help viewer: report errors and make it work from windows build directory

Author: jef-n

src/core/qgscontexthelp.cpp

@@ -22,6 +22,7 @@
 #include <QTextStream>
 
 #include "qgscontexthelp.h"
+#include "qgsmessagelog.h"
 #include "qgsapplication.h"
 #include "qgslogger.h"
 
@@ -56,17 +57,32 @@ QProcess *QgsContextHelp::start()
   QgsDebugMsg( QString( "Help path is %1" ).arg( helpPath ) );
 
   QProcess *process = new QProcess;
-  process->start( helpPath );
 
   // Delete this object if the process terminates
   connect( process, SIGNAL( finished( int, QProcess::ExitStatus ) ), SLOT( processExited() ) );
 
   // Delete the process if the application quits
   connect( qApp, SIGNAL( aboutToQuit() ), process, SLOT( terminate() ) );
 
+  connect( process, SIGNAL( error( QProcess::ProcessError ) ), this, SLOT( error( QProcess::ProcessError ) ) );
+
+#ifdef Q_OS_WIN
+  if ( QgsApplication::isRunningFromBuildDir() )
+  {
+    process->setEnvironment( QStringList() << QString( "PATH=%1;%2" ).arg( getenv( "PATH" ) ).arg( QApplication::applicationDirPath() ) );
+  }
+#endif
+
+  process->start( helpPath );
+
   return process;
 }
 
+void QgsContextHelp::error( QProcess::ProcessError error )
+{
+  QgsMessageLog::logMessage( tr( "Error starting help viewer [%1]" ).arg( error ), tr( "Context help" ) );
+}
+
 void QgsContextHelp::showContext( QString context )
 {
   init();

src/core/qgscontexthelp.h

@@ -21,12 +21,8 @@
 
 #include <QObject>
 #include <QHash>
+#include <QProcess>
 
-class QProcess;
-
-#ifdef Q_OS_MACX
-#define QGSCONTEXTHELP_REUSE 1
-#endif
 /** \ingroup core
  * Provides a context based help browser for a dialog.
  *
@@ -35,11 +31,6 @@ class QProcess;
  * viewer using QProcess and ensures that only one viewer is open.
  * The viewer will be terminated if open when the main application quits.
  *
- * If the compile-time flag QGSCONTEXTHELP_REUSE is defined, the help viewer
- * will be reused if it is still open. If this flag is not set, the viewer
- * process will be terminated if open and restarted; this makes it the top
- * window for window managers such as Linux/GNOME which will make a window
- * active but not bring it to the top if raised programatically.
  */
 class CORE_EXPORT QgsContextHelp : public QObject
 {
@@ -49,6 +40,7 @@ class CORE_EXPORT QgsContextHelp : public QObject
 
   private slots:
     void processExited();
+    void error( QProcess::ProcessError error );
 
   private:
     //! Constructor