calc.c File Reference

#include "libcss/hint.h"
#include "select/calc.h"
#include "select/helpers.h"
#include "select/unit.h"
#include "utils/utils.h"

Macros
#define	DEFAULT_STACK_SIZE   32
#define	CANARY   "A css_calculator has leaked"
#define	CANARY_SLEN   SLEN(CANARY)
#define	CALC_PUSH(unit, value)
#define	CALC_POP(unit, value)

Functions
css_error	css_calculator_create (css_calculator **out)
css_calculator *	css_calculator_ref (css_calculator *calc)
void	css_calculator_unref (css_calculator *calc)
css_error	css_calculator_calculate (css_calculator *calc, const css_unit_ctx *unit_ctx, int32_t available, lwc_string *expr, const css_computed_style *style, css_unit *unit_out, css_fixed *value_out)

Macro Definition Documentation

CALC_POP

#define CALC_POP	(		unit,
			value
	)

Value:

        do {                                                                   \
                ret = css__calculator_pop(calc, &unit, &value);                \
                if (ret != CSS_OK) {                                           \
                        return ret;                                            \
                }                                                              \
        } while (0)

CALC_PUSH

#define CALC_PUSH	(		unit,
			value
	)

Value:

        do {                                                                   \
                ret = css__calculator_push(calc, unit, value);                 \
                if (ret != CSS_OK) {                                           \
                        return ret;                                            \
                }                                                              \
        } while (0)

CANARY

#define CANARY   "A css_calculator has leaked"

CANARY_SLEN

#define CANARY_SLEN   SLEN(CANARY)

DEFAULT_STACK_SIZE

#define DEFAULT_STACK_SIZE   32

The default number of entries on a calculator stack

Function Documentation

css_calculator_calculate()

css_error css_calculator_calculate	(	css_calculator *	calc,
		const css_unit_ctx *	unit_ctx,
		int32_t	available,
		lwc_string *	expr,
		const css_computed_style *	style,
		css_unit *	unit_out,
		css_fixed *	value_out
	)

Perform a calculation

To resolve the value of a calc() property, call this function. This will interpret the bytecode in the given expression, with the given display context and available space, and will fill out the computed unit and value.

Parameters

calc	The calculator to use
unit_ctx	The display context for resolving units
available	The available space (for percentages)
style	The style from which the expression was derived
expr	The expression to compute
unit_out	The computed unit is placed here
value_out	The computed value is placed here

Returns

CSS_OK if computation succeeded, otherwise likely CSS_INVALID or CSS_NOMEM

css_calculator_create()

css_error css_calculator_create

(

css_calculator **

out

)

Create a new CSS calculator

This creates a new CSS calculator with a reference count of one.

The caller is responsible for calling css_calculator_unref when it is done with this calculator.

Parameters

out	The created calculator in saved here

Returns

CSS_OK if no problems were encountered, likely CSS_NOMEM if there were

css_calculator_ref()

css_calculator * css_calculator_ref

(

css_calculator *

calc

)

Add a ref to a CSS calculator

If you are storing a calculator in more than one place you should ref it when storing it into a new place. You will neeed to call css_calculator_unref to match any call to this.

Parameters

calc	The calculator to add a reference to

Returns

The same calculator pointer for ease of use

css_calculator_unref()

void css_calculator_unref

(

css_calculator *

calc

)

Unref a CSS calculator

Every call to css_calculator_create or css_calculator_ref must be matched with a call to this function. When the last ref is removed then the underlying calculator is freed.

Parameters

calc	The calculator to unref