STORM-721 FIXED Fix for text clipping in a textbox without a scroller.

Committed on behalf of Richard Linden:
This patch makes clipping work consistently with text and embedded widgets. The widgets will only be displayed if the corresponding text they are embedded in is displayed.  There is also a new param "clip" for text widgets that can be used to disable clipping entirely.  I introduced this as a potential work around due to the fact that we *used* to assume that text was never clipped in the vertical direction unless we had scrolling turned on.  This hasn't been the case for over a year, but now we can selectively turn off vertical text clipping with (clip="false") if we have to.

2 files changed, 80 insertions, 27 deletions

diff --git a/indra/llui/lltextbase.cpp b/indra/llui/lltextbase.cpp
index 49537ef78f..82269282ef 100644
--- a/indra/llui/lltextbase.cpp
+++ b/indra/llui/lltextbase.cpp
@@ -157,6 +157,7 @@ LLTextBase::Params::Params()
 	read_only("read_only", false),
 	v_pad("v_pad", 0),
 	h_pad("h_pad", 0),
+	clip("clip", true),
 	clip_partial("clip_partial", true),
 	line_spacing("line_spacing"),
 	max_text_length("max_length", 255),
@@ -199,6 +200,7 @@ LLTextBase::LLTextBase(const LLTextBase::Params &p)
 	mVAlign(p.font_valign),
 	mLineSpacingMult(p.line_spacing.multiple),
 	mLineSpacingPixels(p.line_spacing.pixels),
+	mClip(p.clip),
 	mClipPartial(p.clip_partial && !p.allow_scroll),
 	mTrackEnd( p.track_end ),
 	mScrollIndex(-1),
@@ -334,7 +336,7 @@ void LLTextBase::drawSelectionBackground()
 
 		// binary search for line that starts before top of visible buffer
 		line_list_t::const_iterator line_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), content_display_rect.mTop, compare_bottom());
-		line_list_t::const_iterator end_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), content_display_rect.mBottom, compare_top());
+		line_list_t::const_iterator end_iter = std::upper_bound(mLineInfoList.begin(), mLineInfoList.end(), content_display_rect.mBottom, compare_top());
 
 		bool done = false;
 
@@ -512,7 +514,6 @@ void LLTextBase::drawText()
 		selection_right = llmax( mSelectionStart, mSelectionEnd );
 	}
 
-	LLRect scrolled_view_rect = getVisibleDocumentRect();
 	std::pair<S32, S32> line_range = getVisibleLines(mClipPartial);
 	S32 first_line = line_range.first;
 	S32 last_line = line_range.second;
@@ -545,10 +546,10 @@ void LLTextBase::drawText()
 			line_end = next_start;
 		}
 
-		LLRect text_rect(line.mRect.mLeft + mVisibleTextRect.mLeft - scrolled_view_rect.mLeft,
-						line.mRect.mTop - scrolled_view_rect.mBottom + mVisibleTextRect.mBottom,
-						llmin(mDocumentView->getRect().getWidth(), line.mRect.mRight) - scrolled_view_rect.mLeft,
-						line.mRect.mBottom - scrolled_view_rect.mBottom + mVisibleTextRect.mBottom);
+		LLRect text_rect(line.mRect);
+		text_rect.mRight = llmin(mDocumentView->getRect().getWidth(), text_rect.mRight); // clamp right edge to document extents
+		text_rect.translate(mVisibleTextRect.mLeft, mVisibleTextRect.mBottom); // translate into display region of text widget
+		text_rect.translate(mDocumentView->getRect().mLeft, mDocumentView->getRect().mBottom); // adjust by scroll position
 
 		// draw a single line of text
 		S32 seg_start = line_start;
@@ -993,14 +994,28 @@ void LLTextBase::draw()
 		updateScrollFromCursor();
 	}
 
-	LLRect doc_rect;
+	LLRect text_rect;
 	if (mScroller)
 	{
-		mScroller->localRectToOtherView(mScroller->getContentWindowRect(), &doc_rect, this);
+		mScroller->localRectToOtherView(mScroller->getContentWindowRect(), &text_rect, this);
 	}
 	else
 	{
-		doc_rect = getLocalRect();
+		LLRect visible_lines_rect;
+		std::pair<S32, S32> line_range = getVisibleLines(mClipPartial);
+		for (S32 i = line_range.first; i < line_range.second; i++)
+		{
+			if (visible_lines_rect.isEmpty())
+			{
+				visible_lines_rect = mLineInfoList[i].mRect;
+			}
+			else
+			{
+				visible_lines_rect.unionWith(mLineInfoList[i].mRect);
+			}
+		}
+		text_rect = visible_lines_rect;
+		text_rect.translate(mDocumentView->getRect().mLeft, mDocumentView->getRect().mBottom);
 	}
 
 	if (mBGVisible)
@@ -1010,28 +1025,37 @@ void LLTextBase::draw()
 		LLRect bg_rect = mVisibleTextRect;
 		if (mScroller)
 		{
-			bg_rect.intersectWith(doc_rect);
+			bg_rect.intersectWith(text_rect);
 		}
 		LLColor4 bg_color = mReadOnly 
 							? mReadOnlyBgColor.get()
 							: hasFocus() 
 								? mFocusBgColor.get() 
 								: mWriteableBgColor.get();
-		gl_rect_2d(doc_rect, bg_color % alpha, TRUE);
+		gl_rect_2d(text_rect, bg_color % alpha, TRUE);
 	}
 
-	// draw document view
-	LLUICtrl::draw();
-
-	{
-		// only clip if we support scrolling...
-		// since convention is that text boxes never vertically truncate their contents
-		// regardless of rect bounds
-		LLLocalClipRect clip(doc_rect, mScroller != NULL);
+ 	bool should_clip = mClip || mScroller != NULL;
+ 	{ LLLocalClipRect clip(text_rect, should_clip);
+ 
+ 		// draw document view
+ 		if (mScroller)
+		{
+ 			drawChild(mScroller);
+ 		}
+ 		else
+ 		{
+ 			drawChild(mDocumentView);
+ 		}
+ 
 		drawSelectionBackground();
 		drawText();
 		drawCursor();
 	}
+ 
+ 	mDocumentView->setVisible(FALSE);
+ 	LLUICtrl::draw();
+ 	mDocumentView->setVisible(TRUE);
 }
 
 
@@ -1415,7 +1439,7 @@ S32	LLTextBase::getFirstVisibleLine() const
 	return iter - mLineInfoList.begin();
 }
 
-std::pair<S32, S32>	LLTextBase::getVisibleLines(bool fully_visible) 
+std::pair<S32, S32>	LLTextBase::getVisibleLines(bool require_fully_visible) 
 {
 	LLRect visible_region = getVisibleDocumentRect();
 	line_list_t::const_iterator first_iter;
@@ -1424,14 +1448,14 @@ std::pair<S32, S32>	LLTextBase::getVisibleLines(bool fully_visible)
 	// make sure we have an up-to-date mLineInfoList
 	reflow();
 
-	if (fully_visible)
+	if (require_fully_visible)
 	{
 		first_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mTop, compare_top());
-		last_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mBottom, compare_bottom());
+		last_iter = std::upper_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mBottom, compare_bottom());
 	}
 	else
 	{
-		first_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mTop, compare_bottom());
+		first_iter = std::upper_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mTop, compare_bottom());
 		last_iter = std::lower_bound(mLineInfoList.begin(), mLineInfoList.end(), visible_region.mBottom, compare_top());
 	}
 	return std::pair<S32, S32>(first_iter - mLineInfoList.begin(), last_iter - mLineInfoList.begin());
@@ -2405,14 +2429,41 @@ LLRect LLTextBase::getVisibleDocumentRect() const
 	{
 		return mScroller->getVisibleContentRect();
 	}
-	else
+	else if (mClip)
 	{
-		// entire document rect is visible when not scrolling
+		LLRect visible_text_rect = getVisibleTextRect();
+		LLRect doc_rect = mDocumentView->getRect();
+		visible_text_rect.translate(-doc_rect.mLeft, -doc_rect.mBottom);
+
+		// reject partially visible lines
+		LLRect visible_lines_rect;
+		for (line_list_t::const_iterator it = mLineInfoList.begin(), end_it = mLineInfoList.end();
+			it != end_it;
+			++it)
+		{
+			bool line_visible = mClipPartial ? visible_text_rect.contains(it->mRect) : visible_text_rect.overlaps(it->mRect);
+			if (line_visible)
+			{
+				if (visible_lines_rect.isEmpty())
+				{
+					visible_lines_rect = it->mRect;
+				}
+				else
+				{
+					visible_lines_rect.unionWith(it->mRect);
+				}
+			}
+		}
+		return visible_lines_rect;
+	}
+	else
+	{	// entire document rect is visible
 		// but offset according to height of widget
+	
 		LLRect doc_rect = mDocumentView->getLocalRect();
 		doc_rect.mLeft -= mDocumentView->getRect().mLeft;
 		// adjust for height of text above widget baseline
-		doc_rect.mBottom = doc_rect.getHeight() - mVisibleTextRect.getHeight();
+		doc_rect.mBottom = llmin(0, doc_rect.getHeight() - mVisibleTextRect.getHeight());
 		return doc_rect;
 	}
 }
diff --git a/indra/llui/lltextbase.h b/indra/llui/lltextbase.h
index aafcf8ceb0..7d545a1ba6 100644
--- a/indra/llui/lltextbase.h
+++ b/indra/llui/lltextbase.h
@@ -265,6 +265,7 @@ public:
 								use_ellipses,
 								parse_urls,
 								parse_highlights,
+								clip,
 								clip_partial;
 								
 		Optional<S32>			v_pad,
@@ -338,7 +339,7 @@ public:
 	void					addDocumentChild(LLView* view);
 	void					removeDocumentChild(LLView* view);
 	const LLView*			getDocumentView() const { return mDocumentView; }
-	LLRect					getVisibleTextRect() { return mVisibleTextRect; }
+	LLRect					getVisibleTextRect() const { return mVisibleTextRect; }
 	LLRect					getTextBoundingRect();
 	LLRect					getVisibleDocumentRect() const;
 
@@ -552,6 +553,7 @@ protected:
 	bool						mTrackEnd;			// if true, keeps scroll position at end of document during resize
 	bool						mReadOnly;
 	bool						mBGVisible;			// render background?
+	bool						mClip;				// clip text to widget rect
 	bool						mClipPartial;		// false if we show lines that are partially inside bounding rect
 	bool						mPlainText;			// didn't use Image or Icon segments
 	S32							mMaxTextByteLength;	// Maximum length mText is allowed to be in bytes