src/js/pannellum.js
function onDocumentMouseUp(event) {
    if (!isUserInteracting) {
        return;
    }
    isUserInteracting = false;
    if (Date.now() - latestInteraction > 15) {
        // Prevents jump when user rapidly moves mouse, stops, and then
        // releases the mouse button
        speed.pitch = speed.yaw = 0;
    }
    uiContainer.classList.add('pnlm-grab');
    uiContainer.classList.remove('pnlm-grabbing');
    latestInteraction = Date.now();

    fireEvent('mouseup', event);
}
function onDocumentMouseUp(event) {
    if (!isUserInteracting) {
        return;
    }
    isUserInteracting = false;
    if (Date.now() - latestInteraction > 15) {
        // Prevents jump when user rapidly moves mouse, stops, and then
        // releases the mouse button
        speed.pitch = speed.yaw = 0;
    }
    uiContainer.classList.add('pnlm-grab');
    uiContainer.classList.remove('pnlm-grabbing');
    latestInteraction = Date.now();

    fireEvent('mouseup', event);
}
Event handler for mouse up events. Stops panning.
@private