From ad53b0e2e26756f169eb5400fb0cdcd33f3bcfe5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=A0imon=20Brandner?= Date: Thu, 22 Apr 2021 14:56:12 +0200 Subject: [PATCH] Add normalizeWheelEvent() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Šimon Brandner --- src/utils/Mouse.ts | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 src/utils/Mouse.ts diff --git a/src/utils/Mouse.ts b/src/utils/Mouse.ts new file mode 100644 index 0000000000..a85c6492c4 --- /dev/null +++ b/src/utils/Mouse.ts @@ -0,0 +1,50 @@ +/* +Copyright 2021 Šimon Brandner + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +/** + * Different browsers use different deltaModes. This causes different behaviour. + * To avoid that we use this function to convert any event to pixels. + * @param {WheelEvent} event to normalize + * @returns {WheelEvent} normalized event event + */ +export function normalizeWheelEvent(event: WheelEvent): WheelEvent { + const LINE_HEIGHT = 18; + + let deltaX; + let deltaY; + let deltaZ; + + if (event.deltaMode === 1) { // Units are lines + deltaX = (event.deltaX * LINE_HEIGHT); + deltaY = (event.deltaY * LINE_HEIGHT); + deltaZ = (event.deltaZ * LINE_HEIGHT); + } else { + deltaX = event.deltaX; + deltaY = event.deltaY; + deltaZ = event.deltaZ; + } + + return new WheelEvent( + "syntheticWheel", + { + deltaMode: 0, + deltaY: deltaY, + deltaX: deltaX, + deltaZ: deltaZ, + ...event, + }, + ); +}