DiskUsage: added ability to cancel an ongoing scan. fixes #6801.

Also, progress now goes from 0.0 to 1.0 rather than from 0.00 to 100.00
(to avoid a * 100, followed by a / 100)

src/apps/diskusage/ControlsView.cpp

@@ -248,6 +248,7 @@ ControlsView::VolumeTabView::MessageReceived(BMessage* message)
 			}
 			break;
 
+		case kBtnCancel:
 		case kBtnRescan:
 			ViewForTab(Selection())->MessageReceived(message);
 			break;
@@ -361,6 +362,7 @@ ControlsView::MessageReceived(BMessage* msg)
 			fVolumeTabView->MessageReceived(msg);
 			break;
 
+		case kBtnCancel:
 		case kBtnRescan:
 			fVolumeTabView->MessageReceived(msg);
 			break;
@@ -385,10 +387,18 @@ ControlsView::ShowInfo(const FileInfo* info)
 
 
 void
-ControlsView::SetRescanEnabled(bool enabled)
+ControlsView::EnableRescan()
 {
 	((VolumeView*)fVolumeTabView->ViewForTab(
-		fVolumeTabView->Selection()))->SetRescanEnabled(enabled);
+		fVolumeTabView->Selection()))->EnableRescan();
+}
+
+
+void
+ControlsView::EnableCancel()
+{
+	((VolumeView*)fVolumeTabView->ViewForTab(
+		fVolumeTabView->Selection()))->EnableCancel();
 }
 
 

src/apps/diskusage/ControlsView.h

@@ -28,7 +28,8 @@ public:
 			BVolume*			FindDeviceFor(dev_t device,
 									bool invoke = false);
 
-			void				SetRescanEnabled(bool enabled);
+			void				EnableRescan();
+			void				EnableCancel();
 			void				ShowInfo(const FileInfo* info);
 
 private:

src/apps/diskusage/DiskUsage.h

@@ -42,7 +42,7 @@ const float	kMinButtonWidth		= 60.0;
 
 const float	kProgBarWidth		= 150.0;
 const float	kProgBarHeight		= 16.0;
-const float	kReportInterval		= 2.5;
+const float	kReportInterval		= 0.0025;
 
 const float	kDefaultPieSize		= 400.0;
 const float	kPieCenterSize		= 80.0;
@@ -57,6 +57,7 @@ extern bool helpFileWasFound;
 
 #define kMenuSelectVol				'gMSV'
 #define kBtnRescan					'gBRF'
+#define kBtnCancel					'gCAN'
 #define kBtnHelp					'gHLP'
 #define kScanRefresh				'gSRF'
 #define kScanProgress				'gSPR'

src/apps/diskusage/MainWindow.cpp

@@ -51,9 +51,8 @@ void
 MainWindow::MessageReceived(BMessage* message)
 {
 	switch (message->what) {
+		case kBtnCancel:
 		case kBtnRescan:
-			fControlsView->MessageReceived(message);
-			break;
 		case B_SIMPLE_DATA:
 		case B_REFS_RECEIVED:
 			fControlsView->MessageReceived(message);
@@ -83,9 +82,16 @@ MainWindow::QuitRequested()
 
 
 void
-MainWindow::SetRescanEnabled(bool enabled)
+MainWindow::EnableRescan()
 {
-	fControlsView->SetRescanEnabled(enabled);
+	fControlsView->EnableRescan();
+}
+
+
+void
+MainWindow::EnableCancel()
+{
+	fControlsView->EnableCancel();
 }
 
 

src/apps/diskusage/MainWindow.h

@@ -26,7 +26,8 @@ public:
 	virtual	void				MessageReceived(BMessage* message);
 	virtual	bool				QuitRequested();
 
-			void				SetRescanEnabled(bool enabled);
+			void				EnableRescan();
+			void				EnableCancel();
 			BVolume*			FindDeviceFor(dev_t device,
 									bool invoke = false);
 

src/apps/diskusage/PieView.cpp

@@ -181,23 +181,26 @@ void
 PieView::MessageReceived(BMessage* message)
 {
 	switch (message->what) {
+		case kBtnCancel:
+			if (fScanner != NULL)
+				fScanner->Cancel();
+			break;
 		case kBtnRescan:
 			if (fVolume != NULL) {
 				if (fScanner != NULL)
 					fScanner->Refresh();
 				else
 					_ShowVolume(fVolume);
-
+				fWindow->EnableCancel();
 				Invalidate();
 			}
 			break;
-
+		
-		case kScanProgress:
 		case kScanDone:
-		{
+			fWindow->EnableRescan();
+		case kScanProgress:
 			Invalidate();
 			break;
-		}
 
 		default:
 			BView::MessageReceived(message);
@@ -300,12 +303,8 @@ PieView::Draw(BRect updateRect)
 		if (fScanner->IsBusy()) {
 			// Show progress of scanning.
 			_DrawProgressBar(updateRect);
-			if (fWindow != NULL)
+		} else if (fScanner->Snapshot() != NULL) {
-				fWindow->SetRescanEnabled(false);
-		} else {
 			_DrawPieChart(updateRect);
-			if (fWindow != NULL)
-				fWindow->SetRescanEnabled(true);
 			if (fUpdateFileAt) {
 				fWindow->ShowInfo(_FileAt(fLastWhere));
 				fUpdateFileAt = false;
@@ -362,8 +361,7 @@ PieView::_DrawProgressBar(BRect updateRect)
 	float by = floorf((b.top + b.Height() - kProgBarHeight) / 2.0);
 	float ex = bx + kProgBarWidth;
 	float ey = by + kProgBarHeight;
-	float mx = bx + floorf((kProgBarWidth - 2.0)
+	float mx = bx + floorf((kProgBarWidth - 2.0) * fScanner->Progress() + 0.5);
-		* fScanner->Progress() / 100.0 + 0.5);
 
 	const rgb_color kBarColor = {50, 150, 255, 255};
 	BRect barFrame(bx, by, ex, ey);

src/apps/diskusage/Scanner.cpp

@@ -35,7 +35,8 @@ Scanner::Scanner(BVolume *v, BHandler *handler)
 	fDesiredPath(),
 	fTask(),
 	fBusy(false),
-	fQuitRequested(false)
+	fQuitRequested(false),
+	fPreviousSnapshot(NULL)
 {
 	Run();
 }
@@ -88,6 +89,16 @@ Scanner::Refresh(FileInfo* startInfo)
 }
 
 
+void
+Scanner::Cancel()
+{
+	if (!fBusy)
+		return;
+
+	fQuitRequested = true;
+}
+
+
 void
 Scanner::SetDesiredPath(string &path)
 {
@@ -133,22 +144,29 @@ 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) {
-		delete fSnapshot;
 		fSnapshot = new VolumeSnapshot(fVolume);
 		stringScan.ReplaceFirst("%refName%", fSnapshot->name.c_str());
 		fTask = stringScan.String();
 		fVolumeBytesInUse = fSnapshot->capacity - fSnapshot->freeBytes;
 		fVolumeBytesScanned = 0;
 		fProgress = 0.0;
-		fLastReport = -100.0;
+		fLastReport = -1.0;
 
 		BDirectory root;
 		fVolume->GetRootDirectory(&root);
 		fSnapshot->rootDir = _GetFileInfo(&root, NULL);
-
+		if (fSnapshot->rootDir == NULL) {
+			delete fSnapshot;
+			fSnapshot = fPreviousSnapshot;
+			fBusy = false;
+			fListener.SendMessage(&fDoneMessage);
+			return;
+		}
 		FileInfo* freeSpace = new FileInfo;
 		freeSpace->pseudo = true;
 		BString string(B_TRANSLATE("Free on %refName%"));
@@ -166,14 +184,21 @@ Scanner::_RunScan(FileInfo* startInfo)
 		fTask = stringScan.String();
 		fVolumeBytesInUse = fSnapshot->capacity - fSnapshot->freeBytes;
 		fVolumeBytesScanned = fVolumeBytesInUse - startInfo->size; //best guess
-		fProgress = 100.0 * fVolumeBytesScanned / fVolumeBytesInUse;
+		fProgress = fVolumeBytesScanned / fVolumeBytesInUse;
-		fLastReport = -100.0;
+		fLastReport = -1.0;
 
 		BDirectory startDir(&startInfo->ref);
 		if (startDir.InitCheck() == B_OK) {
 			FileInfo *parent = startInfo->parent;
 			vector<FileInfo *>::iterator i = parent->children.begin();
 			FileInfo* newInfo = _GetFileInfo(&startDir, parent);
+			if (newInfo == NULL) {
+				delete fSnapshot;
+				fSnapshot = fPreviousSnapshot;
+				fBusy = false;
+				fListener.SendMessage(&fDoneMessage);
+				return;				
+			}
 			while (i != parent->children.end() && *i != startInfo)
 				i++;
 
@@ -206,7 +231,7 @@ Scanner::_GetFileInfo(BDirectory* dir, FileInfo* parent)
 
 	while (true) {
 		if (fQuitRequested)
-			break;
+			return NULL;
 
 		if (dir->GetNextEntry(&entry) == B_ENTRY_NOT_FOUND)
 			break;
@@ -223,7 +248,7 @@ Scanner::_GetFileInfo(BDirectory* dir, FileInfo* parent)
 
 			// Send a progress report periodically.
 			fVolumeBytesScanned += child->size;
-			fProgress = 100.0 * fVolumeBytesScanned / fVolumeBytesInUse;
+			fProgress = (float)fVolumeBytesScanned / fVolumeBytesInUse;
 			if (fProgress - fLastReport > kReportInterval) {
 				fLastReport = fProgress;
 				fListener.SendMessage(&fProgressMessage);

src/apps/diskusage/Scanner.h

@@ -35,12 +35,13 @@ public:
 			VolumeSnapshot*		Snapshot() const
 									{ return fBusy ? NULL : fSnapshot; }
 			void				Refresh(FileInfo* startInfo = NULL);
+			void				Cancel();
 			bool				IsBusy() const
 									{ return fBusy; }
 			const char*			Task() const
 									{ return fTask.c_str(); }
 			float				Progress() const
-									{ return min_c(100.0, fProgress); }
+									{ return min_c(1.0, fProgress); }
 			FileInfo*			CurrentDir() const
 									{ return fBusy ? NULL : fSnapshot->currentDir; }
 			void				ChangeDir(FileInfo* info)
@@ -71,6 +72,8 @@ private:
 			string				fTask;
 			bool				fBusy;
 			bool				fQuitRequested;
+
+			VolumeSnapshot*		fPreviousSnapshot;
 };
 
 #endif // SCANNER_H

src/apps/diskusage/StatusView.cpp

@@ -97,16 +97,18 @@ StatusView::~StatusView()
 
 
 void
-StatusView::SetRescanEnabled(bool enabled)
+StatusView::EnableRescan()
 {
-	fRefreshBtn->SetEnabled(enabled);
+	fRefreshBtn->SetLabel(B_TRANSLATE("Rescan"));
+	fRefreshBtn->SetMessage(new BMessage(kBtnRescan));
 }
 
 
 void
-StatusView::SetBtnLabel(const char* label)
+StatusView::EnableCancel()
 {
-	fRefreshBtn->SetLabel(label);
+	fRefreshBtn->SetLabel(B_TRANSLATE("Abort"));
+	fRefreshBtn->SetMessage(new BMessage(kBtnCancel));
 }
 
 

src/apps/diskusage/StatusView.h

@@ -24,8 +24,8 @@ public:
 	virtual						~StatusView();
 
 			void				ShowInfo(const FileInfo* info);
-			void				SetBtnLabel(const char* label);
+			void				EnableRescan();
-			void				SetRescanEnabled(bool enabled);
+			void				EnableCancel();
 
 private:
 			BStringView*		fPathView;

src/apps/diskusage/VolumeView.cpp

@@ -52,9 +52,16 @@ VolumeView::~VolumeView()
 
 
 void
-VolumeView::SetRescanEnabled(bool enabled)
+VolumeView::EnableRescan()
 {
-	fStatusView->SetRescanEnabled(enabled);
+	fStatusView->EnableRescan();
+}
+
+
+void
+VolumeView::EnableCancel()
+{
+	fStatusView->EnableCancel();
 }
 
 
@@ -62,7 +69,7 @@ void
 VolumeView::SetPath(BPath path)
 {
 	fPieView->SetPath(path);
-	fStatusView->SetBtnLabel(B_TRANSLATE("Rescan"));
+	EnableRescan();
 }
 
 
@@ -70,9 +77,9 @@ void
 VolumeView::MessageReceived(BMessage* msg)
 {
 	switch(msg->what) {
+		case kBtnCancel:
 		case kBtnRescan:
 			fPieView->MessageReceived(msg);
-			fStatusView->SetBtnLabel(B_TRANSLATE("Rescan"));
 			break;
 
 		default:

src/apps/diskusage/VolumeView.h

@@ -30,7 +30,8 @@ public:
 	virtual						~VolumeView();
 
 	virtual	void				MessageReceived(BMessage* message);
-			void				SetRescanEnabled(bool enabled);
+			void				EnableRescan();
+			void				EnableCancel();
 			void				SetPath(BPath path);
 			void				ShowInfo(const FileInfo* info);