Move the CanSave logic to the subtitle formats as it's obviously format-specific

Originally committed to SVN as r6625.

aegisub/src/ass_file.cpp

@@ -225,45 +225,9 @@ void AssFile::SaveMemory(std::vector<char> &dst) {
 	}
 }
 
-bool AssFile::CanSave() {
-	// ASS format?
-	wxString ext = filename.Lower().Right(4);
-	if (ext == ".ass") return true;
-
-	// Never save texts
-	if (ext == ".txt") return false;
-
-	// Check if it's a known extension
-	if (!SubtitleFormat::GetWriter(filename)) return false;
-
-	// Scan through the lines
-	AssStyle defstyle;
-	AssStyle *curstyle;
-	AssDialogue *curdiag;
-	for (entryIter cur=Line.begin();cur!=Line.end();cur++) {
-		// Check style, if anything non-default is found, return false
-		curstyle = dynamic_cast<AssStyle*>(*cur);
-		if (curstyle) {
-			if (curstyle->GetEntryData() != defstyle.GetEntryData()) return false;
-		}
-
-		// Check for attachments, if any is found, return false
-		if (dynamic_cast<AssAttachment*>(*cur)) return false;
-
-		// Check dialog
-		curdiag = dynamic_cast<AssDialogue*>(*cur);
-		if (curdiag) {
-			// Overrides?
-			curdiag->ParseASSTags();
-			for (size_t i=0;i<curdiag->Blocks.size();i++) {
-				if (curdiag->Blocks[i]->GetType() != BLOCK_PLAIN) return false;
-			}
-			curdiag->ClearBlocks();
-		}
-	}
-
-	// Success
-	return true;
+bool AssFile::CanSave() const {
+	const SubtitleFormat *writer = SubtitleFormat::GetWriter(filename);
+	return writer && writer->CanSave(this);
 }
 
 void AssFile::AddLine(wxString data, int *version, AssAttachment **attach) {

aegisub/src/ass_file.h

@@ -146,7 +146,7 @@ public:
 	/// Add file name to the MRU list
 	void AddToRecent(wxString file);
 	/// Can the file be saved in its current format?
-	bool CanSave();
+	bool CanSave() const;
 	/// @brief Get the list of wildcards supported
 	/// @param mode 0 = open, 1 = save, 2 = export
 	static wxString GetWildcardList(int mode);

aegisub/src/subtitle_format.cpp

@@ -36,14 +36,17 @@
 
 #include "config.h"
 
+#include "subtitle_format.h"
+
 #ifndef AGI_PRE
 #include <wx/intl.h>
 #include <wx/choicdlg.h> // Keep this last so wxUSE_CHOICEDLG is set.
 #endif
 
+#include "ass_attachment.h"
 #include "ass_dialogue.h"
 #include "ass_file.h"
-#include "subtitle_format.h"
+#include "ass_style.h"
 #include "subtitle_format_ass.h"
 #include "subtitle_format_encore.h"
 #include "subtitle_format_microdvd.h"
@@ -75,7 +78,28 @@ bool SubtitleFormat::CanWriteFile(wxString const& filename) const {
 	return GetWriteWildcards().Index(filename.AfterLast('.'), false) != wxNOT_FOUND;
 }
 
-/// @brief Ask the user to enter the FPS
+bool SubtitleFormat::CanSave(const AssFile *subs) const {
+	AssStyle defstyle;
+	for (std::list<AssEntry*>::const_iterator cur = subs->Line.begin(); cur != subs->Line.end(); ++cur) {
+		// Check style, if anything non-default is found, return false
+		if (const AssStyle *curstyle = dynamic_cast<const AssStyle*>(*cur)) {
+			if (curstyle->GetEntryData() != defstyle.GetEntryData())
+				return false;
+		}
+
+		// Check for attachments, if any is found, return false
+		if (dynamic_cast<const AssAttachment*>(*cur)) return false;
+
+		// Check dialog
+		if (const AssDialogue *curdiag = dynamic_cast<const AssDialogue*>(*cur)) {
+			if (curdiag->GetStrippedText() != curdiag->Text)
+				return false;
+		}
+	}
+
+	return true;
+}
+
 FractionalTime SubtitleFormat::AskForFPS(bool showSMPTE) const {
 	wxArrayString choices;
 	bool drop = false;

aegisub/src/subtitle_format.h

@@ -103,16 +103,22 @@ public:
 
 	/// @brief Check if the given file can be read by this format
 	///
-	/// Default implement ion simply checks if the file's extension is in the
+	/// Default implementation simply checks if the file's extension is in the
 	/// format's wildcard list
 	virtual bool CanReadFile(wxString const& filename) const;
 
 	/// @brief Check if the given file can be written by this format
 	///
-	/// Default implement ion simply checks if the file's extension is in the
+	/// Default implementation simply checks if the file's extension is in the
 	/// format's wildcard list
 	virtual bool CanWriteFile(wxString const& filename) const;
 
+	/// @brief Check if the given subtitles can be losslessly written by this format
+	///
+	/// Default implementation rejects files with attachments, non-default
+	/// styles, and any overrides
+	virtual bool CanSave(const AssFile *file) const;
+
 	/// Load a subtitle file
 	/// @param[out] target Destination to read lines into
 	/// @param filename File to load

aegisub/src/subtitle_format_ass.h

@@ -48,6 +48,9 @@ public:
 	wxArrayString GetReadWildcards() const;
 	wxArrayString GetWriteWildcards() const;
 
+	// Naturally the ASS subtitle format can save all Ass files
+	bool CanSave(const AssFile*) const { return true; }
+
 	void ReadFile(AssFile *target, wxString const& filename, wxString const& forceEncoding) const;
 	void WriteFile(const AssFile *src, wxString const& filename, wxString const& encoding) const;
 };

aegisub/src/subtitle_format_txt.h

@@ -47,6 +47,9 @@ public:
 	wxArrayString GetReadWildcards() const;
 	wxArrayString GetWriteWildcards() const;
 
+	// TXT format supports so little that it should always require an export
+	bool CanSave(const AssFile*) const { return false; }
+
 	bool CanWriteFile(wxString const& filename) const;
 	void ReadFile(AssFile *target, wxString const& filename, wxString const& forceEncoding) const;
 	void WriteFile(const AssFile *src, wxString const& filename, wxString const& encoding) const;