Guess UI scale for copy-config dialog

This dialog shows before the new user wizard,
where a user would configure HDPI/UI scaling.

gtk2_ardour/ardour_ui.cc

@@ -215,6 +215,10 @@ static const gchar *_record_mode_strings[] = {
 static bool
 ask_about_configuration_copy (string const & old_dir, string const & new_dir, int version)
 {
+	/* guess screen scaling */
+	UIConfiguration::instance ().set_font_scale (1024 * guess_default_ui_scale ());
+	UIConfiguration::instance ().reset_dpi ();
+
 	ArdourMessageDialog msg (string_compose (
 	                          _("%1 %2.x has discovered configuration files from %1 %3.x.\n\n"
 	                            "Would you like these files to be copied and used for %1 %2.x?\n\n"
@@ -367,6 +371,7 @@ ARDOUR_UI::ARDOUR_UI (int *argcp, char **argvp[], const char* localedir)
 	record_mode_strings = I18N (_record_mode_strings);
 
 	if (ARDOUR::handle_old_configuration_files (boost::bind (ask_about_configuration_copy, _1, _2, _3))) {
+
 		{
 			/* "touch" the been-here-before path now that config has been migrated */
 			PBD::ScopedFileDescriptor fout (g_open (been_here_before_path ().c_str(), O_CREAT|O_TRUNC|O_RDWR, 0666));

gtk2_ardour/new_user_wizard.cc

@@ -171,7 +171,18 @@ using the program.</span> \
 	hbox->show ();
 	cbox->show ();
 
-	guess_default_ui_scale ();
+	int ui_scale = guess_default_ui_scale ();
+	if (ui_scale <= 100) {
+		ui_font_scale.set_active (0); // 100%
+	} else if (ui_scale <= 150) {
+		ui_font_scale.set_active (1); // 150%
+	} else if (ui_scale <= 200) {
+		ui_font_scale.set_active (2); // 200%
+	} else {
+		ui_font_scale.set_active (3); // 250%
+	}
+	rescale_ui ();
+
 	ui_font_scale.signal_changed ().connect (sigc::mem_fun (*this, &NewUserWizard::rescale_ui));
 #endif
 
@@ -189,7 +200,7 @@ void
 NewUserWizard::rescale_ui ()
 {
 	int rn = ui_font_scale.get_active_row_number ();
-	if (rn < 0 ) {
+	if (rn < 0) {
 		return;
 	}
 	float ui_scale = 100 + rn * 50;
@@ -197,41 +208,6 @@ NewUserWizard::rescale_ui ()
 	UIConfiguration::instance ().reset_dpi ();
 }
 
-void
-NewUserWizard::guess_default_ui_scale ()
-{
-	gint width = 0;
-	gint height = 0;
-	GdkScreen* screen = gdk_display_get_screen (gdk_display_get_default (), 0);
-	gint n_monitors = gdk_screen_get_n_monitors (screen);
-
-	if (!screen) {
-		return;
-	}
-
-	for (gint i = 0; i < n_monitors; ++i) {
-		GdkRectangle rect;
-		gdk_screen_get_monitor_geometry (screen, i, &rect);
-		width = std::max (width, rect.width);
-		height = std::max (height, rect.height);
-	}
-
-	float wx = width  / 1920.f;
-	float hx = height / 1080.f;
-	float sx = std::min (wx, hx);
-
-	if (sx < 1.25) {
-		ui_font_scale.set_active (0); // 100%
-	} else if (sx < 1.6) {
-		ui_font_scale.set_active (1); // 150%
-	} else if (sx < 2.1) {
-		ui_font_scale.set_active (2); // 200%
-	} else {
-		ui_font_scale.set_active (3); // 250%
-	}
-	rescale_ui ();
-}
-
 void
 NewUserWizard::default_dir_changed ()
 {

gtk2_ardour/new_user_wizard.h

@@ -77,7 +77,6 @@ private:
 	/* Welcome */
 	Gtk::ComboBoxText ui_font_scale;
 	void rescale_ui ();
-	void guess_default_ui_scale ();
 
 	/* first page */
 	Gtk::FileChooserButton* default_dir_chooser;

gtk2_ardour/utils.cc

@@ -642,6 +642,40 @@ ARDOUR_UI_UTILS::key_is_legal_for_numeric_entry (guint keyval)
 	return false;
 }
 
+int
+ARDOUR_UI_UTILS::guess_default_ui_scale ()
+{
+	gint width = 0;
+	gint height = 0;
+	GdkScreen* screen = gdk_display_get_screen (gdk_display_get_default (), 0);
+	gint n_monitors = gdk_screen_get_n_monitors (screen);
+
+	if (!screen) {
+		return 100;
+	}
+
+	for (gint i = 0; i < n_monitors; ++i) {
+		GdkRectangle rect;
+		gdk_screen_get_monitor_geometry (screen, i, &rect);
+		width = std::max (width, rect.width);
+		height = std::max (height, rect.height);
+	}
+
+	float wx = width  / 1920.f;
+	float hx = height / 1080.f;
+	float sx = std::min (wx, hx);
+
+	if (sx < 1.25) {
+		return 100;
+	} else if (sx < 1.6) {
+		return 150;
+	} else if (sx < 2.1) {
+		return 200;
+	} else {
+		return 250;
+	}
+}
+
 void
 ARDOUR_UI_UTILS::resize_window_to_proportion_of_monitor (Gtk::Window* window, int max_width, int max_height)
 {

gtk2_ardour/utils.h

@@ -95,6 +95,8 @@ const char* const *get_xpm_data (std::string path);
 std::string longest (std::vector<std::string>&);
 bool key_is_legal_for_numeric_entry (guint keyval);
 
+int guess_default_ui_scale ();
+
 void resize_window_to_proportion_of_monitor (Gtk::Window*, int, int);
 
 std::string escape_underscores (std::string const &);