javascript - Drag rotate interaction in OpenLayers 3 on Linux -

i'd use openlayers 3 rotation interaction on browser running under linux. allows map rotate dragging whilst pressing alt , ctrl. works fine on windows, not in redhat 6u2 , other distributions alt key reserved x-windows drag window behaviour.

firstly customized dragrotate ol.events.condition.shiftkeyonly, worked, conflicted zoom-box functionality, i.e. draws blue zoom box whilst rotating.

var map = new ol.map({     layers: [     new ol.layer.tile({         source: new ol.source.osm()     })],     target: 'map',     view: new ol.view({         center: [-25860000, 4130000],         zoom: 10     }),     interactions: ol.interaction.defaults().extend([new ol.interaction.dragrotate({         condition: ol.events.condition.shiftkeyonly     })]) }); 

i'd retain shift-drag zoom box , use other key/combination, maybe 'r+shift'? i've tried customize condition. see jsfiddle

var customcondition = function(mapbrowserevent) {    return false; // todo };  var map = new ol.map({     layers: [     new ol.layer.tile({         source: new ol.source.osm()     })],     target: 'map',     view: new ol.view({         center: [-25860000, 4130000],         zoom: 10     }),     interactions: ol.interaction.defaults().extend([new ol.interaction.dragrotate({         condition: customcondition     })]) }); 

i can't find in api implementing custom conditions other ol.events , mapbrowserevent documentation. using debugger can't find attributes in structure or nested originalevent contains keycode etc.

• how can implement customcondition function detect when given key pressed during drag?
• is there other way of implementing drag rotate works in linux

here custom condition - ctrl + shift:

ol.events.condition.custom = function(mapbrowserevent) {     var browserevent = mapbrowserevent.originalevent;     return (browserevent.ctrlkey && browserevent.shiftkey); };  var map = new ol.map({     layers: [     new ol.layer.tile({         source: new ol.source.osm()     })],     target: 'map',     view: new ol.view({         center: [-25860000, 4130000],         zoom: 10     }),     interactions: ol.interaction.defaults().extend([new ol.interaction.dragrotate({         condition: ol.events.condition.custom     })]) });