question about flashing window under linux

[andrewmcveigh]

when I add a widget to a form, a popup frame appears for about 1/2 second which shows the contents of the form, and then it disappears. It even happens when I move a widget etc.

Is there any way to get rid of this? Some option I should be setting?

Andrew

[Eric Clayberg]

Is there any way to get rid of this?

It depends on which window manager you are using. Some window managers (like the one in KDE) don't allow the preview window to appear off-screen. The window manager in Gnome does allow this (as does the one in Windows and in OSX). If you are using Linux, I would suggest using the Gnome window manager (Metacity).

[andrewmcveigh]

Hmm, I am using Gnome, and also Metacity (Ubuntu dapper drake).

Is there any way to control where the preview window gets placed? I have 2 screens, and I would gladly place it out of the way on the 2nd screen. At the moment I have no control over it -- it often jumps up in front of the designer window.

Cheers,
Andrew

[andrewmcveigh]

actually the preview window has started consistently showing itself at the top of the 2nd screen now. It seems to remain constant for each eclipse startup, but is sometimes in front of the designer. I guess I could always move eclipse around the preview window

Perhaps if the window can't be removed, could it be made dockable in eclipse as a preview or something like that?

Andrew

[andrewmcveigh]

even with the linux glitches, it is quite an awesome product. very slick.

I've managed to create some nice stuff without much effort. The support for composites is a big win.

Andrew

[Eric Clayberg]

The preview window isn't even supposed to show up on screen, Designer opens it at a position of -10000, -10000. Some window managers don't like that and force it into the visible portion of the screen.

[andrewmcveigh]

i've tried the recommended window manager and I can't get it to not show.

would it be possible to request an enhancement to add the preview location as a preference option? i.e. I could set it to the 2nd screen always?

Andrew

[Eric Clayberg]

i've tried the recommended window manager and I can't get it to not show.

It actually depends on the version of the window manager. For example, it works fine in Ubuntu 6.10, but doesn't work in 7.04. Apparently, the later versions of Metacity have a bug/feature that causes them to be too "smart".

would it be possible to request an enhancement to add the preview location as a preference option?

The latest build includes options to set the X/Y position of the preview window on the Designer > General pref page.

[andrewmcveigh]

many thanks for adding the feature. I'll try it out tonight.

Cheers,
Andrew

[andrewmcveigh]

thanks -- it works fine.

Cheers,
Andrew
p.s. just for the record, if X and Y are set so that any part of the window goes off the screen, the preview window appears in a random place (which stays fixed for that eclipse session).

[Eric Clayberg]

just for the record, if X and Y are set so that any part of the window goes off the screen, the preview window appears in a random place (which stays fixed for that eclipse session).

You can thank your super smart window manager for that.

[Eric Clayberg]

In order to create the graphics that you see in the design view, Designer creates an off screen window containing the various widgets and they takes a screen snapshot of them. This works very well under Windows, OSX and some versions of Linux. Recent versions of the Metacity window manager (more recent than 2.1.4), however, have been modified/"fixed" to disallow windows to be opened off screen. This forces the preview window to appear on screen leading to an annoying flashing effect any time you make a change. The solution is to disable the Metacity "fully_onscreen" constraint by patching the Metacity source code and rebuilding and installing the patched version into your system.

Here are the steps to follow (from the Designer FAQ):

1) Download the Metacity source code from ftp://ftp.gnome.org/pub/gnome/sources/metacity/

2) Unpack the source code tarball into any temporary directory.

3) Chdir into this directory (with the unpacked code).

4) Find window.c file and open it with your favourite texteditor.

5) Find a line with "window->require_fully_onscreen = TRUE;"

6) Replace it with "window->require_fully_onscreen = FALSE;"

7) Save the changes and close the editor.

8) Open a terminal and chdir into the directory with the source code (nice if you have already done this)

9) Run "./configure".

10) Run "make all".

11) Make sure that steps 9 & 10 completed without errors.

12) Become root (or execute the next command via "sudo" depending on the Linux you are running)

13) Run "make install" (or "sudo make install").

14) Save your work and close any application you are working with.

15) End your session (or press Ctrl-Alt-Delete to restart the x-server) and log in again.

16) You are done!

[andrewmcveigh]

thanks for the instructions, i'll give it a try...

Cheers,
Andrew
p.s. you don't have instructions for getting it working with Compviz/Beryl do you

[Alexander.Mitin]

you don't have instructions for getting it working with Compviz/Beryl do you

We don't recommend using Compiz/Beryl because it is still a little buggy.

[vanort]

You sure the window manager deserves all the blame here? I get similar behavior on Windows XP.

I don't see any flickering until I try the 'test/preview' feature for my dialog. After that, then I get flickering of windows popping in and out every time I modify a property from the property editor.

So seems there's something up besides just some window managers being too smart for GWT.

Designer 1.7.0
Eclipse 3.2

I would be testing on Linux, but under Ubuntu 7.04, I get an undefined symbol (NS...) error on startup of Designer when going to the visual mode.