05 The class TextStyle

See example 7

The text styles control the format of text output. Text styles define the font as well as the text color and the background color. There are getters and setters for all of the attributes of a text style. You can define the following attributes in a text style:

• name
• bold
• italic
• underline
• sizeDelta – relative change of the size in terms of the base text style (positive or negative)
• size – absolute size of the font in points
• fontFamily – the font e.g., Helvetica
• textColor
• backgroundColor

The default text style has a font size of nine points and uses the font family Helvetica. The text color is black, and the background is white. The flags bold, italic and underline are false and the sizeDelta value is zero.

There is a flag for almost every attribute in a text style which reflects if the attribute has been set or if the value of the base text style should be used. The only exception is $sizeDelta which value is used directly. Therefore, a getter function in the text style class looks like this.

public function isBold(): bool
{
    if ($this->boldSet) {
        return $this->bold;
    }
    return $this->defaultStyle != null && $this->defaultStyle->isBold();
}

First there is check if the value has been set, if yes, the function returns the value of the object otherwise it returns the value of the base style. In the constructor of a text style the flags all are set to false.

The flags will be set by the setter function as you can see in the following example.

public function setBold(bool $bold): void
{
    $this->boldSet = true;
    $this->bold = $bold;
}

}

You can reset all of these flags by calling the resetToDefault function for a text style.