reactive programming - How hook observable starting on delayed subscription in rxjava -

usability: when user press button, search starts after 3000 msec. when search starts, progress bar should shown.

i have delayed subscription:

observable<searchresult> delayedsearch = search .delaysubscription(3000, timeunit.milliseconds) //not working .doonsubscribe(() -> log(should appear progress bar))  delayedsearch.subscribe(result -> log(should disappear progress bar)); 

problem: can't hook start observable's execution.
how best way solve problem? or maybe solution?

i found solution.
create showprogress observable:

observable showprogress = observable.create(subscriber -> {             log("showprogress")             subscriber.onnext(null);             subscriber.oncompleted();         }).subscribeon(androidschedulers.mainthread()); 

and add before searching:

observable<searchresult> searchwithprogress = showprogress.flatmap((func1) o -> search); 

so can use this:

observable<searchresult> delayedsearch = searchwithprogress.delaysubscription(3000, timeunit.milliseconds);  delayedsearch.subscribe(result -> log(hideprogress);