void Axis::OverscrollBy(ParentLayerCoord aOverscroll) {
MOZ_ASSERT(CanScroll());
// We can get some spurious calls to OverscrollBy() with near-zero values
// due to rounding error. Ignore those (they might trip the asserts below.)
if (FuzzyEqualsAdditive(aOverscroll.value, 0.0f, COORDINATE_EPSILON)) {
return;
}
EndOverscrollAnimation();
aOverscroll = ApplyResistance(aOverscroll);
if (aOverscroll > 0) {
#ifdef DEBUG
if (!FuzzyEqualsCoordinate(GetCompositionEnd().value, GetPageEnd().value)) {
nsPrintfCString message("composition end (%f) is not equal (within error) to page end (%f)\n",
GetCompositionEnd().value, GetPageEnd().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH("GFX: Overscroll issue > 0");
}
#endif
MOZ_ASSERT(mOverscroll >= 0);
} else if (aOverscroll < 0) {
#ifdef DEBUG
if (!FuzzyEqualsCoordinate(GetOrigin().value, GetPageStart().value)) {
nsPrintfCString message("composition origin (%f) is not equal (within error) to page origin (%f)\n",
GetOrigin().value, GetPageStart().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH("GFX: Overscroll issue < 0");
}
#endif
MOZ_ASSERT(mOverscroll <= 0);
}
mOverscroll += aOverscroll;
}
void Axis::OverscrollBy(ParentLayerCoord aOverscroll) {
MOZ_ASSERT(CanScroll());
StopSamplingOverscrollAnimation();
aOverscroll = ApplyResistance(aOverscroll);
if (aOverscroll > 0) {
#ifdef DEBUG
if (!FuzzyEqualsCoordinate(GetCompositionEnd().value, GetPageEnd().value)) {
nsPrintfCString message("composition end (%f) is not equal (within error) to page end (%f)\n",
GetCompositionEnd().value, GetPageEnd().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH();
}
#endif
MOZ_ASSERT(mOverscroll >= 0);
} else if (aOverscroll < 0) {
#ifdef DEBUG
if (!FuzzyEqualsCoordinate(GetOrigin().value, GetPageStart().value)) {
nsPrintfCString message("composition origin (%f) is not equal (within error) to page origin (%f)\n",
GetOrigin().value, GetPageStart().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH();
}
#endif
MOZ_ASSERT(mOverscroll <= 0);
}
mOverscroll += aOverscroll;
}
void Axis::OverscrollBy(CSSCoord aOverscroll) {
MOZ_ASSERT(CanScroll());
aOverscroll = ApplyResistance(aOverscroll);
if (aOverscroll > 0) {
#ifdef DEBUG
if (!FuzzyEqualsAdditive(GetCompositionEnd().value, GetPageEnd().value, COORDINATE_EPSILON)) {
nsPrintfCString message("composition end (%f) is not within COORDINATE_EPISLON of page end (%f)\n",
GetCompositionEnd().value, GetPageEnd().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH();
}
#endif
MOZ_ASSERT(mOverscroll >= 0);
} else if (aOverscroll < 0) {
#ifdef DEBUG
if (!FuzzyEqualsAdditive(GetOrigin().value, GetPageStart().value, COORDINATE_EPSILON)) {
nsPrintfCString message("composition origin (%f) is not within COORDINATE_EPISLON of page origin (%f)\n",
GetOrigin().value, GetPageStart().value);
NS_ASSERTION(false, message.get());
MOZ_CRASH();
}
#endif
MOZ_ASSERT(mOverscroll <= 0);
}
mOverscroll += aOverscroll;
}
float Axis::GetExcess() {
switch (GetOverscroll()) {
case OVERSCROLL_MINUS: return GetOrigin() - GetPageStart();
case OVERSCROLL_PLUS: return GetCompositionEnd() - GetPageEnd();
case OVERSCROLL_BOTH: return (GetCompositionEnd() - GetPageEnd()) +
(GetPageStart() - GetOrigin());
default: return 0;
}
}
CSSCoord Axis::ClampOriginToScrollableRect(CSSCoord aOrigin) const
{
CSSToParentLayerScale zoom = GetScaleForAxis(GetFrameMetrics().GetZoom());
ParentLayerCoord origin = aOrigin * zoom;
ParentLayerCoord result;
if (origin < GetPageStart()) {
result = GetPageStart();
} else if (origin + GetCompositionLength() > GetPageEnd()) {
result = GetPageEnd() - GetCompositionLength();
} else {
return aOrigin;
}
return result / zoom;
}
float Axis::DisplacementWillOverscrollAmount(int32_t aDisplacement) {
switch (DisplacementWillOverscroll(aDisplacement)) {
case OVERSCROLL_MINUS: return (GetOrigin() + aDisplacement) - GetPageStart();
case OVERSCROLL_PLUS: return (GetCompositionEnd() + aDisplacement) - GetPageEnd();
// Don't handle overscrolled in both directions; a displacement can't cause
// this, it must have already been zoomed out too far.
default: return 0;
}
}
float Axis::ScaleWillOverscrollAmount(float aScale, int32_t aFocus) {
float originAfterScale = (GetOrigin() + aFocus) * aScale - aFocus;
switch (ScaleWillOverscroll(aScale, aFocus)) {
case OVERSCROLL_MINUS: return originAfterScale - GetPageStart() * aScale;
case OVERSCROLL_PLUS: return (originAfterScale + GetCompositionLength()) -
NS_lround(GetPageEnd() * aScale);
// Don't handle OVERSCROLL_BOTH. Client code is expected to deal with it.
default: return 0;
}
}
float Axis::ScaleWillOverscrollAmount(float aScale, float aFocus) {
float originAfterScale = (GetOrigin() + aFocus) - (aFocus / aScale);
bool both = ScaleWillOverscrollBothSides(aScale);
bool minus = originAfterScale < GetPageStart();
bool plus = (originAfterScale + (GetCompositionLength() / aScale)) > GetPageEnd();
if ((minus && plus) || both) {
// If we ever reach here it's a bug in the client code.
MOZ_ASSERT(false, "In an OVERSCROLL_BOTH condition in ScaleWillOverscrollAmount");
return 0;
}
if (minus) {
return originAfterScale - GetPageStart();
}
if (plus) {
return originAfterScale + (GetCompositionLength() / aScale) - GetPageEnd();
}
return 0;
}
void Axis::OverscrollBy(CSSCoord aOverscroll) {
MOZ_ASSERT(CanScroll());
aOverscroll = ApplyResistance(aOverscroll);
if (aOverscroll > 0) {
MOZ_ASSERT(FuzzyEqualsAdditive(GetCompositionEnd().value, GetPageEnd().value, COORDINATE_EPSILON));
MOZ_ASSERT(mOverscroll >= 0);
} else if (aOverscroll < 0) {
MOZ_ASSERT(FuzzyEqualsAdditive(GetOrigin().value, GetPageStart().value, COORDINATE_EPSILON));
MOZ_ASSERT(mOverscroll <= 0);
}
mOverscroll += aOverscroll;
}
ParentLayerCoord Axis::DisplacementWillOverscrollAmount(ParentLayerCoord aDisplacement) const {
ParentLayerCoord newOrigin = GetOrigin() + aDisplacement;
ParentLayerCoord newCompositionEnd = GetCompositionEnd() + aDisplacement;
// If the current pan plus a displacement takes the window to the left of or
// above the current page rect.
bool minus = newOrigin < GetPageStart();
// If the current pan plus a displacement takes the window to the right of or
// below the current page rect.
bool plus = newCompositionEnd > GetPageEnd();
if (minus && plus) {
// Don't handle overscrolled in both directions; a displacement can't cause
// this, it must have already been zoomed out too far.
return 0;
}
if (minus) {
return newOrigin - GetPageStart();
}
if (plus) {
return newCompositionEnd - GetPageEnd();
}
return 0;
}
CSSCoord Axis::ScaleWillOverscrollAmount(float aScale, CSSCoord aFocus) const {
// Internally, do computations in ParentLayer coordinates *before* the scale
// is applied.
CSSToParentLayerScale zoom = GetFrameMetrics().GetZoom().ToScaleFactor();
ParentLayerCoord focus = aFocus * zoom;
ParentLayerCoord originAfterScale = (GetOrigin() + focus) - (focus / aScale);
bool both = ScaleWillOverscrollBothSides(aScale);
bool minus = GetPageStart() - originAfterScale > COORDINATE_EPSILON;
bool plus = (originAfterScale + (GetCompositionLength() / aScale)) - GetPageEnd() > COORDINATE_EPSILON;
if ((minus && plus) || both) {
// If we ever reach here it's a bug in the client code.
MOZ_ASSERT(false, "In an OVERSCROLL_BOTH condition in ScaleWillOverscrollAmount");
return 0;
}
if (minus) {
return (originAfterScale - GetPageStart()) / zoom;
}
if (plus) {
return (originAfterScale + (GetCompositionLength() / aScale) - GetPageEnd()) / zoom;
}
return 0;
}
Axis::Overscroll Axis::ScaleWillOverscroll(float aScale, int32_t aFocus) {
float originAfterScale = (GetOrigin() + aFocus) * aScale - aFocus;
bool both = ScaleWillOverscrollBothSides(aScale);
bool minus = originAfterScale < GetPageStart() * aScale;
bool plus = (originAfterScale + GetCompositionLength()) > GetPageEnd() * aScale;
if ((minus && plus) || both) {
return OVERSCROLL_BOTH;
}
if (minus) {
return OVERSCROLL_MINUS;
}
if (plus) {
return OVERSCROLL_PLUS;
}
return OVERSCROLL_NONE;
}
Axis::Overscroll Axis::DisplacementWillOverscroll(int32_t aDisplacement) {
// If the current pan plus a displacement takes the window to the left of or
// above the current page rect.
bool minus = GetOrigin() + aDisplacement < GetPageStart();
// If the current pan plus a displacement takes the window to the right of or
// below the current page rect.
bool plus = GetCompositionEnd() + aDisplacement > GetPageEnd();
if (minus && plus) {
return OVERSCROLL_BOTH;
}
if (minus) {
return OVERSCROLL_MINUS;
}
if (plus) {
return OVERSCROLL_PLUS;
}
return OVERSCROLL_NONE;
}
Axis::Overscroll Axis::GetOverscroll() {
// If the current pan takes the window to the left of or above the current
// page rect.
bool minus = GetOrigin() < GetPageStart();
// If the current pan takes the window to the right of or below the current
// page rect.
bool plus = GetCompositionEnd() > GetPageEnd();
if (minus && plus) {
return OVERSCROLL_BOTH;
}
if (minus) {
return OVERSCROLL_MINUS;
}
if (plus) {
return OVERSCROLL_PLUS;
}
return OVERSCROLL_NONE;
}
bool Axis::HasRoomToPan() const {
return GetOrigin() > GetPageStart()
|| GetCompositionEnd() < GetPageEnd();
}
ParentLayerCoord Axis::GetScrollRangeEnd() const {
return GetPageEnd() - GetCompositionLength();
}
