Initial commit

src/kernel/calculator.c

@@ -0,0 +1,170 @@
+#include "calculator.h"
+#include "graphics.h"
+#include "wm.h"
+#include <stdbool.h>
+#include <stddef.h>
+
+Window win_calculator;
+
+static long long calc_acc = 0;
+static long long calc_curr = 0;
+static char calc_op = 0;
+static bool calc_new_entry = true;
+static bool calc_error = false;
+
+// Helper to convert int to string
+static void int_to_str(long long n, char *buf) {
+    if (n == 0) {
+        buf[0] = '0'; buf[1] = 0; return;
+    }
+    
+    int i = 0;
+    bool neg = n < 0;
+    if (neg) n = -n;
+    
+    char temp[32];
+    while (n > 0) {
+        temp[i++] = '0' + (n % 10);
+        n /= 10;
+    }
+    if (neg) temp[i++] = '-';
+    
+    int j = 0;
+    while (i > 0) {
+        buf[j++] = temp[--i];
+    }
+    buf[j] = 0;
+}
+
+static void update_display(Window *win) {
+    if (calc_error) {
+        char *err = "Error";
+        int i = 0; while(err[i]) { win->buffer[i] = err[i]; i++; }
+        win->buffer[i] = 0;
+    } else {
+        int_to_str(calc_curr, win->buffer);
+    }
+    win->buf_len = 0; while(win->buffer[win->buf_len]) win->buf_len++;
+}
+
+static void calculator_paint(Window *win) {
+    // Background
+    draw_rect(win->x + 4, win->y + 24, win->w - 8, win->h - 28, COLOR_LTGRAY);
+    
+    // Display Area
+    draw_bevel_rect(win->x + 10, win->y + 30, win->w - 20, 25, true);
+    // Right align text
+    int text_w = win->buf_len * 8;
+    int text_x = win->x + win->w - 15 - text_w;
+    draw_string(text_x, win->y + 38, win->buffer, COLOR_BLACK);
+    
+    // Buttons
+    const char *labels[] = {
+        "7", "8", "9", "/",
+        "4", "5", "6", "*",
+        "1", "2", "3", "-",
+        "0", "C", "=", "+"
+    };
+    
+    int bw = 30;
+    int bh = 25;
+    int gap = 5;
+    int start_x = win->x + 10;
+    int start_y = win->y + 65;
+    
+    for (int i = 0; i < 16; i++) {
+        int r = i / 4;
+        int c = i % 4;
+        draw_button(start_x + c*(bw+gap), start_y + r*(bh+gap), bw, bh, labels[i], false);
+    }
+}
+
+static void do_op(void) {
+    if (calc_op == '+') calc_acc += calc_curr;
+    else if (calc_op == '-') calc_acc -= calc_curr;
+    else if (calc_op == '*') calc_acc *= calc_curr;
+    else if (calc_op == '/') {
+        if (calc_curr == 0) calc_error = true;
+        else calc_acc /= calc_curr;
+    } else {
+        calc_acc = calc_curr;
+    }
+}
+
+static void calculator_click(Window *win, int x, int y) {
+    int bw = 30;
+    int bh = 25;
+    int gap = 5;
+    int start_x = 10;
+    int start_y = 65;
+    
+    for (int i = 0; i < 16; i++) {
+        int r = i / 4;
+        int c = i % 4;
+        int bx = start_x + c*(bw+gap);
+        int by = start_y + r*(bh+gap);
+        
+        if (x >= bx && x < bx + bw && y >= by && y < by + bh) {
+            // Clicked button i
+            const char *labels[] = {
+                "7", "8", "9", "/",
+                "4", "5", "6", "*",
+                "1", "2", "3", "-",
+                "0", "C", "=", "+"
+            };
+            char lbl = labels[i][0];
+            
+            if (lbl >= '0' && lbl <= '9') {
+                if (calc_new_entry || calc_curr == 0) {
+                    calc_curr = lbl - '0';
+                    calc_new_entry = false;
+                } else {
+                    calc_curr = calc_curr * 10 + (lbl - '0');
+                }
+                calc_error = false;
+            } else if (lbl == 'C') {
+                calc_curr = 0;
+                calc_acc = 0;
+                calc_op = 0;
+                calc_new_entry = true;
+                calc_error = false;
+            } else if (lbl == '=') {
+                do_op();
+                calc_curr = calc_acc;
+                calc_op = 0;
+                calc_new_entry = true;
+            } else {
+                if (!calc_new_entry) {
+                    if (calc_op) do_op();
+                    else calc_acc = calc_curr;
+                }
+                calc_op = lbl;
+                calc_new_entry = true;
+            }
+            
+            update_display(win);
+            wm_paint(); // Request repaint
+            return;
+        }
+    }
+}
+
+void calculator_init(void) {
+    win_calculator.title = "Calculator";
+    win_calculator.x = 200;
+    win_calculator.y = 200;
+    win_calculator.w = 160;
+    win_calculator.h = 200;
+    win_calculator.visible = false;
+    win_calculator.focused = false;
+    win_calculator.z_index = 0;
+    win_calculator.paint = calculator_paint;
+    win_calculator.handle_click = calculator_click;
+    win_calculator.handle_right_click = NULL;
+    
+    calc_curr = 0;
+    calc_acc = 0;
+    calc_op = 0;
+    calc_new_entry = true;
+    update_display(&win_calculator);
+}