Only prompt to update references to a renamed style if there actually are any

Originally committed to SVN as r6537.

aegisub/src/dialog_style_editor.cpp

@@ -65,6 +65,73 @@
 #include "utils.h"
 #include "validators.h"
 
+/// Style rename helper that walks a file searching for a style and optionally
+/// updating references to it
+class StyleRenamer {
+	agi::Context *c;
+	bool found_any;
+	bool do_replace;
+	wxString source_name;
+	wxString new_name;
+
+	/// Process a single override parameter to check if it's \r with this style name
+	static void ProcessTag(wxString tag, int, AssOverrideParameter* param, void *userData) {
+		StyleRenamer *self = static_cast<StyleRenamer*>(userData);
+		if (tag == "\\r" && param->GetType() == VARDATA_TEXT && param->Get<wxString>() == self->source_name) {
+			if (self->do_replace)
+				param->Set(self->new_name);
+			else
+				self->found_any = true;
+		}
+	}
+
+	void Walk(bool replace) {
+		found_any = false;
+		do_replace = replace;
+
+		for (entryIter it = c->ass->Line.begin(); it != c->ass->Line.end(); ++it) {
+			AssDialogue *diag = dynamic_cast<AssDialogue*>(*it);
+			if (!diag) continue;
+
+			if (diag->Style == source_name) {
+				if (replace)
+					diag->Style = new_name;
+				else
+					found_any = true;
+			}
+
+			diag->ParseASSTags();
+			diag->ProcessParameters(&StyleRenamer::ProcessTag, this);
+			if (replace)
+				diag->UpdateText();
+			diag->ClearBlocks();
+
+			if (found_any) return;
+		}
+	}
+
+public:
+	StyleRenamer(agi::Context *c, wxString const& source_name, wxString const& new_name)
+	: c(c)
+	, found_any(false)
+	, do_replace(false)
+	, source_name(source_name)
+	, new_name(new_name)
+	{
+	}
+
+	/// Check if there are any uses of the original style name in the file
+	bool NeedsReplace() {
+		Walk(false);
+		return found_any;
+	}
+
+	/// Replace all uses of the original style name with the new one
+	void Replace() {
+		Walk(true);
+	}
+};
+
 static void add_with_label(wxSizer *sizer, wxWindow *parent, wxString const& label, wxWindow *ctrl) {
 	sizer->Add(new wxStaticText(parent, -1, label), wxSizerFlags().Center().Right().Border(wxLEFT | wxRIGHT));
 	sizer->Add(ctrl, wxSizerFlags(1).Left().Expand());
@@ -350,14 +417,6 @@ wxString DialogStyleEditor::GetStyleName() const {
 	return style->name;
 }
 
-/// @brief Update appearances of a renamed style in \r tags
-static void ReplaceStyle(wxString tag, int, AssOverrideParameter* param, void *userData) {
-	wxArrayString strings = *((wxArrayString*)userData);
-	if (tag == "\\r" && param->GetType() == VARDATA_TEXT && param->Get<wxString>() == strings[0]) {
-		param->Set(strings[1]);
-	}
-}
-
 void DialogStyleEditor::Apply(bool apply, bool close) {
 	if (apply) {
 		wxString newStyleName = StyleName->GetValue();
@@ -379,24 +438,19 @@ void DialogStyleEditor::Apply(bool apply, bool close) {
 		bool did_rename = false;
 		if (work->name != newStyleName) {
 			if (!store && !is_new) {
+				StyleRenamer renamer(c, work->name, newStyleName);
+				if (renamer.NeedsReplace()) {
 					// See if user wants to update style name through script
-				int answer = wxMessageBox(_("Do you want to change all instances of this style in the script to this new name?"), _("Update script?"), wxYES_NO | wxCANCEL);
+					int answer = wxMessageBox(
+						_("Do you want to change all instances of this style in the script to this new name?"),
+						_("Update script?"),
+						wxYES_NO | wxCANCEL);
 
 					if (answer == wxCANCEL) return;
 
 					if (answer == wxYES) {
 						did_rename = true;
-					int n = c->subsGrid->GetRows();
+						renamer.Replace();
-					wxArrayString strings;
-					strings.Add(work->name);
-					strings.Add(newStyleName);
-					for (int i=0;i<n;i++) {
-						AssDialogue *curDiag = c->subsGrid->GetDialogue(i);
-						if (curDiag->Style == work->name) curDiag->Style = newStyleName;
-						curDiag->ParseASSTags();
-						curDiag->ProcessParameters(ReplaceStyle, &strings);
-						curDiag->UpdateText();
-						curDiag->ClearBlocks();
 					}
 				}
 			}