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Merge pull request #6170 from Rob--W/zoom-at-cursor

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Zoom relative to cursor position via mouse wheel
This commit is contained in:
Yury Delendik 2015-07-03 13:14:11 -05:00
commit 3ffed9d083
1 changed files with 18 additions and 1 deletions
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19
web/viewer.js
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@ -1811,14 +1811,31 @@ function handleMouseWheel(evt) {
evt.wheelDelta / MOUSE_WHEEL_DELTA_FACTOR;
var direction = (ticks < 0) ? 'zoomOut' : 'zoomIn';
if (PDFViewerApplication.pdfViewer.isInPresentationMode) {
var pdfViewer = PDFViewerApplication.pdfViewer;
if (pdfViewer.isInPresentationMode) {
evt.preventDefault();
PDFViewerApplication.scrollPresentationMode(ticks *
MOUSE_WHEEL_DELTA_FACTOR);
} else if (evt.ctrlKey || evt.metaKey) {
// Only zoom the pages, not the entire viewer.
evt.preventDefault();
var previousScale = pdfViewer.currentScale;
PDFViewerApplication[direction](Math.abs(ticks));
var currentScale = pdfViewer.currentScale;
if (previousScale !== currentScale) {
// After scaling the page via zoomIn/zoomOut, the position of the upper-
// left corner is restored. When the mouse wheel is used, the position
// under the cursor should be restored instead.
var scaleCorrectionFactor = currentScale / previousScale - 1;
var rect = pdfViewer.container.getBoundingClientRect();
var dx = evt.clientX - rect.left;
var dy = evt.clientY - rect.top;
pdfViewer.container.scrollLeft += dx * scaleCorrectionFactor;
pdfViewer.container.scrollTop += dy * scaleCorrectionFactor;
}
}
}