Fix dragger issues for real, optimized space/tab/newline filtering

All for the Clipboard monitor:

* Correct truncating needs the width of the Replicant's string view,
  not of the whole Replicant view.

* To avoid issues with newlines in the string view, remove all but
  the first line of the displayed clip.

* Possible small optimization in filtering out space, tab, newline
  by not always testing for all three, but removing it as soon as
  it is found and moving on to the next char.

More replicant display improvements

ReplView.cpp

@@ -52,14 +52,9 @@ ReplView::ReplView()
 		(fheight.ascent + fheight.descent + fheight.leading) * 1.3));
 	SetExplicitMaxSize(BSize(B_SIZE_UNLIMITED, B_SIZE_UNSET));
 
-	static const float spacing = be_control_look->DefaultLabelSpacing();
-
-	BLayoutBuilder::Group<>(this, B_HORIZONTAL)
-		.SetInsets(spacing, spacing / 2, spacing, spacing / 2.5)
-		.Add(fContentsView)
-		.AddGroup(B_HORIZONTAL)
-			.Add(dragger)
-			.End()
+	BLayoutBuilder::Group<>(this, B_HORIZONTAL, 0)
+		.Add(fContentsView, 100)
+		.Add(dragger)
 		.End();
 }
 
@@ -109,7 +104,7 @@ ReplView::AttachedToWindow()
 	BView::AttachedToWindow();
 
 	fCurrentClip = _GetClipboard().String();
-	TruncateClip(Bounds().Width());
+	TruncateClip(Bounds().Width() - 7); // respect dragger width
 
 	be_clipboard->StartWatching(this);
 
@@ -146,7 +141,7 @@ ReplView::MessageReceived(BMessage* msg)
 			if (fCurrentClip.Length() == 0)
 				break;
 
-			TruncateClip(Bounds().Width());
+			TruncateClip(Bounds().Width() - 7); // respect dragger width
 			break;
 		}
 		case B_ABOUT_REQUESTED:
@@ -190,14 +185,26 @@ ReplView::MessageReceived(BMessage* msg)
 void
 ReplView::TruncateClip(float width)
 {
-	static const float spacing = be_control_look->DefaultLabelSpacing();
 	BString clip(fCurrentClip);
 
-	// Remove empty lines, spaces, tabs from beginning of clip
-	while (clip.StartsWith(" ") || clip.StartsWith("\n") || clip.StartsWith("\t"))
-		clip.Remove(0, 1); // Remove first char
+	// Remove spaces, tabs. empty lines from beginning of clip
+	while (true) {
+		if (clip.StartsWith(" "))
+			clip.Remove(0, 1);
+		else if (clip.StartsWith("\t"))
+			clip.Remove(0, 1);
+		else if (clip.StartsWith("\n"))
+			clip.Remove(0, 1);
+		else
+			break;
+	}
+	// Remove all but the first line
+	int32 newline = clip.FindFirst("\n");
+	if (newline >= 0)
+		clip.Remove(newline, clip.Length());
 
-	TruncateString(&clip, B_TRUNCATE_END, width - spacing * 8);
+	static const float spacing = be_control_look->DefaultLabelSpacing();
+	TruncateString(&clip, B_TRUNCATE_END, width - spacing * 5);
 	fContentsView->SetText(clip);
 }