Move Style classes into Common folder (#432)

src/Spout/Writer/Common/Creator/Style/BorderBuilder.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Creator\Style;
+
+use Box\Spout\Writer\Common\Entity\Style\Border;
+use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Writer\Common\Entity\Style\Color;
+
+/**
+ * Class BorderBuilder
+ *
+ * @package \Box\Spout\Writer\Common\Creator\Style
+ */
+class BorderBuilder
+{
+    /**
+     * @var Border
+     */
+    protected $border;
+
+    public function __construct()
+    {
+        $this->border = new Border();
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderTop($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::TOP, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderRight($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::RIGHT, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderBottom($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::BOTTOM, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderLeft($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::LEFT, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @return Border
+     */
+    public function build()
+    {
+        return $this->border;
+    }
+}

src/Spout/Writer/Common/Creator/Style/StyleBuilder.php

@@ -0,0 +1,162 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Creator\Style;
+
+use Box\Spout\Writer\Common\Entity\Style\Border;
+use Box\Spout\Writer\Common\Entity\Style\Style;
+
+/**
+ * Class StyleBuilder
+ * Builder to create new styles
+ *
+ * @package Box\Spout\Writer\Common\Creator\Style
+ */
+class StyleBuilder
+{
+    /** @var Style Style to be created */
+    protected $style;
+
+    /**
+     *
+     */
+    public function __construct()
+    {
+        $this->style = new Style();
+    }
+
+    /**
+     * Makes the font bold.
+     *
+     * @api
+     * @return StyleBuilder
+     */
+    public function setFontBold()
+    {
+        $this->style->setFontBold();
+        return $this;
+    }
+
+    /**
+     * Makes the font italic.
+     *
+     * @api
+     * @return StyleBuilder
+     */
+    public function setFontItalic()
+    {
+        $this->style->setFontItalic();
+        return $this;
+    }
+
+    /**
+     * Makes the font underlined.
+     *
+     * @api
+     * @return StyleBuilder
+     */
+    public function setFontUnderline()
+    {
+        $this->style->setFontUnderline();
+        return $this;
+    }
+
+    /**
+     * Makes the font struck through.
+     *
+     * @api
+     * @return StyleBuilder
+     */
+    public function setFontStrikethrough()
+    {
+        $this->style->setFontStrikethrough();
+        return $this;
+    }
+
+    /**
+     * Sets the font size.
+     *
+     * @api
+     * @param int $fontSize Font size, in pixels
+     * @return StyleBuilder
+     */
+    public function setFontSize($fontSize)
+    {
+        $this->style->setFontSize($fontSize);
+        return $this;
+    }
+
+    /**
+     * Sets the font color.
+     *
+     * @api
+     * @param string $fontColor ARGB color (@see Color)
+     * @return StyleBuilder
+     */
+    public function setFontColor($fontColor)
+    {
+        $this->style->setFontColor($fontColor);
+        return $this;
+    }
+
+    /**
+     * Sets the font name.
+     *
+     * @api
+     * @param string $fontName Name of the font to use
+     * @return StyleBuilder
+     */
+    public function setFontName($fontName)
+    {
+        $this->style->setFontName($fontName);
+        return $this;
+    }
+
+    /**
+     * Makes the text wrap in the cell if requested
+     *
+     * @api
+     * @param bool $shouldWrap Should the text be wrapped
+     * @return StyleBuilder
+     */
+    public function setShouldWrapText($shouldWrap = true)
+    {
+        $this->style->setShouldWrapText($shouldWrap);
+        return $this;
+    }
+
+    /**
+     * Set a border
+     *
+     * @param Border $border
+     * @return $this
+     */
+    public function setBorder(Border $border)
+    {
+        $this->style->setBorder($border);
+        return $this;
+    }
+
+    /**
+     *  Sets a background color
+     *
+     * @api
+     * @param string $color ARGB color (@see Color)
+     * @return StyleBuilder
+     */
+    public function setBackgroundColor($color)
+    {
+        $this->style->setBackgroundColor($color);
+        return $this;
+    }
+
+    /**
+     * Returns the configured style. The style is cached and can be reused.
+     *
+     * @api
+     * @return Style
+     */
+    public function build()
+    {
+        return $this->style;
+    }
+}

src/Spout/Writer/Common/Entity/Style/Border.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Entity\Style;
+
+/**
+ * Class Border
+ *
+ * @package \Box\Spout\Writer\Common\Entity\Style
+ */
+class Border
+{
+    const LEFT = 'left';
+    const RIGHT = 'right';
+    const TOP = 'top';
+    const BOTTOM = 'bottom';
+
+    const STYLE_NONE = 'none';
+    const STYLE_SOLID = 'solid';
+    const STYLE_DASHED = 'dashed';
+    const STYLE_DOTTED = 'dotted';
+    const STYLE_DOUBLE = 'double';
+
+    const WIDTH_THIN = 'thin';
+    const WIDTH_MEDIUM = 'medium';
+    const WIDTH_THICK = 'thick';
+
+    /** @var array A list of BorderPart objects for this border. */
+    private $parts = [];
+
+    /**
+     * @param array|void $borderParts
+     */
+    public function __construct(array $borderParts = [])
+    {
+        $this->setParts($borderParts);
+    }
+
+    /**
+     * @param string $name The name of the border part
+     * @return null|BorderPart
+     */
+    public function getPart($name)
+    {
+        return $this->hasPart($name) ? $this->parts[$name] : null;
+    }
+
+    /**
+     * @param string $name The name of the border part
+     * @return bool
+     */
+    public function hasPart($name)
+    {
+        return isset($this->parts[$name]);
+    }
+
+    /**
+     * @return array
+     */
+    public function getParts()
+    {
+        return $this->parts;
+    }
+
+    /**
+     * Set BorderParts
+     * @param array $parts
+     * @return void
+     */
+    public function setParts($parts)
+    {
+        unset($this->parts);
+        foreach ($parts as $part) {
+            $this->addPart($part);
+        }
+    }
+
+    /**
+     * @param BorderPart $borderPart
+     * @return Border
+     */
+    public function addPart(BorderPart $borderPart)
+    {
+        $this->parts[$borderPart->getName()] = $borderPart;
+        return $this;
+    }
+}

src/Spout/Writer/Common/Entity/Style/BorderPart.php

@@ -0,0 +1,186 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Entity\Style;
+
+use Box\Spout\Writer\Exception\Border\InvalidNameException;
+use Box\Spout\Writer\Exception\Border\InvalidStyleException;
+use Box\Spout\Writer\Exception\Border\InvalidWidthException;
+
+/**
+ * Class BorderPart
+ *
+ * @package \Box\Spout\Writer\Common\Entity\Style
+ */
+class BorderPart
+{
+    /**
+     * @var string The style of this border part.
+     */
+    protected $style;
+
+    /**
+     * @var string The name of this border part.
+     */
+    protected $name;
+
+    /**
+     * @var string The color of this border part.
+     */
+    protected $color;
+
+    /**
+     * @var string The width of this border part.
+     */
+    protected $width;
+
+    /**
+     * @var array Allowed style constants for parts.
+     */
+    protected static $allowedStyles = [
+        'none',
+        'solid',
+        'dashed',
+        'dotted',
+        'double'
+    ];
+
+    /**
+     * @var array Allowed names constants for border parts.
+     */
+    protected static $allowedNames = [
+        'left',
+        'right',
+        'top',
+        'bottom',
+    ];
+
+    /**
+     * @var array Allowed width constants for border parts.
+     */
+    protected static $allowedWidths = [
+        'thin',
+        'medium',
+        'thick',
+    ];
+
+    /**
+     * @param string $name @see  BorderPart::$allowedNames
+     * @param string $color A RGB color code
+     * @param string $width @see BorderPart::$allowedWidths
+     * @param string $style @see BorderPart::$allowedStyles
+     * @throws InvalidNameException
+     * @throws InvalidStyleException
+     * @throws InvalidWidthException
+     */
+    public function __construct($name, $color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->setName($name);
+        $this->setColor($color);
+        $this->setWidth($width);
+        $this->setStyle($style);
+    }
+
+    /**
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * @param string $name The name of the border part @see BorderPart::$allowedNames
+     * @throws InvalidNameException
+     * @return void
+     */
+    public function setName($name)
+    {
+        if (!in_array($name, self::$allowedNames)) {
+            throw new InvalidNameException($name);
+        }
+        $this->name = $name;
+    }
+
+    /**
+     * @return string
+     */
+    public function getStyle()
+    {
+        return $this->style;
+    }
+
+    /**
+     * @param string $style The style of the border part @see BorderPart::$allowedStyles
+     * @throws InvalidStyleException
+     * @return void
+     */
+    public function setStyle($style)
+    {
+        if (!in_array($style, self::$allowedStyles)) {
+            throw new InvalidStyleException($style);
+        }
+        $this->style = $style;
+    }
+
+    /**
+     * @return string
+     */
+    public function getColor()
+    {
+        return $this->color;
+    }
+
+    /**
+     * @param string $color The color of the border part @see Color::rgb()
+     * @return void
+     */
+    public function setColor($color)
+    {
+        $this->color = $color;
+    }
+
+    /**
+     * @return string
+     */
+    public function getWidth()
+    {
+        return $this->width;
+    }
+
+    /**
+     * @param string $width The width of the border part @see BorderPart::$allowedWidths
+     * @throws InvalidWidthException
+     * @return void
+     */
+    public function setWidth($width)
+    {
+        if (!in_array($width, self::$allowedWidths)) {
+            throw new InvalidWidthException($width);
+        }
+        $this->width = $width;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedStyles()
+    {
+        return self::$allowedStyles;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedNames()
+    {
+        return self::$allowedNames;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedWidths()
+    {
+        return self::$allowedWidths;
+    }
+}

src/Spout/Writer/Common/Entity/Style/Color.php

@@ -0,0 +1,87 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Entity\Style;
+
+use Box\Spout\Writer\Exception\InvalidColorException;
+
+/**
+ * Class Color
+ * This class provides constants and functions to work with colors
+ *
+ * @package Box\Spout\Writer\Common\Entity\Style
+ */
+class Color
+{
+    /** Standard colors - based on Office Online */
+    const BLACK = '000000';
+    const WHITE = 'FFFFFF';
+    const RED = 'FF0000';
+    const DARK_RED = 'C00000';
+    const ORANGE = 'FFC000';
+    const YELLOW = 'FFFF00';
+    const LIGHT_GREEN = '92D040';
+    const GREEN = '00B050';
+    const LIGHT_BLUE = '00B0E0';
+    const BLUE = '0070C0';
+    const DARK_BLUE = '002060';
+    const PURPLE = '7030A0';
+
+    /**
+     * Returns an RGB color from R, G and B values
+     *
+     * @api
+     * @param int $red Red component, 0 - 255
+     * @param int $green Green component, 0 - 255
+     * @param int $blue Blue component, 0 - 255
+     * @return string RGB color
+     */
+    public static function rgb($red, $green, $blue)
+    {
+        self::throwIfInvalidColorComponentValue($red);
+        self::throwIfInvalidColorComponentValue($green);
+        self::throwIfInvalidColorComponentValue($blue);
+
+        return strtoupper(
+            self::convertColorComponentToHex($red) .
+            self::convertColorComponentToHex($green) .
+            self::convertColorComponentToHex($blue)
+        );
+    }
+
+    /**
+     * Throws an exception is the color component value is outside of bounds (0 - 255)
+     *
+     * @param int $colorComponent
+     * @return void
+     * @throws \Box\Spout\Writer\Exception\InvalidColorException
+     */
+    protected static function throwIfInvalidColorComponentValue($colorComponent)
+    {
+        if (!is_int($colorComponent) || $colorComponent < 0 || $colorComponent > 255) {
+            throw new InvalidColorException("The RGB components must be between 0 and 255. Received: $colorComponent");
+        }
+    }
+
+    /**
+     * Converts the color component to its corresponding hexadecimal value
+     *
+     * @param int $colorComponent Color component, 0 - 255
+     * @return string Corresponding hexadecimal value, with a leading 0 if needed. E.g "0f", "2d"
+     */
+    protected static function convertColorComponentToHex($colorComponent)
+    {
+        return str_pad(dechex($colorComponent), 2, '0', STR_PAD_LEFT);
+    }
+
+    /**
+     * Returns the ARGB color of the given RGB color,
+     * assuming that alpha value is always 1.
+     *
+     * @param string $rgbColor RGB color like "FF08B2"
+     * @return string ARGB color
+     */
+    public static function toARGB($rgbColor)
+    {
+        return 'FF' . $rgbColor;
+    }
+}

src/Spout/Writer/Common/Entity/Style/Style.php

@@ -0,0 +1,379 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Entity\Style;
+
+/**
+ * Class Style
+ * Represents a style to be applied to a cell
+ *
+ * @package Box\Spout\Writer\Common\Entity\Style
+ */
+class Style
+{
+    /** Default font values */
+    const DEFAULT_FONT_SIZE = 11;
+    const DEFAULT_FONT_COLOR = Color::BLACK;
+    const DEFAULT_FONT_NAME = 'Arial';
+
+    /** @var int|null Style ID */
+    private $id = null;
+
+    /** @var bool Whether the font should be bold */
+    private $fontBold = false;
+    /** @var bool Whether the bold property was set */
+    private $hasSetFontBold = false;
+
+    /** @var bool Whether the font should be italic */
+    private $fontItalic = false;
+    /** @var bool Whether the italic property was set */
+    private $hasSetFontItalic = false;
+
+    /** @var bool Whether the font should be underlined */
+    private $fontUnderline = false;
+    /** @var bool Whether the underline property was set */
+    private $hasSetFontUnderline = false;
+
+    /** @var bool Whether the font should be struck through */
+    private $fontStrikethrough = false;
+    /** @var bool Whether the strikethrough property was set */
+    private $hasSetFontStrikethrough = false;
+
+    /** @var int Font size */
+    private $fontSize = self::DEFAULT_FONT_SIZE;
+    /** @var bool Whether the font size property was set */
+    private $hasSetFontSize = false;
+
+    /** @var string Font color */
+    private $fontColor = self::DEFAULT_FONT_COLOR;
+    /** @var bool Whether the font color property was set */
+    private $hasSetFontColor = false;
+
+    /** @var string Font name */
+    private $fontName = self::DEFAULT_FONT_NAME;
+    /** @var bool Whether the font name property was set */
+    private $hasSetFontName = false;
+
+    /** @var bool Whether specific font properties should be applied */
+    private $shouldApplyFont = false;
+
+    /** @var bool Whether the text should wrap in the cell (useful for long or multi-lines text) */
+    private $shouldWrapText = false;
+    /** @var bool Whether the wrap text property was set */
+    private $hasSetWrapText = false;
+
+    /** @var Border */
+    private $border = null;
+
+    /** @var bool Whether border properties should be applied */
+    private $shouldApplyBorder = false;
+
+    /** @var string Background color */
+    private $backgroundColor = null;
+
+    /** @var bool */
+    private $hasSetBackgroundColor = false;
+
+
+    /**
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * @param int $id
+     * @return Style
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+        return $this;
+    }
+
+    /**
+     * @return Border
+     */
+    public function getBorder()
+    {
+        return $this->border;
+    }
+
+    /**
+     * @param Border $border
+     * @return Style
+     */
+    public function setBorder(Border $border)
+    {
+        $this->shouldApplyBorder = true;
+        $this->border = $border;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function shouldApplyBorder()
+    {
+        return $this->shouldApplyBorder;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isFontBold()
+    {
+        return $this->fontBold;
+    }
+
+    /**
+     * @return Style
+     */
+    public function setFontBold()
+    {
+        $this->fontBold = true;
+        $this->hasSetFontBold = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontBold()
+    {
+        return $this->hasSetFontBold;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isFontItalic()
+    {
+        return $this->fontItalic;
+    }
+
+    /**
+     * @return Style
+     */
+    public function setFontItalic()
+    {
+        $this->fontItalic = true;
+        $this->hasSetFontItalic = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontItalic()
+    {
+        return $this->hasSetFontItalic;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isFontUnderline()
+    {
+        return $this->fontUnderline;
+    }
+
+    /**
+     * @return Style
+     */
+    public function setFontUnderline()
+    {
+        $this->fontUnderline = true;
+        $this->hasSetFontUnderline = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontUnderline()
+    {
+        return $this->hasSetFontUnderline;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isFontStrikethrough()
+    {
+        return $this->fontStrikethrough;
+    }
+
+    /**
+     * @return Style
+     */
+    public function setFontStrikethrough()
+    {
+        $this->fontStrikethrough = true;
+        $this->hasSetFontStrikethrough = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontStrikethrough()
+    {
+        return $this->hasSetFontStrikethrough;
+    }
+
+    /**
+     * @return int
+     */
+    public function getFontSize()
+    {
+        return $this->fontSize;
+    }
+
+    /**
+     * @param int $fontSize Font size, in pixels
+     * @return Style
+     */
+    public function setFontSize($fontSize)
+    {
+        $this->fontSize = $fontSize;
+        $this->hasSetFontSize = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontSize()
+    {
+        return $this->hasSetFontSize;
+    }
+
+    /**
+     * @return string
+     */
+    public function getFontColor()
+    {
+        return $this->fontColor;
+    }
+
+    /**
+     * Sets the font color.
+     *
+     * @param string $fontColor ARGB color (@see Color)
+     * @return Style
+     */
+    public function setFontColor($fontColor)
+    {
+        $this->fontColor = $fontColor;
+        $this->hasSetFontColor = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontColor()
+    {
+        return $this->hasSetFontColor;
+    }
+
+    /**
+     * @return string
+     */
+    public function getFontName()
+    {
+        return $this->fontName;
+    }
+
+    /**
+     * @param string $fontName Name of the font to use
+     * @return Style
+     */
+    public function setFontName($fontName)
+    {
+        $this->fontName = $fontName;
+        $this->hasSetFontName = true;
+        $this->shouldApplyFont = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetFontName()
+    {
+        return $this->hasSetFontName;
+    }
+
+    /**
+     * @return bool
+     */
+    public function shouldWrapText()
+    {
+        return $this->shouldWrapText;
+    }
+
+    /**
+     * @param bool|void $shouldWrap Should the text be wrapped
+     * @return Style
+     */
+    public function setShouldWrapText($shouldWrap = true)
+    {
+        $this->shouldWrapText = $shouldWrap;
+        $this->hasSetWrapText = true;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasSetWrapText()
+    {
+        return $this->hasSetWrapText;
+    }
+
+    /**
+     * @return bool Whether specific font properties should be applied
+     */
+    public function shouldApplyFont()
+    {
+        return $this->shouldApplyFont;
+    }
+
+    /**
+     * Sets the background color
+     * @param string $color ARGB color (@see Color)
+     * @return Style
+     */
+    public function setBackgroundColor($color)
+    {
+        $this->hasSetBackgroundColor = true;
+        $this->backgroundColor = $color;
+        return $this;
+    }
+
+    /**
+     * @return string
+     */
+    public function getBackgroundColor()
+    {
+        return $this->backgroundColor;
+    }
+
+    /**
+     *
+     * @return bool Whether the background color should be applied
+     */
+    public function shouldApplyBackgroundColor()
+    {
+        return $this->hasSetBackgroundColor;
+    }
+}

src/Spout/Writer/Common/Helper/StyleHelperAbstract.php

@@ -2,6 +2,9 @@
 
 namespace Box\Spout\Writer\Common\Helper;
 
+use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Writer\Common\Manager\StyleManager;
+
 /**
  * Class StyleHelperAbstract
  * This class provides helper functions to manage styles
@@ -10,6 +13,9 @@ namespace Box\Spout\Writer\Common\Helper;
  */
 abstract class StyleHelperAbstract implements StyleHelperInterface
 {
+    /** @var StyleManager Style manager */
+    private $styleManager;
+
     /** @var array [SERIALIZED_STYLE] => [STYLE_ID] mapping table, keeping track of the registered styles */
     protected $serializedStyleToStyleIdMappingTable = [];
 
@@ -17,10 +23,13 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
     protected $styleIdToStyleMappingTable = [];
 
     /**
-     * @param \Box\Spout\Writer\Style\Style $defaultStyle
+     * @param Style $defaultStyle
+     * @param StyleManager $styleManager
      */
-    public function __construct($defaultStyle)
+    public function __construct(Style $defaultStyle, StyleManager $styleManager)
     {
+        $this->styleManager = $styleManager;
+
         // This ensures that the default style is the first one to be registered
         $this->registerStyle($defaultStyle);
     }
@@ -29,12 +38,12 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
      * Registers the given style as a used style.
      * Duplicate styles won't be registered more than once.
      *
-     * @param \Box\Spout\Writer\Style\Style $style The style to be registered
-     * @return \Box\Spout\Writer\Style\Style The registered style, updated with an internal ID.
+     * @param Style $style The style to be registered
+     * @return Style The registered style, updated with an internal ID.
      */
     public function registerStyle($style)
     {
-        $serializedStyle = $style->serialize();
+        $serializedStyle = $this->styleManager->serialize($style);
 
         if (!$this->hasStyleAlreadyBeenRegistered($style)) {
             $nextStyleId = count($this->serializedStyleToStyleIdMappingTable);
@@ -50,12 +59,12 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
     /**
      * Returns whether the given style has already been registered.
      *
-     * @param \Box\Spout\Writer\Style\Style $style
+     * @param Style $style
      * @return bool
      */
     protected function hasStyleAlreadyBeenRegistered($style)
     {
-        $serializedStyle = $style->serialize();
+        $serializedStyle = $this->styleManager->serialize($style);
 
         // Using isset here because it is way faster than array_key_exists...
         return isset($this->serializedStyleToStyleIdMappingTable[$serializedStyle]);
@@ -65,7 +74,7 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
      * Returns the registered style associated to the given serialization.
      *
      * @param string $serializedStyle The serialized style from which the actual style should be fetched from
-     * @return \Box\Spout\Writer\Style\Style
+     * @return Style
      */
     protected function getStyleFromSerializedStyle($serializedStyle)
     {
@@ -74,7 +83,7 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
     }
 
     /**
-     * @return \Box\Spout\Writer\Style\Style[] List of registered styles
+     * @return Style[] List of registered styles
      */
     protected function getRegisteredStyles()
     {
@@ -84,7 +93,7 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
     /**
      * Returns the default style
      *
-     * @return \Box\Spout\Writer\Style\Style Default style
+     * @return Style Default style
      */
     protected function getDefaultStyle()
     {
@@ -96,9 +105,9 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
      * Apply additional styles if the given row needs it.
      * Typically, set "wrap text" if a cell contains a new line.
      *
-     * @param \Box\Spout\Writer\Style\Style $style The original style
+     * @param Style $style The original style
      * @param array $dataRow The row the style will be applied to
-     * @return \Box\Spout\Writer\Style\Style The updated style
+     * @return Style The updated style
      */
     public function applyExtraStylesIfNeeded($style, $dataRow)
     {
@@ -115,9 +124,9 @@ abstract class StyleHelperAbstract implements StyleHelperInterface
      *        A workaround would be to encode "\n" as "_x000D_" but it does not work
      *        on the Windows version of Excel...
      *
-     * @param \Box\Spout\Writer\Style\Style $style The original style
+     * @param Style $style The original style
      * @param array $dataRow The row the style will be applied to
-     * @return \Box\Spout\Writer\Style\Style The eventually updated style
+     * @return Style The eventually updated style
      */
     protected function applyWrapTextIfCellContainsNewLine($style, $dataRow)
     {

src/Spout/Writer/Common/Helper/StyleHelperInterface.php

@@ -13,8 +13,8 @@ interface StyleHelperInterface
      * Registers the given style as a used style.
      * Duplicate styles won't be registered more than once.
      *
-     * @param \Box\Spout\Writer\Style\Style $style The style to be registered
-     * @return \Box\Spout\Writer\Style\Style The registered style, updated with an internal ID.
+     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style The style to be registered
+     * @return \Box\Spout\Writer\Common\Entity\Style\Style The registered style, updated with an internal ID.
      */
     public function registerStyle($style);
 
@@ -22,9 +22,9 @@ interface StyleHelperInterface
      * Apply additional styles if the given row needs it.
      * Typically, set "wrap text" if a cell contains a new line.
      *
-     * @param \Box\Spout\Writer\Style\Style $style The original style
+     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style The original style
      * @param array $dataRow The row the style will be applied to
-     * @return \Box\Spout\Writer\Style\Style The updated style
+     * @return \Box\Spout\Writer\Common\Entity\Style\Style The updated style
      */
     public function applyExtraStylesIfNeeded($style, $dataRow);
 }

src/Spout/Writer/Common/Manager/StyleManager.php

@@ -0,0 +1,118 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Manager;
+
+use Box\Spout\Writer\Common\Entity\Style\Style;
+
+/**
+ * Class StyleManager
+ * Manages styles to be applied to a cell
+ *
+ * @package Box\Spout\Writer\Common\Manager\Style
+ */
+class StyleManager
+{
+    /**
+     * Serializes the style for future comparison with other styles.
+     * The ID is excluded from the comparison, as we only care about
+     * actual style properties.
+     *
+     * @param Style $style
+     * @return string The serialized style
+     */
+    public function serialize(Style $style)
+    {
+        // In order to be able to properly compare style, set static ID value
+        $currentId = $style->getId();
+        $style->setId(0);
+
+        $serializedStyle = serialize($style);
+
+        $style->setId($currentId);
+
+        return $serializedStyle;
+    }
+
+    /**
+     * Merges the current style with the given style, using the given style as a base. This means that:
+     *   - if current style and base style both have property A set, use current style property's value
+     *   - if current style has property A set but base style does not, use current style property's value
+     *   - if base style has property A set but current style does not, use base style property's value
+     *
+     * @NOTE: This function returns a new style.
+     *
+     * @param Style $style
+     * @param Style $baseStyle
+     * @return Style New style corresponding to the merge of the 2 styles
+     */
+    public function merge(Style $style, Style $baseStyle)
+    {
+        $mergedStyle = clone $style;
+
+        $this->mergeFontStyles($mergedStyle, $style, $baseStyle);
+        $this->mergeOtherFontProperties($mergedStyle, $style, $baseStyle);
+        $this->mergeCellProperties($mergedStyle, $style, $baseStyle);
+
+        return $mergedStyle;
+    }
+
+    /**
+     * @param Style $styleToUpdate (passed as reference)
+     * @param Style $style
+     * @param Style $baseStyle
+     * @return void
+     */
+    private function mergeFontStyles(Style $styleToUpdate, Style $style, Style $baseStyle)
+    {
+        if (!$style->hasSetFontBold() && $baseStyle->isFontBold()) {
+            $styleToUpdate->setFontBold();
+        }
+        if (!$style->hasSetFontItalic() && $baseStyle->isFontItalic()) {
+            $styleToUpdate->setFontItalic();
+        }
+        if (!$style->hasSetFontUnderline() && $baseStyle->isFontUnderline()) {
+            $styleToUpdate->setFontUnderline();
+        }
+        if (!$style->hasSetFontStrikethrough() && $baseStyle->isFontStrikethrough()) {
+            $styleToUpdate->setFontStrikethrough();
+        }
+    }
+
+    /**
+     * @param Style $styleToUpdate Style to update (passed as reference)
+     * @param Style $style
+     * @param Style $baseStyle
+     * @return void
+     */
+    private function mergeOtherFontProperties(Style $styleToUpdate, Style $style, Style $baseStyle)
+    {
+        if (!$style->hasSetFontSize() && $baseStyle->getFontSize() !== Style::DEFAULT_FONT_SIZE) {
+            $styleToUpdate->setFontSize($baseStyle->getFontSize());
+        }
+        if (!$style->hasSetFontColor() && $baseStyle->getFontColor() !== Style::DEFAULT_FONT_COLOR) {
+            $styleToUpdate->setFontColor($baseStyle->getFontColor());
+        }
+        if (!$style->hasSetFontName() && $baseStyle->getFontName() !== Style::DEFAULT_FONT_NAME) {
+            $styleToUpdate->setFontName($baseStyle->getFontName());
+        }
+    }
+
+    /**
+     * @param Style $styleToUpdate Style to update (passed as reference)
+     * @param Style $style
+     * @param Style $baseStyle
+     * @return void
+     */
+    private function mergeCellProperties(Style $styleToUpdate, Style $style, Style $baseStyle)
+    {
+        if (!$style->hasSetWrapText() && $baseStyle->shouldWrapText()) {
+            $styleToUpdate->setShouldWrapText();
+        }
+        if (!$style->getBorder() && $baseStyle->shouldApplyBorder()) {
+            $styleToUpdate->setBorder($baseStyle->getBorder());
+        }
+        if (!$style->shouldApplyBackgroundColor() && $baseStyle->shouldApplyBackgroundColor()) {
+            $styleToUpdate->setBackgroundColor($baseStyle->getBackgroundColor());
+        }
+    }
+}

src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php

@@ -12,7 +12,7 @@ use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\Exception\SheetNotFoundException;
 use Box\Spout\Writer\Exception\WriterException;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
-use Box\Spout\Writer\Style\Style;
+use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Class WorkbookManagerAbstract

src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php

@@ -8,7 +8,7 @@ use Box\Spout\Writer\Common\Entity\Workbook;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\Exception\SheetNotFoundException;
 use Box\Spout\Writer\Exception\WriterException;
-use Box\Spout\Writer\Style\Style;
+use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Interface WorkbookManagerInterface

src/Spout/Writer/Common/Manager/WorksheetManagerInterface.php

@@ -3,7 +3,7 @@
 namespace Box\Spout\Writer\Common\Manager;
 
 use Box\Spout\Writer\Common\Entity\Worksheet;
-use Box\Spout\Writer\Style\Style;
+use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Interface WorksheetManagerInterface