Bug 174143

Summary:	pre-edit buffer not emptied after IME deactivated
Product:	[Fedora] Fedora	Reporter:	Lawrence Lim <llim>
Component:	scim	Assignee:	Jens Petersen <petersen>
Status:	CLOSED RAWHIDE	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	eng-i18n-bugs, james.su, qshen, tools-bugs
Target Milestone:	---	Keywords:	FutureFeature, i18n
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2006-03-17 09:18:52 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	150221, 167798

Description Lawrence Lim 2005-11-25 04:01:33 UTC

Description of problem:
Currently, if the IME is deactivated while pre-edit buffer |= NULL, when the IME
gets activated again, what was in the pre-edit buffer before will show up.

Version-Release number of selected component (if applicable):
scim-1.4.2-6

How reproducible:
Always

Steps to Reproduce:
1.in ja locale start gedit application (not locale specific)
2.activate scim
3.enter 'aka'
4.deactivate by ctrl-SPACE
5.activate scim again
  
Actual results:
Pre-edit buffer not empty

Expected results:
Pre-edit buffer should be emptied

Additional info:
Tried with CJK IME with similar behaviour.

Comment 1 Qian Shen 2005-12-06 02:06:52 UTC

I have talked with Su Zhe about this bug. He said this trigger hot key should be
handled in IMEs. I think it means each IME should be update except it has
handled this hot key. 

I wrote a test patch, just make IC reset when the IME is deactived. It seems
work well. But Su Zhe think it's not a good way, because reset() has special usage.

Below is my patch for reference :

--- gtkimcontextscim.cpp.orig   2005-12-06 10:11:27.732624776 +0800
+++ gtkimcontextscim.cpp        2005-12-02 15:36:36.000000000 +0800
@@ -1256,8 +1256,10 @@
     if (hotkey_action == SCIM_FRONTEND_HOTKEY_TRIGGER) {
         if (!ic->impl->is_on)
             turn_on_ic (ic);
-        else
+        else {
             turn_off_ic (ic);
+            ic->impl->si->reset(); //qshen
+        }
         ret = true;
     } else if (hotkey_action == SCIM_FRONTEND_HOTKEY_ON) {
         if (!ic->impl->is_on)

Comment 2 Qian Shen 2005-12-06 02:30:25 UTC

I think it's better to handle this deactivate/activate hot key in frontend/gtkim
moudle, because it's a global setting for frontend. We can set it in SCIM setup
window | frontend | global setting. The common setting for this hot key is
"Control+space".

SCIM gtkim moudle names this hotkey as SCIM_CONFIG_HOTKEYS_FRONTEND_TRIGGER, and
handles it in filter_hotkeys() . The X11 frontend has similar handling code for
this hotkey.

We konw that preedit string is managed by IC. Gtk-im transfer IC to SCIM, SCIM
transfer IC to IME instance. IME can be accessed through IME APIs, but the only
API to handle preedit string is reset() .

So there are 2 choices to handle this bug. One is using reset() in
frontend/gtkim module, Another is handling the hotkey in IME inside.

Comment 3 Qian Shen 2006-01-04 02:29:40 UTC

I had a talk with James Su. He said the hotkey should be handled in IMEs. He
didn't accepted editing the front end module.

Comment 4 James Su 2006-01-11 04:08:43 UTC

This behaviour should be implemented in each IMEngine.
When scim is deactivated, the focus_out () method will be invoked, then IMEngine
may do anything in this method, for example clearing the preedit string.

Comment 5 Jens Petersen 2006-01-11 07:24:31 UTC

Thanks for the comment James.  Are there any IMEs for which resetting
pre-edit is not desirable?

Comment 6 James Su 2006-01-11 08:04:11 UTC

AFAIK, some input methods provided by upcoming scim-m17n with m17n 1.3.x have
such behaviour.

Comment 8 Jens Petersen 2007-03-05 23:58:36 UTC

Patch has been reverted in Fedora devel since December.