ParagraphLayout: Refactored _GetEmptyLayoutBounds().

Even for an empty Paragraph, some meaningful bounds can be computed when
it contains an empty TextSpan. However, this is not yet achieved, since
no LineInfo is generated for such an empty Paragraph.

src/apps/haiku-depot/textview/ParagraphLayout.cpp

@@ -342,11 +342,7 @@ ParagraphLayout::GetLineBounds(int32 lineIndex, float& x1, float& y1,
 	_ValidateLayout();
 
 	if (fGlyphInfos.CountItems() == 0) {
-		x1 = 0.0f;
-		y1 = 0.0f;
-		x2 = 0.0f;
-		y2 = 0.0f;
-
+		_GetEmptyLayoutBounds(x1, y1, x2, y2);
 		return;
 	}
 
@@ -381,11 +377,7 @@ ParagraphLayout::GetTextBounds(int32 textOffset, float& x1, float& y1,
 	_ValidateLayout();
 
 	if (fGlyphInfos.CountItems() == 0) {
-		x1 = 0.0f;
-		y1 = 0.0f;
-		x2 = 0.0f;
-		y2 = 0.0f;
-
+		_GetEmptyLayoutBounds(x1, y1, x2, y2);
 		return;
 	}
 
@@ -948,3 +940,28 @@ ParagraphLayout::_DrawSpan(BView* view, BPoint offset,
 
 	view->DrawString(span.Text(), offset, &delta);
 }
+
+
+void
+ParagraphLayout::_GetEmptyLayoutBounds(float& x1, float& y1, float& x2,
+	float& y2) const
+{
+	if (fLineInfos.CountItems() == 0) {
+		x1 = 0.0f;
+		y1 = 0.0f;
+		x2 = 0.0f;
+		y2 = 0.0f;
+
+		return;
+	}
+
+	// If the paragraph had at least a single empty TextSpan, the layout
+	// can compute some meaningful bounds.
+	const Bullet& bullet = fParagraphStyle.Bullet();
+	x1 = fParagraphStyle.LineInset() + fParagraphStyle.FirstLineInset()
+		+ bullet.Spacing();
+	x2 = x1;
+	const LineInfo& lineInfo = fLineInfos.ItemAt(0);
+	y1 = lineInfo.y;
+	y2 = lineInfo.y + lineInfo.height;
+}

src/apps/haiku-depot/textview/ParagraphLayout.h

@@ -231,6 +231,9 @@ private:
 									const TextSpan& span,
 									int32 textOffset) const;
 
+			void				_GetEmptyLayoutBounds(float& x1, float& y1,
+									float& x2, float& y2) const;
+
 private:
 			TextSpanList		fTextSpans;
 			ParagraphStyle		fParagraphStyle;