blob: 4d8b72f8e5bcb0e832d3ec3ddc2ee9292b49fe86 [file] [log] [blame]
/*
* Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
* Copyright (C) 2009 Antonio Gomes <tonikitoo@webkit.org>
*
* 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. ``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
* 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 "SpatialNavigation.h"
#include "Frame.h"
#include "FrameTree.h"
#include "FrameView.h"
#include "HTMLAreaElement.h"
#include "HTMLImageElement.h"
#include "HTMLMapElement.h"
#include "HTMLSelectElement.h"
#include "IntRect.h"
#include "Node.h"
#include "Page.h"
#include "RenderInline.h"
#include "RenderLayer.h"
#include "Settings.h"
namespace WebCore {
static bool areRectsFullyAligned(FocusDirection, const LayoutRect&, const LayoutRect&);
static bool areRectsPartiallyAligned(FocusDirection, const LayoutRect&, const LayoutRect&);
static bool areRectsMoreThanFullScreenApart(FocusDirection, const LayoutRect& curRect, const LayoutRect& targetRect, const LayoutSize& viewSize);
static bool isRectInDirection(FocusDirection, const LayoutRect&, const LayoutRect&);
static void deflateIfOverlapped(LayoutRect&, LayoutRect&);
static LayoutRect rectToAbsoluteCoordinates(Frame* initialFrame, const LayoutRect&);
static void entryAndExitPointsForDirection(FocusDirection, const LayoutRect& startingRect, const LayoutRect& potentialRect, LayoutPoint& exitPoint, LayoutPoint& entryPoint);
static bool isScrollableNode(const Node*);
FocusCandidate::FocusCandidate(Node* node, FocusDirection direction)
: visibleNode(nullptr)
, focusableNode(nullptr)
, enclosingScrollableBox(nullptr)
, distance(maxDistance())
, alignment(None)
, isOffscreen(true)
, isOffscreenAfterScrolling(true)
{
ASSERT(is<Element>(node));
if (is<HTMLAreaElement>(*node)) {
HTMLAreaElement& area = downcast<HTMLAreaElement>(*node);
HTMLImageElement* image = area.imageElement();
if (!image || !image->renderer())
return;
visibleNode = image;
rect = virtualRectForAreaElementAndDirection(&area, direction);
} else {
if (!node->renderer())
return;
visibleNode = node;
rect = nodeRectInAbsoluteCoordinates(node, true /* ignore border */);
}
focusableNode = node;
isOffscreen = hasOffscreenRect(visibleNode);
isOffscreenAfterScrolling = hasOffscreenRect(visibleNode, direction);
}
bool isSpatialNavigationEnabled(const Frame* frame)
{
return (frame && frame->settings().spatialNavigationEnabled());
}
static RectsAlignment alignmentForRects(FocusDirection direction, const LayoutRect& curRect, const LayoutRect& targetRect, const LayoutSize& viewSize)
{
// If we found a node in full alignment, but it is too far away, ignore it.
if (areRectsMoreThanFullScreenApart(direction, curRect, targetRect, viewSize))
return None;
if (areRectsFullyAligned(direction, curRect, targetRect))
return Full;
if (areRectsPartiallyAligned(direction, curRect, targetRect))
return Partial;
return None;
}
static inline bool isHorizontalMove(FocusDirection direction)
{
return direction == FocusDirectionLeft || direction == FocusDirectionRight;
}
static inline LayoutUnit start(FocusDirection direction, const LayoutRect& rect)
{
return isHorizontalMove(direction) ? rect.y() : rect.x();
}
static inline LayoutUnit middle(FocusDirection direction, const LayoutRect& rect)
{
LayoutPoint center(rect.center());
return isHorizontalMove(direction) ? center.y(): center.x();
}
static inline LayoutUnit end(FocusDirection direction, const LayoutRect& rect)
{
return isHorizontalMove(direction) ? rect.maxY() : rect.maxX();
}
// This method checks if rects |a| and |b| are fully aligned either vertically or
// horizontally. In general, rects whose central point falls between the top or
// bottom of each other are considered fully aligned.
// Rects that match this criteria are preferable target nodes in move focus changing
// operations.
// * a = Current focused node's rect.
// * b = Focus candidate node's rect.
static bool areRectsFullyAligned(FocusDirection direction, const LayoutRect& a, const LayoutRect& b)
{
LayoutUnit aStart, bStart, aEnd, bEnd;
switch (direction) {
case FocusDirectionLeft:
aStart = a.x();
bEnd = b.maxX();
break;
case FocusDirectionRight:
aStart = b.x();
bEnd = a.maxX();
break;
case FocusDirectionUp:
aStart = a.y();
bEnd = b.y();
break;
case FocusDirectionDown:
aStart = b.y();
bEnd = a.y();
break;
default:
ASSERT_NOT_REACHED();
return false;
}
if (aStart < bEnd)
return false;
aStart = start(direction, a);
bStart = start(direction, b);
LayoutUnit aMiddle = middle(direction, a);
LayoutUnit bMiddle = middle(direction, b);
aEnd = end(direction, a);
bEnd = end(direction, b);
// Picture of the totally aligned logic:
//
// Horizontal Vertical Horizontal Vertical
// **************************** *****************************
// * _ * _ _ _ _ * * _ * _ _ *
// * |_| _ * |_|_|_|_| * * _ |_| * |_|_| *
// * |_|....|_| * . * * |_|....|_| * . *
// * |_| |_| (1) . * * |_| |_| (2) . *
// * |_| * _._ * * |_| * _ _._ _ *
// * * |_|_| * * * |_|_|_|_| *
// * * * * * *
// **************************** *****************************
// Horizontal Vertical Horizontal Vertical
// **************************** *****************************
// * _......_ * _ _ _ _ * * _ * _ _ _ _ *
// * |_| |_| * |_|_|_|_| * * |_| _ * |_|_|_|_| *
// * |_| |_| * . * * |_| |_| * . *
// * |_| (3) . * * |_|....|_| (4) . *
// * * ._ _ * * * _ _. *
// * * |_|_| * * * |_|_| *
// * * * * * *
// **************************** *****************************
return ((bMiddle >= aStart && bMiddle <= aEnd) // (1)
|| (aMiddle >= bStart && aMiddle <= bEnd) // (2)
|| (bStart == aStart) // (3)
|| (bEnd == aEnd)); // (4)
}
// This method checks if |start| and |dest| have a partial intersection, either
// horizontally or vertically.
// * a = Current focused node's rect.
// * b = Focus candidate node's rect.
static bool areRectsPartiallyAligned(FocusDirection direction, const LayoutRect& a, const LayoutRect& b)
{
LayoutUnit aStart = start(direction, a);
LayoutUnit bStart = start(direction, b);
LayoutUnit bMiddle = middle(direction, b);
LayoutUnit aEnd = end(direction, a);
LayoutUnit bEnd = end(direction, b);
// Picture of the partially aligned logic:
//
// Horizontal Vertical
// ********************************
// * _ * _ _ _ *
// * |_| * |_|_|_| *
// * |_|.... _ * . . *
// * |_| |_| * . . *
// * |_|....|_| * ._._ _ *
// * |_| * |_|_|_| *
// * |_| * *
// * * *
// ********************************
//
// ... and variants of the above cases.
return ((bStart >= aStart && bStart <= aEnd)
|| (bMiddle >= aStart && bMiddle <= aEnd)
|| (bEnd >= aStart && bEnd <= aEnd));
}
static bool areRectsMoreThanFullScreenApart(FocusDirection direction, const LayoutRect& curRect, const LayoutRect& targetRect, const LayoutSize& viewSize)
{
ASSERT(isRectInDirection(direction, curRect, targetRect));
switch (direction) {
case FocusDirectionLeft:
return curRect.x() - targetRect.maxX() > viewSize.width();
case FocusDirectionRight:
return targetRect.x() - curRect.maxX() > viewSize.width();
case FocusDirectionUp:
return curRect.y() - targetRect.maxY() > viewSize.height();
case FocusDirectionDown:
return targetRect.y() - curRect.maxY() > viewSize.height();
default:
ASSERT_NOT_REACHED();
return true;
}
}
// Return true if rect |a| is below |b|. False otherwise.
static inline bool below(const LayoutRect& a, const LayoutRect& b)
{
return a.y() > b.maxY();
}
// Return true if rect |a| is on the right of |b|. False otherwise.
static inline bool rightOf(const LayoutRect& a, const LayoutRect& b)
{
return a.x() > b.maxX();
}
static bool isRectInDirection(FocusDirection direction, const LayoutRect& curRect, const LayoutRect& targetRect)
{
switch (direction) {
case FocusDirectionLeft:
return targetRect.maxX() <= curRect.x();
case FocusDirectionRight:
return targetRect.x() >= curRect.maxX();
case FocusDirectionUp:
return targetRect.maxY() <= curRect.y();
case FocusDirectionDown:
return targetRect.y() >= curRect.maxY();
default:
ASSERT_NOT_REACHED();
return false;
}
}
// Checks if |node| is offscreen the visible area (viewport) of its container
// document. In case it is, one can scroll in direction or take any different
// desired action later on.
bool hasOffscreenRect(Node* node, FocusDirection direction)
{
// Get the FrameView in which |node| is (which means the current viewport if |node|
// is not in an inner document), so we can check if its content rect is visible
// before we actually move the focus to it.
FrameView* frameView = node->document().view();
if (!frameView)
return true;
ASSERT(!frameView->needsLayout());
LayoutRect containerViewportRect = frameView->visibleContentRect();
// We want to select a node if it is currently off screen, but will be
// exposed after we scroll. Adjust the viewport to post-scrolling position.
// If the container has overflow:hidden, we cannot scroll, so we do not pass direction
// and we do not adjust for scrolling.
switch (direction) {
case FocusDirectionLeft:
containerViewportRect.setX(containerViewportRect.x() - Scrollbar::pixelsPerLineStep());
containerViewportRect.setWidth(containerViewportRect.width() + Scrollbar::pixelsPerLineStep());
break;
case FocusDirectionRight:
containerViewportRect.setWidth(containerViewportRect.width() + Scrollbar::pixelsPerLineStep());
break;
case FocusDirectionUp:
containerViewportRect.setY(containerViewportRect.y() - Scrollbar::pixelsPerLineStep());
containerViewportRect.setHeight(containerViewportRect.height() + Scrollbar::pixelsPerLineStep());
break;
case FocusDirectionDown:
containerViewportRect.setHeight(containerViewportRect.height() + Scrollbar::pixelsPerLineStep());
break;
default:
break;
}
RenderObject* render = node->renderer();
if (!render)
return true;
LayoutRect rect(render->absoluteClippedOverflowRect());
if (rect.isEmpty())
return true;
return !containerViewportRect.intersects(rect);
}
bool scrollInDirection(Frame* frame, FocusDirection direction)
{
ASSERT(frame);
if (frame && canScrollInDirection(frame->document(), direction)) {
LayoutUnit dx;
LayoutUnit dy;
switch (direction) {
case FocusDirectionLeft:
dx = - Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionRight:
dx = Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionUp:
dy = - Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionDown:
dy = Scrollbar::pixelsPerLineStep();
break;
default:
ASSERT_NOT_REACHED();
return false;
}
frame->view()->scrollBy(IntSize(dx, dy));
return true;
}
return false;
}
bool scrollInDirection(Node* container, FocusDirection direction)
{
ASSERT(container);
if (is<Document>(*container))
return scrollInDirection(downcast<Document>(*container).frame(), direction);
if (!container->renderBox())
return false;
if (canScrollInDirection(container, direction)) {
LayoutUnit dx;
LayoutUnit dy;
switch (direction) {
case FocusDirectionLeft:
dx = - std::min<LayoutUnit>(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollLeft());
break;
case FocusDirectionRight:
ASSERT(container->renderBox()->scrollWidth() > (container->renderBox()->scrollLeft() + container->renderBox()->clientWidth()));
dx = std::min<LayoutUnit>(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollWidth() - (container->renderBox()->scrollLeft() + container->renderBox()->clientWidth()));
break;
case FocusDirectionUp:
dy = - std::min<LayoutUnit>(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollTop());
break;
case FocusDirectionDown:
ASSERT(container->renderBox()->scrollHeight() - (container->renderBox()->scrollTop() + container->renderBox()->clientHeight()));
dy = std::min<LayoutUnit>(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollHeight() - (container->renderBox()->scrollTop() + container->renderBox()->clientHeight()));
break;
default:
ASSERT_NOT_REACHED();
return false;
}
container->renderBox()->enclosingLayer()->scrollByRecursively(IntSize(dx, dy));
return true;
}
return false;
}
static void deflateIfOverlapped(LayoutRect& a, LayoutRect& b)
{
if (!a.intersects(b) || a.contains(b) || b.contains(a))
return;
LayoutUnit deflateFactor = -fudgeFactor();
// Avoid negative width or height values.
if ((a.width() + 2 * deflateFactor > 0) && (a.height() + 2 * deflateFactor > 0))
a.inflate(deflateFactor);
if ((b.width() + 2 * deflateFactor > 0) && (b.height() + 2 * deflateFactor > 0))
b.inflate(deflateFactor);
}
bool isScrollableNode(const Node* node)
{
if (!node)
return false;
ASSERT(!node->isDocumentNode());
auto* renderer = node->renderer();
return is<RenderBox>(renderer) && downcast<RenderBox>(*renderer).canBeScrolledAndHasScrollableArea() && node->hasChildNodes();
}
Node* scrollableEnclosingBoxOrParentFrameForNodeInDirection(FocusDirection direction, Node* node)
{
ASSERT(node);
Node* parent = node;
do {
if (is<Document>(*parent))
parent = downcast<Document>(*parent).document().frame()->ownerElement();
else
parent = parent->parentNode();
} while (parent && !canScrollInDirection(parent, direction) && !is<Document>(*parent));
return parent;
}
bool canScrollInDirection(const Node* container, FocusDirection direction)
{
ASSERT(container);
if (is<HTMLSelectElement>(*container))
return false;
if (is<Document>(*container))
return canScrollInDirection(downcast<Document>(*container).frame(), direction);
if (!isScrollableNode(container))
return false;
switch (direction) {
case FocusDirectionLeft:
return (container->renderer()->style().overflowX() != Overflow::Hidden && container->renderBox()->scrollLeft() > 0);
case FocusDirectionUp:
return (container->renderer()->style().overflowY() != Overflow::Hidden && container->renderBox()->scrollTop() > 0);
case FocusDirectionRight:
return (container->renderer()->style().overflowX() != Overflow::Hidden && container->renderBox()->scrollLeft() + container->renderBox()->clientWidth() < container->renderBox()->scrollWidth());
case FocusDirectionDown:
return (container->renderer()->style().overflowY() != Overflow::Hidden && container->renderBox()->scrollTop() + container->renderBox()->clientHeight() < container->renderBox()->scrollHeight());
default:
ASSERT_NOT_REACHED();
return false;
}
}
bool canScrollInDirection(const Frame* frame, FocusDirection direction)
{
if (!frame->view())
return false;
ScrollbarMode verticalMode;
ScrollbarMode horizontalMode;
frame->view()->calculateScrollbarModesForLayout(horizontalMode, verticalMode);
if ((direction == FocusDirectionLeft || direction == FocusDirectionRight) && ScrollbarAlwaysOff == horizontalMode)
return false;
if ((direction == FocusDirectionUp || direction == FocusDirectionDown) && ScrollbarAlwaysOff == verticalMode)
return false;
LayoutSize size = frame->view()->totalContentsSize();
LayoutPoint scrollPosition = frame->view()->scrollPosition();
LayoutRect rect = frame->view()->unobscuredContentRectIncludingScrollbars();
// FIXME: wrong in RTL documents.
switch (direction) {
case FocusDirectionLeft:
return scrollPosition.x() > 0;
case FocusDirectionUp:
return scrollPosition.y() > 0;
case FocusDirectionRight:
return rect.width() + scrollPosition.x() < size.width();
case FocusDirectionDown:
return rect.height() + scrollPosition.y() < size.height();
default:
ASSERT_NOT_REACHED();
return false;
}
}
// FIXME: This is completely broken. This should be deleted and callers should be calling ScrollView::contentsToWindow() instead.
static LayoutRect rectToAbsoluteCoordinates(Frame* initialFrame, const LayoutRect& initialRect)
{
LayoutRect rect = initialRect;
for (Frame* frame = initialFrame; frame; frame = frame->tree().parent()) {
if (Element* element = frame->ownerElement()) {
do {
rect.move(LayoutUnit(element->offsetLeft()), LayoutUnit(element->offsetTop()));
} while ((element = element->offsetParent()));
rect.moveBy((-frame->view()->scrollPosition()));
}
}
return rect;
}
LayoutRect nodeRectInAbsoluteCoordinates(Node* node, bool ignoreBorder)
{
ASSERT(node && node->renderer() && !node->document().view()->needsLayout());
if (is<Document>(*node))
return frameRectInAbsoluteCoordinates(downcast<Document>(*node).frame());
LayoutRect rect;
if (RenderObject* renderer = node->renderer())
rect = rectToAbsoluteCoordinates(node->document().frame(), renderer->absoluteBoundingBoxRect());
// For authors that use border instead of outline in their CSS, we compensate by ignoring the border when calculating
// the rect of the focused element.
if (ignoreBorder) {
rect.move(node->renderer()->style().borderLeftWidth(), node->renderer()->style().borderTopWidth());
rect.setWidth(rect.width() - node->renderer()->style().borderLeftWidth() - node->renderer()->style().borderRightWidth());
rect.setHeight(rect.height() - node->renderer()->style().borderTopWidth() - node->renderer()->style().borderBottomWidth());
}
return rect;
}
LayoutRect frameRectInAbsoluteCoordinates(Frame* frame)
{
return rectToAbsoluteCoordinates(frame, frame->view()->visibleContentRect());
}
// This method calculates the exitPoint from the startingRect and the entryPoint into the candidate rect.
// The line between those 2 points is the closest distance between the 2 rects.
void entryAndExitPointsForDirection(FocusDirection direction, const LayoutRect& startingRect, const LayoutRect& potentialRect, LayoutPoint& exitPoint, LayoutPoint& entryPoint)
{
switch (direction) {
case FocusDirectionLeft:
exitPoint.setX(startingRect.x());
entryPoint.setX(potentialRect.maxX());
break;
case FocusDirectionUp:
exitPoint.setY(startingRect.y());
entryPoint.setY(potentialRect.maxY());
break;
case FocusDirectionRight:
exitPoint.setX(startingRect.maxX());
entryPoint.setX(potentialRect.x());
break;
case FocusDirectionDown:
exitPoint.setY(startingRect.maxY());
entryPoint.setY(potentialRect.y());
break;
default:
ASSERT_NOT_REACHED();
}
switch (direction) {
case FocusDirectionLeft:
case FocusDirectionRight:
if (below(startingRect, potentialRect)) {
exitPoint.setY(startingRect.y());
entryPoint.setY(potentialRect.maxY());
} else if (below(potentialRect, startingRect)) {
exitPoint.setY(startingRect.maxY());
entryPoint.setY(potentialRect.y());
} else {
exitPoint.setY(std::max(startingRect.y(), potentialRect.y()));
entryPoint.setY(exitPoint.y());
}
break;
case FocusDirectionUp:
case FocusDirectionDown:
if (rightOf(startingRect, potentialRect)) {
exitPoint.setX(startingRect.x());
entryPoint.setX(potentialRect.maxX());
} else if (rightOf(potentialRect, startingRect)) {
exitPoint.setX(startingRect.maxX());
entryPoint.setX(potentialRect.x());
} else {
exitPoint.setX(std::max(startingRect.x(), potentialRect.x()));
entryPoint.setX(exitPoint.x());
}
break;
default:
ASSERT_NOT_REACHED();
}
}
bool areElementsOnSameLine(const FocusCandidate& firstCandidate, const FocusCandidate& secondCandidate)
{
if (firstCandidate.isNull() || secondCandidate.isNull())
return false;
if (!firstCandidate.visibleNode->renderer() || !secondCandidate.visibleNode->renderer())
return false;
if (!firstCandidate.rect.intersects(secondCandidate.rect))
return false;
if (is<HTMLAreaElement>(*firstCandidate.focusableNode) || is<HTMLAreaElement>(*secondCandidate.focusableNode))
return false;
if (!firstCandidate.visibleNode->renderer()->isRenderInline() || !secondCandidate.visibleNode->renderer()->isRenderInline())
return false;
if (firstCandidate.visibleNode->renderer()->containingBlock() != secondCandidate.visibleNode->renderer()->containingBlock())
return false;
return true;
}
// Consider only those nodes as candidate which are exactly in the focus-direction.
// e.g. If we are moving down then the nodes that are above current focused node should be considered as invalid.
bool isValidCandidate(FocusDirection direction, const FocusCandidate& current, FocusCandidate& candidate)
{
LayoutRect currentRect = current.rect;
LayoutRect candidateRect = candidate.rect;
switch (direction) {
case FocusDirectionLeft:
return candidateRect.x() < currentRect.maxX();
case FocusDirectionUp:
return candidateRect.y() < currentRect.maxY();
case FocusDirectionRight:
return candidateRect.maxX() > currentRect.x();
case FocusDirectionDown:
return candidateRect.maxY() > currentRect.y();
default:
ASSERT_NOT_REACHED();
}
return false;
}
void distanceDataForNode(FocusDirection direction, const FocusCandidate& current, FocusCandidate& candidate)
{
if (areElementsOnSameLine(current, candidate)) {
if ((direction == FocusDirectionUp && current.rect.y() > candidate.rect.y()) || (direction == FocusDirectionDown && candidate.rect.y() > current.rect.y())) {
candidate.distance = 0;
candidate.alignment = Full;
return;
}
}
LayoutRect nodeRect = candidate.rect;
LayoutRect currentRect = current.rect;
deflateIfOverlapped(currentRect, nodeRect);
if (!isRectInDirection(direction, currentRect, nodeRect))
return;
LayoutPoint exitPoint;
LayoutPoint entryPoint;
LayoutUnit sameAxisDistance;
LayoutUnit otherAxisDistance;
entryAndExitPointsForDirection(direction, currentRect, nodeRect, exitPoint, entryPoint);
switch (direction) {
case FocusDirectionLeft:
sameAxisDistance = exitPoint.x() - entryPoint.x();
otherAxisDistance = absoluteValue(exitPoint.y() - entryPoint.y());
break;
case FocusDirectionUp:
sameAxisDistance = exitPoint.y() - entryPoint.y();
otherAxisDistance = absoluteValue(exitPoint.x() - entryPoint.x());
break;
case FocusDirectionRight:
sameAxisDistance = entryPoint.x() - exitPoint.x();
otherAxisDistance = absoluteValue(entryPoint.y() - exitPoint.y());
break;
case FocusDirectionDown:
sameAxisDistance = entryPoint.y() - exitPoint.y();
otherAxisDistance = absoluteValue(entryPoint.x() - exitPoint.x());
break;
default:
ASSERT_NOT_REACHED();
return;
}
float x = (entryPoint.x() - exitPoint.x()) * (entryPoint.x() - exitPoint.x());
float y = (entryPoint.y() - exitPoint.y()) * (entryPoint.y() - exitPoint.y());
float euclidianDistance = sqrt(x + y);
// Loosely based on http://www.w3.org/TR/WICD/#focus-handling
// df = dotDist + dx + dy + 2 * (xdisplacement + ydisplacement) - sqrt(Overlap)
float distance = euclidianDistance + sameAxisDistance + 2 * otherAxisDistance;
candidate.distance = roundf(distance);
LayoutSize viewSize = candidate.visibleNode->document().page()->mainFrame().view()->visibleContentRect().size();
candidate.alignment = alignmentForRects(direction, currentRect, nodeRect, viewSize);
}
bool canBeScrolledIntoView(FocusDirection direction, const FocusCandidate& candidate)
{
ASSERT(candidate.visibleNode && candidate.isOffscreen);
LayoutRect candidateRect = candidate.rect;
for (Node* parentNode = candidate.visibleNode->parentNode(); parentNode; parentNode = parentNode->parentNode()) {
if (!parentNode->renderer())
continue;
LayoutRect parentRect = nodeRectInAbsoluteCoordinates(parentNode);
if (!candidateRect.intersects(parentRect)) {
if (((direction == FocusDirectionLeft || direction == FocusDirectionRight) && parentNode->renderer()->style().overflowX() == Overflow::Hidden)
|| ((direction == FocusDirectionUp || direction == FocusDirectionDown) && parentNode->renderer()->style().overflowY() == Overflow::Hidden))
return false;
}
if (parentNode == candidate.enclosingScrollableBox)
return canScrollInDirection(parentNode, direction);
}
return true;
}
// The starting rect is the rect of the focused node, in document coordinates.
// Compose a virtual starting rect if there is no focused node or if it is off screen.
// The virtual rect is the edge of the container or frame. We select which
// edge depending on the direction of the navigation.
LayoutRect virtualRectForDirection(FocusDirection direction, const LayoutRect& startingRect, LayoutUnit width)
{
LayoutRect virtualStartingRect = startingRect;
switch (direction) {
case FocusDirectionLeft:
virtualStartingRect.setX(virtualStartingRect.maxX() - width);
virtualStartingRect.setWidth(width);
break;
case FocusDirectionUp:
virtualStartingRect.setY(virtualStartingRect.maxY() - width);
virtualStartingRect.setHeight(width);
break;
case FocusDirectionRight:
virtualStartingRect.setWidth(width);
break;
case FocusDirectionDown:
virtualStartingRect.setHeight(width);
break;
default:
ASSERT_NOT_REACHED();
}
return virtualStartingRect;
}
LayoutRect virtualRectForAreaElementAndDirection(HTMLAreaElement* area, FocusDirection direction)
{
ASSERT(area);
ASSERT(area->imageElement());
// Area elements tend to overlap more than other focusable elements. We flatten the rect of the area elements
// to minimize the effect of overlapping areas.
LayoutRect rect = virtualRectForDirection(direction, rectToAbsoluteCoordinates(area->document().frame(), area->computeRect(area->imageElement()->renderer())), 1);
return rect;
}
HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate& candidate)
{
return candidate.isFrameOwnerElement() ? downcast<HTMLFrameOwnerElement>(candidate.visibleNode) : nullptr;
}
} // namespace WebCore