74f35cea77
A common pattern when using libtextscreen is to want to show or hide particular UI components depending on the values of particular variables. It is also common to want to only add things to the UI if a particular boolean condition is true. Add a new conditional widget to cover the first case, and a convenience TXT_If() function for the latter.
63 lines
1.8 KiB
C
63 lines
1.8 KiB
C
//
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// Copyright(C) 2016 Simon Howard
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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#ifndef TXT_CONDITIONAL_H
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#define TXT_CONDITIONAL_H
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/**
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* @file txt_conditional.h
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*
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* Conditional widget.
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*/
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/**
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* Conditional widget.
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*
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* A conditional widget contains another widget, and conditionally
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* shows or hides it based on the value of a variable.
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*/
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typedef struct txt_conditional_s txt_conditional_t;
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#include "txt_widget.h"
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/**
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* Create a new conditional widget.
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*
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* @param var The variable to check.
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* @param expected_value If the variable has this value, the widget is shown.
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* @param child The inner widget to show or hide.
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* @return Pointer to the new conditional widget.
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*/
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txt_conditional_t *TXT_NewConditional(int *var, int expected_value,
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TXT_UNCAST_ARG(child));
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/**
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* Return the given child widget if the given boolean condition is true.
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*
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* If the condition is not true, the child widget is destroyed and a dummy
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* "null" widget is returned that shows nothing.
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*
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* @param condition Boolean condition - true or false value.
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* @param child Widget to conditionally return.
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* @return Either child (if condition is true) or a null
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* widget.
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*/
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txt_widget_t *TXT_If(int condition, TXT_UNCAST_ARG(child));
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#endif /* #ifndef TXT_CONDITIONAL_H */
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