ref: dc054603a1f95f03ea9f6a7b79cda23032c5c2a6
dir: /textscreen/txt_conditional.c/
// // 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. // #include <stdlib.h> #include <string.h> #include "txt_conditional.h" #include "txt_strut.h" struct txt_conditional_s { txt_widget_t widget; int *var; int expected_value; txt_widget_t *child; }; static int ConditionTrue(txt_conditional_t *conditional) { return *conditional->var == conditional->expected_value; } static int TXT_CondSelectable(TXT_UNCAST_ARG(conditional)) { TXT_CAST_ARG(txt_conditional_t, conditional); return ConditionTrue(conditional) && TXT_SelectableWidget(conditional->child); } static void TXT_CondSizeCalc(TXT_UNCAST_ARG(conditional)) { TXT_CAST_ARG(txt_conditional_t, conditional); if (!ConditionTrue(conditional)) { conditional->widget.w = 0; conditional->widget.h = 0; } else { TXT_CalcWidgetSize(conditional->child); conditional->widget.w = conditional->child->w; conditional->widget.h = conditional->child->h; } } static void TXT_CondLayout(TXT_UNCAST_ARG(conditional)) { TXT_CAST_ARG(txt_conditional_t, conditional); if (ConditionTrue(conditional)) { conditional->child->x = conditional->widget.x; conditional->child->y = conditional->widget.y; TXT_LayoutWidget(conditional->child); } } static void TXT_CondDrawer(TXT_UNCAST_ARG(conditional)) { TXT_CAST_ARG(txt_conditional_t, conditional); if (ConditionTrue(conditional)) { TXT_DrawWidget(conditional->child); } } static void TXT_CondDestructor(TXT_UNCAST_ARG(conditional)) { TXT_CAST_ARG(txt_conditional_t, conditional); TXT_DestroyWidget(conditional->child); } static void TXT_CondFocused(TXT_UNCAST_ARG(conditional), int focused) { TXT_CAST_ARG(txt_conditional_t, conditional); if (ConditionTrue(conditional)) { TXT_SetWidgetFocus(conditional->child, focused); } } static int TXT_CondKeyPress(TXT_UNCAST_ARG(conditional), int key) { TXT_CAST_ARG(txt_conditional_t, conditional); if (ConditionTrue(conditional)) { return TXT_WidgetKeyPress(conditional->child, key); } return 0; } static void TXT_CondMousePress(TXT_UNCAST_ARG(conditional), int x, int y, int b) { TXT_CAST_ARG(txt_conditional_t, conditional); if (ConditionTrue(conditional)) { TXT_WidgetMousePress(conditional->child, x, y, b); } } txt_widget_class_t txt_conditional_class = { TXT_CondSelectable, TXT_CondSizeCalc, TXT_CondDrawer, TXT_CondKeyPress, TXT_CondDestructor, TXT_CondMousePress, TXT_CondLayout, TXT_CondFocused, }; txt_conditional_t *TXT_NewConditional(int *var, int expected_value, TXT_UNCAST_ARG(child)) { TXT_CAST_ARG(txt_widget_t, child); txt_conditional_t *conditional; conditional = malloc(sizeof(txt_conditional_t)); TXT_InitWidget(conditional, &txt_conditional_class); conditional->var = var; conditional->expected_value = expected_value; conditional->child = child; child->parent = &conditional->widget; return conditional; } // "Static" conditional that returns an empty strut if the given static // value is false. Kind of like a conditional but we only evaluate it at // creation time. txt_widget_t *TXT_If(int conditional, TXT_UNCAST_ARG(child)) { TXT_CAST_ARG(txt_widget_t, child); if (conditional) { return child; } else { txt_strut_t *nullwidget; TXT_DestroyWidget(child); nullwidget = TXT_NewStrut(0, 0); return &nullwidget->widget; } }