Instead of one item keeping the item + its position and sorting that
list, keep the items in 1 array and put the positions into a 2nd array.
This is generally slower while sorting, but allows multiple improvements:
1. We can replace items with keys
This allows avoiding multiple slow lookups when using complex
comparisons
2. We can keep multiple position arrays
This allows doing a sorting in the background without actually
emitting items-changed() until the array is completely sorted.
3. The main list tracks the items in the original model
So only a single memmove() is necessary there, while the old version
had to upgrade the position in every item.
Benchmarks:
sorting a model of simple strings
old new
256,000 items 256ms 268ms
512,000 items 569ms 638ms
sorting a model of file trees, directories first, by size
old new
64,000 items 350ms 364ms
128,000 items 667ms 691ms
removing half the model
old new
512,000 items 24ms 15ms
1,024,000 items 49ms 25ms
This was preventing any sort of building on macOS, even though the quartz
backend is currently non-functional. Fixing this is a pre-requisite to
getting a new macOS backend compiling.
Instead of an array of arrays, let's use an array of dictionaries; it's
easier to add optional keys without requiring to remember where to put
empty arrays.
char ** arrays are null-terminated everywhere, so make sure they are in
splice(), too.
Also fix the argument to be a const char * const * like in the
constructor.
Simplify all view model APIs and always return G_TYPE_OBJECT as the
item-type for every model.
It turns out nobody uses item-type anyway.
So instead of adding lots of APIs, forcing people to think about it and
trying to figure out how to handle filter or map models that modify item
types, just having an easy life is a better approach.
All the models need to be able to deal with any type of object going
through anyway.
Verify that the selection filter changes mirror
the selection changes of the underlying model,
as expected. These tests verify the fixes in
the previous commit.
One of the widget-factory focus tests is flaky in ci,
perhaps due to font changes causing size computations
to go slightly differently.
Drop this for now.
In particular, track which items remain in ::items-changed
signal emissions.
But the main use case is sorting, which causes items-changed(0, n, n)
to be emitted.
In 99.9% of all cases, these are just NULL, NULL.
So just do away with these arguments, people can
use the setters for the rare cases where they want
the scrolled window to use a different adjustment.
This is a list model holding strings, initialized
from a char **. String lists are buildable as well,
and that replaces the buildable support in GktDropDowns.
