NS_IMETHODIMP
nsListBoxBodyFrame::ScrollToIndex(PRInt32 aRowIndex)
{
if (( aRowIndex < 0 ) || (mRowHeight == 0))
return NS_OK;
PRInt32 newIndex = aRowIndex;
PRInt32 delta = mCurrentIndex > newIndex ? mCurrentIndex - newIndex : newIndex - mCurrentIndex;
PRBool up = newIndex < mCurrentIndex;
// Check to be sure we're not scrolling off the bottom of the tree
PRInt32 lastPageTopRow = GetRowCount() - (GetAvailableHeight() / mRowHeight);
if (lastPageTopRow < 0)
lastPageTopRow = 0;
if (aRowIndex > lastPageTopRow)
return NS_OK;
mCurrentIndex = newIndex;
// Since we're going to flush anyway, we need to not do this off an event
DoInternalPositionChangedSync(up, delta);
// This change has to happen immediately.
// Flush any pending reflow commands.
// XXXbz why, exactly?
mContent->GetDocument()->FlushPendingNotifications(Flush_Layout);
return NS_OK;
}
NS_IMETHODIMP
nsListBoxBodyFrame::VisibilityChanged(nsISupports* aScrollbar, PRBool aVisible)
{
PRInt32 lastPageTopRow = GetRowCount() - (GetAvailableHeight() / mRowHeight);
if (lastPageTopRow < 0)
lastPageTopRow = 0;
PRInt32 delta = mCurrentIndex - lastPageTopRow;
if (delta > 0) {
mCurrentIndex = lastPageTopRow;
InternalPositionChanged(PR_TRUE, delta);
}
return NS_OK;
}
NS_IMETHODIMP
nsListBoxBodyFrame::VisibilityChanged(bool aVisible)
{
if (mRowHeight == 0)
return NS_OK;
PRInt32 lastPageTopRow = GetRowCount() - (GetAvailableHeight() / mRowHeight);
if (lastPageTopRow < 0)
lastPageTopRow = 0;
PRInt32 delta = mCurrentIndex - lastPageTopRow;
if (delta > 0) {
mCurrentIndex = lastPageTopRow;
InternalPositionChanged(true, delta);
}
return NS_OK;
}
void
nsListBoxBodyFrame::CreateRows()
{
// Get our client rect.
nsRect clientRect;
GetClientRect(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;
nsIBox* 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 = nsnull;
}
nsresult
nsListBoxBodyFrame::EnsureIndexIsVisible(PRInt32 aRowIndex)
{
if (aRowIndex < 0)
return NS_ERROR_ILLEGAL_VALUE;
PRInt32 rows = 0;
if (mRowHeight)
rows = GetAvailableHeight()/mRowHeight;
if (rows <= 0)
rows = 1;
PRInt32 bottomIndex = mCurrentIndex + rows;
// if row is visible, ignore
if (mCurrentIndex <= aRowIndex && aRowIndex < bottomIndex)
return NS_OK;
PRInt32 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::DoInternalPositionChanged(bool aUp, PRInt32 aDelta)
{
if (aDelta == 0)
return NS_OK;
nsRefPtr<nsPresContext> presContext(PresContext());
nsBoxLayoutState state(presContext);
// begin timing how long it takes to scroll a row
PRTime start = PR_Now();
nsWeakFrame weakThis(this);
mContent->GetDocument()->FlushPendingNotifications(Flush_Layout);
if (!weakThis.IsAlive()) {
return NS_OK;
}
{
nsAutoScriptBlocker scriptBlocker;
PRInt32 visibleRows = 0;
if (mRowHeight)
visibleRows = GetAvailableHeight()/mRowHeight;
if (aDelta < visibleRows) {
PRInt32 loseRows = aDelta;
if (aUp) {
// scrolling up, destroy rows from the bottom downwards
ReverseDestroyRows(loseRows);
mRowsToPrepend += aDelta;
mLinkupFrame = nsnull;
}
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 = nsnull;
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();
PRTime difTime;
LL_SUB(difTime, end, start);
PRInt32 newTime;
LL_L2I(newTime, difTime);
newTime /= aDelta;
// average old and new
mTimePerRow = (newTime + mTimePerRow)/2;
return NS_OK;
}
nsresult
nsListBoxBodyFrame::GetNumberOfVisibleRows(PRInt32 *aResult)
{
*aResult= mRowHeight ? GetAvailableHeight() / mRowHeight : 0;
return NS_OK;
}
