Re: [Plplot-devel] plplot_pyqt

[Hazen B. <hba...@ma...>]

Alan W. Irwin wrote:
> On 2009-06-15 14:57-0400 Hazen Babcock wrote:
> 
>> Alan W. Irwin wrote:
>>> On 2009-06-15 12:30-0400 Hazen Babcock wrote:
>>>
>>>> Hi Alan,
>>>>
>>>> I'm getting closer, but I can see that there is at least one missing 
>>>> dependency. I need to link to the qt.so library that is generated by our 
>>>> Qt bindings, but I can't figure out what its name is in our build system. 
>>>> At present I have this:
>>>>
>>>> target_link_libraries(
>>>>  plplot_pyqt
>>>>  plplot${LIB_TAG}
>>>>  ${QT_LIBRARIES}
>>>>  )
>>>>
>>>> And I think I need something like this:
>>>>
>>>> target_link_libraries(
>>>>  plplot_pyqt
>>>>  ${PLPLOT_QT_LIBRARY}
>>>>  plplot${LIB_TAG}
>>>>  ${QT_LIBRARIES}
>>>>  )
>>> I suggest trying something like this:
>>>
>>> if(ENABLE_DYNDRIVERS)
>>>   target_link_libraries(
>>>    plplot_pyqt
>>>    qt
>>>    plplot${LIB_TAG}
>>>    ${QT_LIBRARIES}
>>>    )
>>> else(ENABLE_DYNDRIVERS)
>>>   target_link_libraries(
>>>    plplot_pyqt
>>>    plplot${LIB_TAG}
>>>    ${QT_LIBRARIES}
>>>    )
>>> endif(ENABLE_DYNDRIVERS)
>>>
>>> "qt" is the target name for the qt device driver build for the
>>> ENABLE_DYNDRIVERS case.  So I think if you insert "qt" in the
>>> target_link_libraries list for that case, cmake will do the rest.  Of
>>> course, if ENABLE_DYNDRIVERS is OFF, you have to treat that as a separate
>>> case since there is no qt target name and the qt device code is part of the
>>> PLplot core library (referenced by the plplot${LIB_TAG} target name above).
>> This works in that it causes qt to get built first but it still does not seem 
>> to get linked correctly. I also tried adding:
>>
>>    include_directories(
>>      ${CMAKE_BINARY_DIR}/drivers
>>      )
>>
>> Since that is the location of qt.so but that did not seem to help.
> 
> The include_directories command is to help locate compiler headers in the
> build tree so that idea won't work for this purpose.
> 
> I believe the problem here is that you are attempting to use qt.so as a
> library rather than as the shared object (what cmake calls a module) that is
> normally dynamically loaded by PLplot at run time. The difference in
> properties between how cmake libraries and cmake modules are treated by
> cmake may be confusing cmake about how to link results that depend on qt.so
> as a library.
> 
> I had similar problems with building qt_example with the new build
> system for the installed examples.  There (see
> examples/c++/CMakeLists.txt_installed_examples_cxx) I used the target
> PROPERTY, IMPORTED_LOCATION_NOCONFIG, to get the location (full path
> name) to use for target_link_libraries.  Of course, that won't work in
> this case because qt here is an internal (not exported) target.  My guess,
> though, is
> 
> if(ENABLE_DYNDRIVERS)
>    get_target_property(qt_LOCATION qt LOCATION)
>    target_link_libraries(
>      plplot_pyqt
>      ${qt_LOCATION}
>      plplot${LIB_TAG}
>      ${QT_LIBRARIES}
>      )
> else(....
> 
> might work to make sure that target_link_libraries sets rpath correctly when
> your plplot_pyqt python extension module is being built.
> 
>> I also have two other issues:
>> (1) plplot_pyqt.so is built as libplplot_pyqt.so
>> How do I avoid getting the lib tag on the front?
> 
> Use set_target_properties(...) to set the PREFIX to "".  See how
> the target plplot_widgetmodule (which is also a python extension module)
> is built in bindings/python/CMakeLists.txt.
> 
>> (2) I seem to have to explicitly do "make generate_pyqt_source" before doing 
>> "make". How do I make that happen automatically?
> 
> When dependencies are a problem (as appears to be the case here) I often
> find that solutions can only be found by experimentation.  I suggest you go
> ahead and check in your plplot_pyqt work so I can make such experiments.

Ok. I just checked in my progress so far. I'm still struggling to get 
plplot_pyqt.so correctly linked to qt.so. Once that works though I think 
that we should be all set and running:

./examples/python/plplot_pyqt/pyqt_test.py

should just work.

-Hazen