VisibleSelection CharacterGranularityStrategy::updateExtent(const IntPoint& extentPoint, LocalFrame* frame)
{
const VisiblePosition& extentPosition = visiblePositionForContentsPoint(extentPoint, frame);
const VisibleSelection& selection = frame->selection().selection();
if (selection.visibleBase().deepEquivalent() == extentPosition.deepEquivalent())
return selection;
return VisibleSelection(selection.visibleBase(), extentPosition);
}
VisibleSelection DirectionGranularityStrategy::updateExtent(
const IntPoint& extentPoint,
LocalFrame* frame) {
const VisibleSelection& selection = frame->selection().selection();
if (m_state == StrategyState::Cleared)
m_state = StrategyState::Expanding;
VisiblePosition oldOffsetExtentPosition = selection.visibleExtent();
IntPoint oldExtentLocation = positionLocation(oldOffsetExtentPosition);
IntPoint oldOffsetExtentPoint =
oldExtentLocation + m_diffExtentPointFromExtentPosition;
IntPoint oldExtentPoint =
IntPoint(oldOffsetExtentPoint.x() - m_offset, oldOffsetExtentPoint.y());
// Apply the offset.
IntPoint newOffsetExtentPoint = extentPoint;
int dx = extentPoint.x() - oldExtentPoint.x();
if (m_offset != 0) {
if (m_offset > 0 && dx > 0)
m_offset = std::max(0, m_offset - dx);
else if (m_offset < 0 && dx < 0)
m_offset = std::min(0, m_offset - dx);
newOffsetExtentPoint.move(m_offset, 0);
}
VisiblePosition newOffsetExtentPosition =
visiblePositionForContentsPoint(newOffsetExtentPoint, frame);
IntPoint newOffsetLocation = positionLocation(newOffsetExtentPosition);
// Reset the offset in case of a vertical change in the location (could be
// due to a line change or due to an unusual layout, e.g. rotated text).
bool verticalChange = newOffsetLocation.y() != oldExtentLocation.y();
if (verticalChange) {
m_offset = 0;
m_granularity = CharacterGranularity;
newOffsetExtentPoint = extentPoint;
newOffsetExtentPosition =
visiblePositionForContentsPoint(extentPoint, frame);
}
const VisiblePosition base = selection.visibleBase();
// Do not allow empty selection.
if (newOffsetExtentPosition.deepEquivalent() == base.deepEquivalent())
return selection;
// The direction granularity strategy, particularly the "offset" feature
// doesn't work with non-horizontal text (e.g. when the text is rotated).
// So revert to the behavior equivalent to the character granularity
// strategy if we detect that the text's baseline coordinate changed
// without a line change.
if (verticalChange &&
inSameLine(newOffsetExtentPosition, oldOffsetExtentPosition)) {
return createVisibleSelection(selection.visibleBase(),
newOffsetExtentPosition);
}
int oldExtentBaseOrder = selection.isBaseFirst() ? 1 : -1;
int newExtentBaseOrder;
bool thisMoveShrunkSelection;
if (newOffsetExtentPosition.deepEquivalent() ==
oldOffsetExtentPosition.deepEquivalent()) {
if (m_granularity == CharacterGranularity)
return selection;
// If we are in Word granularity, we cannot exit here, since we may pass
// the middle of the word without changing the position (in which case
// the selection needs to expand).
thisMoveShrunkSelection = false;
newExtentBaseOrder = oldExtentBaseOrder;
} else {
bool selectionExpanded = arePositionsInSpecifiedOrder(
newOffsetExtentPosition, oldOffsetExtentPosition, oldExtentBaseOrder);
bool extentBaseOrderSwitched =
selectionExpanded
? false
: !arePositionsInSpecifiedOrder(newOffsetExtentPosition, base,
oldExtentBaseOrder);
newExtentBaseOrder =
extentBaseOrderSwitched ? -oldExtentBaseOrder : oldExtentBaseOrder;
// Determine the word boundary, i.e. the boundary extending beyond which
// should change the granularity to WordGranularity.
VisiblePosition wordBoundary;
if (extentBaseOrderSwitched) {
// Special case.
// If the extent-base order was switched, then the selection is now
// expanding in a different direction than before. Therefore we
// calculate the word boundary in this new direction and based on
// the |base| position.
wordBoundary = nextWordBound(base, newExtentBaseOrder > 0
? SearchDirection::SearchForward
: SearchDirection::SearchBackwards,
BoundAdjust::NextBoundIfOnBound);
m_granularity = CharacterGranularity;
} else {
// Calculate the word boundary based on |oldExtentWithGranularity|.
// If selection was shrunk in the last update and the extent is now
// exactly on the word boundary - we need to take the next bound as
// the bound of the current word.
wordBoundary = nextWordBound(oldOffsetExtentPosition,
oldExtentBaseOrder > 0
? SearchDirection::SearchForward
: SearchDirection::SearchBackwards,
m_state == StrategyState::Shrinking
? BoundAdjust::NextBoundIfOnBound
: BoundAdjust::CurrentPosIfOnBound);
}
bool expandedBeyondWordBoundary;
if (selectionExpanded)
expandedBeyondWordBoundary = arePositionsInSpecifiedOrder(
newOffsetExtentPosition, wordBoundary, newExtentBaseOrder);
else if (extentBaseOrderSwitched)
expandedBeyondWordBoundary = arePositionsInSpecifiedOrder(
newOffsetExtentPosition, wordBoundary, newExtentBaseOrder);
else
expandedBeyondWordBoundary = false;
// The selection is shrunk if the extent changes position to be closer to
// the base, and the extent/base order wasn't switched.
thisMoveShrunkSelection = !extentBaseOrderSwitched && !selectionExpanded;
if (expandedBeyondWordBoundary)
m_granularity = WordGranularity;
else if (thisMoveShrunkSelection)
m_granularity = CharacterGranularity;
}
VisiblePosition newSelectionExtent = newOffsetExtentPosition;
if (m_granularity == WordGranularity) {
// Determine the bounds of the word where the extent is located.
// Set the selection extent to one of the two bounds depending on
// whether the extent is passed the middle of the word.
VisiblePosition boundBeforeExtent =
nextWordBound(newOffsetExtentPosition, SearchDirection::SearchBackwards,
BoundAdjust::CurrentPosIfOnBound);
VisiblePosition boundAfterExtent =
nextWordBound(newOffsetExtentPosition, SearchDirection::SearchForward,
BoundAdjust::CurrentPosIfOnBound);
int xMiddleBetweenBounds = (positionLocation(boundAfterExtent).x() +
positionLocation(boundBeforeExtent).x()) /
2;
bool offsetExtentBeforeMiddle =
newOffsetExtentPoint.x() < xMiddleBetweenBounds;
newSelectionExtent =
offsetExtentBeforeMiddle ? boundBeforeExtent : boundAfterExtent;
// Update the offset if selection expanded in word granularity.
if (newSelectionExtent.deepEquivalent() !=
selection.visibleExtent().deepEquivalent() &&
((newExtentBaseOrder > 0 && !offsetExtentBeforeMiddle) ||
(newExtentBaseOrder < 0 && offsetExtentBeforeMiddle))) {
m_offset = positionLocation(newSelectionExtent).x() - extentPoint.x();
}
}
// Only update the state if the selection actually changed as a result of
// this move.
if (newSelectionExtent.deepEquivalent() !=
selection.visibleExtent().deepEquivalent())
m_state = thisMoveShrunkSelection ? StrategyState::Shrinking
: StrategyState::Expanding;
m_diffExtentPointFromExtentPosition =
extentPoint + IntSize(m_offset, 0) - positionLocation(newSelectionExtent);
VisibleSelection newSelection = selection;
newSelection.setExtent(newSelectionExtent);
return newSelection;
}