gimp/libgimpwidgets/gimpeevl.h
Ell a9e357d72d libgimpwidgets: fix percentage use in size-entry arithmetic when lower-bound != 0
In GimpSizeEntry, the value corresponding to 0%, as per
gimp_size_entry_set_size(), may be non-zero.  This works correctly
when using the size entry in percentage mode, but not when using
precentage as part of arithmetic.

Fix this by adding an 'offset' parameter to eevl's unit-resolution
callback, which can be specifies a constant value to add as part
of unit conversion, after scaling the converted value by the
conversion factor.  In GimpSizeEntry, use this parameter to offset
percentages by their lower bound.
2020-01-06 21:35:52 +02:00

99 lines
3.5 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimpeevl.h
* Copyright (C) 2008-2009 Fredrik Alstromer <roe@excu.se>
* Copyright (C) 2008-2009 Martin Nordholts <martinn@svn.gnome.org>
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <https://www.gnu.org/licenses/>.
*/
#ifndef __GIMP_EEVL_H__
#define __GIMP_EEVL_H__
G_BEGIN_DECLS
/**
* GimpEevlQuantity:
* @value: In reference units.
* @dimension: in has a dimension of 1, in^2 has a dimension of 2 etc
*/
typedef struct
{
gdouble value;
gint dimension;
} GimpEevlQuantity;
/**
* GimpEevlUnitResolverProc:
* @identifier: Identifier of unit to resolve or %NULL if default unit
* should be resolved.
* @factor: Units per reference unit. For example, in GIMP the
* reference unit is inches so resolving "mm" should
* return 25.4 since there are 25.4 millimeters per inch.
* @offset: Offset to apply after scaling the value according to @factor.
* @data: Data given to gimp_eevl_evaluate().
*
* Returns: If the unit was successfully resolved or not.
*
*/
typedef gboolean (* GimpEevlUnitResolverProc) (const gchar *identifier,
GimpEevlQuantity *factor,
gdouble *offset,
gpointer data);
/**
* GimpEevlOptions:
* @unit_resolver_proc: Unit resolver callback.
* @data: Data passed to unit resolver.
* @ratio_expressions: Allow ratio expressions
* @ratio_invert: Invert ratios
* @ratio_quantity: Quantity to multiply ratios by
*/
typedef struct
{
GimpEevlUnitResolverProc unit_resolver_proc;
gpointer data;
gboolean ratio_expressions;
gboolean ratio_invert;
GimpEevlQuantity ratio_quantity;
} GimpEevlOptions;
#define GIMP_EEVL_OPTIONS_INIT \
((const GimpEevlOptions) \
{ \
.unit_resolver_proc = NULL, \
.data = NULL, \
\
.ratio_expressions = FALSE, \
.ratio_invert = FALSE, \
.ratio_quantity = {0.0, 0} \
})
gboolean gimp_eevl_evaluate (const gchar *string,
const GimpEevlOptions *options,
GimpEevlQuantity *result,
const gchar **error_pos,
GError **error);
G_END_DECLS
#endif /* __GIMP_EEVL_H__ */