Update frames computed label in a separate thread to avoid holding up the GUI.

4 files changed, 69 insertions, 13 deletions

diff --git a/src/wx/properties_dialog.cc b/src/wx/properties_dialog.cc
index 122d647ca..0a997bc41 100644
--- a/src/wx/properties_dialog.cc
+++ b/src/wx/properties_dialog.cc
@@ -19,6 +19,7 @@
 
 #include <iomanip>
 #include <boost/lexical_cast.hpp>
+#include <boost/bind.hpp>
 #include "lib/film.h"
 #include "lib/config.h"
 #include "properties_dialog.h"
@@ -29,6 +30,7 @@ using namespace boost;
 
 PropertiesDialog::PropertiesDialog (wxWindow* parent, Film* film)
 	: wxDialog (parent, wxID_ANY, _("Film Properties"), wxDefaultPosition, wxDefaultSize, wxDEFAULT_DIALOG_STYLE)
+	, _film (film)
 {
 	wxFlexGridSizer* table = new wxFlexGridSizer (2, 3, 6);
 
@@ -45,11 +47,11 @@ PropertiesDialog::PropertiesDialog (wxWindow* parent, Film* film)
 	table->Add (_total_disk, 1, wxALIGN_CENTER_VERTICAL);
 
 	add_label_to_sizer (table, this, "Frames already encoded");
-	_encoded = new wxStaticText (this, wxID_ANY, std_to_wx (""));
+	_encoded = new ThreadedStaticText (this, "calculating...", boost::bind (&PropertiesDialog::frames_already_encoded, this));
 	table->Add (_encoded, 1, wxALIGN_CENTER_VERTICAL);
 	
-	_frames->SetLabel (std_to_wx (lexical_cast<string> (film->length ())));
-	double const disk = ((double) Config::instance()->j2k_bandwidth() / 8) * film->length() / (film->frames_per_second () * 1073741824);
+	_frames->SetLabel (std_to_wx (lexical_cast<string> (_film->length ())));
+	double const disk = ((double) Config::instance()->j2k_bandwidth() / 8) * _film->length() / (_film->frames_per_second () * 1073741824);
 	stringstream s;
 	s << fixed << setprecision (1) << disk << "Gb";
 	_disk_for_frames->SetLabel (std_to_wx (s.str ()));
@@ -58,13 +60,6 @@ PropertiesDialog::PropertiesDialog (wxWindow* parent, Film* film)
 	t << fixed << setprecision (1) << (disk * 2) << "Gb";
 	_total_disk->SetLabel (std_to_wx (t.str ()));
 
-	stringstream u;
-	u << film->encoded_frames();
-	if (film->length()) {
-		u << " (" << (film->encoded_frames() * 100 / film->length()) << "%)";
-	}
-	_encoded->SetLabel (std_to_wx (u.str ()));
-
 	wxBoxSizer* overall_sizer = new wxBoxSizer (wxVERTICAL);
 	overall_sizer->Add (table, 0, wxALL, 8);
 	
@@ -76,3 +71,14 @@ PropertiesDialog::PropertiesDialog (wxWindow* parent, Film* film)
 	SetSizer (overall_sizer);
 	overall_sizer->SetSizeHints (this);
 }
+
+string
+PropertiesDialog::frames_already_encoded () const
+{
+	stringstream u;
+	u << _film->encoded_frames();
+	if (_film->length()) {
+		u << " (" << (_film->encoded_frames() * 100 / _film->length()) << "%)";
+	}
+	return u.str ();
+}
diff --git a/src/wx/properties_dialog.h b/src/wx/properties_dialog.h
index 25c11e8d0..f72c83419 100644
--- a/src/wx/properties_dialog.h
+++ b/src/wx/properties_dialog.h
@@ -20,6 +20,7 @@
 #include <wx/wx.h>
 
 class Film;
+class ThreadedStaticText;
 
 class PropertiesDialog : public wxDialog
 {
@@ -27,9 +28,12 @@ public:
 	PropertiesDialog (wxWindow *, Film *);
 
 private:
+	std::string frames_already_encoded () const;
+
+	Film* _film;
 	wxStaticText* _frames;
 	wxStaticText* _disk_for_frames;
 	wxStaticText* _total_disk;
-	wxStaticText* _encoded;
+	ThreadedStaticText* _encoded;
 };
 
diff --git a/src/wx/wx_util.cc b/src/wx/wx_util.cc
index 7655fe60d..5a9986215 100644
--- a/src/wx/wx_util.cc
+++ b/src/wx/wx_util.cc
@@ -18,12 +18,14 @@
 */
 
 /** @file src/wx/wx_util.cc
- *  @brief Some utility functions.
+ *  @brief Some utility functions and classes.
  */
 
+#include <boost/thread.hpp>
 #include "wx_util.h"
 
 using namespace std;
+using namespace boost;
 
 wxStaticText *
 add_label_to_sizer (wxSizer* s, wxWindow* p, string t, int prop)
@@ -52,3 +54,31 @@ std_to_wx (string s)
 {
 	return wxString (s.c_str(), wxConvUTF8);
 }
+
+int const ThreadedStaticText::_update_event_id = 10000;
+
+/** @param parent Parent for the wxStaticText.
+ *  @param initial Initial text for the wxStaticText while the computation is being run.
+ *  @param fn Function which works out what the wxStaticText content should be and returns it.
+ */
+ThreadedStaticText::ThreadedStaticText (wxWindow* parent, string initial, function<string ()> fn)
+	: wxStaticText (parent, wxID_ANY, std_to_wx (initial))
+{
+	Connect (_update_event_id, wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler (ThreadedStaticText::thread_finished), 0, this);
+	thread t (bind (&ThreadedStaticText::run, this, fn));
+}
+
+void
+ThreadedStaticText::run (function<string ()> fn)
+{
+	/* Run the thread and post the result to the GUI thread via AddPendingEvent */
+	wxCommandEvent ev (wxEVT_COMMAND_TEXT_UPDATED, _update_event_id);
+	ev.SetString (std_to_wx (fn ()));
+	GetEventHandler()->AddPendingEvent (ev);
+}
+
+void
+ThreadedStaticText::thread_finished (wxCommandEvent& ev)
+{
+	SetLabel (ev.GetString ());
+}
diff --git a/src/wx/wx_util.h b/src/wx/wx_util.h
index d0b838c36..555a3ab0e 100644
--- a/src/wx/wx_util.h
+++ b/src/wx/wx_util.h
@@ -18,12 +18,28 @@
 */
 
 #include <wx/wx.h>
+#include <boost/function.hpp>
 
 /** @file src/wx/wx_util.h
- *  @brief Some utility functions.
+ *  @brief Some utility functions and classes.
  */
 
 extern void error_dialog (wxWindow *, std::string);
 extern wxStaticText* add_label_to_sizer (wxSizer *, wxWindow *, std::string, int prop = 0);
 extern std::string wx_to_std (wxString);
 extern wxString std_to_wx (std::string);
+
+/** A wxStaticText whose content is computed in a separate thread, to avoid holding
+ *  up the GUI while work is done.
+ */
+class ThreadedStaticText : public wxStaticText
+{
+public:
+	ThreadedStaticText (wxWindow* parent, std::string initial, boost::function<std::string ()> fn);
+
+private:
+	void run (boost::function<std::string ()> fn);
+	void thread_finished (wxCommandEvent& ev);
+
+	static const int _update_event_id;
+};