Re: [Qgis-user] WMS Rendering Problems
Hi Tom,
You are right, resizing is a problem. I did some further tests on Linux and
Mac, and found that resizing is a problem on both plattforms (maybe also on
win, I didn't test). So I don't think it is a Mac specific issue. Also I
found resizing can be a problem with large vector layers.
r7316 doesn't fix the Mac WMS rendering problem; I am also using a Mac
G4. To reproduce the bug, open a WMS layer and then resize or maximize
the window. The layer is cleared and not redrawn. Other widgets such as
the status and tool bars are sometimes drawn at incorrect locations too.
Maximizing worked on my G4 perfectly. I observed problems with the status and
tool bar when resizing the window with the mouse (both on G4 and Linux).
My guess is that the begin() of the second draw event is ignored as
superfluous because the painter is already active. The second draw event
then draws and successfully closes the painter. At this point, the
resumed first draw is attempting to draw into an inactive painter.
That's why I tried to protect the QGraphicsRectItem from paint events in
r7316:
if (mCanvas-isDirty())
{
setEnabled(false);
mCanvas-render();
setEnabled(true);
}
If the item is disabled, it does not receive events during the rendering. I
have the impression that concurrent paint events are not the only problem.
Maybe Qts update optimisation of QWidget and QGraphicsView is also a cause?
It's probably best
left for QGIS 1.1. For now, we should see if nested draw events can be
eliminated without a major redesign.
I totally agree. As 0.9.1 is meant as a bugfix release, it would be nice to
have a solution with minimal code changes.
Regards,
Marco
On Sunday 04 November 2007 06:51:46 Tom Elwertowski wrote:
Marco Hugentobler wrote:
I think that the WMS refresh problem is due to a problem with
QGraphicsView/QGraphicsRectItem, which I tried to adress with r7316. This
fix works for me on Kubuntu7.10, Win XP (msys) and Mac (G4).
From what I can see, the synchronous requesting works as expected and is
left at the time QHttp sends the done() signal (once all the requested
data is available). The painting is then done into QImage, which I think
is plattform independent (software rendering).
Asynchronous requesting of WMS layers could still be a possibility for
the future. Maybe combined with Tims idea of a composite manager? I think
that such functionality should be developed in a branch as there is a
high risk of side effects.
Hi Marco,
r7316 doesn't fix the Mac WMS rendering problem; I am also using a Mac
G4. To reproduce the bug, open a WMS layer and then resize or maximize
the window. The layer is cleared and not redrawn. Other widgets such as
the status and tool bars are sometimes drawn at incorrect locations too.
Resizing a window by dragging the size control is a gold standard for
testing Mac drawing code. If there are problems, they are most likely to
show up while resizing a window.
The problem is that the WMS implementation is not Qt processEvent
safe. Moving to asynchronous network events is one way to make the code
processEvent safe. Moving the synchronous transfer outside the draw
event might also work. Using threads for drawing is probably the best
solution. I chose the asynchronous approach because it seemed closest to
a bug fix than a redesign.
This is the problematic sequence of events:
1. Resize window
2. WMS provider initiates draw event.
3. draw routine discovers layer needs refresh from WMS server.
4. draw routine issues network request.
5. QgsHttpTransaction calls processEvents so that network request can
leave local machine.
6. processEvents now runs other events while waiting for the remote
response.
7. there are drawing events pending due to setStatus signals from
QgsHttpTransaction and QgsRasterLayer as well as for drawing the
overview canvas. If a drag resize is in progress, there are also
additional draw events due to the continued resizing of the main canvas.
This is the bug -- a Mac draw event cannot be interrupted by another
draw event.
8. eventually we resume interrupted draw events which are not able to be
resumed.
Here is the Mac terminal log:
Warning: QWidget::repaint: Recursive repaint detected
Warning: QCoreGraphicsPaintEngine::begin: Painter already active
Warning: QPainter::begin(): Returned false
Warning: QPainter::end: Painter not active, aborted
followed by many of:
Warning: QWidget: It is dangerous to leave painters active on a widget
outside of the PaintEvent
My guess is that the begin() of the second draw event is ignored as
superfluous because the painter is already active. The second draw event
then draws and successfully closes the painter. At this point, the
resumed first draw is attempting to draw into an inactive painter.
If we don't change anything, we need to tell users that QGIS/Mac does
not support resizing or maximizing project windows containing
[Qgis-user] Automatic translation of menus
A problem related with translation. I've found that even if I select English during install I get the QGis gui in Spanish, probably because of the locale. There should be a way of actually selecting the language in the Options. I want to present some data using QGis to a group of international students and having the menus in Spanish is a problem. It is also a problem for reporting bugs and problems to this list. Is there any way of having the menus in English? Thanks! Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra Jaume Almera (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: [EMAIL PROTECTED] http://www.ija.csic.es/gt/obster ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
[Qgis-user] Graduated color
I'm using QGis 0.9.0 for Win. When I select Graduate Color as the legend for AREA in the vector layer lakes from the sample data, I get different colors as expected but only the 2 extremes in the legend, while I was expecting a continuous bar. Instead, if I select graduate symbol I do get a full legend with as many colors as selected classes, as expected. Is this a bug or am I misunderstanding the tools? Thanks Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra Jaume Almera (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: [EMAIL PROTECTED] http://www.ija.csic.es/gt/obster ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
[Qgis-user] Project Projection
I'm using QGis 0.9.0 fro Win. I follow the manual section 7.2.1. Specifying a Projection. I open a the spearfish mapset and display the raster layer spot.image, then select Project Properties/Projection and enable OTF. Click OK and the displayed raster vanishes. I open the Projection menu and the selected projection is still the one by default (lonlat) instead of the one of spot.image (utm). This seems in contradiction with the manual: One way to specify the map projection is to first load a layer with the projection you want for the entire map. Then open the Project Properties dialog and click on the Enable on the fly projection checkbox. You can now close the Project Properties dialog and add additional layers to the map. If I do select the utm settings of spot.image in Project Properties/Projection, the display seems to work fine. BTW, if I were displaying now another layer for the same geographic area but in another projection with OTF enabled, could I save the layer in the new projection? In other words, can QGis be used to reproject layers and save them with the new projections? Thanks, Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra Jaume Almera (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: [EMAIL PROTECTED] http://www.ija.csic.es/gt/obster ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
[Qgis-user] Automatic translation of menus
Hi Agus in Windows there is only one way how to set language used in QGIS -- it is necessary to set English language (or ither preffered language) in Regional and Language Options window from Control panel (or set in directly in Registry). Command line parameter lang works only in Linux and language which you have chosen during the install process is used in Install wizard only. Lubos Agustin Lobo [EMAIL PROTECTED] wrote: You are right, sorry about it: I'm using the Windows version for 0.9.0 Agus Hans Cats escribi?: You don't say what platform you are on, but if you are on Linux start qgis from the command line with the command 'LC_ALL=en_US qgis'. Hans 2007/11/5, Agustin Lobo [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: A problem related with translation. I've found that even if I select English during install I get the QGis gui in Spanish, probably because of the locale. There should be a way of actually selecting the language in the Options. I want to present some data using QGis to a group of international students and having the menus in Spanish is a problem. It is also a problem for reporting bugs and problems to this list. Is there any way of having the menus in English? Thanks! Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra Jaume Almera (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] http://www.ija.csic.es/gt/obster ___ Qgis-user mailing list Qgis-user@lists.qgis.org mailto:Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user -- Dr. Agustin Lobo Institut de Ciencies de la Terra Jaume Almera (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: [EMAIL PROTECTED] http://www.ija.csic.es/gt/obster -- ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user End of Qgis-user Digest, Vol 21, Issue 8 ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
Re: [Qgis-user] [Qgis-developer] 'Publish to web' plugin for QGIS mapserver
Marco Hugentobler ha scritto: On the QGIS mapserver page (http://karlinapp.ethz.ch/qgis_wms/download/index.html) there are sources and binary packages available, both for 'QGIS mapserver' and the 'publish to web' Plugin. Hi Marco. Have you thought of making a real deb package of it? It would be great to allow more users to install it and test it. The DebianGIS project is here to help. All the best. pc -- Paolo Cavallini, see: http://www.faunalia.it/pc signature.asc Description: OpenPGP digital signature ___ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
