SerialConnect: use ints for font metrics

As pointed by Ingo, using a float here is useless because we want each
line to be the same integer number of pixels. Now thigs are drawn
properly and the view has the exact same size as Terminal's one (tested
with font sizes 10 and 18, so different leading values don't seem to be
a problem).

Thanks for reviewing!

src/apps/serialconnect/TermView.cpp

@@ -141,9 +141,9 @@ void
 TermView::GetPreferredSize(float* width, float* height)
 {
 	if (width != NULL)
-		*width = kDefaultWidth * fFontWidth + 2 * kBorderSpacing;
+		*width = kDefaultWidth * fFontWidth + 2 * kBorderSpacing - 1;
 	if (height != NULL)
-		*height = kDefaultHeight * fFontHeight + 2 * kBorderSpacing;
+		*height = kDefaultHeight * fFontHeight + 2 * kBorderSpacing - 1;
 }
 
 
@@ -194,7 +194,8 @@ TermView::_Init()
 
 	font_height height;
 	GetFontHeight(&height);
-	fFontHeight = height.ascent + height.descent + height.leading + 1;
+	fFontHeight = ceilf(height.ascent) + ceilf(height.descent)
+		+ ceilf(height.leading);
 	fFontWidth = be_fixed_font->StringWidth("X");
 	fTerm = vterm_new(kDefaultHeight, kDefaultWidth);
 
@@ -338,8 +339,6 @@ TermView::_PushLine(int cols, const VTermScreenCell* cells)
 
 	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

src/apps/serialconnect/TermView.h

@@ -49,8 +49,8 @@ class TermView: public BView
 		VTerm* fTerm;
 		VTermScreen* fTermScreen;
 		BList fScrollBuffer;
-		float fFontWidth;
-		float fFontHeight;
+		int fFontWidth;
+		int fFontHeight;
 
 		static const VTermScreenCallbacks sScreenCallbacks;