Initial commit

src/kernel/editor.c

@@ -0,0 +1,445 @@
+#include "editor.h"
+#include "graphics.h"
+#include "fat32.h"
+#include "wm.h"
+#include <stdbool.h>
+#include <stddef.h>
+
+// === Text Editor State ===
+Window win_editor;
+
+#define EDITOR_MAX_LINES 128
+#define EDITOR_MAX_LINE_LEN 256
+#define EDITOR_LINE_HEIGHT 16
+#define EDITOR_CHAR_WIDTH 8
+
+typedef struct {
+    char content[EDITOR_MAX_LINE_LEN];
+    int length;
+} EditorLine;
+
+static EditorLine lines[EDITOR_MAX_LINES];
+static int line_count = 1;
+static int cursor_line = 0;
+static int cursor_col = 0;
+static int scroll_top = 0;
+static char open_filename[256] = "";
+static bool file_modified = false;
+
+// === Helper Functions ===
+
+static size_t editor_strlen(const char *str) {
+    size_t len = 0;
+    while (str[len]) len++;
+    return len;
+}
+
+static void editor_strcpy(char *dest, const char *src) {
+    while (*src) *dest++ = *src++;
+    *dest = 0;
+}
+
+static int editor_strcmp(const char *s1, const char *s2) {
+    while (*s1 && (*s1 == *s2)) {
+        s1++;
+        s2++;
+    }
+    return *(const unsigned char*)s1 - *(const unsigned char*)s2;
+}
+
+// === Editor Logic ===
+
+// Forward declaration
+static void editor_ensure_cursor_visible(void);
+
+static void editor_clear_all(void) {
+    for (int i = 0; i < EDITOR_MAX_LINES; i++) {
+        lines[i].content[0] = 0;
+        lines[i].length = 0;
+    }
+    line_count = 1;
+    cursor_line = 0;
+    cursor_col = 0;
+    scroll_top = 0;
+    open_filename[0] = 0;
+    file_modified = false;
+}
+
+void editor_open_file(const char *filename) {
+    editor_clear_all();
+    editor_strcpy(open_filename, filename);
+    
+    FAT32_FileHandle *fh = fat32_open(filename, "r");
+    if (!fh) {
+        // New file
+        file_modified = false;
+        return;
+    }
+    
+    // Read file content
+    char buffer[16384];
+    int bytes_read = fat32_read(fh, buffer, sizeof(buffer));
+    fat32_close(fh);
+    
+    if (bytes_read <= 0) {
+        file_modified = false;
+        return;
+    }
+    
+    // Parse into lines
+    int line = 0;
+    int col = 0;
+    
+    for (int i = 0; i < bytes_read && line < EDITOR_MAX_LINES; i++) {
+        char ch = buffer[i];
+        
+        if (ch == '\n') {
+            lines[line].content[col] = 0;
+            lines[line].length = col;
+            line++;
+            col = 0;
+        } else if (ch != '\r') {
+            if (col < EDITOR_MAX_LINE_LEN - 1) {
+                lines[line].content[col] = ch;
+                col++;
+            }
+        }
+    }
+    
+    if (col > 0) {
+        lines[line].content[col] = 0;
+        lines[line].length = col;
+        line++;
+    }
+    
+    line_count = (line > 0) ? line : 1;
+    file_modified = false;
+}
+
+static void editor_save_file(void) {
+    if (!open_filename[0]) {
+        // No filename set
+        return;
+    }
+    
+    FAT32_FileHandle *fh = fat32_open(open_filename, "w");
+    if (!fh) {
+        return;
+    }
+    
+    // Write lines
+    for (int i = 0; i < line_count; i++) {
+        fat32_write(fh, lines[i].content, lines[i].length);
+        fat32_write(fh, "\n", 1);
+    }
+    
+    fat32_close(fh);
+    file_modified = false;
+}
+
+// Insert character at cursor position
+static void editor_insert_char(char ch) {
+    if (cursor_line >= EDITOR_MAX_LINES) return;
+    
+    EditorLine *line = &lines[cursor_line];
+    
+    if (ch == '\n') {
+        // Split line - shift all lines below down first
+        if (line_count >= EDITOR_MAX_LINES) return;
+        
+        // Shift all lines from cursor_line+1 onwards down by one position
+        for (int j = line_count; j > cursor_line; j--) {
+            lines[j] = lines[j - 1];
+        }
+        line_count++;
+        
+        // Clear the new line completely (zero entire buffer)
+        for (int k = 0; k < EDITOR_MAX_LINE_LEN; k++) {
+            lines[cursor_line + 1].content[k] = 0;
+        }
+        lines[cursor_line + 1].length = 0;
+        
+        // Now split the current line at cursor position
+        int current_len = lines[cursor_line].length;
+        int new_len = current_len - cursor_col;
+        
+        // Copy the second part to the new line
+        for (int i = 0; i < new_len; i++) {
+            lines[cursor_line + 1].content[i] = lines[cursor_line].content[cursor_col + i];
+        }
+        lines[cursor_line + 1].content[new_len] = 0;
+        lines[cursor_line + 1].length = new_len;
+        
+        // Truncate current line
+        lines[cursor_line].content[cursor_col] = 0;
+        lines[cursor_line].length = cursor_col;
+        
+        cursor_line++;
+        cursor_col = 0;
+    } else if (ch == '\b') {
+        // Backspace
+        if (cursor_col > 0) {
+            for (int i = cursor_col - 1; i < line->length; i++) {
+                line->content[i] = line->content[i + 1];
+            }
+            line->length--;
+            cursor_col--;
+        } else if (cursor_line > 0) {
+            // Merge with previous line
+            EditorLine *prev = &lines[cursor_line - 1];
+            int merge_point = prev->length;
+            
+            for (int i = 0; i < line->length; i++) {
+                if (merge_point + i < EDITOR_MAX_LINE_LEN - 1) {
+                    prev->content[merge_point + i] = line->content[i];
+                }
+            }
+            prev->content[merge_point + line->length] = 0;
+            prev->length = merge_point + line->length;
+            
+            // Shift lines up
+            for (int i = cursor_line; i < line_count - 1; i++) {
+                lines[i] = lines[i + 1];
+            }
+            lines[line_count - 1].length = 0;
+            lines[line_count - 1].content[0] = 0;
+            
+            cursor_line--;
+            cursor_col = merge_point;
+            line_count--;
+        }
+    } else if (ch >= 32 && ch <= 126) {
+        // Regular character
+        if (cursor_col < EDITOR_MAX_LINE_LEN - 1) {
+            // Shift characters right
+            for (int i = line->length; i > cursor_col; i--) {
+                line->content[i] = line->content[i - 1];
+            }
+            line->content[cursor_col] = ch;
+            line->length++;
+            cursor_col++;
+        }
+    }
+    
+    file_modified = true;
+    editor_ensure_cursor_visible();
+}
+
+// Ensure cursor is visible by adjusting scroll position
+static void editor_ensure_cursor_visible(void) {
+    int visible_lines = 22;  // Allow ~24 lines to use available window space
+    
+    // Scroll up if cursor is above visible area
+    if (cursor_line < scroll_top) {
+        scroll_top = cursor_line;
+    }
+    
+    // Scroll down if cursor is below visible area
+    if (cursor_line >= scroll_top + visible_lines) {
+        scroll_top = cursor_line - visible_lines + 1;
+    }
+}
+
+// === Paint Function ===
+
+static void editor_paint(Window *win) {
+    int offset_x = win->x + 4;
+    int offset_y = win->y + 24;
+    int content_width = win->w - 8;
+    int content_height = win->h - 28;
+    
+    // Draw filename and save button area at top of content
+    draw_rect(offset_x, offset_y, content_width, 25, COLOR_GRAY);
+    draw_string(offset_x + 10, offset_y + 5, "File: ", COLOR_BLACK);
+    draw_string(offset_x + 55, offset_y + 5, open_filename, COLOR_BLACK);
+    
+    // Draw save button
+    draw_button(offset_x + content_width - 80, offset_y + 3, 70, 20, "Save", false);
+    
+    // Draw modification indicator
+    if (file_modified) {
+        draw_string(offset_x + content_width - 200, offset_y + 5, "[Modified]", COLOR_RED);
+    }
+    
+    // Fill editor background
+    draw_rect(offset_x, offset_y + 30, content_width, content_height - 55, COLOR_WHITE);
+    
+    // Draw line numbers and content
+    int visible_lines = (content_height - 55) / EDITOR_LINE_HEIGHT;
+    int max_line = scroll_top + visible_lines;
+    if (max_line > line_count) max_line = line_count;
+    
+    for (int i = scroll_top; i < max_line; i++) {
+        int display_y = offset_y + 35 + (i - scroll_top) * EDITOR_LINE_HEIGHT;
+        
+        // Draw line number
+        char line_num_str[16];
+        int temp = i + 1;
+        int str_len = 0;
+        if (temp == 0) {
+            line_num_str[0] = '0';
+            str_len = 1;
+        } else {
+            while (temp > 0) {
+                line_num_str[str_len++] = (temp % 10) + '0';
+                temp /= 10;
+            }
+            // Reverse
+            for (int j = 0; j < str_len / 2; j++) {
+                char t = line_num_str[j];
+                line_num_str[j] = line_num_str[str_len - 1 - j];
+                line_num_str[str_len - 1 - j] = t;
+            }
+        }
+        line_num_str[str_len] = 0;
+        draw_string(offset_x + 4, display_y, line_num_str, COLOR_DKGRAY);
+        
+        // Draw line content
+        draw_string(offset_x + 40, display_y, lines[i].content, COLOR_BLACK);
+        
+        // Draw cursor if on this line
+        if (i == cursor_line) {
+            int cursor_x = offset_x + 40 + (cursor_col * EDITOR_CHAR_WIDTH);
+            draw_rect(cursor_x, display_y, 2, 10, COLOR_BLACK);
+        }
+    }
+    
+    // Draw status bar at bottom
+    draw_rect(offset_x, offset_y + content_height - 20, content_width, 20, COLOR_GRAY);
+    draw_string(offset_x + 10, offset_y + content_height - 15, "Line: ", COLOR_WHITE);
+    
+    char line_str[32];
+    int temp = cursor_line + 1;
+    int idx = 0;
+    while (temp > 0) {
+        line_str[idx++] = (temp % 10) + '0';
+        temp /= 10;
+    }
+    for (int j = 0; j < idx / 2; j++) {
+        char t = line_str[j];
+        line_str[j] = line_str[idx - 1 - j];
+        line_str[idx - 1 - j] = t;
+    }
+    line_str[idx] = 0;
+    
+    draw_string(offset_x + 60, offset_y + content_height - 15, line_str, COLOR_WHITE);
+    draw_string(offset_x + 100, offset_y + content_height - 15, "  Col: ", COLOR_WHITE);
+    
+    char col_str[32];
+    temp = cursor_col + 1;
+    idx = 0;
+    while (temp > 0) {
+        col_str[idx++] = (temp % 10) + '0';
+        temp /= 10;
+    }
+    for (int j = 0; j < idx / 2; j++) {
+        char t = col_str[j];
+        col_str[j] = col_str[idx - 1 - j];
+        col_str[idx - 1 - j] = t;
+    }
+    col_str[idx] = 0;
+    
+    draw_string(offset_x + 170, offset_y + content_height - 15, col_str, COLOR_WHITE);
+}
+
+// === Key Handler ===
+
+static void editor_handle_key(Window *win, char c) {
+    if (c == 'q' || c == 'Q') {
+        if (file_modified) {
+        }
+        win->visible = false;
+        return;
+    }
+    
+    // Arrow keys - UP
+    if (c == 17) {
+        if (cursor_line > 0) {
+            cursor_line--;
+            if (cursor_col > (int)lines[cursor_line].length) {
+                cursor_col = lines[cursor_line].length;
+            }
+            if (cursor_line < scroll_top) {
+                scroll_top = cursor_line;
+            }
+        }
+        return;
+    }
+    
+    // Arrow keys - DOWN
+    if (c == 18) {
+        if (cursor_line < line_count - 1) {
+            cursor_line++;
+            if (cursor_col > (int)lines[cursor_line].length) {
+                cursor_col = lines[cursor_line].length;
+            }
+            int visible_lines = 20;
+            if (cursor_line >= scroll_top + visible_lines) {
+                scroll_top = cursor_line - visible_lines + 1;
+            }
+        }
+        return;
+    }
+    
+    // Arrow keys - LEFT
+    if (c == 19) {
+        if (cursor_col > 0) {
+            cursor_col--;
+        } else if (cursor_line > 0) {
+            cursor_line--;
+            cursor_col = lines[cursor_line].length;
+        }
+        return;
+    }
+    
+    // Arrow keys - RIGHT
+    if (c == 20) {
+        if (cursor_col < (int)lines[cursor_line].length) {
+            cursor_col++;
+        } else if (cursor_line < line_count - 1) {
+            cursor_line++;
+            cursor_col = 0;
+        }
+        return;
+    }
+    
+    // Regular character input
+    editor_insert_char(c);
+}
+
+// === Click Handler ===
+
+static void editor_handle_click(Window *win, int x, int y) {
+    // x and y are relative to window origin
+    int content_width = win->w - 8;
+    
+    // Check save button - position is at (4 + content_width - 80, 24 + 3) = (4 + w - 8 - 80, 27)
+    // Button dimensions: 70 wide, 20 tall
+    int button_x = 4 + content_width - 80;
+    int button_y = 24 + 3;
+    
+    if (x >= button_x && x < button_x + 70 &&
+        y >= button_y && y < button_y + 20) {
+        editor_save_file();
+        return;
+    }
+}
+
+// === Initialization ===
+
+void editor_init(void) {
+    win_editor.title = "Text Editor";
+    win_editor.x = 100;
+    win_editor.y = 150;
+    win_editor.w = 700;
+    win_editor.h = 450;
+    win_editor.visible = false;
+    win_editor.focused = false;
+    win_editor.z_index = 0;
+    win_editor.paint = editor_paint;
+    win_editor.handle_key = editor_handle_key;
+    win_editor.handle_click = editor_handle_click;
+    win_editor.handle_right_click = NULL;
+    
+    editor_clear_all();
+}