Improve cell selection

[jeanp413]

Improves the selection while dragging with the mouse, shift + click , shift + home, shift + end.
Took as reference the HxD editor

Fixes #78

[lramos15]

Thanks for the PR! I have a few pieces of work I need to get done first, but I promise to review this before the next release. Can you please ensure you've run eslint against your code and that you have updated all jsdoc comments I saw one which was missing the force variable that I didn't know what it meant. I would remove shift + page up, shift + page down as I feel like they have the most limited use cases and are definitely going to be the buggiest / hardest to implement. As for the shift + home and shift + end those shouldn't have to wait for render as the row you're working for is the current row which the user has focus which gurantees it is on the DOM.

[jeanp413]

Sorry, I meant shift + ctrl + home, shift + ctrl + end (updated the original post).
Another related issue is when you select a lot of cells either with dragging + scrolling or shift + click + scrolling, the cells that go out of view (and therefore removed from the DOM) lost its selected state. Again, to fix this I need to run the select logic after the render method finished

[lramos15]

I think the real fix is that the render method doesn't render the selection as well. If it did that it wouldn't have to worry about being waited on before making a selection. This used to be the case but since the addition of multiselect I didn't fix the webview state manager to hold more than one selection #95. I think the major fix would be some sort of decorations layer which holds whatever extra metadata related to the cell and then gets rendered on top. I don't really want to merge something that introduces more bugs so I would recommend pulling the more buggy things into a second PR and we can work on getting the first one merged.

[jeanp413]

Reverted the selection with pg up, pg down, ctrl+home and ctrl+end. Let me know if more changes are needed.
BTW right now the rangeSelect logic is a bit complicated to avoid calling querySelectorAll used in getElementsWithGivenOffset. I guess this will be refactored in the future to hold the references to the dom nodes and the logic to select a range would be much simpler.

[lramos15]

Once merge conflicts are resolved I'm ready to review your PR whenever you're ready for my review. Sorry I was working on a large feature for this iteration and wanted to make sure it was complete in time. I added preservation of the entire selection range via the WebviewStateManager see media/selectHandler.ts for that. This should allow you to preserve your selections and not have to wait for the render method. Let me know if you're blocked on anything.

[jeanp413]

@lramos15 it's ready for review, resolved the merge conflicts and updated the selection logic

[lramos15]

Sorry for all the comments, I tried to be thorough. This is really great work and seems to work well when I tested it, I see there were a lot of random tabs or spaces I had. One thing that feels really broken to me is pressing shift with moving the arrow keys. Let me know if you have any questions.

[lramos15]

Ideally we would switch away from keycodes here as it's been deprecated. This is also a debt that I need to fix which will make it easier to understand what's going on here as event.keyCode === 35 doesn't convey home as well as event.key === "Home"

[jeanp413]

Pushed some changes addressing the feedback

[lramos15]

Looks good to me, thanks for the PR!