Added basic integer calculator functionality.

29jm · Dec 10, 2020 · cfd2883 · cfd2883
1 parent 3b55ee5
commit cfd2883
Showing 1 changed file with 105 additions and 10 deletions.
diff --git a/modules/src/calc.c b/modules/src/calc.c
@@ -6,25 +6,116 @@
 #include <string.h>
 #include <ctype.h>
 
+#define MAXDIGIT 10
+#define NUL_ACTION 0x0
+#define ADD_ACTION 0x1
+#define SUB_ACTION 0x2
+#define MUL_ACTION 0x4
+#define DIV_ACTION 0x8
+#define EQU_ACTION 0x10
+
 uint32_t w = 302;
 uint32_t h = 350;
-char buf[256];
+long int display = 0;
+long int accumulate = 0;
+uint32_t action = NUL_ACTION;
+uint32_t numdigits = 0;
+char buf[MAXDIGIT];
+char dispbuf[MAXDIGIT];
 button_t* text_field;
 
-void num_clicked(button_t* btn) {
-    // uint32_t n = strlen(buf);
+void clear_buffer(void) {
+    for (int counter = 0; counter < MAXDIGIT; counter++)
+        buf[counter] = 0;
+    buf[0] = '0';
+    numdigits = 0;
+    accumulate = 0;
+}
+
+void update_buffer(void) {
+    for (int counter = 0; counter < MAXDIGIT; counter++)
+        dispbuf[counter] = 0;
+
+    if (display)
+        itoa(display, dispbuf, 10);
+    else
+        dispbuf[0] = '0';
+}
+
+void clear_vars(void) {
+    clear_buffer();
+    display = 0;
+    action = NUL_ACTION;
+}
 
+void take_action(void) {
+    switch (action) {
+    case ADD_ACTION:
+        display = display + accumulate;
+        break;
+    case SUB_ACTION:
+        display = display - accumulate;
+        break;
+    case MUL_ACTION:
+        display = display * accumulate;
+        break;
+    case DIV_ACTION:
+        if (accumulate == 0) {
+            printf("Division by zero!\n");
+            clear_vars();
+        }
+        else if (display == 0)
+            display = 0;
+        else
+            display = display / accumulate;
+        break;
+    case EQU_ACTION:
+        break;
+    default:
+        display = accumulate;
+        break;
+    }
+    update_buffer();
+    clear_buffer();
+}
+
+void num_clicked(button_t* btn) {
     switch (btn->text[0]) {
-    case '=': // TODO: do stuff
+    case '=':
+        take_action();
+        action = EQU_ACTION;
+        break;
     case 'C':
-        buf[0] = 0;
+        clear_vars();
+        update_buffer();
+        break;
+    case '+':
+        take_action();
+        action = ADD_ACTION;
+        break;
+    case '-':
+        take_action();
+        action = SUB_ACTION;
+        break;
+    case '*':
+        take_action();
+        action = MUL_ACTION;
+        break;
+    case '/':
+        take_action();
+        action = DIV_ACTION;
         break;
     default:
-        // strcpy(buf+n, btn->text);
+        if (numdigits < (MAXDIGIT - 2)) {
+            buf[numdigits++] = btn->text[0];
+            accumulate = strtol(buf, NULL, 10);
+            strcpy(dispbuf, buf);
+        }
+        else
+            printf("Numeric Overflow!\n");
         break;
     }
-
-    // button_set_text(text_field, buf);
+    strcpy(text_field->text, dispbuf);
 }
 
 int main() {
@@ -36,7 +127,7 @@ int main() {
     vbox_t* main_vb = vbox_new();
     ui_set_root(app, (widget_t*) main_vb);
 
-    button_t* text_field = button_new("TODO");
+    text_field = button_new("          ");
     text_field->widget.flags |= UI_EXPAND_HORIZONTAL;
     vbox_add(main_vb, (widget_t*) text_field);
 
@@ -116,6 +207,10 @@ int main() {
         vbox_add(actions_vb, (widget_t*) action_btn);
     }
 
+    clear_vars();
+    update_buffer();
+    strcpy(text_field->text, dispbuf);
+
     while (true) {
         wm_event_t event = snow_get_event(win);
 
@@ -130,4 +225,4 @@ int main() {
     }
 
     return 0;
-}
+}