DiskUsage: minor clean up

* remove unused code.
* make fPreviousSnapshot local.
* change app_flags to B_SINGLE_LAUNCH
  when it is invoked by add-on reuses an already scanned volume

src/apps/diskusage/App.cpp

@@ -25,18 +25,9 @@
 App::App()
 	:
 	BApplication(kAppSignature),
-	fMainWindow(NULL), fSavedRefsReceived(NULL)
+	fMainWindow(NULL),
+	fSavedRefsReceived(NULL)
 {
-	// Get a reference to the help file.
-	BPath path;
-	if (find_directory(B_BEOS_DOCUMENTATION_DIRECTORY, &path) == B_OK
-		&& path.Append(kHelpFileName) == B_OK) {
-		printf("help file =? %s\n", path.Path());
-		BEntry entry(path.Path());
-		helpFileWasFound = entry.Exists();
-		entry.GetRef(&helpFileRef);
-	} else
-		helpFileWasFound = false;
 }
 
 

src/apps/diskusage/DiskUsage.cpp

@@ -17,8 +17,6 @@
 #undef B_TRANSLATION_CONTEXT
 #define B_TRANSLATION_CONTEXT "DiskUsage"
 
-entry_ref helpFileRef;
-bool helpFileWasFound = false;
 
 int
 main() 

src/apps/diskusage/DiskUsage.h

@@ -52,13 +52,10 @@ const float	kPieOuterMargin		= 10.0;
 const float	kMinSegmentSpan		= 2.0;
 const float	kDragThreshold		= 5.0;
 
-extern entry_ref helpFileRef;
-extern bool helpFileWasFound;
 
 #define kMenuSelectVol				'gMSV'
 #define kBtnRescan					'gBRF'
 #define kBtnCancel					'gCAN'
-#define kBtnHelp					'gHLP'
 #define kScanRefresh				'gSRF'
 #define kScanProgress				'gSPR'
 #define kScanDone					'gSDN'

src/apps/diskusage/DiskUsage.rdef

@@ -14,7 +14,7 @@ resource app_version {
 		long_info = "1.0.2 ©1999 Mike Steed, ©2008-2011 Haiku"
 };
 
-resource app_flags B_MULTIPLE_LAUNCH;
+resource app_flags B_SINGLE_LAUNCH;
 
 resource file_types message {
 		"types" = "application/x-vnd.Be-volume",

src/apps/diskusage/MainWindow.cpp

@@ -58,11 +58,6 @@ MainWindow::MessageReceived(BMessage* message)
 			fControlsView->MessageReceived(message);
 			break;
 
-		case kBtnHelp:
-			if (helpFileWasFound)
-				be_roster->Launch(&helpFileRef);
-			break;
-
 		default:
 			BWindow::MessageReceived(message);
 			break;

src/apps/diskusage/Scanner.cpp

@@ -35,8 +35,7 @@ Scanner::Scanner(BVolume *v, BHandler *handler)
 	fDesiredPath(),
 	fTask(),
 	fBusy(false),
-	fQuitRequested(false),
+	fQuitRequested(false)
-	fPreviousSnapshot(NULL)
 {
 	Run();
 }
@@ -144,11 +143,11 @@ Scanner::_DirectoryContains(FileInfo* currentDir, entry_ref* ref)
 void
 Scanner::_RunScan(FileInfo* startInfo)
 {
-	fPreviousSnapshot = fSnapshot;
 	fQuitRequested = false;
 	BString stringScan(B_TRANSLATE("Scanning %refName%"));
 
 	if (startInfo == NULL || startInfo == fSnapshot->rootDir) {
+		VolumeSnapshot* previousSnapshot = fSnapshot;
 		fSnapshot = new VolumeSnapshot(fVolume);
 		stringScan.ReplaceFirst("%refName%", fSnapshot->name.c_str());
 		fTask = stringScan.String();
@@ -162,7 +161,7 @@ Scanner::_RunScan(FileInfo* startInfo)
 		fSnapshot->rootDir = _GetFileInfo(&root, NULL);
 		if (fSnapshot->rootDir == NULL) {
 			delete fSnapshot;
-			fSnapshot = fPreviousSnapshot;
+			fSnapshot = previousSnapshot;
 			fBusy = false;
 			fListener.SendMessage(&fDoneMessage);
 			return;
@@ -177,7 +176,7 @@ Scanner::_RunScan(FileInfo* startInfo)
 
 		fSnapshot->currentDir = NULL;
 
-		delete fPreviousSnapshot;
+		delete previousSnapshot;
 	} else {
 		off_t previousVolumeCapacity = fSnapshot->capacity;
 		off_t previousVolumeFreeBytes = fSnapshot->freeBytes;

src/apps/diskusage/Scanner.h

@@ -72,8 +72,6 @@ private:
 			string				fTask;
 			bool				fBusy;
 			bool				fQuitRequested;
-
-			VolumeSnapshot*		fPreviousSnapshot;
 };
 
 #endif // SCANNER_H