[web/grab_to_pan.js] Inline the isLeftMouseReleased helper function

Given the support information listed in the function itself, the [MDN compatibility data](https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/buttons#browser_compatibility), and the [currently supported browsers](4bb9de4b00/gulpfile.js (L79-L87)) in the PDF.js project we should be able to simplify the code by inlining the function instead.
This commit is contained in:
Jonas Jenwald 2021-11-09 12:46:34 +01:00
parent 7a428345db
commit ed6af0f844

View File

@ -142,7 +142,8 @@ GrabToPan.prototype = {
*/
_onmousemove: function GrabToPan__onmousemove(event) {
this.element.removeEventListener("scroll", this._endPan, true);
if (isLeftMouseReleased(event)) {
if (!(event.buttons & 1)) {
// The left mouse button is released.
this._endPan();
return;
}
@ -177,38 +178,4 @@ GrabToPan.prototype = {
},
};
/**
* Whether the left mouse is not pressed.
* @param event {MouseEvent}
* @returns {boolean} True if the left mouse button is not pressed,
* False if unsure or if the left mouse button is pressed.
*/
function isLeftMouseReleased(event) {
if ("buttons" in event) {
// http://www.w3.org/TR/DOM-Level-3-Events/#events-MouseEvent-buttons
// Firefox 15+
// Chrome 43+
// Safari 11.1+
return !(event.buttons & 1);
}
if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
// Browser sniffing because it's impossible to feature-detect
// whether event.which for onmousemove is reliable.
const chrome = window.chrome;
const isChrome15OrOpera15plus = chrome && (chrome.webstore || chrome.app);
// ^ Chrome 15+ ^ Opera 15+
const isSafari6plus =
/Apple/.test(navigator.vendor) &&
/Version\/([6-9]\d*|[1-5]\d+)/.test(navigator.userAgent);
if (isChrome15OrOpera15plus || isSafari6plus) {
// Chrome 14+
// Opera 15+
// Safari 6.0+
return event.which === 0;
}
}
return false;
}
export { GrabToPan };