wp_get_typography_font_size_value

wp_get_typography_font_size_value: 這個函式返回指定排版選項的字型大小值（畫素）。它需要兩個引數：排版選項名稱和一個預設值，如果該選項未被設定，則返回: 該函式從資料庫中檢索排版選項，並返回轉換為畫素的字型大小值。

根據給定的字型大小預設，返回一個字型大小值。

考慮到流體排版引數，並試圖根據可用的、有效的值來返回一個CSS公式。

function wp_get_typography_font_size_value( $preset, $should_use_fluid_typography = false ) {
	if ( ! isset( $preset['size'] ) ) {
		return null;
	}

	/*
	 * Catches empty values and 0/'0'.
	 * Fluid calculations cannot be performed on 0.
	 */
	if ( empty( $preset['size'] ) ) {
		return $preset['size'];
	}

	// Checks if fluid font sizes are activated.
	$typography_settings         = wp_get_global_settings( array( 'typography' ) );
	$should_use_fluid_typography = isset( $typography_settings['fluid'] ) && true === $typography_settings['fluid'] ? true : $should_use_fluid_typography;

	if ( ! $should_use_fluid_typography ) {
		return $preset['size'];
	}

	// Defaults.
	$default_maximum_viewport_width   = '1600px';
	$default_minimum_viewport_width   = '768px';
	$default_minimum_font_size_factor = 0.75;
	$default_maximum_font_size_factor = 1.5;
	$default_scale_factor             = 1;
	$default_minimum_font_size_limit  = '14px';

	// Font sizes.
	$fluid_font_size_settings = isset( $preset['fluid'] ) ? $preset['fluid'] : null;

	// A font size has explicitly bypassed fluid calculations.
	if ( false === $fluid_font_size_settings ) {
		return $preset['size'];
	}

	// Try to grab explicit min and max fluid font sizes.
	$minimum_font_size_raw = isset( $fluid_font_size_settings['min'] ) ? $fluid_font_size_settings['min'] : null;
	$maximum_font_size_raw = isset( $fluid_font_size_settings['max'] ) ? $fluid_font_size_settings['max'] : null;

	// Font sizes.
	$preferred_size = wp_get_typography_value_and_unit( $preset['size'] );

	// Protect against unsupported units.
	if ( empty( $preferred_size['unit'] ) ) {
		return $preset['size'];
	}

	// If no fluid max font size is available, create one using max font size factor.
	if ( ! $maximum_font_size_raw ) {
		$maximum_font_size_raw = round( $preferred_size['value'] * $default_maximum_font_size_factor, 3 ) . $preferred_size['unit'];
	}

	// If no fluid min font size is available, create one using min font size factor.
	if ( ! $minimum_font_size_raw ) {
		$minimum_font_size_raw = round( $preferred_size['value'] * $default_minimum_font_size_factor, 3 ) . $preferred_size['unit'];
	}

	// Normalizes the minimum font size limit according to the incoming unit, so we can perform checks using it.
	$minimum_font_size_limit = wp_get_typography_value_and_unit(
		$default_minimum_font_size_limit,
		array(
			'coerce_to' => $preferred_size['unit'],
		)
	);

	if ( ! empty( $minimum_font_size_limit ) ) {
		/*
		 * If a minimum size was not passed to this function
		 * and the user-defined font size is lower than $minimum_font_size_limit,
		 * then use the user-defined font size as the minimum font-size.
		 */
		if ( ! isset( $fluid_font_size_settings['min'] ) && $preferred_size['value'] < $minimum_font_size_limit['value'] ) {
			$minimum_font_size_raw = implode( '', $preferred_size );
		} else {
			$minimum_font_size_parsed = wp_get_typography_value_and_unit(
				$minimum_font_size_raw,
				array(
					'coerce_to' => $preferred_size['unit'],
				)
			);

			/*
			 * If the passed or calculated minimum font size is lower than $minimum_font_size_limit
			 * use $minimum_font_size_limit instead.
			 */
			if ( ! empty( $minimum_font_size_parsed ) && $minimum_font_size_parsed['value'] < $minimum_font_size_limit['value'] ) {
				$minimum_font_size_raw = implode( '', $minimum_font_size_limit );
			}
		}
	}

	$fluid_font_size_value = wp_get_computed_fluid_typography_value(
		array(
			'minimum_viewport_width' => $default_minimum_viewport_width,
			'maximum_viewport_width' => $default_maximum_viewport_width,
			'minimum_font_size'      => $minimum_font_size_raw,
			'maximum_font_size'      => $maximum_font_size_raw,
			'scale_factor'           => $default_scale_factor,
		)
	);

	if ( ! empty( $fluid_font_size_value ) ) {
		return $fluid_font_size_value;
	}

	return $preset['size'];
}