Source/WebCore/rendering/CaretRectComputation.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "CaretRectComputation.h"

 #include "Editing.h"
 #include "InlineIteratorLine.h"
 #include "InlineIteratorTextBox.h"
 #include "RenderBlockFlow.h"
 #include "RenderInline.h"
 #include "RenderLineBreak.h"
 #include "RenderSVGInlineText.h"
 #include "RenderText.h"

 namespace WebCore {

 static LayoutRect computeCaretRectForEmptyElement(const RenderBoxModelObject& renderer, LayoutUnit width, LayoutUnit textIndentOffset, CaretRectMode caretRectMode)
 {
     ASSERT(!renderer.firstChild());

     // FIXME: This does not take into account either :first-line or :first-letter
     // However, as soon as some content is entered, the line boxes will be
     // constructed and this kludge is not called any more. So only the caret size
     // of an empty :first-line'd block is wrong. I think we can live with that.
     const RenderStyle& currentStyle = renderer.firstLineStyle();

     enum CaretAlignment { AlignLeft, AlignRight, AlignCenter };

     CaretAlignment alignment = AlignLeft;

     switch (currentStyle.textAlign()) {
     case TextAlignMode::Left:
     case TextAlignMode::WebKitLeft:
         break;
     case TextAlignMode::Center:
     case TextAlignMode::WebKitCenter:
         alignment = AlignCenter;
         break;
     case TextAlignMode::Right:
     case TextAlignMode::WebKitRight:
         alignment = AlignRight;
         break;
     case TextAlignMode::Justify:
     case TextAlignMode::Start:
         if (!currentStyle.isLeftToRightDirection())
             alignment = AlignRight;
         break;
     case TextAlignMode::End:
         if (currentStyle.isLeftToRightDirection())
             alignment = AlignRight;
         break;
     }

     LayoutUnit x = renderer.borderLeft() + renderer.paddingLeft();
     LayoutUnit maxX = width - renderer.borderRight() - renderer.paddingRight();

     switch (alignment) {
     case AlignLeft:
         if (currentStyle.isLeftToRightDirection())
             x += textIndentOffset;
         break;
     case AlignCenter:
         x = (x + maxX) / 2;
         if (currentStyle.isLeftToRightDirection())
             x += textIndentOffset / 2;
         else
             x -= textIndentOffset / 2;
         break;
     case AlignRight:
         x = maxX - caretWidth;
         if (!currentStyle.isLeftToRightDirection())
             x -= textIndentOffset;
         break;
     }
     x = std::min(x, std::max<LayoutUnit>(maxX - caretWidth, 0));

     auto lineHeight = renderer.lineHeight(true, currentStyle.isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
     auto height = std::min(lineHeight, LayoutUnit { currentStyle.fontMetrics().height() });
     auto y = renderer.paddingTop() + renderer.borderTop() + (lineHeight > height ? (lineHeight - height) / 2 : LayoutUnit { });

     auto rect = LayoutRect(x, y, caretWidth, height);

     if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
         rect.shiftMaxXEdgeTo(width);

     return currentStyle.isHorizontalWritingMode() ? rect : rect.transposedRect();
 }

 static LayoutRect computeCaretRectForLinePosition(const InlineIterator::LineIterator& line, float logicalLeftPosition, CaretRectMode caretRectMode)
 {
     auto& containingBlock = line->containingBlock();
     auto lineSelectionRect = line->selectionRect();

     int height = lineSelectionRect.height();
     int top = lineSelectionRect.y();

     // Distribute the caret's width to either side of the offset.
     float left = logicalLeftPosition;
     int caretWidthLeftOfOffset = caretWidth / 2;
     left -= caretWidthLeftOfOffset;
     int caretWidthRightOfOffset = caretWidth - caretWidthLeftOfOffset;
     left = roundf(left);

     float lineLeft = lineSelectionRect.x();
     float lineRight = lineSelectionRect.maxX();

     bool rightAligned = false;
     switch (containingBlock.style().textAlign()) {
     case TextAlignMode::Right:
     case TextAlignMode::WebKitRight:
         rightAligned = true;
         break;
     case TextAlignMode::Left:
     case TextAlignMode::WebKitLeft:
     case TextAlignMode::Center:
     case TextAlignMode::WebKitCenter:
         break;
     case TextAlignMode::Justify:
     case TextAlignMode::Start:
         rightAligned = !containingBlock.style().isLeftToRightDirection();
         break;
     case TextAlignMode::End:
         rightAligned = containingBlock.style().isLeftToRightDirection();
         break;
     }

     float leftEdge = std::min<float>(0, lineLeft);
     float rightEdge = std::max<float>(containingBlock.logicalWidth(), lineRight);

     if (rightAligned) {
         left = std::max(left, leftEdge);
         left = std::min(left, lineRight - caretWidth);
     } else {
         left = std::min(left, rightEdge - caretWidthRightOfOffset);
         left = std::max(left, lineLeft);
     }

     auto rect = IntRect(left, top, caretWidth, height);

     if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
         rect.shiftMaxXEdgeTo(lineRight);

     return containingBlock.style().isHorizontalWritingMode() ? rect : rect.transposedRect();
 }

 static LayoutRect computeCaretRectForText(const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
 {
     if (!runAndOffset.run)
         return { };

     auto& textRun = downcast<InlineIterator::TextBoxIterator>(runAndOffset.run);
     auto line = textRun->line();

     float position = textRun->positionForOffset(runAndOffset.offset);
     return computeCaretRectForLinePosition(line, position, caretRectMode);
 }

 static LayoutRect computeCaretRectForLineBreak(const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
 {
     ASSERT(!runAndOffset.offset);

     if (!runAndOffset.run)
         return { };

     auto line = runAndOffset.run->line();
     return computeCaretRectForLinePosition(line, line->contentLogicalLeft(), caretRectMode);
 }

 static LayoutRect computeCaretRectForSVGInlineText(const InlineRunAndOffset& runAndOffset, CaretRectMode)
 {
     auto* box = runAndOffset.run ? runAndOffset.run->legacyInlineBox() : nullptr;
     auto caretOffset = runAndOffset.offset;

     if (!is<LegacyInlineTextBox>(box))
         return { };

     auto& textBox = downcast<LegacyInlineTextBox>(*box);
     if (caretOffset < textBox.start() || caretOffset > textBox.start() + textBox.len())
         return { };

     // Use the edge of the selection rect to determine the caret rect.
     if (caretOffset < textBox.start() + textBox.len()) {
         LayoutRect rect = textBox.localSelectionRect(caretOffset, caretOffset + 1);
         LayoutUnit x = textBox.isLeftToRightDirection() ? rect.x() : rect.maxX();
         return LayoutRect(x, rect.y(), caretWidth, rect.height());
     }

     LayoutRect rect = textBox.localSelectionRect(caretOffset - 1, caretOffset);
     LayoutUnit x = textBox.isLeftToRightDirection() ? rect.maxX() : rect.x();
     return { x, rect.y(), caretWidth, rect.height() };
 }

 static LayoutRect computeCaretRectForBox(const RenderBox& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
 {
     // VisiblePositions at offsets inside containers either a) refer to the positions before/after
     // those containers (tables and select elements) or b) refer to the position inside an empty block.
     // They never refer to children.
     // FIXME: Paint the carets inside empty blocks differently than the carets before/after elements.

     LayoutRect rect(renderer.location(), LayoutSize(caretWidth, renderer.height()));
     bool ltr = runAndOffset.run ? runAndOffset.run->isLeftToRightDirection() : renderer.style().isLeftToRightDirection();

     if ((!runAndOffset.offset) ^ ltr)
         rect.move(LayoutSize(renderer.width() - caretWidth, 0_lu));

     if (runAndOffset.run) {
         auto line = runAndOffset.run->line();
         LayoutUnit top = line->top();
         rect.setY(top);
         rect.setHeight(line->bottom() - top);
     }

     // If height of box is smaller than font height, use the latter one,
     // otherwise the caret might become invisible.
     //
     // Also, if the box is not a replaced element, always use the font height.
     // This prevents the "big caret" bug described in:
     // <rdar://problem/3777804> Deleting all content in a document can result in giant tall-as-window insertion point
     //
     // FIXME: ignoring :first-line, missing good reason to take care of
     LayoutUnit fontHeight = renderer.style().fontMetrics().height();
     if (fontHeight > rect.height() || (!renderer.isReplacedOrInlineBlock() && !renderer.isTable()))
         rect.setHeight(fontHeight);

     // Move to local coords
     rect.moveBy(-renderer.location());

     // FIXME: Border/padding should be added for all elements but this workaround
     // is needed because we use offsets inside an "atomic" element to represent
     // positions before and after the element in deprecated editing offsets.
     if (renderer.element() && !(editingIgnoresContent(*renderer.element()) || isRenderedTable(renderer.element()))) {
         rect.setX(rect.x() + renderer.borderLeft() + renderer.paddingLeft());
         rect.setY(rect.y() + renderer.paddingTop() + renderer.borderTop());
     }

     if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
         rect.shiftMaxXEdgeTo(renderer.x() + renderer.width());

     return renderer.isHorizontalWritingMode() ? rect : rect.transposedRect();
 }

 static LayoutRect computeCaretRectForBlock(const RenderBlock& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
 {
     // Do the normal calculation in most cases.
     if (renderer.firstChild())
         return computeCaretRectForBox(renderer, runAndOffset, caretRectMode);

     return computeCaretRectForEmptyElement(renderer, renderer.width(), renderer.textIndentOffset(), caretRectMode);
 }

 static LayoutRect computeCaretRectForInline(const RenderInline& renderer)
 {
     if (renderer.firstChild()) {
         // This condition is possible if the RenderInline is at an editing boundary,
         // i.e. the VisiblePosition is:
         //   <RenderInline editingBoundary=true>|<RenderText> </RenderText></RenderInline>
         // FIXME: need to figure out how to make this return a valid rect, note that
         // there are no line boxes created in the above case.
         return { };
     }

     LayoutRect caretRect = computeCaretRectForEmptyElement(renderer, renderer.horizontalBorderAndPaddingExtent(), 0, CaretRectMode::Normal);

     if (LegacyInlineBox* firstBox = renderer.firstLineBox())
         caretRect.moveBy(LayoutPoint(firstBox->topLeft()));

     return caretRect;
 }

 LayoutRect computeLocalCaretRect(const RenderObject& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
 {
     if (is<RenderSVGInlineText>(renderer))
         return computeCaretRectForSVGInlineText(runAndOffset, caretRectMode);

     if (is<RenderText>(renderer))
         return computeCaretRectForText(runAndOffset, caretRectMode);

     if (is<RenderLineBreak>(renderer))
         return computeCaretRectForLineBreak(runAndOffset, caretRectMode);

     if (is<RenderBlock>(renderer))
         return computeCaretRectForBlock(downcast<RenderBlock>(renderer), runAndOffset, caretRectMode);

     if (is<RenderBox>(renderer))
         return computeCaretRectForBox(downcast<RenderBox>(renderer), runAndOffset, caretRectMode);

     if (is<RenderInline>(renderer))
         return computeCaretRectForInline(downcast<RenderInline>(renderer));

     return { };
 }

 };
	/*
	* Copyright (C) 2020 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "CaretRectComputation.h"

	#include "Editing.h"
	#include "InlineIteratorLine.h"
	#include "InlineIteratorTextBox.h"
	#include "RenderBlockFlow.h"
	#include "RenderInline.h"
	#include "RenderLineBreak.h"
	#include "RenderSVGInlineText.h"
	#include "RenderText.h"

	namespace WebCore {

	static LayoutRect computeCaretRectForEmptyElement(const RenderBoxModelObject& renderer, LayoutUnit width, LayoutUnit textIndentOffset, CaretRectMode caretRectMode)
	{
	ASSERT(!renderer.firstChild());

	// FIXME: This does not take into account either :first-line or :first-letter
	// However, as soon as some content is entered, the line boxes will be
	// constructed and this kludge is not called any more. So only the caret size
	// of an empty :first-line'd block is wrong. I think we can live with that.
	const RenderStyle& currentStyle = renderer.firstLineStyle();

	enum CaretAlignment { AlignLeft, AlignRight, AlignCenter };

	CaretAlignment alignment = AlignLeft;

	switch (currentStyle.textAlign()) {
	case TextAlignMode::Left:
	case TextAlignMode::WebKitLeft:
	break;
	case TextAlignMode::Center:
	case TextAlignMode::WebKitCenter:
	alignment = AlignCenter;
	break;
	case TextAlignMode::Right:
	case TextAlignMode::WebKitRight:
	alignment = AlignRight;
	break;
	case TextAlignMode::Justify:
	case TextAlignMode::Start:
	if (!currentStyle.isLeftToRightDirection())
	alignment = AlignRight;
	break;
	case TextAlignMode::End:
	if (currentStyle.isLeftToRightDirection())
	alignment = AlignRight;
	break;
	}

	LayoutUnit x = renderer.borderLeft() + renderer.paddingLeft();
	LayoutUnit maxX = width - renderer.borderRight() - renderer.paddingRight();

	switch (alignment) {
	case AlignLeft:
	if (currentStyle.isLeftToRightDirection())
	x += textIndentOffset;
	break;
	case AlignCenter:
	x = (x + maxX) / 2;
	if (currentStyle.isLeftToRightDirection())
	x += textIndentOffset / 2;
	else
	x -= textIndentOffset / 2;
	break;
	case AlignRight:
	x = maxX - caretWidth;
	if (!currentStyle.isLeftToRightDirection())
	x -= textIndentOffset;
	break;
	}
	x = std::min(x, std::max<LayoutUnit>(maxX - caretWidth, 0));

	auto lineHeight = renderer.lineHeight(true, currentStyle.isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
	auto height = std::min(lineHeight, LayoutUnit { currentStyle.fontMetrics().height() });
	auto y = renderer.paddingTop() + renderer.borderTop() + (lineHeight > height ? (lineHeight - height) / 2 : LayoutUnit { });

	auto rect = LayoutRect(x, y, caretWidth, height);

	if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
	rect.shiftMaxXEdgeTo(width);

	return currentStyle.isHorizontalWritingMode() ? rect : rect.transposedRect();
	}

	static LayoutRect computeCaretRectForLinePosition(const InlineIterator::LineIterator& line, float logicalLeftPosition, CaretRectMode caretRectMode)
	{
	auto& containingBlock = line->containingBlock();
	auto lineSelectionRect = line->selectionRect();

	int height = lineSelectionRect.height();
	int top = lineSelectionRect.y();

	// Distribute the caret's width to either side of the offset.
	float left = logicalLeftPosition;
	int caretWidthLeftOfOffset = caretWidth / 2;
	left -= caretWidthLeftOfOffset;
	int caretWidthRightOfOffset = caretWidth - caretWidthLeftOfOffset;
	left = roundf(left);

	float lineLeft = lineSelectionRect.x();
	float lineRight = lineSelectionRect.maxX();

	bool rightAligned = false;
	switch (containingBlock.style().textAlign()) {
	case TextAlignMode::Right:
	case TextAlignMode::WebKitRight:
	rightAligned = true;
	break;
	case TextAlignMode::Left:
	case TextAlignMode::WebKitLeft:
	case TextAlignMode::Center:
	case TextAlignMode::WebKitCenter:
	break;
	case TextAlignMode::Justify:
	case TextAlignMode::Start:
	rightAligned = !containingBlock.style().isLeftToRightDirection();
	break;
	case TextAlignMode::End:
	rightAligned = containingBlock.style().isLeftToRightDirection();
	break;
	}

	float leftEdge = std::min<float>(0, lineLeft);
	float rightEdge = std::max<float>(containingBlock.logicalWidth(), lineRight);

	if (rightAligned) {
	left = std::max(left, leftEdge);
	left = std::min(left, lineRight - caretWidth);
	} else {
	left = std::min(left, rightEdge - caretWidthRightOfOffset);
	left = std::max(left, lineLeft);
	}

	auto rect = IntRect(left, top, caretWidth, height);

	if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
	rect.shiftMaxXEdgeTo(lineRight);

	return containingBlock.style().isHorizontalWritingMode() ? rect : rect.transposedRect();
	}

	static LayoutRect computeCaretRectForText(const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
	{
	if (!runAndOffset.run)
	return { };

	auto& textRun = downcast<InlineIterator::TextBoxIterator>(runAndOffset.run);
	auto line = textRun->line();

	float position = textRun->positionForOffset(runAndOffset.offset);
	return computeCaretRectForLinePosition(line, position, caretRectMode);
	}

	static LayoutRect computeCaretRectForLineBreak(const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
	{
	ASSERT(!runAndOffset.offset);

	if (!runAndOffset.run)
	return { };

	auto line = runAndOffset.run->line();
	return computeCaretRectForLinePosition(line, line->contentLogicalLeft(), caretRectMode);
	}

	static LayoutRect computeCaretRectForSVGInlineText(const InlineRunAndOffset& runAndOffset, CaretRectMode)
	{
	auto* box = runAndOffset.run ? runAndOffset.run->legacyInlineBox() : nullptr;
	auto caretOffset = runAndOffset.offset;

	if (!is<LegacyInlineTextBox>(box))
	return { };

	auto& textBox = downcast<LegacyInlineTextBox>(*box);
	if (caretOffset < textBox.start() \|\| caretOffset > textBox.start() + textBox.len())
	return { };

	// Use the edge of the selection rect to determine the caret rect.
	if (caretOffset < textBox.start() + textBox.len()) {
	LayoutRect rect = textBox.localSelectionRect(caretOffset, caretOffset + 1);
	LayoutUnit x = textBox.isLeftToRightDirection() ? rect.x() : rect.maxX();
	return LayoutRect(x, rect.y(), caretWidth, rect.height());
	}

	LayoutRect rect = textBox.localSelectionRect(caretOffset - 1, caretOffset);
	LayoutUnit x = textBox.isLeftToRightDirection() ? rect.maxX() : rect.x();
	return { x, rect.y(), caretWidth, rect.height() };
	}

	static LayoutRect computeCaretRectForBox(const RenderBox& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
	{
	// VisiblePositions at offsets inside containers either a) refer to the positions before/after
	// those containers (tables and select elements) or b) refer to the position inside an empty block.
	// They never refer to children.
	// FIXME: Paint the carets inside empty blocks differently than the carets before/after elements.

	LayoutRect rect(renderer.location(), LayoutSize(caretWidth, renderer.height()));
	bool ltr = runAndOffset.run ? runAndOffset.run->isLeftToRightDirection() : renderer.style().isLeftToRightDirection();

	if ((!runAndOffset.offset) ^ ltr)
	rect.move(LayoutSize(renderer.width() - caretWidth, 0_lu));

	if (runAndOffset.run) {
	auto line = runAndOffset.run->line();
	LayoutUnit top = line->top();
	rect.setY(top);
	rect.setHeight(line->bottom() - top);
	}

	// If height of box is smaller than font height, use the latter one,
	// otherwise the caret might become invisible.
	//
	// Also, if the box is not a replaced element, always use the font height.
	// This prevents the "big caret" bug described in:
	// <rdar://problem/3777804> Deleting all content in a document can result in giant tall-as-window insertion point
	//
	// FIXME: ignoring :first-line, missing good reason to take care of
	LayoutUnit fontHeight = renderer.style().fontMetrics().height();
	if (fontHeight > rect.height() \|\| (!renderer.isReplacedOrInlineBlock() && !renderer.isTable()))
	rect.setHeight(fontHeight);

	// Move to local coords
	rect.moveBy(-renderer.location());

	// FIXME: Border/padding should be added for all elements but this workaround
	// is needed because we use offsets inside an "atomic" element to represent
	// positions before and after the element in deprecated editing offsets.
	if (renderer.element() && !(editingIgnoresContent(*renderer.element()) \|\| isRenderedTable(renderer.element()))) {
	rect.setX(rect.x() + renderer.borderLeft() + renderer.paddingLeft());
	rect.setY(rect.y() + renderer.paddingTop() + renderer.borderTop());
	}

	if (caretRectMode == CaretRectMode::ExpandToEndOfLine)
	rect.shiftMaxXEdgeTo(renderer.x() + renderer.width());

	return renderer.isHorizontalWritingMode() ? rect : rect.transposedRect();
	}

	static LayoutRect computeCaretRectForBlock(const RenderBlock& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
	{
	// Do the normal calculation in most cases.
	if (renderer.firstChild())
	return computeCaretRectForBox(renderer, runAndOffset, caretRectMode);

	return computeCaretRectForEmptyElement(renderer, renderer.width(), renderer.textIndentOffset(), caretRectMode);
	}

	static LayoutRect computeCaretRectForInline(const RenderInline& renderer)
	{
	if (renderer.firstChild()) {
	// This condition is possible if the RenderInline is at an editing boundary,
	// i.e. the VisiblePosition is:
	// <RenderInline editingBoundary=true>\|<RenderText> </RenderText></RenderInline>
	// FIXME: need to figure out how to make this return a valid rect, note that
	// there are no line boxes created in the above case.
	return { };
	}

	LayoutRect caretRect = computeCaretRectForEmptyElement(renderer, renderer.horizontalBorderAndPaddingExtent(), 0, CaretRectMode::Normal);

	if (LegacyInlineBox* firstBox = renderer.firstLineBox())
	caretRect.moveBy(LayoutPoint(firstBox->topLeft()));

	return caretRect;
	}

	LayoutRect computeLocalCaretRect(const RenderObject& renderer, const InlineRunAndOffset& runAndOffset, CaretRectMode caretRectMode)
	{
	if (is<RenderSVGInlineText>(renderer))
	return computeCaretRectForSVGInlineText(runAndOffset, caretRectMode);

	if (is<RenderText>(renderer))
	return computeCaretRectForText(runAndOffset, caretRectMode);

	if (is<RenderLineBreak>(renderer))
	return computeCaretRectForLineBreak(runAndOffset, caretRectMode);

	if (is<RenderBlock>(renderer))
	return computeCaretRectForBlock(downcast<RenderBlock>(renderer), runAndOffset, caretRectMode);

	if (is<RenderBox>(renderer))
	return computeCaretRectForBox(downcast<RenderBox>(renderer), runAndOffset, caretRectMode);

	if (is<RenderInline>(renderer))
	return computeCaretRectForInline(downcast<RenderInline>(renderer));

	return { };
	}

	};