Added code to allow for an external chm viewer to be used for unix OS.

src/drivers/Qt/ConsoleWindow.cpp

@@ -227,6 +227,7 @@ consoleWin_t::consoleWin_t(QWidget *parent)
 	refreshRate = 0.0;
 	updateCounter = 0;
 	recentRomMenuReset = false;
+	helpWin = 0;
 
 	// Viewport Cursor Type and Visibility
 	loadCursor();
@@ -1890,22 +1891,24 @@ void consoleWin_t::createMainMenu(void)
 	helpMenu->addAction(msgLogAct);
 
 	// Help -> Documentation Online
-	act = new QAction(tr("&Docs (Online)"), this);
+	subMenu = helpMenu->addMenu( tr("&Documentation") );
+	subMenu->setIcon( style()->standardIcon( QStyle::SP_DialogHelpButton ) );
+
+	// Help -> Documentation Online
+	act = new QAction(tr("&Online"), this);
 	act->setStatusTip(tr("Documentation"));
-	act->setIcon( style()->standardIcon( QStyle::SP_DialogHelpButton ) );
+	//act->setIcon( style()->standardIcon( QStyle::SP_DialogHelpButton ) );
 	connect(act, SIGNAL(triggered()), this, SLOT(openOnlineDocs(void)) );
 	
-	helpMenu->addAction(act);
+	subMenu->addAction(act);
 
-#ifdef WIN32
 	// Help -> Documentation Offline
-	act = new QAction(tr("&Docs (Offline)"), this);
+	act = new QAction(tr("&Local"), this);
 	act->setStatusTip(tr("Documentation"));
-	act->setIcon( style()->standardIcon( QStyle::SP_DialogHelpButton ) );
+	//act->setIcon( style()->standardIcon( QStyle::SP_DialogHelpButton ) );
 	connect(act, SIGNAL(triggered()), this, SLOT(openOfflineDocs(void)) );
 
-	helpMenu->addAction(act);
-#endif
+	subMenu->addAction(act);
 };
 //---------------------------------------------------------------------------
 int consoleWin_t::loadVideoDriver( int driverId )
@@ -4172,6 +4175,8 @@ void consoleWin_t::updatePeriodic(void)
 		recWavAct->setEnabled( FCEU_IsValidUI( FCEUI_RECORDMOVIE ) && !FCEUI_WaveRecordRunning() );
 		recAsWavAct->setEnabled( FCEU_IsValidUI( FCEUI_RECORDMOVIE ) && !FCEUI_WaveRecordRunning() );
 		stopWavAct->setEnabled( FCEUI_WaveRecordRunning() );
+
+		helpPageMaint();
 	}
 
 	if ( errorMsgValid )

src/drivers/Qt/ConsoleWindow.h

@@ -171,6 +171,9 @@ class  consoleWin_t : public QMainWindow
 		void setMenuAccessPauseEnable(bool enable);
 		void setContextMenuEnable(bool enable);
 		void setSoundUseGlobalFocus(bool enable);
+
+		void OpenHelpWindow(std::string subpage = "");
+
 	protected:
 		consoleMenuBar *menubar;
 
@@ -266,6 +269,11 @@ class  consoleWin_t : public QMainWindow
 
 		double       refreshRate;
 		unsigned int updateCounter;
+#ifdef WIN32
+		HWND   helpWin;
+#else
+		int    helpWin;
+#endif
 	protected:
 		void resizeEvent(QResizeEvent *event) override;
 		void closeEvent(QCloseEvent *event) override;
@@ -291,6 +299,9 @@ class  consoleWin_t : public QMainWindow
 		void loadState(int slot);
 		void transferVideoBuffer(void);
 		void syncAutoFirePatternMenu(void);
+		void helpPageMaint(void);
+
+		std::string find_chm(void);
 
 	public slots:
 		void openDebugWindow(void);

src/drivers/Qt/HelpPages.cpp

@@ -1,37 +1,205 @@
+/* FCE Ultra - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ *  Copyright (C) 2020 mjbudd77
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 // HelpPages.cpp
 
 #include <string>
+#include <QFile>
+#include <QFileDialog>
+#include <QStandardPaths>
 
 #include "driver.h"
 #include "Qt/HelpPages.h"
+#include "Qt/fceuWrapper.h"
 #include "Qt/ConsoleWindow.h"
+#include "Qt/ConsoleUtilities.h"
 
 #ifdef WIN32
 #include <Windows.h>
 #include <htmlhelp.h>
+#else // Linux or Unix or APPLE
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#endif
 
-void OpenHelpWindow(std::string subpage)
+#if  defined(__linux__) || defined(__unix__) || defined(__APPLE__)
+static int forkHelpFileViewer( const char *chmViewer, const char *filepath );
+#endif
+
+void consoleWin_t::OpenHelpWindow(std::string subpage)
 {
-	HWND helpWin;
-	std::string helpFileName = FCEUI_GetBaseDirectory();
-	helpFileName += "\\..\\doc\\fceux.chm";
+	std::string helpFileName;
+
+	g_config->getOption ("SDL.HelpFilePath", &helpFileName );
+
+	if ( helpFileName.length() == 0 )
+	{
+		std::string helpFileName = FCEUI_GetBaseDirectory();
+		helpFileName += "\\..\\doc\\fceux.chm";
+	}
+
+	if ( !QFile( QString::fromStdString(helpFileName) ).exists() )
+	{
+		helpFileName = find_chm();
+	}
+
+	if ( helpFileName.length() == 0 )
+	{
+		return;
+	}
+
+#ifdef WIN32
 	if (subpage.length() > 0)
 	{
 		helpFileName = helpFileName + "::/" + subpage + ".htm";
 	}
+#else
+	// Subpage indexing is not supported by linux chm viewer
+#endif
+
 	//printf("Looking for HelpFile '%s'\n", helpFileName.c_str() );
-	helpWin = HtmlHelp( HWND(consoleWindow->winId()), helpFileName.c_str(), HH_DISPLAY_TOPIC, (DWORD)NULL);
+
+#ifdef WIN32
+	// Windows specific HtmlHelp library function
+	helpWin = HtmlHelp( HWND(winId()), helpFileName.c_str(), HH_DISPLAY_TOPIC, (DWORD)NULL);
 	if ( helpWin == NULL )
 	{
 		printf("Error: Failed to open help file '%s'\n", helpFileName.c_str() );
 	}
-}
-
 #else
+	if ( helpWin > 0 )
+	{
+		printf("There is already a CHM Viewer open somewhere...\n");
+		return;
+	}
+	std::string helpFileViewer;
+	g_config->getOption ("SDL.HelpFileViewer", &helpFileViewer );
 
-void OpenHelpWindow(std::string subpage)
-{
-	printf("Local CHM Help File Reference is only supported on Windows OS\n");
+	helpWin = forkHelpFileViewer( helpFileViewer.c_str(), helpFileName.c_str() );
+#endif
 }
 
+void consoleWin_t::helpPageMaint(void)
+{
+#ifdef WIN32
+	// Does any help page cleanup need to be done in windows?
+#else
+	if ( helpWin > 0 )
+	{	// Calling waitpid is important to ensure that CHM viewer process is cleaned up
+		// in the event that it exits. Otherwise zombie processes will be left.
+		int pid, wstat=0;
+
+		pid = waitpid( -1, &wstat, WNOHANG );
+
+		if ( pid == helpWin )
+		{
+			//printf("Help CHM Viewer Closed\n");
+			helpWin = 0;
+		}
+	}
+
+#endif
+}
+std::string consoleWin_t::find_chm(void)
+{
+	int ret, useNativeFileDialogVal;
+	QString filename;
+	std::string last;
+	char dir[512];
+	QFileDialog  dialog(this, tr("Open Help File") );
+	QList<QUrl> urls;
+	//QDir d;
+
+	urls << QUrl::fromLocalFile( QDir::rootPath() );
+	urls << QUrl::fromLocalFile(QStandardPaths::standardLocations(QStandardPaths::HomeLocation).first());
+	urls << QUrl::fromLocalFile(QStandardPaths::standardLocations(QStandardPaths::DownloadLocation).first());
+	urls << QUrl::fromLocalFile( QDir( FCEUI_GetBaseDirectory() ).absolutePath() );
+
+	dialog.setFileMode(QFileDialog::ExistingFile);
+
+	dialog.setNameFilter(tr("Compiled HTML Files (*.chm *.CHM) ;; All files (*)"));
+
+	dialog.setViewMode(QFileDialog::List);
+	dialog.setFilter( QDir::AllEntries | QDir::AllDirs | QDir::Hidden );
+	dialog.setLabelText( QFileDialog::Accept, tr("Open") );
+
+	g_config->getOption ("SDL.HelpFilePath", &last );
+
+	if ( last.size() > 0 )
+	{
+		getDirFromFile( last.c_str(), dir );
+
+		dialog.setDirectory( tr(dir) );
+	}
+	else
+	{
+		dialog.setDirectory( QDir( FCEUI_GetBaseDirectory() ).absolutePath() );
+	}
+
+	// Check config option to use native file dialog or not
+	g_config->getOption ("SDL.UseNativeFileDialog", &useNativeFileDialogVal);
+
+	dialog.setOption(QFileDialog::DontUseNativeDialog, !useNativeFileDialogVal);
+	dialog.setSidebarUrls(urls);
+
+	ret = dialog.exec();
+
+	if ( ret )
+	{
+		QStringList fileList;
+		fileList = dialog.selectedFiles();
+
+		if ( fileList.size() > 0 )
+		{
+			filename = fileList[0];
+		}
+	}
+
+	if ( filename.isNull() )
+	{
+		return last;
+	}
+	//qDebug() << "selected file path : " << filename.toUtf8();
+
+	g_config->setOption ("SDL.HelpFilePath", filename.toStdString().c_str() );
+
+	return filename.toStdString();
+}
+
+#if  defined(__linux__) || defined(__unix__) || defined(__APPLE__)
+static int forkHelpFileViewer( const char *chmViewer, const char *filepath )
+{
+	int pid = 0;
+
+	if ( chmViewer[0] == 0 )
+	{
+		return -1;
+	}
+
+	pid = fork();
+
+	if ( pid == 0 )
+	{  // Child process
+		execl( chmViewer, chmViewer, filepath, NULL );
+		exit(0);	
+	}
+	return pid;
+}
 #endif

src/drivers/Qt/HelpPages.h

@@ -1,3 +1,2 @@
 // HelpPages.h
 
-void OpenHelpWindow(std::string subpage = "");

src/drivers/Qt/config.cpp

@@ -707,6 +707,12 @@ InitConfig()
 	config->addOption("_lastsavestateas", "SDL.LastSaveStateAs", savPath );
 	config->addOption("_lastopenmovie", "SDL.LastOpenMovie", movPath);
 	config->addOption("_lastloadlua", "SDL.LastLoadLua", "");
+	config->addOption("SDL.HelpFilePath", "");
+#ifdef WIN32
+	config->addOption("SDL.HelpFileViewer", "");
+#else
+	config->addOption("SDL.HelpFileViewer", "/usr/bin/xchm");
+#endif
 
 	for (unsigned int i=0; i<10; i++)
 	{