can insert and remove characters

edit.jai

@@ -2,7 +2,7 @@ FPS          :: 60;
 MS_PER_FRAME :: 1000 / FPS;
 
 buffer: string;
-lines: [..]String_Builder;
+lines: [..][..]u8;
 line_height: int;
 
 my_font: *Simp.Dynamic_Font;
@@ -55,11 +55,21 @@ main :: () {
                 if event.key_code == {
                     case .ESCAPE; should_quit = true;
 
+                    case .BACKSPACE; handle_backspace();
+
                     case .ARROW_UP;    #through;
                     case .ARROW_DOWN;  #through;
                     case .ARROW_LEFT;  #through;
                     case .ARROW_RIGHT; handle_arrow(event.key_code);
                 }
+
+                if #char "A" <= event.key_code && event.key_code <= #char "z" {
+                    key := event.key_code;
+                    if !event.shift_pressed {
+                        key += #char "a" - #char "A";
+                    }
+                    insert_character_at_cursor(cast(u8) key);
+                }
             }
         }
 
@@ -81,7 +91,7 @@ render_edit_buffer :: () {
     for line_buffer: visible_lines {
         Simp.set_shader_for_text();
 
-        line_str := tbuilder_to_string(*line_buffer);
+        line_str := array_view_to_string(line_buffer);
 
         prefix: string;
         suffix: string;
@@ -116,6 +126,12 @@ render_edit_buffer :: () {
     }
 }
 
+insert_character_at_cursor :: (char: u8) {
+    line := *get_visible_lines()[cursor_y];
+    array_insert_at(line, char, cursor_x);
+    cursor_x += 1;
+}
+
 handle_window_resizes :: (window: Window_Type) {
     for Input.get_window_resizes() {
         Simp.update_window(it.window);
@@ -132,6 +148,26 @@ handle_window_resizes :: (window: Window_Type) {
     }
 }
 
+handle_backspace :: () {
+    if cursor_x == 0 && cursor_y == 0 {
+        return;
+    }
+
+    cursor_line_index := cursor_y + first_line;
+    current_line := *lines[cursor_line_index];
+    if cursor_x == 0 {
+        prev_line := *lines[cursor_line_index - 1];
+        prev_count := prev_line.count;
+        array_add(prev_line, current_line.*);
+        array_remove_at(*lines, cursor_line_index);
+        cursor_y -= 1;
+        cursor_x = prev_count;
+    } else {
+        array_remove_at(current_line, cursor_x - 1);
+        cursor_x -= 1;
+    }
+}
+
 handle_arrow :: (key_code: Input.Key_Code) {
     visible_lines := get_visible_lines();
 
@@ -148,7 +184,7 @@ handle_arrow :: (key_code: Input.Key_Code) {
         case .ARROW_LEFT;
             if cursor_x == 0 && cursor_y != 0 {
                 prev_line := visible_lines[cursor_y - 1];
-                len := builder_string_length(*prev_line);
+                len := prev_line.count;
                 cursor_y = max(0, cursor_y - 1);
                 cursor_x = len;
             } else if cursor_x != 0 {
@@ -156,7 +192,7 @@ handle_arrow :: (key_code: Input.Key_Code) {
             }
         case .ARROW_RIGHT;
             line := visible_lines[cursor_y];
-            len := builder_string_length(*line);
+            len := line.count;
             if cursor_x == len {
                 cursor_x = 0;
                 cursor_y += 1;
@@ -166,7 +202,7 @@ handle_arrow :: (key_code: Input.Key_Code) {
     }
 }
 
-get_visible_lines :: () -> []String_Builder {
+get_visible_lines :: () -> [][..]u8 {
     num_lines_in_screen := window_height / line_height - 1;
     return array_view(lines, first_line, num_lines_in_screen);
 }
@@ -190,13 +226,15 @@ string_to_line :: (str: string, cursor_char_index := -1) -> string, string {
     while char_index < str.count {
         defer char_index += 1;
         c := str.data[char_index];
-        
+
         if c == #char "\t" {
+
             // s := string.{data=str.data + start, count=(char_index + 1) - start};
             // append(current_builder, s);
             // append(current_builder, "    ");
             // start = char_index + 1;
             // cursor_index += 4;
+
         } else {
             cursor_index += 1;
         }
@@ -208,7 +246,7 @@ string_to_line :: (str: string, cursor_char_index := -1) -> string, string {
             start = char_index + 1;
         } 
     }
-    
+
 
     s := string.{data=str.data + start, count=str.count - start};
     append(current_builder, s);
@@ -229,17 +267,16 @@ read_file_lines :: (file_path: string) -> bool {
     file_contents, ok := read_entire_file(file_path);
     if !ok return ok;
 
-    for lines reset(*it);
+    for lines free(*it);
     free(lines.data);
-    lines = [..]String_Builder.{};
+    lines = [..][..]u8.{};
 
     lines_temp := split(file_contents, "\n");
     defer free(lines_temp.data);
 
     for line: lines_temp {
-        builder: String_Builder;
-        init_string_builder(*builder);
-        append(*builder, line);
+        builder: [..]u8;
+        array_add(*builder, array_view(line));
         array_add(*lines, builder);
     }
 
@@ -255,9 +292,24 @@ my_init_fonts :: () {
     assert(my_font != null);
 }
 
-tbuilder_to_string :: (builder: *String_Builder) -> string {
-    s := builder_to_string(builder, do_reset = false,, temp);
-    return s;
+array_add :: (xs: *[..]$T, to_append: []T) {
+    array_reserve(xs, xs.count + to_append.count);
+
+    memcpy(xs.data + xs.count, to_append.data, to_append.count * size_of(T));
+    xs.count += to_append.count;
+}
+
+array_view :: (s: string) -> []u8 {
+    return []u8.{count=s.count, data=s.data};
+}
+
+array_view_to_string :: (chars: []u8) -> string {
+    return string.{count=chars.count, data=chars.data};
+}
+
+array_remove_at :: (xs: *[..]$T, index: int) {
+    xs.count -= 1;
+    memcpy(xs.data + index, xs.data + index + 1, xs.count - index);
 }
 
 #import "Basic";