Bug 49399 - Writer, select text with keyboard is slow in large documents.
Summary: Writer, select text with keyboard is slow in large documents.
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
(earliest affected)
3.5.3 release
Hardware: x86 (IA32) Windows (All)
: medium normal
Assignee: Not Assigned
Depends on:
Reported: 2012-05-02 12:35 UTC by Jamee Mikell
Modified: 2013-07-08 21:21 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:
Regression By:

Large document for selection testing (62.29 KB, application/vnd.oasis.opendocument.text)
2012-05-02 12:35 UTC, Jamee Mikell

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Description Jamee Mikell 2012-05-02 12:35:12 UTC
Created attachment 60920 [details]
Large document for selection testing

** System **

Win7 64-bit, Core i5-480M, 8GB RAM, LO 3.5.3 (release), only English dictionaries installed. Only default extensions that come with LO are installed.

** Problem Description **

In a large (>700 page) document in Writer 3.5.3, selecting using shift+arrows is slow--approximately 4 characters per second based on a 10-second sample. (I see a CPU spike from <2% to 20% or more while selecting.) Selecting like this is a common operation for typists selecting a word or short phrase (should be a lot faster than moving a hand to grab the mouse, then repositioning it on the keyboard). 3.4.x did not exhibit this problem.

This problem seems to have a time component to it. Immediately after opening, selection performs as expected. After 5-10 minutes, selection is noticeably slower. Time varies. In the large test document (attached) slow down started after 15-20 minutes in initial tests. During this time, I tested selecting near the beginning, end, and middle initially, then test selection intermittently while writing up this bug until I saw performance problems. Test operation was move around the document, select and deselect a few times to compare performance. No copy, no paste, no cut, etc. (In the live document where I first saw this, typical operations are typical typing/editing with occasional search or search/replace.)

In subsequent tests to verify reproducability, the large document's slow selection was sometimes noticeable within 1 minute of opening compared to the smaller document and significant in less than 10 minutes. 

** Other Observations **

As a control, I copied the first 6 pages and pasted them in a new document with the same formatting, saved it, then opened both documents at once. The small document does not exhibit slow selection or a significant CPU spike even 10-15 minutes after the large document does.

The document is plain text. Margins 0.75" except top at 0.5". Header "Test Document <pg#>" right justified. Portrait orientation. ODT format. View is set as 2-columns (2 pages side by side).

Selection with left/right arrow keys shows the most pronounced performance lag, but up/down lags enough to be very noticeable. There is visible jumpiness with drag select in the test document as well.

Selection using shift and pgup/pgdn seems to perform about the in either test document (large or 6-page). Maybe slightly delayed in larger document, but the difference is tiny at worst--not like arrow key selection.

This does not seem to affect arrow or ctrl+arrow movement commands. (Or if it does is minimal.)
Comment 1 Jean-Baptiste Faure 2012-05-06 07:40:41 UTC
@Jamee: if you are using changes recording, I suggest you to try again with change recording disabled.

Best regards. JBF
Comment 2 Jamee Mikell 2012-05-21 09:44:44 UTC
(In reply to comment #1)
> @Jamee: if you are using changes recording, I suggest you to try again with
> change recording disabled.
> Best regards. JBF

Edit | Changes | Record was off (not checked), but Show was checked. I've been testing for a while with various settings in Edit | Changes, but these settings don't seem to affect the problem.

What else might I look at?
Comment 3 QA Administrators 2013-05-26 22:32:18 UTC
Dear Bug Submitter,

This bug has been in NEEDINFO status with no change for at least 6 months. Please provide the requested information as soon as possible and mark the bug as UNCONFIRMED. Due to regular bug tracker maintenance, if the bug is still in NEEDINFO status with no change in 30 days the QA team will close the bug as INVALID due to lack of needed information.

For more information about our NEEDINFO policy please read the wiki located here: 

If you have already provided the requested information, please mark the bug as UNCONFIRMED so that the QA team knows that the bug is ready to be confirmed.

Thank you for helping us make LibreOffice even better for everyone!

Warm Regards,
QA Team
Comment 4 Jean-Baptiste Faure 2013-05-30 20:04:35 UTC
@Jamee: did you make the same tests with LibreOffice 4.0.x ?

Best regards. JBF
Comment 5 QA Administrators 2013-07-08 21:21:33 UTC
Dear Bug Submitter,

Please read this message in its entirety before proceeding.

Your bug report is being closed as INVALID due to inactivity and a lack of information which is needed in order to accurately reproduce and confirm the problem. We encourage you to retest your bug against the latest release. If the issue is still present in the latest stable release, we need the following information (please ignore any that you've already provided):

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