Add 'Tap tempo' button to 'Edit tempo' dialogue

Add a 'Tap tempo' button to the 'Edit tempo' dialogue box that uses
gettimeofday() to time the interval between successive clicks and sets the
beats-per-minute appropriately.

diff --git a/gtk2_ardour/tempo_dialog.cc b/gtk2_ardour/tempo_dialog.cc
index 7c0e510aff8fd92dbcddb388788db25d7d109f6c..9173393ff5d3bcc04d6a01974bb560cb54029e55 100644 (file)
--- a/gtk2_ardour/tempo_dialog.cc
+++ b/gtk2_ardour/tempo_dialog.cc
@@ -42,6 +42,7 @@ TempoDialog::TempoDialog (TempoMap& map, framepos_t frame, const string&)
        , when_bar_label (_("bar:"), ALIGN_LEFT, ALIGN_CENTER)
        , when_beat_label (_("beat:"), ALIGN_LEFT, ALIGN_CENTER)
        , pulse_selector_label (_("Pulse note"), ALIGN_LEFT, ALIGN_CENTER)
+       , tap_tempo_button (_("Tap tempo"))
 {
        Timecode::BBT_Time when;
        Tempo tempo (map.tempo_at (frame));
@@ -57,6 +58,7 @@ TempoDialog::TempoDialog (TempoSection& section, const string&)
        , when_bar_label (_("bar:"), ALIGN_LEFT, ALIGN_CENTER)
        , when_beat_label (_("beat:"), ALIGN_LEFT, ALIGN_CENTER)
        , pulse_selector_label (_("Pulse note"), ALIGN_LEFT, ALIGN_CENTER)
+       , tap_tempo_button (_("Tap tempo"))
 {
        init (section.start(), section.beats_per_minute(), section.note_type(), section.movable());
 }
@@ -162,6 +164,8 @@ TempoDialog::init (const Timecode::BBT_Time& when, double bpm, double note_type,
        set_default_response (RESPONSE_ACCEPT);
 
        bpm_spinner.show ();
+       tap_tempo_button.show ();
+       get_vbox()->pack_end (tap_tempo_button);
 
        set_name ("MetricDialog");
 
@@ -174,6 +178,7 @@ TempoDialog::init (const Timecode::BBT_Time& when, double bpm, double note_type,
        when_beat_entry.signal_activate().connect (sigc::bind (sigc::mem_fun (*this, &TempoDialog::response), RESPONSE_ACCEPT));
        when_beat_entry.signal_key_release_event().connect (sigc::mem_fun (*this, &TempoDialog::entry_key_release), false);
        pulse_selector.signal_changed().connect (sigc::mem_fun (*this, &TempoDialog::pulse_change));
+       tap_tempo_button.signal_clicked().connect (sigc::mem_fun (*this, &TempoDialog::tap_tempo));
 }
 
 void
@@ -249,6 +254,27 @@ TempoDialog::pulse_change ()
         set_response_sensitive (RESPONSE_ACCEPT, true);
 }
 
+void
+TempoDialog::tap_tempo ()
+{
+       struct timeval now;
+       gettimeofday (&now, NULL);
+
+       if (last_tap.tv_sec >= 0 || last_tap.tv_usec > 0) {
+               struct timeval diff;
+               double interval, bpm;
+               timersub (&now, &last_tap, &diff);
+               interval = diff.tv_sec + diff.tv_usec * 1.0e-6;
+       
+               bpm = 60.0 / interval;
+               if (bpm >= 20) {
+                       bpm_spinner.set_value (bpm);
+               }
+       }
+       last_tap = now;
+
+       
+}
 
 MeterDialog::MeterDialog (TempoMap& map, framepos_t frame, const string&)
        : ArdourDialog (_("New Meter"))

diff --git a/gtk2_ardour/tempo_dialog.h b/gtk2_ardour/tempo_dialog.h
index ba269a44259a1408c7e4c3a14ed5346d2255fab7..848b55cb59968fec52d9197dfbd3eb85ff2b2402 100644 (file)
--- a/gtk2_ardour/tempo_dialog.h
+++ b/gtk2_ardour/tempo_dialog.h
@@ -52,10 +52,13 @@ private:
        bool bpm_button_release (GdkEventButton* );
        bool entry_key_release (GdkEventKey* );
        void pulse_change ();
+       void tap_tempo ();
 
        typedef std::map<std::string,float> NoteTypes;
        NoteTypes note_types;
 
+       struct timeval last_tap;
+
        Gtk::ComboBoxText pulse_selector;
        Gtk::Adjustment   bpm_adjustment;
        Gtk::SpinButton   bpm_spinner;
@@ -64,6 +67,7 @@ private:
        Gtk::Label   when_bar_label;
        Gtk::Label   when_beat_label;
        Gtk::Label   pulse_selector_label;
+       Gtk::Button  tap_tempo_button;
 };
 
 class MeterDialog : public ArdourDialog