Implement word selection for textfield, start word selection by double clicking and dragging

[ShaharMS]

Heres a PR that implements word selection.

To summarize, i made two external, non-completion variables - __wordSelection and __wordSelectionInitialIndex.

• __wordSelection is used to check if the textfield is currently "double clicked". if so, regular dragging is modified to only account for word starts/endings as indices
• __wordSelectionInitialIndex is used to know where to start the selection from, and to which direction (for example, if __caretIndex > __wordSelectionInitialIndex, we need to select from the start of the first selected word to the end of the last. othewise, select from the end of the first word selected, to the start of the last)

I also made two non-completeion functions to calculate the selection indices:

This one is used to set __caretIndex
https://github.com/ShaharMS/openfl/blob/f8d1f60c2391d6aaf0ebdb1be6e1a08b7aad443a/src/openfl/text/TextField.hx#L1964-L1987

And this one is used to set __selectionIndex
https://github.com/ShaharMS/openfl/blob/f8d1f60c2391d6aaf0ebdb1be6e1a08b7aad443a/src/openfl/text/TextField.hx#L1989-L2011

[joshtynjala]

regular dragging is modified to only account for word starts/endings as indices

Interesting! I knew that double-clicking a word would select the whole word, but I didn't know that if you dragged after double-clicking, it would expand selection to whole words instead of character by character.

[ShaharMS]

another thing i didnt know (which i plan to implement too) is that a triple click selects an entire pragraph, and dragging selects from the initial paragraph to the one under the mouse. i thought it selected lines, but thats probably because i use vscode too much😆

[ShaharMS]

Another thing, you might have noticed i removed the event listener for DOUBLE_CLICK. i still kept the function just in-case we want to revert some things, but the event listener can be removed

[ShaharMS]

would this be merged right after 9.2? if so, should i also add the triple click, paragraph-selection capabilities?

[ShaharMS]

I know what to fix to make CI working, I'll do the fix after 9.2 is out

[Dimensionscape]

It just your use of the final keyword. This is only supported since haxe 4. Since we still support backwards compatibility with older versions, you should avoid using syntax only available in new releases of Haxe.

[ShaharMS]

can someone trigger CI to check the last commit? i wan to see if there's anything i missed

[ShaharMS]

Can this be merged now? i want to work on the other selection changes, but I'm wating for this to get merged

[ShaharMS]

Bumping this, the selection changes, or at least further modification of the way openfl does text selection is really needed, especially for web platforms, on which OpenFl's textfields stick out like a sore thumb...
#2587 may still be relevant. If not, ill merge from develop and make progress on this PR

And another question - if this PR is still both relevant & applicable, can it be merged into 9.4.0-Dev instead? seems more fitting imo

[joshtynjala]

I merged #2587 the other day, and I'd like to merge this one too (into 9.4.0-Dev). I think that this one should be updated to use clickCount, now that it is available (instead of the decideDoubleClick extra listener workaround), but I'm guessing that's probably the only change necessary.

[ShaharMS]

I'm quite busy today, and there's also some work to do with paragraph selection iirc (triple clilck)
Will probably get to fix things tomorrow

[ShaharMS]

All is pretty much done! some things have changed since the start of this pr:

• There are now two "special" selection modes: __wordSelection and __lineSelection. Double click selects text by word, while triple click selects text by line. Both support dragging, and maintain the selection mode throughout the drag
• __wordSelectionInitialIndex has been renamed to __specialSelectionInitialIndex
• __getPositionByWord and __getOppositeWordBound has been slightly changed to support line selection too, and are now called __getPositionByIdentifier and __getOppositeIdentifierBound.
• onDoubleClick callback has been completely removed, as it has no use now - it was used for word selection only, and it's behavior wasn't consistent with most other text inputs/editors, as you had to release the mouse to select a word. It is now inside the MOUSE_DOWN, MOUSE_UP and MOUSE_MOVE callbacks

Things i haven't tested:

• phones. They should behave the same in theory, though

Things i haven't implemented/done:

• word selection using ctrl+shift+→ ←. works a little differently, and I didn't want to clutter this PR too much
• fixing line selection ignoring the original line's length when dropping/rising to another, shorter line. Not too related to this PR, so i decided to do this in another PR if needed

[joshtynjala]

@ShaharMS I may have some more feedback after I get into testing the code, but just reading through it, can you remove the doubleClickEnabled = true line in the constructor too? It appears to me that is no longer needed with the removal of this_onDoubleClick.

[ShaharMS]

@ShaharMS I may have some more feedback after I get into testing the code, but just reading through it, can you remove the doubleClickEnabled = true line in the constructor too? It appears to me that is no longer needed with the removal of this_onDoubleClick.

Or maybe go all the way and only allow these types of selection when doubleClickEnabled is true? Which route should I go?

[joshtynjala]

I checked the other day, and TextField's doubleClickEnabled is false in Flash. So just remove that line, and it's all good.

[ShaharMS]

@joshtynjala line removed. Can this be merged?

[joshtynjala]

Thanks! When I have time again, I'll do some testing, and merge it if everything looks good.