Add hotloading for translation files. Fixes #2915.

This was SVN commit r15947.

source/gui/GUIManager.cpp

@@ -272,6 +272,15 @@ Status CGUIManager::ReloadChangedFile(const VfsPath& path)
 	return INFO::OK;
 }
 
+Status CGUIManager::ReloadAllPages()
+{
+	// TODO: this can crash if LoadPage runs an init script which modifies the page stack and breaks our iterators
+	for (PageStackType::iterator it = m_PageStack.begin(); it != m_PageStack.end(); ++it)
+		LoadPage(*it);
+
+	return INFO::OK;
+}
+
 CScriptVal CGUIManager::GetSavedGameData(ScriptInterface*& pPageScriptInterface)
 {
 	JSContext* cx = top()->GetScriptInterface()->GetContext();

source/gui/GUIManager.h

@@ -92,6 +92,11 @@ public:
 	 */
 	Status ReloadChangedFile(const VfsPath& path);
 
+	/**
+	 * Called when we should reload all pages (e.g. translation hotloading update).
+	 */
+	Status ReloadAllPages();
+
 	/**
 	 * Pass input events to the currently active GUI page.
 	 */

source/i18n/L10n.cpp

@@ -25,17 +25,23 @@
 
 #include <iostream>
 #include <string>
+#include <boost/algorithm/string.hpp>
 #include <boost/concept_check.hpp>
 
+#include "gui/GUIManager.h"
 #include "lib/file/file_system.h"
 #include "lib/utf8.h"
-
 #include "ps/CLogger.h"
 #include "ps/ConfigDB.h"
 #include "ps/Filesystem.h"
 #include "ps/GameSetup/GameSetup.h"
 
 
+static Status ReloadChangedFileCB(void* param, const VfsPath& path)
+{
+	return static_cast<L10n*>(param)->ReloadChangedFile(path);
+}
+
 L10n::L10n()
 	: currentLocaleIsOriginalGameLocale(false), useLongStrings(false), dictionary(new tinygettext::Dictionary())
 {
@@ -52,10 +58,15 @@ L10n::L10n()
 
 	LoadListOfAvailableLocales();
 	ReevaluateCurrentLocaleAndReload();
+
+	// Handle hotloading
+	RegisterFileReloadFunc(ReloadChangedFileCB, this);
 }
 
 L10n::~L10n()
 {
+	UnregisterFileReloadFunc(ReloadChangedFileCB, this);
+
 	for (std::vector<Locale*>::iterator iterator = availableLocales.begin(); iterator != availableLocales.end(); ++iterator)
 		delete *iterator;
 	delete dictionary;
@@ -437,6 +448,46 @@ VfsPath L10n::LocalizePath(VfsPath sourcePath)
 	return path;
 }
 
+Status L10n::ReloadChangedFile(const VfsPath& path)
+{
+	if (!boost::algorithm::starts_with(path.string(), L"l10n/"))
+		return INFO::OK;
+
+	if (path.Extension() != L".po")
+		return INFO::OK;
+
+	// If the file was deleted, ignore it
+	if (!VfsFileExists(path))
+		return INFO::OK;
+
+	std::wstring dictName = GetFallbackToAvailableDictLocale(currentLocale);
+	if (useLongStrings)
+		dictName = L"long";
+	if (dictName.empty())
+		return INFO::OK;
+
+	// Only the currently used language is loaded, so ignore all others
+	if (path.string().rfind(dictName) == std::string::npos)
+		return INFO::OK;
+
+	LOGMESSAGE(L"Hotloading translations from '%ls'", path.string().c_str());
+
+	CVFSFile file;
+	if (file.Load(g_VFS, path) != PSRETURN_OK)
+	{
+		LOGERROR(L"Failed to read translations from '%ls'", path.string().c_str());
+		return ERR::FAIL;
+	}
+
+	std::string content = file.DecodeUTF8();
+	ReadPoIntoDictionary(content, dictionary);
+
+	if (g_GUI)
+		g_GUI->ReloadAllPages();
+
+	return INFO::OK;
+}
+
 void L10n::LoadDictionaryForCurrentLocale()
 {
 	delete dictionary;

source/i18n/L10n.h

@@ -528,6 +528,12 @@ public:
 	 */
 	VfsPath LocalizePath(VfsPath sourcePath);
 
+	/**
+	 * Loads @p path into the dictionary if it is a translation file of the
+	 * @link L10n::GetCurrentLocale() current locale@endlink.
+	 */
+	Status ReloadChangedFile(const VfsPath& path);
+
 private:
 
 	/**