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gecko-dev/layout/xul/nsListBoxBodyFrame.cpp

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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->GetScrollbarStyles().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->GetScrollbarStyles().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);
AutoWeakFrame 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);
AutoWeakFrame 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);
AutoWeakFrame weakFrame(this);
int32_t newPos = aScrollbar->MoveToNewPosition();
if (!weakFrame.IsAlive()) {
return;
}
UpdateIndex(newPos);
}
void
nsListBoxBodyFrame::RepeatButtonScroll(nsScrollbarFrame* aScrollbar)
{
AutoWeakFrame 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,
LazyComputeBehavior::Allow);
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;
AutoWeakFrame 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(FlushType::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)
{
AutoWeakFrame 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();
AutoWeakFrame weakThis(this);
mContent->GetComposedDoc()->FlushPendingNotifications(FlushType::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(FlushType::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();
AutoWeakFrame 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.GetFrame() : nullptr;
}
// top frame was cleared out
mTopFrame = GetFirstFrame();
mBottomFrame = mTopFrame;
if (mTopFrame && mRowsToPrepend <= 0) {
return mTopFrame->IsXULBoxFrame() ? mTopFrame.GetFrame() : 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.GetFrame() : 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;
AutoWeakFrame 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;
AutoWeakFrame 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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