Function coerceSelectionsCache

src/components/selections/select.js:678–710

(evt, gd, dragOptions)

}

function coerceSelectionsCache(evt, gd, dragOptions) {
    var fullLayout = gd._fullLayout;
    var plotinfo = dragOptions.plotinfo;
    var dragmode = dragOptions.dragmode;

    var selectingOnSameSubplot = (
        fullLayout._lastSelectedSubplot &&
        fullLayout._lastSelectedSubplot === plotinfo.id
    );

    var hasModifierKey = (evt.shiftKey || evt.altKey) &&
        !(drawMode(dragmode) && openMode(dragmode));

    if(
        selectingOnSameSubplot &&
        hasModifierKey &&
        plotinfo.selection &&
        plotinfo.selection.selectionDefs &&
        !dragOptions.selectionDefs
    ) {
        // take over selection definitions from prev mode, if any
        dragOptions.selectionDefs = plotinfo.selection.selectionDefs;
        dragOptions.mergedPolygons = plotinfo.selection.mergedPolygons;
    } else if(!hasModifierKey || !plotinfo.selection) {
        clearSelectionsCache(dragOptions);
    }

    // clear selection outline when selecting a different subplot
    if(!selectingOnSameSubplot) {
        clearOutline(gd);
        fullLayout._lastSelectedSubplot = plotinfo.id;
    }
}

function hasActiveShape(gd) {
    return gd._fullLayout._activeShapeIndex >= 0;