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Try to avoid to interpret wheel events as pinch-to-zoom ones (bug 1810800)

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Calixte Denizet 2023-01-24 18:35:15 +01:00
parent 673f6820d1
commit 1cb482be6a
1 changed files with 20 additions and 8 deletions
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28
web/app.js
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@ -2659,7 +2659,26 @@ function webViewerWheel(evt) {
// https://developer.mozilla.org/en-US/docs/Web/API/WheelEvent#browser_compatibility
// Hence if ctrlKey is true but ctrl key hasn't been pressed then we can
// infer that we have a pinch-to-zoom.
const isPinchToZoom = evt.ctrlKey && !PDFViewerApplication._isCtrlKeyDown;
// But the ctrlKey could have been pressed outside of the browser window,
// hence we try to do some magic to guess if the scaleFactor is likely coming
// from a pinch-to-zoom or not.
// It is important that we query deltaMode before delta{X,Y}, so that
// Firefox doesn't switch to DOM_DELTA_PIXEL mode for compat with other
// browsers, see https://bugzilla.mozilla.org/show_bug.cgi?id=1392460.
const deltaMode = evt.deltaMode;
// The following formula is a bit strange but it comes from:
// https://searchfox.org/mozilla-central/rev/d62c4c4d5547064487006a1506287da394b64724/widget/InputData.cpp#618-626
let scaleFactor = Math.exp(-evt.deltaY / 100);
const isPinchToZoom =
evt.ctrlKey &&
!PDFViewerApplication._isCtrlKeyDown &&
deltaMode === WheelEvent.DOM_DELTA_PIXEL &&
evt.deltaX === 0 &&
Math.abs(scaleFactor - 1) < 0.05 &&
evt.deltaZ === 0;
if (
isPinchToZoom ||
@ -2675,9 +2694,6 @@ function webViewerWheel(evt) {
const previousScale = pdfViewer.currentScale;
if (isPinchToZoom && supportsPinchToZoom) {
// The following formula is a bit strange but it comes from:
// https://searchfox.org/mozilla-central/rev/d62c4c4d5547064487006a1506287da394b64724/widget/InputData.cpp#618-626
let scaleFactor = Math.exp(-evt.deltaY / 100);
scaleFactor = PDFViewerApplication._accumulateFactor(
previousScale,
scaleFactor,
@ -2691,10 +2707,6 @@ function webViewerWheel(evt) {
return;
}
} else {
// It is important that we query deltaMode before delta{X,Y}, so that
// Firefox doesn't switch to DOM_DELTA_PIXEL mode for compat with other
// browsers, see https://bugzilla.mozilla.org/show_bug.cgi?id=1392460.
const deltaMode = evt.deltaMode;
const delta = normalizeWheelEventDirection(evt);
let ticks = 0;