Too slow on scrollable panel with only some text on-screen

rohanpm / qingfanyi

Interactive Chinese to English dictionary lookup tool for Linux desktops

GNU General Public License v3.0

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Too slow on scrollable panel with only some text on-screen #15

Closed rohanpm closed 8 years ago

rohanpm commented 8 years ago

Observed in Konversation (Qt5):

If there is a scrollable widget, requesting its text appears to give the entire text, not only what's on the screen. (I think this is different from e.g. Firefox).

As a result, qfy will spend time parsing text which will not be displayed, and it'll become slower and slower as a chat log grows.

It should be worked around & made faster somehow.

rohanpm commented 8 years ago

Some issues making this hard to fix:

getBoundedRanges should be able to return the portion of visible text, but it's unimplemented in qt-at-spi
Bisecting using getRangeExtents to find which portion of text is visible seems like it should work, but the implementation of this seems itself to be unusably slow.