[6/?] grub-core/gfxmenu/gui_list.c - sanity checks for the scrollbar
PATCH 1/1 [6/?] grub-core/gfxmenu/gui_list.c - sanity checks for the scrollbar
some needed checks so we won't see error messages during the boot process
also the patch handles rare cases: when we have too many menu entries and / or too small scrollbar height, the scrollbar thumb's height could be less than it's vertical padding (height of north slice + height of south slice). So the scrollbar thumb will be drawn incorrectly.
In this case we set the height of the thumb to it's vertical padding and recount the position of the thumb.
Signature · 4 lines
With best regards, _______________________________ Vladimir Testov, ROSA Laboratory. www.rosalab.ru
grub-core/gfxmenu/gui_list.c +39 -2
@@ -148,6 +148,33 @@ self->theme_dir); self->need_to_recreate_scrollbar =0 ; + +/* Sanity checks. */ +if (self->scrollbar_frame !=0 && self->scrollbar_thumb !=0 ) + { +grub_gfxmenu_box_t box = self->menu_box; +grub_gfxmenu_box_t frame = self->scrollbar_frame; +grub_gfxmenu_box_t thumb = self->scrollbar_thumb; +int box_vertical_pad = (box->get_top_pad (box) + + box->get_bottom_pad (box)); +int frame_horizontal_pad = (frame->get_left_pad (frame) + + frame->get_right_pad (frame)); +int frame_vertical_pad = (frame->get_top_pad (frame) + + frame->get_bottom_pad (frame)); +int thumb_horizontal_pad = (thumb->get_left_pad (thumb) + + thumb->get_right_pad (thumb)); +int thumb_vertical_pad = (thumb->get_top_pad (thumb) + + thumb->get_bottom_pad (thumb)); +int scrollbar_height = self->bounds.height - box_vertical_pad; + +if (self->scrollbar_width < frame_horizontal_pad + + thumb_horizontal_pad + || scrollbar_height < frame_vertical_pad + thumb_vertical_pad) + { + self->draw_scrollbar =0 ; +return 0 ; + } + } }return (self->scrollbar_frame !=0 && self->scrollbar_thumb !=0 );
@@ -228,8 +255,18 @@ frame->set_content_size (frame, scrollbar_width - frame_horizontal_pad, tracklen); -int thumby = tracktop + tracklen * (value - min) / (max - min); +int thumby;int thumbheight = tracklen * extent / (max - min) +1 ; +if (thumbheight >= thumb_vertical_pad) + { + thumby = tracktop + tracklen * (value - min) / (max - min); + } +else /* Rare occasion. Thumb height is too low. */ + { + thumbheight = thumb_vertical_pad; + thumby = tracktop + ((tracklen - thumb_vertical_pad) * (value - min) + / (max - extent)); + } thumb->set_content_size (thumb, scrollbar_width - frame_horizontal_pad - thumb_horizontal_pad,
@@ -584,7 +621,7 @@ }else if (grub_strcmp (name,"scrollbar_width" ) ==0 ) { - self->scrollbar_width =grub_strtol (value,0 ,10 ); + self->scrollbar_width =grub_strtoul (value,0 ,10 ); }else if (grub_strcmp (name,"scrollbar" ) ==0 ) {