GUI: Fix textbox overflow/crash/hang with 256+ lines (#3536)

* GUI: Fix textbox overflow/crash/hang with 256+ lines * GUI: Textbox calculate lines based on font height * Gui: proper types in text_box Co-authored-by: あく <[email protected]>
flipperdevices · Mar 25, 2024 · c52f28e · c52f28e
1 parent 0a48658
commit c52f28e
Showing 1 changed file with 10 additions and 7 deletions.
diff --git a/applications/services/gui/modules/text_box.c b/applications/services/gui/modules/text_box.c
@@ -100,16 +100,19 @@ static void text_box_insert_endline(Canvas* canvas, TextBoxModel* model) {
     line_num++;
     model->text = furi_string_get_cstr(model->text_formatted);
     model->text_pos = (char*)model->text;
-    if(model->focus == TextBoxFocusEnd && line_num > 5) {
+    size_t lines_on_screen = 56 / canvas_current_font_height(canvas);
+    if(model->focus == TextBoxFocusEnd && line_num > lines_on_screen) {
         // Set text position to 5th line from the end
-        for(uint8_t i = 0; i < line_num - 5; i++) {
-            while(*model->text_pos++ != '\n') {
-            };
+        const char* end = model->text + furi_string_size(model->text_formatted);
+        for(size_t i = 0; i < line_num - lines_on_screen; i++) {
+            while(model->text_pos < end) {
+                if(*model->text_pos++ == '\n') break;
+            }
         }
-        model->scroll_num = line_num - 4;
-        model->scroll_pos = line_num - 5;
+        model->scroll_num = line_num - (lines_on_screen - 1);
+        model->scroll_pos = line_num - lines_on_screen;
     } else {
-        model->scroll_num = MAX(line_num - 4, 0u);
+        model->scroll_num = MAX(line_num - (lines_on_screen - 1), 0u);
         model->scroll_pos = 0;
     }
 }