Effect loading is already tested using integration tests, for example
the maximize test verifies that the maximize effect is loaded _and_ it
actually does something useful when a window is maximized or restored,
testScriptedEffectLoader only verifies that the effect is loaded, which
is less helpful than what integration tests provide us.
But perhaps the main problem with these tests is that they require us
building a mockverse around them. This litters code with ifdef
preprocessor directives and makes changing such code a living nightmare.
Another problem with these two tests is that they cannot use OpenGL
because it means mocking OpenGL, which we obviously not going to do.
With integration tests, it's not a problem.
The bottom line is that unit tests can be useful but they make life
notoriously difficult when it comes to testing components that depend on
other components.
The current code performed two functions:
- metadata was read async
- the event loop is spun between each effect loading
After we merged static and binary plugins this caused a problem for
things like blur and background contrast where loading an effect
influences what we advertise as supported. We don't want plasmashell to
have to reload all it's SVGs.
All KDE provided binary plugins are statically bundled so querying for
plugins is super duper fast anyway. It's not the same kbuildsycococa
path that it used to be.
The C++ plugins tend to be considerably faster in their constructor than
scripted counterparts, and if anything should be loaded lazily it can be
handled inside the effect.
Since binary effects are installed in their own directory, checking
service type is redundant. Also, KPluginMetaData::serviceTypes() has
been deprecated.
Task: https://phabricator.kde.org/T14483
The main motivation behind this change is to prepare kwin for importing
kwayland-server code in libkwin.
As is, builtin effects are linked with libkwin. Some builtin effects
have wayland specific code. If we move wayland stuff in libkwin, there's
going to be a circular dependency between kwin4_effect_builtins and
libkwin targets.
This change intends to break that dependency by linking builtin effects
to kwin executable.
The main issue with that is that EffectLoader would need to discover the
effects indirectly. QStaticPlugin is used for that purpose.
Besides breaking the cyclic dependency, it makes builtin effects use the
same plugin infrastructure in libkwineffects that external effects use.
Metadata in src/effects/effect_builtins.cpp was converted in a list of
python dictionaries, which was fed to a python script that generated
main.cpp and metadata.json files.
Once in a while, we receive complaints from other fellow KDE developers
about the file organization of kwin. This change addresses some of those
complaints by moving all of source code in a separate directory, src/,
thus making the project structure more traditional. Things such as tests
are kept in their own toplevel directories.
This change may wreak havoc on merge requests that add new files to kwin,
but if a patch modifies an already existing file, git should be smart
enough to figure out that the file has been relocated.
We may potentially split the src/ directory further to make navigating
the source code easier, but hopefully this is good enough already.
