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UXP/layout/xul/nsListBoxBodyFrame.cpp
T
Moonchild 21f707390d Issue #1705 - Part 3: Rename ScrollbarStyles to ScrollStyles. 
ScrollbarStyles contains values of overflow, (over)scroll-behavior, etc.
The only one which is marginally related to scroll _bars_ is overflow, which can
be used to hide scrollbar (by making an element not scrollable) or enforce the
scrollbar to display.

It makes more sense to be called ScrollStyles as it's mainly concerning behavior
of scrolling, not scrollbars. Also, with the addition of scrollbar width
properties, the current name can be confusing.
2021-01-14 22:19:53 +08:00

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsListBoxBodyFrame.h"
#include "nsListBoxLayout.h"
#include "mozilla/MathAlgorithms.h"
#include "nsCOMPtr.h"
#include "nsGridRowGroupLayout.h"
#include "nsIServiceManager.h"
#include "nsGkAtoms.h"
#include "nsIContent.h"
#include "nsNameSpaceManager.h"
#include "nsIDocument.h"
#include "nsIDOMMouseEvent.h"
#include "nsIDOMElement.h"
#include "nsIDOMNodeList.h"
#include "nsCSSFrameConstructor.h"
#include "nsIScrollableFrame.h"
#include "nsScrollbarFrame.h"
#include "nsView.h"
#include "nsViewManager.h"
#include "nsStyleContext.h"
#include "nsFontMetrics.h"
#include "nsITimer.h"
#include "mozilla/StyleSetHandle.h"
#include "mozilla/StyleSetHandleInlines.h"
#include "nsPIBoxObject.h"
#include "nsLayoutUtils.h"
#include "nsPIListBoxObject.h"
#include "nsContentUtils.h"
#include "ChildIterator.h"
#include "nsRenderingContext.h"
#include "prtime.h"
#include <algorithm>
#ifdef ACCESSIBILITY
#include "nsAccessibilityService.h"
#endif
using namespace mozilla;
using namespace mozilla::dom;
/////////////// nsListScrollSmoother //////////////////
/* A mediator used to smooth out scrolling. It works by seeing if
* we have time to scroll the amount of rows requested. This is determined
* by measuring how long it takes to scroll a row. If we can scroll the
* rows in time we do so. If not we start a timer and skip the request. We
* do this until the timer finally first because the user has stopped moving
* the mouse. Then do all the queued requests in on shot.
*/
// the longest amount of time that can go by before the use
// notices it as a delay.
#define USER_TIME_THRESHOLD 150000
// how long it takes to layout a single row initial value.
// we will time this after we scroll a few rows.
#define TIME_PER_ROW_INITAL 50000
// if we decide we can't layout the rows in the amount of time. How long
// do we wait before checking again?
#define SMOOTH_INTERVAL 100
class nsListScrollSmoother final : public nsITimerCallback
{
private:
virtual ~nsListScrollSmoother();
public:
NS_DECL_ISUPPORTS
explicit nsListScrollSmoother(nsListBoxBodyFrame* aOuter);
// nsITimerCallback
NS_DECL_NSITIMERCALLBACK
void Start();
void Stop();
bool IsRunning();
nsCOMPtr<nsITimer> mRepeatTimer;
int32_t mDelta;
nsListBoxBodyFrame* mOuter;
};
nsListScrollSmoother::nsListScrollSmoother(nsListBoxBodyFrame* aOuter)
{
mDelta = 0;
mOuter = aOuter;
}
nsListScrollSmoother::~nsListScrollSmoother()
{
Stop();
}
NS_IMETHODIMP
nsListScrollSmoother::Notify(nsITimer *timer)
{
Stop();
NS_ASSERTION(mOuter, "mOuter is null, see bug #68365");
if (!mOuter) return NS_OK;
// actually do some work.
mOuter->InternalPositionChangedCallback();
return NS_OK;
}
bool
nsListScrollSmoother::IsRunning()
{
return mRepeatTimer ? true : false;
}
void
nsListScrollSmoother::Start()
{
Stop();
mRepeatTimer = do_CreateInstance("@mozilla.org/timer;1");
mRepeatTimer->InitWithCallback(this, SMOOTH_INTERVAL, nsITimer::TYPE_ONE_SHOT);
}
void
nsListScrollSmoother::Stop()
{
if ( mRepeatTimer ) {
mRepeatTimer->Cancel();
mRepeatTimer = nullptr;
}
}
NS_IMPL_ISUPPORTS(nsListScrollSmoother, nsITimerCallback)
/////////////// nsListBoxBodyFrame //////////////////
nsListBoxBodyFrame::nsListBoxBodyFrame(nsStyleContext* aContext,
nsBoxLayout* aLayoutManager)
: nsBoxFrame(aContext, false, aLayoutManager),
mTopFrame(nullptr),
mBottomFrame(nullptr),
mLinkupFrame(nullptr),
mScrollSmoother(nullptr),
mRowsToPrepend(0),
mRowCount(-1),
mRowHeight(0),
mAvailableHeight(0),
mStringWidth(-1),
mCurrentIndex(0),
mOldIndex(0),
mYPosition(0),
mTimePerRow(TIME_PER_ROW_INITAL),
mRowHeightWasSet(false),
mScrolling(false),
mAdjustScroll(false),
mReflowCallbackPosted(false)
{
}
nsListBoxBodyFrame::~nsListBoxBodyFrame()
{
NS_IF_RELEASE(mScrollSmoother);
#if USE_TIMER_TO_DELAY_SCROLLING
StopScrollTracking();
mAutoScrollTimer = nullptr;
#endif
}
NS_QUERYFRAME_HEAD(nsListBoxBodyFrame)
NS_QUERYFRAME_ENTRY(nsIScrollbarMediator)
NS_QUERYFRAME_ENTRY(nsListBoxBodyFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsBoxFrame)
////////// nsIFrame /////////////////
void
nsListBoxBodyFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow)
{
nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
// Don't call nsLayoutUtils::GetScrollableFrameFor since we are not its
// scrollframe child yet.
nsIScrollableFrame* scrollFrame = do_QueryFrame(aParent);
if (scrollFrame) {
nsIFrame* verticalScrollbar = scrollFrame->GetScrollbarBox(true);
nsScrollbarFrame* scrollbarFrame = do_QueryFrame(verticalScrollbar);
if (scrollbarFrame) {
scrollbarFrame->SetScrollbarMediatorContent(GetContent());
}
}
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForFrame(this, 1.0f);
mRowHeight = fm->MaxHeight();
}
void
nsListBoxBodyFrame::DestroyFrom(nsIFrame* aDestructRoot)
{
// make sure we cancel any posted callbacks.
if (mReflowCallbackPosted)
PresContext()->PresShell()->CancelReflowCallback(this);
// Revoke any pending position changed events
for (uint32_t i = 0; i < mPendingPositionChangeEvents.Length(); ++i) {
mPendingPositionChangeEvents[i]->Revoke();
}
// Make sure we tell our listbox's box object we're being destroyed.
if (mBoxObject) {
mBoxObject->ClearCachedValues();
}
nsBoxFrame::DestroyFrom(aDestructRoot);
}
nsresult
nsListBoxBodyFrame::AttributeChanged(int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType)
{
nsresult rv = NS_OK;
if (aAttribute == nsGkAtoms::rows) {
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eStyleChange, NS_FRAME_IS_DIRTY);
}
else
rv = nsBoxFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
return rv;
}
/* virtual */ void
nsListBoxBodyFrame::MarkIntrinsicISizesDirty()
{
mStringWidth = -1;
nsBoxFrame::MarkIntrinsicISizesDirty();
}
/////////// nsBox ///////////////
NS_IMETHODIMP
nsListBoxBodyFrame::DoXULLayout(nsBoxLayoutState& aBoxLayoutState)
{
if (mScrolling)
aBoxLayoutState.SetPaintingDisabled(true);
nsresult rv = nsBoxFrame::DoXULLayout(aBoxLayoutState);
// determine the real height for the scrollable area from the total number
// of rows, since non-visible rows don't yet have frames
nsRect rect(nsPoint(0, 0), GetSize());
nsOverflowAreas overflow(rect, rect);
if (mLayoutManager) {
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
ConsiderChildOverflow(overflow, childFrame);
childFrame = childFrame->GetNextSibling();
}
nsSize prefSize = mLayoutManager->GetXULPrefSize(this, aBoxLayoutState);
NS_FOR_FRAME_OVERFLOW_TYPES(otype) {
nsRect& o = overflow.Overflow(otype);
o.height = std::max(o.height, prefSize.height);
}
}
FinishAndStoreOverflow(overflow, GetSize());
if (mScrolling)
aBoxLayoutState.SetPaintingDisabled(false);
// if we are scrolled and the row height changed
// make sure we are scrolled to a correct index.
if (mAdjustScroll)
PostReflowCallback();
return rv;
}
nsSize
nsListBoxBodyFrame::GetXULMinSizeForScrollArea(nsBoxLayoutState& aBoxLayoutState)
{
nsSize result(0, 0);
if (nsContentUtils::HasNonEmptyAttr(GetContent(), kNameSpaceID_None,
nsGkAtoms::sizemode)) {
result = GetXULPrefSize(aBoxLayoutState);
result.height = 0;
nsIScrollableFrame* scrollFrame = nsLayoutUtils::GetScrollableFrameFor(this);
if (scrollFrame &&
scrollFrame->GetScrollStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
nsMargin scrollbars =
scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
result.width += scrollbars.left + scrollbars.right;
}
}
return result;
}
nsSize
nsListBoxBodyFrame::GetXULPrefSize(nsBoxLayoutState& aBoxLayoutState)
{
nsSize pref = nsBoxFrame::GetXULPrefSize(aBoxLayoutState);
int32_t size = GetFixedRowSize();
if (size > -1)
pref.height = size*GetRowHeightAppUnits();
nsIScrollableFrame* scrollFrame = nsLayoutUtils::GetScrollableFrameFor(this);
if (scrollFrame &&
scrollFrame->GetScrollStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
nsMargin scrollbars = scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
pref.width += scrollbars.left + scrollbars.right;
}
return pref;
}
///////////// nsIScrollbarMediator ///////////////
void
nsListBoxBodyFrame::ScrollByPage(nsScrollbarFrame* aScrollbar, int32_t aDirection,
nsIScrollbarMediator::ScrollSnapMode aSnap)
{
// CSS Scroll Snapping is not enabled for XUL, aSnap is ignored
MOZ_ASSERT(aScrollbar != nullptr);
aScrollbar->SetIncrementToPage(aDirection);
nsWeakFrame weakFrame(this);
int32_t newPos = aScrollbar->MoveToNewPosition();
if (!weakFrame.IsAlive()) {
return;
}
UpdateIndex(newPos);
}
void
nsListBoxBodyFrame::ScrollByWhole(nsScrollbarFrame* aScrollbar, int32_t aDirection,
nsIScrollbarMediator::ScrollSnapMode aSnap)
{
// CSS Scroll Snapping is not enabled for XUL, aSnap is ignored
MOZ_ASSERT(aScrollbar != nullptr);
aScrollbar->SetIncrementToWhole(aDirection);
nsWeakFrame weakFrame(this);
int32_t newPos = aScrollbar->MoveToNewPosition();
if (!weakFrame.IsAlive()) {
return;
}
UpdateIndex(newPos);
}
void
nsListBoxBodyFrame::ScrollByLine(nsScrollbarFrame* aScrollbar, int32_t aDirection,
nsIScrollbarMediator::ScrollSnapMode aSnap)
{
// CSS Scroll Snapping is not enabled for XUL, aSnap is ignored
MOZ_ASSERT(aScrollbar != nullptr);
aScrollbar->SetIncrementToLine(aDirection);
nsWeakFrame weakFrame(this);
int32_t newPos = aScrollbar->MoveToNewPosition();
if (!weakFrame.IsAlive()) {
return;
}
UpdateIndex(newPos);
}
void
nsListBoxBodyFrame::RepeatButtonScroll(nsScrollbarFrame* aScrollbar)
{
nsWeakFrame weakFrame(this);
int32_t newPos = aScrollbar->MoveToNewPosition();
if (!weakFrame.IsAlive()) {
return;
}
UpdateIndex(newPos);
}
int32_t
nsListBoxBodyFrame::ToRowIndex(nscoord aPos) const
{
return NS_roundf(float(std::max(aPos, 0)) / mRowHeight);
}
void
nsListBoxBodyFrame::ThumbMoved(nsScrollbarFrame* aScrollbar,
nscoord aOldPos,
nscoord aNewPos)
{
if (mScrolling || mRowHeight == 0)
return;
int32_t newIndex = ToRowIndex(aNewPos);
if (newIndex == mCurrentIndex) {
return;
}
int32_t rowDelta = newIndex - mCurrentIndex;
nsListScrollSmoother* smoother = GetSmoother();
// if we can't scroll the rows in time then start a timer. We will eat
// events until the user stops moving and the timer stops.
if (smoother->IsRunning() || Abs(rowDelta)*mTimePerRow > USER_TIME_THRESHOLD) {
smoother->Stop();
smoother->mDelta = rowDelta;
smoother->Start();
return;
}
smoother->Stop();
mCurrentIndex = newIndex;
smoother->mDelta = 0;
if (mCurrentIndex < 0) {
mCurrentIndex = 0;
return;
}
InternalPositionChanged(rowDelta < 0, Abs(rowDelta));
}
void
nsListBoxBodyFrame::VisibilityChanged(bool aVisible)
{
if (mRowHeight == 0)
return;
int32_t lastPageTopRow = GetRowCount() - (GetAvailableHeight() / mRowHeight);
if (lastPageTopRow < 0)
lastPageTopRow = 0;
int32_t delta = mCurrentIndex - lastPageTopRow;
if (delta > 0) {
mCurrentIndex = lastPageTopRow;
InternalPositionChanged(true, delta);
}
}
nsIFrame*
nsListBoxBodyFrame::GetScrollbarBox(bool aVertical)
{
nsIScrollableFrame* scrollFrame = nsLayoutUtils::GetScrollableFrameFor(this);
return scrollFrame ? scrollFrame->GetScrollbarBox(true) : nullptr;
}
void
nsListBoxBodyFrame::UpdateIndex(int32_t aNewPos)
{
int32_t newIndex = ToRowIndex(nsPresContext::CSSPixelsToAppUnits(aNewPos));
if (newIndex == mCurrentIndex) {
return;
}
bool up = newIndex < mCurrentIndex;
int32_t indexDelta = Abs(newIndex - mCurrentIndex);
mCurrentIndex = newIndex;
InternalPositionChanged(up, indexDelta);
}
///////////// nsIReflowCallback ///////////////
bool
nsListBoxBodyFrame::ReflowFinished()
{
nsAutoScriptBlocker scriptBlocker;
// now create or destroy any rows as needed
CreateRows();
// keep scrollbar in sync
if (mAdjustScroll) {
VerticalScroll(mYPosition);
mAdjustScroll = false;
}
// if the row height changed then mark everything as a style change.
// That will dirty the entire listbox
if (mRowHeightWasSet) {
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eStyleChange, NS_FRAME_IS_DIRTY);
int32_t pos = mCurrentIndex * mRowHeight;
if (mYPosition != pos)
mAdjustScroll = true;
mRowHeightWasSet = false;
}
mReflowCallbackPosted = false;
return true;
}
void
nsListBoxBodyFrame::ReflowCallbackCanceled()
{
mReflowCallbackPosted = false;
}
///////// ListBoxObject ///////////////
int32_t
nsListBoxBodyFrame::GetNumberOfVisibleRows()
{
return mRowHeight ? GetAvailableHeight() / mRowHeight : 0;
}
int32_t
nsListBoxBodyFrame::GetIndexOfFirstVisibleRow()
{
return mCurrentIndex;
}
nsresult
nsListBoxBodyFrame::EnsureIndexIsVisible(int32_t aRowIndex)
{
if (aRowIndex < 0)
return NS_ERROR_ILLEGAL_VALUE;
int32_t rows = 0;
if (mRowHeight)
rows = GetAvailableHeight()/mRowHeight;
if (rows <= 0)
rows = 1;
int32_t bottomIndex = mCurrentIndex + rows;
// if row is visible, ignore
if (mCurrentIndex <= aRowIndex && aRowIndex < bottomIndex)
return NS_OK;
int32_t delta;
bool up = aRowIndex < mCurrentIndex;
if (up) {
delta = mCurrentIndex - aRowIndex;
mCurrentIndex = aRowIndex;
}
else {
// Check to be sure we're not scrolling off the bottom of the tree
if (aRowIndex >= GetRowCount())
return NS_ERROR_ILLEGAL_VALUE;
// Bring it just into view.
delta = 1 + (aRowIndex-bottomIndex);
mCurrentIndex += delta;
}
// Safe to not go off an event here, since this is coming from the
// box object.
DoInternalPositionChangedSync(up, delta);
return NS_OK;
}
nsresult
nsListBoxBodyFrame::ScrollByLines(int32_t aNumLines)
{
int32_t scrollIndex = GetIndexOfFirstVisibleRow(),
visibleRows = GetNumberOfVisibleRows();
scrollIndex += aNumLines;
if (scrollIndex < 0)
scrollIndex = 0;
else {
int32_t numRows = GetRowCount();
int32_t lastPageTopRow = numRows - visibleRows;
if (scrollIndex > lastPageTopRow)
scrollIndex = lastPageTopRow;
}
ScrollToIndex(scrollIndex);
return NS_OK;
}
// walks the DOM to get the zero-based row index of the content
nsresult
nsListBoxBodyFrame::GetIndexOfItem(nsIDOMElement* aItem, int32_t* _retval)
{
if (aItem) {
*_retval = 0;
nsCOMPtr<nsIContent> itemContent(do_QueryInterface(aItem));
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
// we hit a list row, count it
if (child->IsXULElement(nsGkAtoms::listitem)) {
// is this it?
if (child == itemContent)
return NS_OK;
++(*_retval);
}
}
}
// not found
*_retval = -1;
return NS_OK;
}
nsresult
nsListBoxBodyFrame::GetItemAtIndex(int32_t aIndex, nsIDOMElement** aItem)
{
*aItem = nullptr;
if (aIndex < 0)
return NS_OK;
int32_t itemCount = 0;
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
// we hit a list row, check if it is the one we are looking for
if (child->IsXULElement(nsGkAtoms::listitem)) {
// is this it?
if (itemCount == aIndex) {
return CallQueryInterface(child, aItem);
}
++itemCount;
}
}
// not found
return NS_OK;
}
/////////// nsListBoxBodyFrame ///////////////
int32_t
nsListBoxBodyFrame::GetRowCount()
{
if (mRowCount < 0)
ComputeTotalRowCount();
return mRowCount;
}
int32_t
nsListBoxBodyFrame::GetFixedRowSize()
{
nsresult dummy;
nsAutoString rows;
mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::rows, rows);
if (!rows.IsEmpty())
return rows.ToInteger(&dummy);
mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::size, rows);
if (!rows.IsEmpty())
return rows.ToInteger(&dummy);
return -1;
}
void
nsListBoxBodyFrame::SetRowHeight(nscoord aRowHeight)
{
if (aRowHeight > mRowHeight) {
mRowHeight = aRowHeight;
// signal we need to dirty everything
// and we want to be notified after reflow
// so we can create or destory rows as needed
mRowHeightWasSet = true;
PostReflowCallback();
}
}
nscoord
nsListBoxBodyFrame::GetAvailableHeight()
{
nsIScrollableFrame* scrollFrame =
nsLayoutUtils::GetScrollableFrameFor(this);
if (scrollFrame) {
return scrollFrame->GetScrollPortRect().height;
}
return 0;
}
nscoord
nsListBoxBodyFrame::GetYPosition()
{
return mYPosition;
}
nscoord
nsListBoxBodyFrame::ComputeIntrinsicISize(nsBoxLayoutState& aBoxLayoutState)
{
if (mStringWidth != -1)
return mStringWidth;
nscoord largestWidth = 0;
int32_t index = 0;
nsCOMPtr<nsIDOMElement> firstRowEl;
GetItemAtIndex(index, getter_AddRefs(firstRowEl));
nsCOMPtr<nsIContent> firstRowContent(do_QueryInterface(firstRowEl));
if (firstRowContent) {
RefPtr<nsStyleContext> styleContext;
nsPresContext *presContext = aBoxLayoutState.PresContext();
styleContext = presContext->StyleSet()->
ResolveStyleFor(firstRowContent->AsElement(), nullptr);
nscoord width = 0;
nsMargin margin(0,0,0,0);
if (styleContext->StylePadding()->GetPadding(margin))
width += margin.LeftRight();
width += styleContext->StyleBorder()->GetComputedBorder().LeftRight();
if (styleContext->StyleMargin()->GetMargin(margin))
width += margin.LeftRight();
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
if (child->IsXULElement(nsGkAtoms::listitem)) {
nsRenderingContext* rendContext = aBoxLayoutState.GetRenderingContext();
if (rendContext) {
nsAutoString value;
uint32_t textCount = child->GetChildCount();
for (uint32_t j = 0; j < textCount; ++j) {
nsIContent* text = child->GetChildAt(j);
if (text && text->IsNodeOfType(nsINode::eTEXT)) {
text->AppendTextTo(value);
}
}
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForStyleContext(styleContext);
nscoord textWidth =
nsLayoutUtils::AppUnitWidthOfStringBidi(value, this, *fm,
*rendContext);
textWidth += width;
if (textWidth > largestWidth)
largestWidth = textWidth;
}
}
}
}
mStringWidth = largestWidth;
return mStringWidth;
}
void
nsListBoxBodyFrame::ComputeTotalRowCount()
{
mRowCount = 0;
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
if (child->IsXULElement(nsGkAtoms::listitem)) {
++mRowCount;
}
}
}
void
nsListBoxBodyFrame::PostReflowCallback()
{
if (!mReflowCallbackPosted) {
mReflowCallbackPosted = true;
PresContext()->PresShell()->PostReflowCallback(this);
}
}
////////// scrolling
nsresult
nsListBoxBodyFrame::ScrollToIndex(int32_t aRowIndex)
{
if (( aRowIndex < 0 ) || (mRowHeight == 0))
return NS_OK;
int32_t newIndex = aRowIndex;
int32_t delta = mCurrentIndex > newIndex ? mCurrentIndex - newIndex : newIndex - mCurrentIndex;
bool up = newIndex < mCurrentIndex;
// Check to be sure we're not scrolling off the bottom of the tree
int32_t lastPageTopRow = GetRowCount() - (GetAvailableHeight() / mRowHeight);
if (lastPageTopRow < 0)
lastPageTopRow = 0;
if (aRowIndex > lastPageTopRow)
return NS_OK;
mCurrentIndex = newIndex;
nsWeakFrame weak(this);
// Since we're going to flush anyway, we need to not do this off an event
DoInternalPositionChangedSync(up, delta);
if (!weak.IsAlive()) {
return NS_OK;
}
// This change has to happen immediately.
// Flush any pending reflow commands.
// XXXbz why, exactly?
mContent->GetComposedDoc()->FlushPendingNotifications(Flush_Layout);
return NS_OK;
}
nsresult
nsListBoxBodyFrame::InternalPositionChangedCallback()
{
nsListScrollSmoother* smoother = GetSmoother();
if (smoother->mDelta == 0)
return NS_OK;
mCurrentIndex += smoother->mDelta;
if (mCurrentIndex < 0)
mCurrentIndex = 0;
return DoInternalPositionChangedSync(smoother->mDelta < 0,
smoother->mDelta < 0 ?
-smoother->mDelta : smoother->mDelta);
}
nsresult
nsListBoxBodyFrame::InternalPositionChanged(bool aUp, int32_t aDelta)
{
RefPtr<nsPositionChangedEvent> ev =
new nsPositionChangedEvent(this, aUp, aDelta);
nsresult rv = NS_DispatchToCurrentThread(ev);
if (NS_SUCCEEDED(rv)) {
if (!mPendingPositionChangeEvents.AppendElement(ev)) {
rv = NS_ERROR_OUT_OF_MEMORY;
ev->Revoke();
}
}
return rv;
}
nsresult
nsListBoxBodyFrame::DoInternalPositionChangedSync(bool aUp, int32_t aDelta)
{
nsWeakFrame weak(this);
// Process all the pending position changes first
nsTArray< RefPtr<nsPositionChangedEvent> > temp;
temp.SwapElements(mPendingPositionChangeEvents);
for (uint32_t i = 0; i < temp.Length(); ++i) {
if (weak.IsAlive()) {
temp[i]->Run();
}
temp[i]->Revoke();
}
if (!weak.IsAlive()) {
return NS_OK;
}
return DoInternalPositionChanged(aUp, aDelta);
}
nsresult
nsListBoxBodyFrame::DoInternalPositionChanged(bool aUp, int32_t aDelta)
{
if (aDelta == 0)
return NS_OK;
RefPtr<nsPresContext> presContext(PresContext());
nsBoxLayoutState state(presContext);
// begin timing how long it takes to scroll a row
PRTime start = PR_Now();
nsWeakFrame weakThis(this);
mContent->GetComposedDoc()->FlushPendingNotifications(Flush_Layout);
if (!weakThis.IsAlive()) {
return NS_OK;
}
{
nsAutoScriptBlocker scriptBlocker;
int32_t visibleRows = 0;
if (mRowHeight)
visibleRows = GetAvailableHeight()/mRowHeight;
if (aDelta < visibleRows) {
int32_t loseRows = aDelta;
if (aUp) {
// scrolling up, destroy rows from the bottom downwards
ReverseDestroyRows(loseRows);
mRowsToPrepend += aDelta;
mLinkupFrame = nullptr;
}
else {
// scrolling down, destroy rows from the top upwards
DestroyRows(loseRows);
mRowsToPrepend = 0;
}
}
else {
// We have scrolled so much that all of our current frames will
// go off screen, so blow them all away. Weeee!
nsIFrame *currBox = mFrames.FirstChild();
nsCSSFrameConstructor* fc = presContext->PresShell()->FrameConstructor();
fc->BeginUpdate();
while (currBox) {
nsIFrame *nextBox = currBox->GetNextSibling();
RemoveChildFrame(state, currBox);
currBox = nextBox;
}
fc->EndUpdate();
}
// clear frame markers so that CreateRows will re-create
mTopFrame = mBottomFrame = nullptr;
mYPosition = mCurrentIndex*mRowHeight;
mScrolling = true;
presContext->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eResize, NS_FRAME_HAS_DIRTY_CHILDREN);
}
if (!weakThis.IsAlive()) {
return NS_OK;
}
// Flush calls CreateRows
// XXXbz there has to be a better way to do this than flushing!
presContext->PresShell()->FlushPendingNotifications(Flush_Layout);
if (!weakThis.IsAlive()) {
return NS_OK;
}
mScrolling = false;
VerticalScroll(mYPosition);
PRTime end = PR_Now();
int32_t newTime = int32_t(end - start) / aDelta;
// average old and new
mTimePerRow = (newTime + mTimePerRow)/2;
return NS_OK;
}
nsListScrollSmoother*
nsListBoxBodyFrame::GetSmoother()
{
if (!mScrollSmoother) {
mScrollSmoother = new nsListScrollSmoother(this);
NS_ASSERTION(mScrollSmoother, "out of memory");
NS_IF_ADDREF(mScrollSmoother);
}
return mScrollSmoother;
}
void
nsListBoxBodyFrame::VerticalScroll(int32_t aPosition)
{
nsIScrollableFrame* scrollFrame
= nsLayoutUtils::GetScrollableFrameFor(this);
if (!scrollFrame) {
return;
}
nsPoint scrollPosition = scrollFrame->GetScrollPosition();
nsWeakFrame weakFrame(this);
scrollFrame->ScrollTo(nsPoint(scrollPosition.x, aPosition),
nsIScrollableFrame::INSTANT);
if (!weakFrame.IsAlive()) {
return;
}
mYPosition = aPosition;
}
////////// frame and box retrieval
nsIFrame*
nsListBoxBodyFrame::GetFirstFrame()
{
mTopFrame = mFrames.FirstChild();
return mTopFrame;
}
nsIFrame*
nsListBoxBodyFrame::GetLastFrame()
{
return mFrames.LastChild();
}
bool
nsListBoxBodyFrame::SupportsOrdinalsInChildren()
{
return false;
}
////////// lazy row creation and destruction
void
nsListBoxBodyFrame::CreateRows()
{
// Get our client rect.
nsRect clientRect;
GetXULClientRect(clientRect);
// Get the starting y position and the remaining available
// height.
nscoord availableHeight = GetAvailableHeight();
if (availableHeight <= 0) {
bool fixed = (GetFixedRowSize() != -1);
if (fixed)
availableHeight = 10;
else
return;
}
// get the first tree box. If there isn't one create one.
bool created = false;
nsIFrame* box = GetFirstItemBox(0, &created);
nscoord rowHeight = GetRowHeightAppUnits();
while (box) {
if (created && mRowsToPrepend > 0)
--mRowsToPrepend;
// if the row height is 0 then fail. Wait until someone
// laid out and sets the row height.
if (rowHeight == 0)
return;
availableHeight -= rowHeight;
// should we continue? Is the enought height?
if (!ContinueReflow(availableHeight))
break;
// get the next tree box. Create one if needed.
box = GetNextItemBox(box, 0, &created);
}
mRowsToPrepend = 0;
mLinkupFrame = nullptr;
}
void
nsListBoxBodyFrame::DestroyRows(int32_t& aRowsToLose)
{
// We need to destroy frames until our row count has been properly
// reduced. A reflow will then pick up and create the new frames.
nsIFrame* childFrame = GetFirstFrame();
nsBoxLayoutState state(PresContext());
nsCSSFrameConstructor* fc = PresContext()->PresShell()->FrameConstructor();
fc->BeginUpdate();
while (childFrame && aRowsToLose > 0) {
--aRowsToLose;
nsIFrame* nextFrame = childFrame->GetNextSibling();
RemoveChildFrame(state, childFrame);
mTopFrame = childFrame = nextFrame;
}
fc->EndUpdate();
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
void
nsListBoxBodyFrame::ReverseDestroyRows(int32_t& aRowsToLose)
{
// We need to destroy frames until our row count has been properly
// reduced. A reflow will then pick up and create the new frames.
nsIFrame* childFrame = GetLastFrame();
nsBoxLayoutState state(PresContext());
nsCSSFrameConstructor* fc = PresContext()->PresShell()->FrameConstructor();
fc->BeginUpdate();
while (childFrame && aRowsToLose > 0) {
--aRowsToLose;
nsIFrame* prevFrame;
prevFrame = childFrame->GetPrevSibling();
RemoveChildFrame(state, childFrame);
mBottomFrame = childFrame = prevFrame;
}
fc->EndUpdate();
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
static bool
IsListItemChild(nsListBoxBodyFrame* aParent, nsIContent* aChild,
nsIFrame** aChildFrame)
{
*aChildFrame = nullptr;
if (!aChild->IsXULElement(nsGkAtoms::listitem)) {
return false;
}
nsIFrame* existingFrame = aChild->GetPrimaryFrame();
if (existingFrame && existingFrame->GetParent() != aParent) {
return false;
}
*aChildFrame = existingFrame;
return true;
}
//
// Get the nsIFrame for the first visible listitem, and if none exists,
// create one.
//
nsIFrame*
nsListBoxBodyFrame::GetFirstItemBox(int32_t aOffset, bool* aCreated)
{
if (aCreated)
*aCreated = false;
// Clear ourselves out.
mBottomFrame = mTopFrame;
if (mTopFrame) {
return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
}
// top frame was cleared out
mTopFrame = GetFirstFrame();
mBottomFrame = mTopFrame;
if (mTopFrame && mRowsToPrepend <= 0) {
return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
}
// At this point, we either have no frames at all,
// or the user has scrolled upwards, leaving frames
// to be created at the top. Let's determine which
// content needs a new frame first.
nsCOMPtr<nsIContent> startContent;
if (mTopFrame && mRowsToPrepend > 0) {
// We need to insert rows before the top frame
nsIContent* topContent = mTopFrame->GetContent();
nsIContent* topParent = topContent->GetParent();
int32_t contentIndex = topParent->IndexOf(topContent);
contentIndex -= aOffset;
if (contentIndex < 0)
return nullptr;
startContent = topParent->GetChildAt(contentIndex - mRowsToPrepend);
} else {
// This will be the first item frame we create. Use the content
// at the current index, which is the first index scrolled into view
GetListItemContentAt(mCurrentIndex+aOffset, getter_AddRefs(startContent));
}
if (startContent) {
nsIFrame* existingFrame;
if (!IsListItemChild(this, startContent, &existingFrame)) {
return GetFirstItemBox(++aOffset, aCreated);
}
if (existingFrame) {
return existingFrame->IsXULBoxFrame() ? existingFrame : nullptr;
}
// Either append the new frame, or prepend it (at index 0)
// XXX check here if frame was even created, it may not have been if
// display: none was on listitem content
bool isAppend = mRowsToPrepend <= 0;
nsPresContext* presContext = PresContext();
nsCSSFrameConstructor* fc = presContext->PresShell()->FrameConstructor();
nsIFrame* topFrame = nullptr;
fc->CreateListBoxContent(this, nullptr, startContent, &topFrame, isAppend);
mTopFrame = topFrame;
if (mTopFrame) {
if (aCreated)
*aCreated = true;
mBottomFrame = mTopFrame;
return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
} else
return GetFirstItemBox(++aOffset, 0);
}
return nullptr;
}
//
// Get the nsIFrame for the next visible listitem after aBox, and if none
// exists, create one.
//
nsIFrame*
nsListBoxBodyFrame::GetNextItemBox(nsIFrame* aBox, int32_t aOffset,
bool* aCreated)
{
if (aCreated)
*aCreated = false;
nsIFrame* result = aBox->GetNextSibling();
if (!result || result == mLinkupFrame || mRowsToPrepend > 0) {
// No result found. See if there's a content node that wants a frame.
nsIContent* prevContent = aBox->GetContent();
nsIContent* parentContent = prevContent->GetParent();
int32_t i = parentContent->IndexOf(prevContent);
uint32_t childCount = parentContent->GetChildCount();
if (((uint32_t)i + aOffset + 1) < childCount) {
// There is a content node that wants a frame.
nsIContent *nextContent = parentContent->GetChildAt(i + aOffset + 1);
nsIFrame* existingFrame;
if (!IsListItemChild(this, nextContent, &existingFrame)) {
return GetNextItemBox(aBox, ++aOffset, aCreated);
}
if (!existingFrame) {
// Either append the new frame, or insert it after the current frame
bool isAppend = result != mLinkupFrame && mRowsToPrepend <= 0;
nsIFrame* prevFrame = isAppend ? nullptr : aBox;
nsPresContext* presContext = PresContext();
nsCSSFrameConstructor* fc = presContext->PresShell()->FrameConstructor();
fc->CreateListBoxContent(this, prevFrame, nextContent,
&result, isAppend);
if (result) {
if (aCreated)
*aCreated = true;
} else
return GetNextItemBox(aBox, ++aOffset, aCreated);
} else {
result = existingFrame;
}
mLinkupFrame = nullptr;
}
}
if (!result)
return nullptr;
mBottomFrame = result;
NS_ASSERTION(!result->IsXULBoxFrame() || result->GetParent() == this,
"returning frame that is not in childlist");
return result->IsXULBoxFrame() ? result : nullptr;
}
bool
nsListBoxBodyFrame::ContinueReflow(nscoord height)
{
#ifdef ACCESSIBILITY
if (nsIPresShell::IsAccessibilityActive()) {
// Create all the frames at once so screen readers and
// onscreen keyboards can see the full list right away
return true;
}
#endif
if (height <= 0) {
nsIFrame* lastChild = GetLastFrame();
nsIFrame* startingPoint = mBottomFrame;
if (startingPoint == nullptr) {
// We just want to delete everything but the first item.
startingPoint = GetFirstFrame();
}
if (lastChild != startingPoint) {
// We have some hangers on (probably caused by shrinking the size of the window).
// Nuke them.
nsIFrame* currFrame = startingPoint->GetNextSibling();
nsBoxLayoutState state(PresContext());
nsCSSFrameConstructor* fc =
PresContext()->PresShell()->FrameConstructor();
fc->BeginUpdate();
while (currFrame) {
nsIFrame* nextFrame = currFrame->GetNextSibling();
RemoveChildFrame(state, currFrame);
currFrame = nextFrame;
}
fc->EndUpdate();
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
return false;
}
else
return true;
}
NS_IMETHODIMP
nsListBoxBodyFrame::ListBoxAppendFrames(nsFrameList& aFrameList)
{
// append them after
nsBoxLayoutState state(PresContext());
const nsFrameList::Slice& newFrames = mFrames.AppendFrames(nullptr, aFrameList);
if (mLayoutManager)
mLayoutManager->ChildrenAppended(this, state, newFrames);
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
NS_IMETHODIMP
nsListBoxBodyFrame::ListBoxInsertFrames(nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
// insert the frames to our info list
nsBoxLayoutState state(PresContext());
const nsFrameList::Slice& newFrames =
mFrames.InsertFrames(nullptr, aPrevFrame, aFrameList);
if (mLayoutManager)
mLayoutManager->ChildrenInserted(this, state, aPrevFrame, newFrames);
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
//
// Called by nsCSSFrameConstructor when a new listitem content is inserted.
//
void
nsListBoxBodyFrame::OnContentInserted(nsIContent* aChildContent)
{
if (mRowCount >= 0)
++mRowCount;
// The RDF content builder will build content nodes such that they are all
// ready when OnContentInserted is first called, meaning the first call
// to CreateRows will create all the frames, but OnContentInserted will
// still be called again for each content node - so we need to make sure
// that the frame for each content node hasn't already been created.
nsIFrame* childFrame = aChildContent->GetPrimaryFrame();
if (childFrame)
return;
int32_t siblingIndex;
nsCOMPtr<nsIContent> nextSiblingContent;
GetListItemNextSibling(aChildContent, getter_AddRefs(nextSiblingContent), siblingIndex);
// if we're inserting our item before the first visible content,
// then we need to shift all rows down by one
if (siblingIndex >= 0 && siblingIndex-1 <= mCurrentIndex) {
mTopFrame = nullptr;
mRowsToPrepend = 1;
} else if (nextSiblingContent) {
// we may be inserting before a frame that is on screen
nsIFrame* nextSiblingFrame = nextSiblingContent->GetPrimaryFrame();
mLinkupFrame = nextSiblingFrame;
}
CreateRows();
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
//
// Called by nsCSSFrameConstructor when listitem content is removed.
//
void
nsListBoxBodyFrame::OnContentRemoved(nsPresContext* aPresContext,
nsIContent* aContainer,
nsIFrame* aChildFrame,
nsIContent* aOldNextSibling)
{
NS_ASSERTION(!aChildFrame || aChildFrame->GetParent() == this,
"Removing frame that's not our child... Not good");
if (mRowCount >= 0)
--mRowCount;
if (aContainer) {
if (!aChildFrame) {
// The row we are removing is out of view, so we need to try to
// determine the index of its next sibling.
int32_t siblingIndex = -1;
if (aOldNextSibling) {
nsCOMPtr<nsIContent> nextSiblingContent;
GetListItemNextSibling(aOldNextSibling,
getter_AddRefs(nextSiblingContent),
siblingIndex);
}
// if the row being removed is off-screen and above the top frame, we need to
// adjust our top index and tell the scrollbar to shift up one row.
if (siblingIndex >= 0 && siblingIndex-1 < mCurrentIndex) {
NS_PRECONDITION(mCurrentIndex > 0, "mCurrentIndex > 0");
--mCurrentIndex;
mYPosition = mCurrentIndex*mRowHeight;
nsWeakFrame weakChildFrame(aChildFrame);
VerticalScroll(mYPosition);
if (!weakChildFrame.IsAlive()) {
return;
}
}
} else if (mCurrentIndex > 0) {
// At this point, we know we have a scrollbar, and we need to know
// if we are scrolled to the last row. In this case, the behavior
// of the scrollbar is to stay locked to the bottom. Since we are
// removing visible content, the first visible row will have to move
// down by one, and we will have to insert a new frame at the top.
// if the last content node has a frame, we are scrolled to the bottom
nsIContent* lastChild = nullptr;
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
lastChild = child;
}
if (lastChild) {
nsIFrame* lastChildFrame = lastChild->GetPrimaryFrame();
if (lastChildFrame) {
mTopFrame = nullptr;
mRowsToPrepend = 1;
--mCurrentIndex;
mYPosition = mCurrentIndex*mRowHeight;
nsWeakFrame weakChildFrame(aChildFrame);
VerticalScroll(mYPosition);
if (!weakChildFrame.IsAlive()) {
return;
}
}
}
}
}
// if we're removing the top row, the new top row is the next row
if (mTopFrame && mTopFrame == aChildFrame)
mTopFrame = mTopFrame->GetNextSibling();
// Go ahead and delete the frame.
nsBoxLayoutState state(aPresContext);
if (aChildFrame) {
RemoveChildFrame(state, aChildFrame);
}
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
void
nsListBoxBodyFrame::GetListItemContentAt(int32_t aIndex, nsIContent** aContent)
{
*aContent = nullptr;
int32_t itemsFound = 0;
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
if (child->IsXULElement(nsGkAtoms::listitem)) {
++itemsFound;
if (itemsFound-1 == aIndex) {
*aContent = child;
NS_IF_ADDREF(*aContent);
return;
}
}
}
}
void
nsListBoxBodyFrame::GetListItemNextSibling(nsIContent* aListItem, nsIContent** aContent, int32_t& aSiblingIndex)
{
*aContent = nullptr;
aSiblingIndex = -1;
nsIContent *prevKid = nullptr;
FlattenedChildIterator iter(mContent);
for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
if (child->IsXULElement(nsGkAtoms::listitem)) {
++aSiblingIndex;
if (prevKid == aListItem) {
*aContent = child;
NS_IF_ADDREF(*aContent);
return;
}
}
prevKid = child;
}
aSiblingIndex = -1; // no match, so there is no next sibling
}
void
nsListBoxBodyFrame::RemoveChildFrame(nsBoxLayoutState &aState,
nsIFrame *aFrame)
{
MOZ_ASSERT(mFrames.ContainsFrame(aFrame));
MOZ_ASSERT(aFrame != GetContentInsertionFrame());
#ifdef ACCESSIBILITY
nsAccessibilityService* accService = nsIPresShell::AccService();
if (accService) {
nsIContent* content = aFrame->GetContent();
accService->ContentRemoved(PresContext()->PresShell(), content);
}
#endif
mFrames.RemoveFrame(aFrame);
if (mLayoutManager)
mLayoutManager->ChildrenRemoved(this, aState, aFrame);
aFrame->Destroy();
}
// Creation Routines ///////////////////////////////////////////////////////////////////////
already_AddRefed<nsBoxLayout> NS_NewListBoxLayout();
nsIFrame*
NS_NewListBoxBodyFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
nsCOMPtr<nsBoxLayout> layout = NS_NewListBoxLayout();
return new (aPresShell) nsListBoxBodyFrame(aContext, layout);
}
NS_IMPL_FRAMEARENA_HELPERS(nsListBoxBodyFrame)
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