SerialConnect: implement scrollback.

src/apps/serialconnect/SerialWindow.cpp

@@ -13,6 +13,7 @@
 #include <Menu.h>
 #include <MenuBar.h>
 #include <MenuItem.h>
+#include <ScrollView.h>
 #include <SerialPort.h>
 
 #include "SerialApp.h"
@@ -41,13 +42,30 @@ SerialWindow::SerialWindow()
 		B_DOCUMENT_WINDOW, B_QUIT_ON_WINDOW_CLOSE | B_AUTO_UPDATE_SIZE_LIMITS)
 	, fLogFilePanel(NULL)
 {
-	SetLayout(new BGroupLayout(B_VERTICAL, 0.0f));
+	BMenuBar* menuBar = new BMenuBar(Bounds(), "menuBar");
+	menuBar->ResizeToPreferred();
 
-	BMenuBar* menuBar = new BMenuBar("menuBar");
-	fTermView = new TermView();
+	BRect r = Bounds();
+	r.top = menuBar->Bounds().bottom + 1;
+	r.right -= B_V_SCROLL_BAR_WIDTH;
+	fTermView = new TermView(r);
+	fTermView->ResizeToPreferred();
+
+	r = fTermView->Frame();
+	r.left = r.right + 1;
+	r.right = r.left + B_V_SCROLL_BAR_WIDTH;
+	r.top -= 1;
+	r.bottom -= B_H_SCROLL_BAR_HEIGHT - 1;
+	BScrollBar* scrollBar = new BScrollBar(r, "scrollbar", NULL, 0, 0,
+		B_VERTICAL);
+
+	scrollBar->SetTarget(fTermView);
+
+	ResizeTo(r.right - 1, r.bottom + B_H_SCROLL_BAR_HEIGHT - 1);
 
 	AddChild(menuBar);
 	AddChild(fTermView);
+	AddChild(scrollBar);
 
 	fConnectionMenu = new BMenu("Connection");
 	BMenu* fileMenu = new BMenu("File");
@@ -62,7 +80,7 @@ SerialWindow::SerialWindow()
 	// TODO edit menu - what's in it ?
 	//BMenu* editMenu = new BMenu("Edit");
 	//menuBar->AddItem(editMenu);
-	
+
 	BMenuItem* logFile = new BMenuItem("Log to file" B_UTF8_ELLIPSIS,
 		new BMessage(kMsgLogfile));
 	fileMenu->AddItem(logFile);
@@ -78,23 +96,23 @@ SerialWindow::SerialWindow()
 
 	// Configuring all this by menus may be a bit unhandy. Make a setting
 	// window instead ?
-	fBaudrateMenu = new BMenu("Baud rate"); 
+	fBaudrateMenu = new BMenu("Baud rate");
 	fBaudrateMenu->SetRadioMode(true);
 	settingsMenu->AddItem(fBaudrateMenu);
 
-	fParityMenu = new BMenu("Parity"); 
+	fParityMenu = new BMenu("Parity");
 	fParityMenu->SetRadioMode(true);
 	settingsMenu->AddItem(fParityMenu);
 
-	fStopbitsMenu = new BMenu("Stop bits"); 
+	fStopbitsMenu = new BMenu("Stop bits");
 	fStopbitsMenu->SetRadioMode(true);
 	settingsMenu->AddItem(fStopbitsMenu);
 
-	fFlowcontrolMenu = new BMenu("Flow control"); 
+	fFlowcontrolMenu = new BMenu("Flow control");
 	fFlowcontrolMenu->SetRadioMode(true);
 	settingsMenu->AddItem(fFlowcontrolMenu);
 
-	fDatabitsMenu = new BMenu("Data bits"); 
+	fDatabitsMenu = new BMenu("Data bits");
 	fDatabitsMenu->SetRadioMode(true);
 	settingsMenu->AddItem(fDatabitsMenu);
 
@@ -147,7 +165,7 @@ SerialWindow::SerialWindow()
 		message->AddInt32("baudrate", kBaudrateConstants[i]);
 
 		char buffer[7];
-		sprintf(buffer,"%d", kBaudrates[i]);
+		sprintf(buffer, "%d", kBaudrates[i]);
 		BMenuItem* item = new BMenuItem(buffer, message);
 
 		fBaudrateMenu->AddItem(item);
@@ -181,7 +199,6 @@ SerialWindow::SerialWindow()
 }
 
 
-
 SerialWindow::~SerialWindow()
 {
 	delete fLogFilePanel;
@@ -198,7 +215,7 @@ void SerialWindow::MenusBeginning()
 	int deviceCount = serialPort.CountDevices();
 	bool connected = false;
 
-	for(int i = 0; i < deviceCount; i++)
+	for (int i = 0; i < deviceCount; i++)
 	{
 		char buffer[256];
 		serialPort.GetDeviceName(i, buffer, 256);
@@ -210,7 +227,7 @@ void SerialWindow::MenusBeginning()
 
 		const BString& connectedPort = ((SerialApp*)be_app)->GetPort();
 
-		if(connectedPort == buffer) {
+		if (connectedPort == buffer) {
 			connected = true;
 			portItem->SetMarked(true);
 		}
@@ -223,7 +240,7 @@ void SerialWindow::MenusBeginning()
 
 		BMenuItem* disconnect = new BMenuItem("Disconnect",
 			new BMessage(kMsgOpenPort), 'Z', B_OPTION_KEY);
-		if(!connected)
+		if (!connected)
 			disconnect->SetEnabled(false);
 		fConnectionMenu->AddItem(disconnect);
 	} else {
@@ -233,6 +250,7 @@ void SerialWindow::MenusBeginning()
 	}
 }
 
+
 void SerialWindow::MessageReceived(BMessage* message)
 {
 	switch(message->what)
@@ -240,7 +258,7 @@ void SerialWindow::MessageReceived(BMessage* message)
 		case kMsgOpenPort:
 		{
 			BMenuItem* disconnectMenu;
-			if(message->FindPointer("source", (void**)&disconnectMenu) == B_OK)
+			if (message->FindPointer("source", (void**)&disconnectMenu) == B_OK)
 				disconnectMenu->SetMarked(false);
 			be_app->PostMessage(new BMessage(*message));
 			break;
@@ -257,7 +275,7 @@ void SerialWindow::MessageReceived(BMessage* message)
 		case kMsgLogfile:
 		{
 			// Let's lazy init the file panel
-			if(fLogFilePanel == NULL) {
+			if (fLogFilePanel == NULL) {
 				fLogFilePanel = new BFilePanel(B_SAVE_PANEL, &be_app_messenger,
 					NULL, B_FILE_NODE, false);
 				fLogFilePanel->SetMessage(message);
@@ -273,71 +291,63 @@ void SerialWindow::MessageReceived(BMessage* message)
 			parity_mode parity;
 			uint32 flowcontrol;
 
-			if(message->FindInt32("databits", (int32*)&dataBits) == B_OK)
-			{
-				for(int i = 0; i < fDatabitsMenu->CountItems(); i++)
-				{
+			if (message->FindInt32("databits", (int32*)&dataBits) == B_OK) {
+				for (int i = 0; i < fDatabitsMenu->CountItems(); i++) {
 					BMenuItem* item = fDatabitsMenu->ItemAt(i);
 					int32 code;
 					item->Message()->FindInt32("databits", &code);
 
-					if(code == dataBits)
+					if (code == dataBits)
 						item->SetMarked(true);
 				}
 			}
 
-			if(message->FindInt32("stopbits", (int32*)&stopBits) == B_OK)
-			{
-				for(int i = 0; i < fStopbitsMenu->CountItems(); i++)
-				{
+			if (message->FindInt32("stopbits", (int32*)&stopBits) == B_OK) {
+				for (int i = 0; i < fStopbitsMenu->CountItems(); i++) {
 					BMenuItem* item = fStopbitsMenu->ItemAt(i);
 					int32 code;
 					item->Message()->FindInt32("stopbits", &code);
 
-					if(code == stopBits)
+					if (code == stopBits)
 						item->SetMarked(true);
 				}
 			}
 
-			if(message->FindInt32("parity", (int32*)&parity) == B_OK)
+			if (message->FindInt32("parity", (int32*)&parity) == B_OK)
 			{
-				for(int i = 0; i < fParityMenu->CountItems(); i++)
-				{
+				for (int i = 0; i < fParityMenu->CountItems(); i++) {
 					BMenuItem* item = fParityMenu->ItemAt(i);
 					int32 code;
 					item->Message()->FindInt32("parity", &code);
 
-					if(code == parity)
+					if (code == parity)
 						item->SetMarked(true);
 				}
 			}
 
-			if(message->FindInt32("flowcontrol", (int32*)&flowcontrol) == B_OK)
-			{
-				for(int i = 0; i < fFlowcontrolMenu->CountItems(); i++)
-				{
+			if (message->FindInt32("flowcontrol", (int32*)&flowcontrol)
+					== B_OK) {
+				for (int i = 0; i < fFlowcontrolMenu->CountItems(); i++) {
 					BMenuItem* item = fFlowcontrolMenu->ItemAt(i);
 					int32 code;
 					item->Message()->FindInt32("flowcontrol", &code);
 
-					if(code == (int32)flowcontrol)
+					if (code == (int32)flowcontrol)
 						item->SetMarked(true);
 				}
 			}
 
-			if(message->FindInt32("baudrate", &baudrate) == B_OK)
-			{
-				for(int i = 0; i < fBaudrateMenu->CountItems(); i++)
-				{
+			if (message->FindInt32("baudrate", &baudrate) == B_OK) {
+				for (int i = 0; i < fBaudrateMenu->CountItems(); i++) {
 					BMenuItem* item = fBaudrateMenu->ItemAt(i);
 					int32 code;
 					item->Message()->FindInt32("baudrate", &code);
 
-					if(baudrate == code)
+					if (baudrate == code)
 						item->SetMarked(true);
 				}
 			}
-			
+
 			break;
 		}
 		default:

src/apps/serialconnect/SerialWindow.h

@@ -23,6 +23,7 @@ class SerialWindow: public BWindow
 
 	private:
 		TermView* fTermView;
+
 		BMenu* fConnectionMenu;
 		BMenu* fDatabitsMenu;
 		BMenu* fStopbitsMenu;

src/apps/serialconnect/TermView.cpp

@@ -11,27 +11,30 @@
 #include <Entry.h>
 #include <File.h>
 #include <Layout.h>
+#include <ScrollBar.h>
 
 #include "SerialApp.h"
 
 
+struct ScrollBufferItem {
+	int cols;
+	VTermScreenCell cells[];
+};
+
+
 TermView::TermView()
 	:
 	BView("TermView", B_WILL_DRAW | B_FRAME_EVENTS)
 {
-	SetFont(be_fixed_font);
+	_Init();
+}
 
-	font_height height;
-	GetFontHeight(&height);
-	fFontHeight = height.ascent + height.descent + height.leading + 1;
-	fFontWidth = be_fixed_font->StringWidth("X");
-	fTerm = vterm_new(kDefaultHeight, kDefaultWidth);
 
-	fTermScreen = vterm_obtain_screen(fTerm);
-	vterm_screen_set_callbacks(fTermScreen, &sScreenCallbacks, this);
-	vterm_screen_reset(fTermScreen, 1);
-
-	vterm_parser_set_utf8(fTerm, 1);
+TermView::TermView(BRect r)
+	:
+	BView(r, "TermView", B_FOLLOW_ALL_SIDES, B_WILL_DRAW | B_FRAME_EVENTS)
+{
+	_Init();
 }
 
 
@@ -41,7 +44,8 @@ TermView::~TermView()
 }
 
 
-void TermView::AttachedToWindow()
+void
+TermView::AttachedToWindow()
 {
 	MakeFocus();
 
@@ -49,7 +53,7 @@ void TermView::AttachedToWindow()
 	VTermPos firstPos;
 	firstPos.row = 0;
 	firstPos.col = 0;
-	vterm_screen_get_cell(fTermScreen, firstPos, &cell);
+	_GetCell(firstPos, cell);
 
 	rgb_color background;
 	background.red = cell.bg.red;
@@ -61,17 +65,15 @@ void TermView::AttachedToWindow()
 }
 
 
-void TermView::Draw(BRect updateRect)
+void
+TermView::Draw(BRect updateRect)
 {
-	VTermRect updatedChars = PixelsToGlyphs(updateRect);
+	VTermRect updatedChars = _PixelsToGlyphs(updateRect);
 
 	VTermPos pos;
 	font_height height;
 	GetFontHeight(&height);
 
-	int availableRows, availableCols;
-	vterm_get_size(fTerm, &availableRows, &availableCols);
-
 	for (pos.row = updatedChars.start_row; pos.row <= updatedChars.end_row;
 			pos.row++) {
 		float x = updatedChars.start_col * fFontWidth + kBorderSpacing;
@@ -82,19 +84,7 @@ void TermView::Draw(BRect updateRect)
 				pos.col <= updatedChars.end_col;) {
 			VTermScreenCell cell;
 
-			if (pos.col < 0 || pos.row < 0 || pos.col >= availableCols
-					|| pos.row >= availableRows) {
-
-				// All cells outside the used terminal area are drawn with the
-				// same background color as the top-left one.
-				VTermPos firstPos;
-				firstPos.row = 0;
-				firstPos.col = 0;
-				vterm_screen_get_cell(fTermScreen, firstPos, &cell);
-				cell.chars[0] = 0;
-				cell.width = 1;
-			} else
-				vterm_screen_get_cell(fTermScreen, pos, &cell);
+			_GetCell(pos, cell);
 
 			rgb_color foreground, background;
 			foreground.red = cell.fg.red;
@@ -119,7 +109,7 @@ void TermView::Draw(BRect updateRect)
 			BPoint penLocation = PenLocation();
 			FillRect(BRect(penLocation.x, penLocation.y - height.ascent,
 				penLocation.x + cell.width * fFontWidth - 1,
-				penLocation.y + height.descent + height.leading - 1),
+				penLocation.y + height.descent + height.leading),
 				B_SOLID_LOW);
 
 			if (cell.chars[0] == 0) {
@@ -138,15 +128,17 @@ void TermView::Draw(BRect updateRect)
 }
 
 
-void TermView::FrameResized(float width, float height)
+void
+TermView::FrameResized(float width, float height)
 {
-	VTermRect newSize = PixelsToGlyphs(BRect(0, 0, width - 2 * kBorderSpacing,
+	VTermRect newSize = _PixelsToGlyphs(BRect(0, 0, width - 2 * kBorderSpacing,
 				height - 2 * kBorderSpacing));
 	vterm_set_size(fTerm, newSize.end_row, newSize.end_col);
 }
 
 
-void TermView::GetPreferredSize(float* width, float* height)
+void
+TermView::GetPreferredSize(float* width, float* height)
 {
 	if (width != NULL)
 		*width = kDefaultWidth * fFontWidth + 2 * kBorderSpacing;
@@ -155,7 +147,8 @@ void TermView::GetPreferredSize(float* width, float* height)
 }
 
 
-void TermView::KeyDown(const char* bytes, int32 numBytes)
+void
+TermView::KeyDown(const char* bytes, int32 numBytes)
 {
 	BMessage* keyEvent = new BMessage(kMsgDataWrite);
 	keyEvent->AddData("data", B_RAW_TYPE, bytes, numBytes);
@@ -163,7 +156,8 @@ void TermView::KeyDown(const char* bytes, int32 numBytes)
 }
 
 
-void TermView::MessageReceived(BMessage* message)
+void
+TermView::MessageReceived(BMessage* message)
 {
 	switch(message->what)
 	{
@@ -183,7 +177,8 @@ void TermView::MessageReceived(BMessage* message)
 }
 
 
-void TermView::PushBytes(const char* bytes, size_t length)
+void
+TermView::PushBytes(const char* bytes, size_t length)
 {
 	vterm_push_bytes(fTerm, bytes, length);
 }
@@ -192,7 +187,27 @@ void TermView::PushBytes(const char* bytes, size_t length)
 // #pragma mark -
 
 
-VTermRect TermView::PixelsToGlyphs(BRect pixels) const
+void
+TermView::_Init()
+{
+	SetFont(be_fixed_font);
+
+	font_height height;
+	GetFontHeight(&height);
+	fFontHeight = height.ascent + height.descent + height.leading + 1;
+	fFontWidth = be_fixed_font->StringWidth("X");
+	fTerm = vterm_new(kDefaultHeight, kDefaultWidth);
+
+	fTermScreen = vterm_obtain_screen(fTerm);
+	vterm_screen_set_callbacks(fTermScreen, &sScreenCallbacks, this);
+	vterm_screen_reset(fTermScreen, 1);
+
+	vterm_parser_set_utf8(fTerm, 1);
+}
+
+
+VTermRect
+TermView::_PixelsToGlyphs(BRect pixels) const
 {
 	pixels.OffsetBy(-kBorderSpacing, -kBorderSpacing);
 
@@ -201,7 +216,7 @@ VTermRect TermView::PixelsToGlyphs(BRect pixels) const
 	rect.end_col = (int)ceil(pixels.right / fFontWidth);
 	rect.start_row = (int)floor(pixels.top / fFontHeight);
 	rect.end_row = (int)ceil(pixels.bottom / fFontHeight);
-/*
+#if 0
 	printf(
 		"TOP %d ch < %f px\n"
 		"BTM %d ch < %f px\n"
@@ -212,12 +227,12 @@ VTermRect TermView::PixelsToGlyphs(BRect pixels) const
 		rect.start_col, pixels.left,
 		rect.end_col, pixels.right
 	);
-*/
+#endif
 	return rect;
 }
 
 
-BRect TermView::GlyphsToPixels(const VTermRect& glyphs) const
+BRect TermView::_GlyphsToPixels(const VTermRect& glyphs) const
 {
 	BRect rect;
 	rect.top = glyphs.start_row * fFontHeight;
@@ -242,40 +257,128 @@ BRect TermView::GlyphsToPixels(const VTermRect& glyphs) const
 }
 
 
-BRect TermView::GlyphsToPixels(const int width, const int height) const
+BRect
+TermView::_GlyphsToPixels(const int width, const int height) const
 {
 	VTermRect rect;
 	rect.start_row = 0;
 	rect.start_col = 0;
 	rect.end_row = height;
 	rect.end_col = width;
-	return GlyphsToPixels(rect);
+	return _GlyphsToPixels(rect);
 }
 
 
-void TermView::Damage(VTermRect rect)
+void
+TermView::_GetCell(VTermPos pos, VTermScreenCell& cell)
 {
-	Invalidate();
-//	Invalidate(GlyphsToPixels(rect));
+	int availableRows, availableCols;
+	vterm_get_size(fTerm, &availableRows, &availableCols);
+
+	if (pos.col < 0 || pos.row < -kScrollBackSize || pos.col >= availableCols
+			|| pos.row >= availableRows) {
+		// All cells outside the used terminal area are drawn with the same
+		// background color as the top-left one.
+		// TODO should they use the attributes of the closest neighbor instead?
+		VTermPos firstPos;
+		firstPos.row = 0;
+		firstPos.col = 0;
+		vterm_screen_get_cell(fTermScreen, firstPos, &cell);
+		cell.chars[0] = 0;
+		cell.width = 1;
+	} else if (pos.row < 0) {
+		// This is a cell from the scroll-back buffer
+		int offset = - pos.row - 1;
+		ScrollBufferItem* line = (ScrollBufferItem*)fScrollBuffer.ItemAt(offset);
+		if (line == NULL || pos.col >= line->cols) {
+			VTermPos firstPos;
+			firstPos.row = 0;
+			firstPos.col = 0;
+			vterm_screen_get_cell(fTermScreen, firstPos, &cell);
+			cell.chars[0] = 0;
+			cell.width = 1;
+		} else
+			cell = line->cells[pos.col];
+	} else
+		vterm_screen_get_cell(fTermScreen, pos, &cell);
 }
 
 
-/* static */
-int TermView::Damage(VTermRect rect, void* user)
+void
+TermView::_Damage(VTermRect rect)
+{
+//	Invalidate();
+	Invalidate(_GlyphsToPixels(rect));
+}
+
+
+void
+TermView::_PushLine(int cols, const VTermScreenCell* cells)
+{
+	ScrollBufferItem* item = (ScrollBufferItem*)malloc(sizeof(int)
+		+ cols * sizeof(VTermScreenCell));
+	item->cols = cols;
+	memcpy(item->cells, cells, cols * sizeof(VTermScreenCell));
+
+	fScrollBuffer.AddItem(item, 0);
+
+	free(fScrollBuffer.RemoveItem(kScrollBackSize));
+
+	int availableRows, availableCols;
+	vterm_get_size(fTerm, &availableRows, &availableCols);
+
+	VTermRect dirty;
+	dirty.start_col = 0;
+	dirty.end_col = availableCols;
+	dirty.end_row = 0;
+	dirty.start_row = -fScrollBuffer.CountItems();
+	// FIXME we should rather use CopyRect if possible, and only invalidate the
+	// newly exposed area here.
+	Invalidate(_GlyphsToPixels(dirty));
+
+	BScrollBar* scrollBar = ScrollBar(B_VERTICAL);
+	if (scrollBar != NULL) {
+		// FIXME this is not exactly right, it's off by a few pixels so one step
+		// isn't exactly equal to one line.
+		float range = (fScrollBuffer.CountItems() + availableRows) * fFontHeight;
+		scrollBar->SetRange(availableRows * fFontHeight - range, 0.0f);
+		// TODO we need to adjust this in FrameResized, as availableRows can
+		// change
+		scrollBar->SetProportion(availableRows * fFontHeight / range);
+		scrollBar->SetSteps(fFontHeight, fFontHeight * 3);
+	}
+}
+
+
+/* static */ int
+TermView::_Damage(VTermRect rect, void* user)
 {
 	TermView* view = (TermView*)user;
-	view->Damage(rect);
+	view->_Damage(rect);
 
 	return 0;
 }
 
 
-const VTermScreenCallbacks TermView::sScreenCallbacks = {
-	&TermView::Damage,
+/* static */ int
+TermView::_PushLine(int cols, const VTermScreenCell* cells, void* user)
+{
+	TermView* view = (TermView*)user;
+	view->_PushLine(cols, cells);
+
+	return 0;
+}
+
+
+const
+VTermScreenCallbacks TermView::sScreenCallbacks = {
+	&TermView::_Damage,
 	/*.moverect =*/ NULL,
 	/*.movecursor =*/ NULL,
 	/*.settermprop =*/ NULL,
 	/*.setmousefunc =*/ NULL,
 	/*.bell =*/ NULL,
 	/*.resize =*/ NULL,
+	&TermView::_PushLine,
+	/*.sb_popline =*/ NULL,
 };

src/apps/serialconnect/TermView.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012, Adrien Destugues, [email protected]
+ * Copyright 2012-2014, Adrien Destugues, [email protected]
  * Distributed under the terms of the MIT licence.
  */
 
@@ -10,31 +10,45 @@ extern "C" {
 	#include <vterm.h>
 }
 
+
 class TermView: public BView
 {
 	public:
-		TermView();
-		~TermView();
+							TermView();
+							TermView(BRect bounds);
+							~TermView();
+
+				void		AttachedToWindow();
+				void		Draw(BRect updateRect);
+				void		FrameResized(float width, float height);
+				void		GetPreferredSize(float* width, float* height);
+				void		KeyDown(const char* bytes, int32 numBytes);
+				void		MessageReceived(BMessage* message);
+
+				void		PushBytes(const char* bytes, const size_t length);
 
-		void AttachedToWindow();
-		void Draw(BRect updateRect);
-		void FrameResized(float width, float height);
-		void GetPreferredSize(float* width, float* height);
-		void KeyDown(const char* bytes, int32 numBytes);
-		void MessageReceived(BMessage* message);
-		void PushBytes(const char* bytes, const size_t length);
-		
 	private:
-		VTermRect PixelsToGlyphs(BRect pixels) const;
-		BRect GlyphsToPixels(const VTermRect& glyphs) const;
-		BRect GlyphsToPixels(const int width, const int height) const;
-		void Damage(VTermRect rect);
+				void		_Init();
 
-		static int Damage(VTermRect rect, void* user);
+				VTermRect	_PixelsToGlyphs(BRect pixels) const;
+				BRect		_GlyphsToPixels(const VTermRect& glyphs) const;
+				BRect		_GlyphsToPixels(const int width, const int height)
+								const;
+				void		_GetCell(VTermPos pos, VTermScreenCell& cell);
+
+				void		_Damage(VTermRect rect);
+				void		_PushLine(int cols, const VTermScreenCell* cells);
+
+		static	int			_Damage(VTermRect rect, void* user);
+		static	int			_PushLine(int cols, const VTermScreenCell* cells,
+								void* user);
+		static	int			_PopLine(int cols, const VTermScreenCell* cells,
+								void* user);
 
 	private:
 		VTerm* fTerm;
 		VTermScreen* fTermScreen;
+		BList fScrollBuffer;
 		float fFontWidth;
 		float fFontHeight;
 
@@ -43,4 +57,5 @@ class TermView: public BView
 		static const int kDefaultWidth = 80;
 		static const int kDefaultHeight = 25;
 		static const int kBorderSpacing = 3;
+		static const int kScrollBackSize = 1000;
 };