ref: 803e8e43d92ae60b7255905429cec7b63996378c
dir: /textscreen/examples/calculator.c/
// // Copyright(C) 2005-2014 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. // // // Example program: desktop calculator // #include <stdio.h> #include <stdlib.h> #include <string.h> #include "textscreen.h" typedef enum { OP_NONE, OP_PLUS, OP_MINUS, OP_MULT, OP_DIV, } operator_t; int starting_input = 0; int input_value = 0; txt_label_t *input_box; int first_operand; operator_t operator = OP_NONE; void UpdateInputBox(void) { char buf[20]; TXT_snprintf(buf, sizeof(buf), " %i", input_value); TXT_SetLabel(input_box, buf); } void InsertNumber(TXT_UNCAST_ARG(button), TXT_UNCAST_ARG(value)) { TXT_CAST_ARG(int, value); if (starting_input) { input_value = 0; starting_input = 0; } input_value *= 10; input_value += *value; UpdateInputBox(); } void AddNumberButton(txt_table_t *table, int value) { char buf[10]; int *val_copy; val_copy = malloc(sizeof(int)); *val_copy = value; TXT_snprintf(buf, sizeof(buf), " %i ", value); TXT_AddWidget(table, TXT_NewButton2(buf, InsertNumber, val_copy)); } void Operator(TXT_UNCAST_ARG(button), TXT_UNCAST_ARG(op)) { TXT_CAST_ARG(operator_t, op); first_operand = input_value; operator = *op; starting_input = 1; } void AddOperatorButton(txt_table_t *table, const char *label, operator_t op) { char buf[10]; operator_t *op_copy; op_copy = malloc(sizeof(operator_t)); *op_copy = op; TXT_snprintf(buf, sizeof(buf), " %s ", label); TXT_AddWidget(table, TXT_NewButton2(buf, Operator, op_copy)); } void Calculate(TXT_UNCAST_ARG(button), void *unused) { switch (operator) { case OP_PLUS: input_value = first_operand + input_value; break; case OP_MINUS: input_value = first_operand - input_value; break; case OP_MULT: input_value = first_operand * input_value; break; case OP_DIV: input_value = first_operand / input_value; break; case OP_NONE: break; } UpdateInputBox(); operator = OP_NONE; starting_input = 1; } void BuildGUI() { txt_window_t *window; txt_table_t *table; window = TXT_NewWindow("Calculator"); input_box = TXT_NewLabel("asdf"); TXT_SetBGColor(input_box, TXT_COLOR_BLACK); TXT_AddWidget(window, input_box); TXT_AddWidget(window, TXT_NewSeparator(NULL)); TXT_AddWidget(window, TXT_NewStrut(0, 1)); table = TXT_NewTable(4); TXT_AddWidget(window, table); TXT_SetWidgetAlign(table, TXT_HORIZ_CENTER); AddNumberButton(table, 7); AddNumberButton(table, 8); AddNumberButton(table, 9); AddOperatorButton(table, "*", OP_MULT); AddNumberButton(table, 4); AddNumberButton(table, 5); AddNumberButton(table, 6); AddOperatorButton(table, "-", OP_MINUS); AddNumberButton(table, 1); AddNumberButton(table, 2); AddNumberButton(table, 3); AddOperatorButton(table, "+", OP_PLUS); AddNumberButton(table, 0); TXT_AddWidget(table, NULL); TXT_AddWidget(table, TXT_NewButton2(" = ", Calculate, NULL)); AddOperatorButton(table, "/", OP_DIV); TXT_AddWidget(window, TXT_NewStrut(0, 1)); UpdateInputBox(); } int main(int argc, char *argv[]) { if (!TXT_Init()) { fprintf(stderr, "Failed to initialise GUI\n"); exit(-1); } TXT_SetDesktopTitle("Calculator demo"); BuildGUI(); TXT_GUIMainLoop(); TXT_Shutdown(); return 0; }