shithub: choc

ref: 7bb12317044d04b539649041eb3ea69350a1320b
dir: /textscreen/txt_conditional.h/

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//
// Copyright(C) 2016 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program 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 General Public License for more details.
//

#ifndef TXT_CONDITIONAL_H
#define TXT_CONDITIONAL_H

/**
 * @file txt_conditional.h
 *
 * Conditional widget.
 */

/**
 * Conditional widget.
 *
 * A conditional widget contains another widget, and conditionally
 * shows or hides it based on the value of a variable.
 */

typedef struct txt_conditional_s txt_conditional_t;

#include "txt_widget.h"

/**
 * Create a new conditional widget.
 *
 * @param var             The variable to check.
 * @param expected_value  If the variable has this value, the widget is shown.
 * @param child           The inner widget to show or hide.
 * @return                Pointer to the new conditional widget.
 */

txt_conditional_t *TXT_NewConditional(int *var, int expected_value,
                                      TXT_UNCAST_ARG(child));

/**
 * Return the given child widget if the given boolean condition is true.
 *
 * If the condition is not true, the child widget is destroyed and a dummy
 * "null" widget is returned that shows nothing.
 *
 * @param condition        Boolean condition - true or false value.
 * @param child            Widget to conditionally return.
 * @return                 Either child (if condition is true) or a null
 *                         widget.
 */

txt_widget_t *TXT_If(int condition, TXT_UNCAST_ARG(child));

#endif /* #ifndef TXT_CONDITIONAL_H */