123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187 |
- <?xml version="1.0" encoding="utf-8"?>
- <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
- "../../../tools/boostbook/dtd/boostbook.dtd">
- <!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
- Subject to the Boost Software License, Version 1.0.
- (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
- -->
- <section id="date_time.examples.meeting_planner">
- <title>Teleconference Scheduler (partial listing)</title>
- <para>
- The Teleconference Scheduler is a Qt based example (found in the examples/qt directory). Partial listings of <link linkend="meeting_planner_hpp">meeting_planner.hpp</link> and <link linkend="planner_form_cpp">planner_form.cpp</link> are provided to illustrate techniques for using the local_date_time and tz_database objects.
- </para>
-
- <anchor id="planner_form_cpp" />
- <para>
- The planner_form class is derived from a QDialog. This listing illustrates the initialization of a tz_database object and using it to populate combo boxes with region lists. Only the init function is listed here for the sake of brevity.
- </para>
- <programlisting>
- <![CDATA[
- void planner_form::init() {
- try{
- tz_db.load_from_file("../../data/date_time_zonespec.csv");
- }catch(boost::local_time::data_not_accessible dna) {
- std::cerr << "Error with time zone data file: " << dna.what() << std::endl;
- exit(EXIT_FAILURE);
- }catch(boost::local_time::bad_field_count bfc) {
- std::cerr << "Error with time zone data file: " << bfc.what() << std::endl;
- exit(EXIT_FAILURE);
- }
- // populate combo boxes with region names
- typedef std::vector<std::string> vect;
- vect regions = tz_db.region_list();
- vect::const_iterator itr = regions.begin();
- while(itr != regions.end()) {
- comboBox1->insertItem(*itr);
- comboBox2->insertItem(*itr);
- comboBox3->insertItem(*itr);
- ++itr;
- }
- comboBox1->insertItem("<Select Region>", 0);
- comboBox2->insertItem("<Select Region>", 0);
- comboBox3->insertItem("<Select Region>", 0);
- // set up dateEdit
- dateEdit2->setSeparator("-");
- this->reset();
- }
- ]]>
- </programlisting>
-
- <anchor id="meeting_planner_hpp" />
- <para>
- This class coordinates local times across multiple time zones. It accomplishes this by iterating across a collection of time zones and verifying that the target time falls within a set period (a workday).
- </para>
- <programlisting>
- <![CDATA[
- /* The heart of the meeting_planner is the synchronization of different
- * time zones to a single point in time.
- * The class takes a vector of regions and a date. The default time
- * range is 9am to 5pm but can be changed.
- * The resulting time specs are returned as a vector of strings
- */
- #include "boost/date_time/gregorian/gregorian.hpp"
- #include "boost/date_time/posix_time/posix_time.hpp"
- #include "boost/date_time/local_time/local_time.hpp"
- #include "boost/shared_ptr.hpp"
- #include <string>
- #include <vector>
- #include <locale>
- using namespace boost;
- using namespace local_time;
- using namespace posix_time;
- //! Coordinates meeting times accounting for time zone differences
- class meeting_planner {
- public:
- typedef std::vector<shared_ptr<time_zone_base> > vector_type;
- // a multimap is used so time_zones can be sorted according to utc_offset
- typedef std::multimap<posix_time::time_duration, shared_ptr<time_zone_base> > zone_map_type;
- typedef std::vector<std::string> result_type;
-
- meeting_planner(const gregorian::date& d, const vector_type& v)
- : l_time(posix_time::not_a_date_time, shared_ptr<time_zone_base>()),
- workday(ptime(d,hours(9)), time_duration(8,0,0,1))
- {
- vector_type::const_iterator iter = v.begin();
- while(iter != v.end()) {
- time_duration offset(0,0,0);
- if(*iter == NULL) {
- offset = hours(0);
- }
- else{
- // null pointers may wind up in the vector
- // TODO: this should be fixed in tz_database
- offset = (*iter)->base_utc_offset();
- }
- zones.insert(zone_map_type::value_type(offset, *iter));
- ++iter;
- }
- // set l_time to noon UTC
- l_time = local_date_time(posix_time::ptime(d, posix_time::hours(12)),
- shared_ptr<time_zone_base>());
- }
- //! Changes range of valid meeting times (ie. The hours in a workday) times are inclusive
- void change_range(const time_duration& start, const time_duration& end)
- {
- ptime pt(l_time.date(), start);
- // add one unit to make the give times inclusive
- workday = time_period(pt, (end - start) + time_duration::unit());
- }
- //! strings returned in the form of "yyyy-Mon-dd: hh:mm Zzz [repeat]"
- result_type coordinate_time() const
- {
- using namespace posix_time;
- result_type result;
- bool flag = true;
- std::stringstream ss;
- ss.str("");
-
- // set the output format for local_date_time to only give
- // time_of_day & zone offset
- typedef boost::date_time::time_facet<local_date_time, char> ldt_facet;
- ldt_facet* timefacet = new ldt_facet("%H:%M (%q)");
- std::locale loc(std::locale::classic(), timefacet);
- ss.imbue(loc);
-
- // backup a full day and start iterating from there
- // I went overkill because I've got no decent
- // algorithm to set a starting point (yet)
- local_date_time tmp = l_time - gregorian::days(1);
- zone_map_type::const_iterator iter;
- for(int i = 0; i < 48; ++i) {
- iter = zones.begin();
- flag = true;
- tmp += posix_time::hours(1);
-
- while(iter != zones.end() && flag) {
- if(!workday.contains(tmp.local_time_in(iter->second).local_time())) {
- flag = false;
- }
- ++iter;
- }
- if(flag) {
- iter = zones.begin();
- ss << tmp.date() << ':';
- while(iter != zones.end()) {
- ss << ' ' << tmp.local_time_in(iter->second);
- ++iter;
- if(iter != zones.end()) {
- ss << ',';
- }
- }
- result.push_back(ss.str());
- ss.str("");
- }
- }
- if(result.empty()) {
- result.push_back("Scheduling within the time period given is not possible for these time zones.");
- }
- return result;
- }
-
- private:
- zone_map_type zones;
- local_date_time l_time;
- time_period workday;
- };
- ]]>
- </programlisting>
- </section>
|