Hi, I'm working on a project which uses a subclassed GtkTextView as a custom cell renderer for displaying and editing multi-line text in a tree view column.
I didn't write the code, but it appears plausible. It simply implements the GtkCellEditable interface. Since GTK+-2.10.1, there is a rendering bug, where the widget to edit a cell gets allocated zero height, and of course then doesn't display very usefully. (Version number was inferred from the tags in the CVS viewer at this change: http://cvs.gnome.org/viewcvs/gtk%2B/gtk/gtktreeview.c?r1=1.562&r2=1.563 """ 2006-07-18 Kristian Rietveld <[EMAIL PROTECTED]> Fix for #335012, reported by Matteo Nastasi. * gtk/gtktreeview.c (gtk_tree_view_real_start_editing): if the requested space of the editable is smaller than the cell area, put it up above the middle of the cell area. """ ) Since this change, as the tree view handles the initialisation of the custom renderer, it asks the size of the widget. GtkTextView (incorrectly?) returns zero height and width, which causes me to get a zero/one(?) pixel high cell renderer when editing the cell. (Displaying the cell works fine). Could there be a "race" between the gtktreeview wanting to know the size before realising / displaying the widget, and the gtktextview not knowing its size until afterwards? Breakpoint 2, gtk_text_view_size_request (widget=0x82fba20, requisition=0xbfcf4960) at gtktextview.c:2764 2764 in gtktextview.c (gdb) print *(GtkTextView *)0x82fba20 $1 = {parent_instance = {widget = {object = {parent_instance = { g_type_instance = {g_class = 0x8313c78}, ref_count = 1, qdata = 0x8370910}, flags = 2100738}, private_flags = 13312, state = 0 '\0', saved_state = 0 '\0', name = 0x0, style = 0x8146098, requisition = {width = 0, height = 0}, allocation = {x = -1, y = -1, width = 1, height = 1}, window = 0x0, parent = 0x0}, focus_child = 0x0, border_width = 0, need_resize = 0, resize_mode = 0, reallocate_redraws = 0, has_focus_chain = 0}, layout = 0x8311720, buffer = 0x83758d0, selection_drag_handler = 0, scroll_timeout = 0, pixels_above_lines = 0, pixels_below_lines = 0, pixels_inside_wrap = 0, wrap_mode = GTK_WRAP_NONE, justify = GTK_JUSTIFY_LEFT, left_margin = 0, right_margin = 0, indent = 0, tabs = 0x0, editable = 1, overwrite_mode = 0, cursor_visible = 1, need_im_reset = 0, accepts_tab = 1, width_changed = 0, onscreen_validated = 0, mouse_cursor_obscured = 0, text_window = 0x8371a80, left_window = 0x0, right_window = 0x0, top_window = 0x0, bottom_window = 0x0, hadjustment = 0x0, vadjustment = 0x0, xoffset = 0, yoffset = 0, width = 0, height = 0, virtual_cursor_x = -1, virtual_cursor_y = -1, first_para_mark = 0x836e270, first_para_pixels = 0, dnd_mark = 0x836e420, blink_timeout = 0, first_validate_idle = 160, incremental_validate_idle = 161, im_context = 0x8351660, popup_menu = 0x0, drag_start_x = -1, drag_start_y = -1, children = 0x0, pending_scroll = 0x0, pending_place_cursor_button = 0} It looks like the widget is fairly uninitialised at this point: requisition = {width = 0, height = 0}, allocation = {x = -1, y = -1, width = 1, height = 1}, window = 0x0, parent = 0x0}, focus_child = 0x0, border_width = 0, need_resize = 0, resize_mode = 0, reallocate_redraws = 0, has_focus_chain = 0} admittedly, gtk_text_view_size_request actually sets some of these rather than reading them, but I'm unsure whether the layout member actually has any sensible value at this point. It contains: (gdb) print *((GtkTextView *)0x82fba20)->layout $4 = {parent_instance = {g_type_instance = {g_class = 0x82fd748}, ref_count = 2, qdata = 0x0}, screen_width = 0, width = 0, height = 0, buffer = 0x83758d0, default_style = 0x0, ltr_context = 0x0, rtl_context = 0x0, one_style_cache = 0x0, one_display_cache = 0x0, wrap_loop_count = 0, cursor_visible = 0, cursor_direction = 0, keyboard_direction = 0, preedit_string = 0x0, preedit_attrs = 0x0, preedit_len = 0, preedit_cursor = 0} Since I'm not particularly familiar with the (perhaps necessarily) complicated way which GTK handles widget allocation, I'm not sure exactly what is going on here. Any thoughts? Is it a bug in GTK, or simply a new "feature" which needs working around since bug #335012 was fixed? Should I take this to the gtk-devel-list? Regards, -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
