source: code/Website/php-ofc-library/ofc_pie.php

<?php

class pie_value
{
        function pie_value( $value, $label )
        {
                $this->value = $value;
                $this->label = $label;
        }
        
        function set_colour( $colour )
        {
                $this->colour = $colour;
        }
        
        function set_label( $label, $label_colour, $font_size )
        {
                $this->label = $label;
                
                $tmp = 'label-colour';
                $this->$tmp = $label_colour;
                
                $tmp = 'font-size';
                $this->$tmp = $font_size;
                
        }
        
        function set_tooltip( $tip )
        {
                $this->tip = $tip;
        }
        
        function on_click( $event )
        {
                $tmp = 'on-click';
                $this->$tmp = $event;
        }
        
        
        /**
         * An object that inherits from base_pie_animation
         */
        function add_animation( $animation )
        {
                if( !isset( $this->animate ) )
                        $this->animate = array();
                        
                $this->animate[] = $animation;
                
                return $this;
        }
}

class base_pie_animation{}

/**
 * fade the pie slice from $alpha (pie set_alpha) to 100% opaque.
 */
class pie_fade extends base_pie_animation
{
        function pie_fade()
        {
                $this->type="fade";
        }
}

/**
 * Bounce the pie slice out a little
 */
class pie_bounce extends base_pie_animation
{
        /**
         * @param $distance as integer, distance to bounce in pixels
         */
        function pie_bounce( $distance )
        {
                $this->type="bounce";
                $this->distance = $distance;
        }
}

/**
 * Make a pie chart and fill it with pie slices
 */
class pie
{
        function pie()
        {
                $this->type                     = 'pie';
        }
        
        function set_colours( $colours )
        {
                $this->colours = $colours;
        }
        
        /**
         * Sugar wrapped around set_colours
         */
        function colours( $colours )
        {
                $this->set_colours( $colours );
                return $this;
        }
        
        /**
         * @param $alpha as float (0-1) 0.75 = 3/4 visible
         */
        function set_alpha( $alpha )
        {
                $this->alpha = $alpha;
        }
        
        /**
         *sugar wrapped set_alpha
         **/
        function alpha( $alpha )
        {
                $this->set_alpha( $alpha );
                return $this;
        }
        
        /**
         * @param $v as array containing one of
         *  - null
         *  - real or integer number
         *  - a pie_value object
         */
        function set_values( $v )
        {
                $this->values = $v;             
        }

        /**
         * sugar for set_values
         */
        function values( $v )
        {
                $this->set_values( $v );
                return $this;
        }
        
        /**
         * HACK to keep old code working.
         */
        function set_animate( $bool )
        {
                if( $bool )
                        $this->add_animation( new pie_fade() );
                        
        }
        
        /**
         * An object that inherits from base_pie_animation
         */
        function add_animation( $animation )
        {
                if( !isset( $this->animate ) )
                        $this->animate = array();
                        
                $this->animate[] = $animation;
                
                return $this;
        }
        
        /**
         * @param $angle as real number
         */
        function set_start_angle( $angle )
        {
                $tmp = 'start-angle';
                $this->$tmp = $angle;
        }
        
        /**
         * sugar for set_start_angle
         */
        function start_angle($angle)
        {
                $this->set_start_angle( $angle );
                return $this;
        }
        
        /**
         * @param $tip as string. The tooltip text. May contain magic varibles
         */
        function set_tooltip( $tip )
        {
                $this->tip = $tip;
        }
        
        /**
         * sugar for set_tooltip
         */
        function tooltip( $tip )
        {
                $this->set_tooltip( $tip );
                return $this;
        }
        
        function set_gradient_fill()
        {
                $tmp = 'gradient-fill';
                $this->$tmp = true;
        }
        
        function gradient_fill()
        {
                $this->set_gradient_fill();
                return $this;
        }
        
        /**
         * By default each label is the same colour as the slice,
         * but you can ovveride that behaviour using this method.
         * 
         * @param $label_colour as string HEX colour;
         */
        function set_label_colour( $label_colour )
        {
                $tmp = 'label-colour';
                $this->$tmp = $label_colour;    
        }
        
        function label_colour( $label_colour )
        {
                $this->set_label_colour( $label_colour );
                return $this;
        }
        
        /**
         * Turn off the labels
         */
        function set_no_labels()
        {
                $tmp = 'no-labels';
                $this->$tmp = true;
        }
        
        function on_click( $event )
        {
                $tmp = 'on-click';
                $this->$tmp = $event;
        }
        
        /**
         * Fix the radius of the pie chart. Take a look at the magic variable #radius#
         * for helping figure out what radius to set it to.
         * 
         * @param $radius as number
         */
        function radius( $radius )
        {
                $this->radius = $radius;
                return $this;
        }
}