuilder.hpp',
     'graphics/Monochrome.hpp'
 )
 
@@ -21,6 +22,7 @@ ptprnt_srcs = files (
     'printers/P700Printer.cpp',
     'printers/FakePrinter.cpp',
     'graphics/Label.cpp',
+    'graphics/LabelBuilder.cpp',
     'graphics/Bitmap.cpp',
     'graphics/Monochrome.cpp',
     'libusbwrap/UsbDeviceFactory.cpp',