Fixes #4063 Canvas is scrolling on drag and select

[therealharshit]

Fixes #4063 this issue arises after the commit b5be318 I have made the required changes to it fix this issue.
@walterbender please review.

Vedio:

fix-scroll.on.select.mp4

[walterbender]

Works great but you can no longer scroll by dragging the canvas. Not sure what the solution is. Maybe right-mouse button to select? Or long press and drag to select? @pikurasa any suggestions?

[therealharshit]

Works great but you can no longer scroll by dragging the canvas. Not sure what the solution is. Maybe right-mouse button to select? Or long press and drag to select? @pikurasa any suggestions?

@walterbender I think scrolling canvas by dragging was never possible in MB, it can be scrolled with the help of arrow keys.
There was a bug in this b5be318 commit which introduced it and cause this issue.

[therealharshit]

@walterbender @pikurasa I think we should add a new feature in which we can use:

1. Left-mouse button and drag to scroll the canvas.
2. Rigth-mouse button and drag to select.

What do you think, should I work on it.

[walterbender]

We also use long press as a way to indicate right-click on devices w/o buttons (or only single buttons).

[therealharshit]

We also use long press as a way to indicate right-click on devices w/o buttons (or only single buttons).

@walterbender ok I'll work on it.
I think I should raise a new PR for these functionality?
Till then if you want you can merge this PR as it resolves the current issue.

[walterbender]

I don't think it is prudent to merge as is since scrolling the block container is pretty fundamental whereas select is not.

[therealharshit]

I don't think it is prudent to merge as is since scrolling the block container is pretty fundamental whereas select is not.

Ok I'll update my changes in this PR only.

[therealharshit]

@walterbender I have updated my changes to:

1. Left-click to scroll.
2. Right-click to select

Vedio:

scroll-and-select.mp4

Please review.

[walterbender]

It is working for me except that when I right-click, I also get the right-click menu. I can still select the region, but it is not a very good UX.

[walterbender]

Also, we need to test on some touch devices.

[therealharshit]

It is working for me except that when I right-click, I also get the right-click menu. I can still select the region, but it is not a very good UX.

I tested and I didn't get right-click menu when I did right click and drag on canvas to select, right click pie menu open only when we do right click on a block (I think that's fundamental).
@walterbender could you please retest? and please share how to reproduce that.

[walterbender]

I have been testing with Firefox on Fedora. Now I cannot get right click to select. Not sure why. I'll test on Chroma as well.

[walterbender]

Working again after a browser refresh.

[therealharshit]

Previously I was testing it by launching from index.html but this time I have also tested it by launching local web server, and still I didn't get right click menu

pie-issue.mp4

you can see I tried reproducing it but It didn't show up.
I am on windows and testing it on chrome.

@walterbender could you please tell me which of the changes I made could have caused this? or is this issue existed before my changes?
Since I am unable to reproduce it, I need your assistance.

[walterbender]

I tested on chrome with the local server too. Same problem. Question: Are you in advanced mode? The right-click menu only shows up in advanced mode. Also, it would be nice to treat long press as right click too.

[walterbender]

Maybe a solution might be to add select to the right-hand menu instead of invoking it directly from right click and drag?