Created attachment 277855 [details]
Buggy XIM mode indicator

XIM input mode indicator does not work with gtk+ 3.

For example, I am uploading an image of gnome-terminal when
an XIM input module for Japanese input is used.

Please notice a small rectangle box at the lower-left corner.
It should show a Japanese character to indicate the input mode, but
currently it only shows a black box. Useless.


The problem started back in 2012 with gtk+ 2.21.6, I think.
I reported the issue under gtk+ 2 series in
Bug 696624 - Japanese (Korean/Chinese) XIM input mode indicator has not been working for TB and FF under linux. (with known solution) 

Maybe my title for the bug 696624  was not good. The problem is not limited to
thunderbird and firefox. It is general problem for any program that uses 
XIM input with libgtk+ 2.

(BTW, I identified the problematic patch.
https://bugzilla.gnome.org/show_bug.cgi?id=696624#c3

https://git.gnome.org/browse/gtk+/commit/modules/input/gtkimcontextxim.c?id=7f1801eae10b67fb8878eb562ed3614514b96097

)

Unfortunately, the problem is carried over to libgtk+ 3 series.

I am attaching the screen image that shows a problem with gnome-terminal when the XIM-compliant input method for Japanese.
gnome-terminal is liked with gtk++ 3 as shown by
   ldd `which gnome-terminal`
	linux-gate.so.1 (0xb77e1000)
	libvte2_90.so.9 => /usr/lib/libvte2_90.so.9 (0xb7722000)
	libgthread-2.0.so.0 => /usr/lib/i386-linux-gnu/libgthread-2.0.so.0 (0xb771f000)
	libgtk-3.so.0 => /usr/lib/i386-linux-gnu/libgtk-3.so.0 (0xb7257000)
	libgdk-3.so.0 => /usr/lib/i386-linux-gnu/libgdk-3.so.0 (0xb71d9000)
	libatk-1.0.so.0 => /usr/lib/i386-linux-gnu/libatk-1.0.so.0 (0xb71b5000)
	libgio-2.0.so.0 => /usr/lib/i386-linux-gnu/libgio-2.0.so.0 (0xb7033000)
        [...]
Note libgtk-3.so.0 output above. Debian's gtk package seems to be based
on 3.4.2 of gtk++ 3, but I am afraid that the current code has the same
issue: I noticed a bug in the source in git repository.


The mode indicator box shown by gtk++ 3 is as useless as with the case of firefox with libgtk2+ 
(atachment to bug 696624)
https://bug696624.bugzilla-attachments.gnome.org/attachment.cgi?id=239950

and the rectangle should show something like
(attachment to bug 696624).
https://bug696624.bugzilla-attachments.gnome.org/attachment.cgi?id=240021

The code in question has changed significantly and so I am not sure
what function corresponds to the buggy function in gtk++ 2 series, but
the following function is a suspect.

https://git.gnome.org/browse/gtk+/tree/modules/input/gtkimcontextxim.c#n1704

/* Draw the background (normally white) and border for the status window
 */
static gboolean
on_status_window_draw (GtkWidget *widget,
                       cairo_t   *cr)


Please note that the function misses a rectangle draw in comparison to
the function in gtk++ 2, on_status_window_expose_event()
 https://git.gnome.org/browse/gtk+/tree/modules/input/gtkimcontextxim.c?id=2.21.5#n1769.

I think on_status_window_draw missing drawing the border in the current form as well as using a wrong color.

The following is my idea of the corrected function: not tested yet. I need to download
the source files and re-create the library and replace im-xim.so and see if it works.

I think the background assumption is not quite correct (on Debian, for example).


/* Draw the background (normally white) and border for the status window
 */
static gboolean
on_status_window_draw (GtkWidget *widget,
                       cairo_t   *cr)
{
  GtkStyleContext *style;
  GdkRGBA color;

  style = gtk_widget_get_style_context (widget);

  /* text */
  gtk_style_context_get_color (style, 0, &color);
  gdk_cairo_set_source_rgba (cr, &color);
  cairo_paint (cr);

  cairo_rectangle (cr, 
                   0, 0,
                   gtk_widget_get_allocated_width (widget) - 1,
                   gtk_widget_get_allocated_height (widget) - 1);


  /* background */

  gtk_style_context_get_background_color (style, 0, &color);
  gdk_cairo_set_source_rgba (cr, &color);
  cairo_paint (cr);

  cairo_rectangle (cr, 
                   0+1 , 0+1,
                   gtk_widget_get_allocated_width (widget) - 2,
                   gtk_widget_get_allocated_height (widget) - 2);


  cairo_fill (cr);

  return FALSE;
}



TIA