• Agata Cacko's avatar
    Speed up updateView() in tag selection widget · 983ea2ac
    Agata Cacko authored
    Before this commit, to get the tags for the resources,
    Krita would, for every resource separately, set the resource id
    to the filterproxy model and then iterate on that model to get
    the tags. This is inefficient because the filter proxy model
    iterates on all the items in the original model to get the
    matching rows anyway.
    
    This commit ensures that the model has all the resource ids
    at once, so the iterating over the base model rows happens
    only twice (one to filter out inside the proxy model,
    one to iterate on the rows to build the tags list).
    
    NOTE: Setting of the resource ids happens only
    in setResourceIds() function, and updateView() assumes
    it's already done.
    This improves the performance even more (because every
    setResourcesFilter() invalidates the filter inside the model,
    which causes it to iterate and filter out incorrect rows again,
    while having the filter already done means that adding or removing
    on those resources will only add or remove some rows), but the
    performance imrpovements are only on doing repeated actions on
    the same set of resources.
    It can potentially make it a bit more error prone, hence the
    comment above the loop.
    
    A possibility to make it still faster than before this commit,
    but less error prone: just set resources filter just before the
    loop, or set it to empty list and check for resource id being
    in the selected list manually in updateView().
    
    ---
    Credit for Grum999 for the idea and noticing the problem.
    983ea2ac