Add support for touch-based graph navigation and selection #11056
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Frizi
requested review from
farmaazon,
vitvakatu,
kazcw and
AdRiley
as code owners
| if (!holdDragStarted && (isTouch || (state.buttons & PointerButtonMask.Auxiliary) != 0)) { | ||
| if ( | ||
| longpressTimer != null && | ||
| Vec2.FromTuple(state.movement).length() > LONGPRESS_MAX_SLIDE | ||
| ) { | ||
| clearTimeout(longpressTimer) | ||
| longpressTimer = null | ||
| } | ||
| scrollTo(center.value.addScaled(Vec2.FromTuple(state.delta), -1 / scale.value)) | ||
| state.event.stopImmediatePropagation() | ||
| } else if (!isTouch && (state.buttons & PointerButtonMask.Secondary) != 0) { | ||
| const prevScale = scale.value | ||
| updateScale((oldValue) => oldValue * Math.exp(-state.delta[1] / 100)) | ||
| scrollTo( | ||
| center.value | ||
| .sub(gesturePivot) | ||
| .scale(prevScale / scale.value) | ||
| .add(gesturePivot), | ||
| ) | ||
| } else if ( | ||
| state.tap || | ||
| holdDragStarted || | ||
| (!isTouch && (state.buttons & PointerButtonMask.Main) != 0) | ||
| ) { | ||
| callHoldDragListeners({ | ||
| ...state, | ||
| first: holdDragStarted === false, | ||
| dragging: state.dragging || !state.last, | ||
| }) | ||
| holdDragStarted = true | ||
| } |
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If possible, I would put each branch into its own named function. Or, if it's not practical, at least the conditions should be assigned to variables named like isScrolling, 'isZooming' etc.
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The condition do depend on the order in the if-else chain. I think refactoring each individual handler case to a separate function makes it very clear what's happening though.
| holdDragStarted || | ||
| (!isTouch && (state.buttons & PointerButtonMask.Main) != 0) | ||
| ) { | ||
| callHoldDragListeners({ |
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This "holdDrag" is not always "hold drag" - sometimes it's just mouse-clik movement.
(Oh, well, one could interpret it as both "drag after hold" and "drag with button hold" ;) but then it requires docs somewhere.
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Added docs to the "add hold drag listener" exported function, which exactly points out those conditions.
Frizi
requested review from
PabloBuchu,
indiv0,
somebody1234 and
MrFlashAccount
as code owners
Pull Request Description
Fixes #9493
Tested on windows desktop (standard mouse), macbook touchpad and iphone, which should behave similarily to windows touchscreen devices.
Important Notes
Checklist
Please ensure that the following checklist has been satisfied before submitting the PR:
Scala,
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