private void GenerateStickyHeaders( ICustomItemContainerGenerator generator, bool measureInvalidated, ref UIElement focusedElement )
{
CustomItemContainerGenerator customGenerator = ( CustomItemContainerGenerator )generator;
if( !this.AreHeadersStickyCache && !this.AreGroupHeadersStickyCache && !this.AreParentRowsStickyCache )
{
this.RecycleUnusedStickyContainers( generator, m_stickyHeaders, null, ref focusedElement );
m_stickyHeaders.Clear();
return;
}
int numberOfContainerChecked = 0;
StickyContainerInfoList newStickyHeaders = new StickyContainerInfoList();
foreach( LayoutedContainerInfo layoutedContainerInfo in m_layoutedContainers )
{
UIElement container = layoutedContainerInfo.Container;
// For each visible container, we must find what headers should be sticky for it.
List<StickyContainerGenerated> stickyHeaders =
customGenerator.GenerateStickyHeaders( container, this.AreHeadersStickyCache, this.AreGroupHeadersStickyCache, this.AreParentRowsStickyCache );
stickyHeaders.Sort( StickyContainerGeneratedComparer.Singleton );
// For each sticky headers returned, we must get the index of the last container
// that could need that container to be sticky.
foreach( StickyContainerGenerated stickyHeaderInfo in stickyHeaders )
{
UIElement stickyContainer = ( UIElement )stickyHeaderInfo.StickyContainer;
if( newStickyHeaders.ContainsContainer( stickyContainer ) )
continue;
int lastContainerIndex = customGenerator.GetLastHoldingContainerIndexForStickyHeader( stickyContainer );
StickyContainerInfo stickyContainerInfo = new StickyContainerInfo( stickyContainer, stickyHeaderInfo.Index, lastContainerIndex );
newStickyHeaders.Add( stickyContainerInfo );
if( focusedElement == stickyContainer )
{
focusedElement = null;
}
this.HandleGeneratedStickyContainerPreparation( stickyHeaderInfo, measureInvalidated );
}
// We only need to find the sticky headers for one
// more element than what is already sticky.
int visibleStickyHeadersCount = ( int )Math.Ceiling( this.GetStickyHeadersRegionHeight( newStickyHeaders ) / m_containerHeight );
if( ( ++numberOfContainerChecked - visibleStickyHeadersCount ) >= 1 )
break;
}
foreach( StickyContainerInfo stickyHeaderInfo in newStickyHeaders )
{
UIElement container = stickyHeaderInfo.Container;
int index = m_layoutedContainers.IndexOfContainer( container );
if( index > -1 )
{
m_layoutedContainers.RemoveAt( index );
}
m_layoutedContainersToRecycle.Remove( container );
}
this.RecycleUnusedStickyContainers( generator, m_stickyHeaders, newStickyHeaders, ref focusedElement );
m_stickyHeaders.Clear();
m_stickyHeaders.AddRange( newStickyHeaders );
m_stickyHeaders.Sort( StickyContainerInfoComparer.Singleton );
}
private void GenerateContainers(
ICustomItemContainerGenerator generator,
int pageStartIndex,
int pageEndIndex,
bool measureInvalidated,
ref UIElement focusedElement )
{
HashSet<UIElement> unusedLayoutedContainers = new HashSet<UIElement>( m_layoutedContainers.Select( item => item.Container ) );
m_layoutedContainers.Clear();
ScrollDirection scrollDirection = this.AnimatedScrollInfo.VerticalScrollingDirection;
GeneratorPosition position;
GeneratorDirection direction;
int currentIndex;
int step;
if( ( scrollDirection == ScrollDirection.Forward )
|| ( scrollDirection == ScrollDirection.None ) )
{
position = generator.GeneratorPositionFromIndex( pageStartIndex );
direction = GeneratorDirection.Forward;
currentIndex = pageStartIndex;
step = 1;
}
else
{
position = generator.GeneratorPositionFromIndex( pageEndIndex );
direction = GeneratorDirection.Backward;
currentIndex = pageEndIndex;
step = -1;
}
using( generator.StartAt( position, direction, true ) )
{
while( ( currentIndex >= pageStartIndex ) && ( currentIndex <= pageEndIndex ) )
{
UIElement container = this.GenerateContainer( generator, currentIndex, measureInvalidated, true );
if( container == null )
break;
if( focusedElement == container )
{
focusedElement = null;
}
// The container is now part of the page layout. Add it to the list.
m_layoutedContainers.Add( new LayoutedContainerInfo( currentIndex, container ) );
m_layoutedContainersToRecycle.Remove( container );
unusedLayoutedContainers.Remove( container );
currentIndex += step;
}
}
// A ScrollViewer may measure forever if the containers that are "underneath" the horizontal
// scrollbar are the ones that required the scrollbar in the first place.
if( m_lastVisiblePageIndexes != PageIndexes.Empty )
{
int remainingItemCount = ( m_lastVisiblePageIndexes.EndIndex - m_lastVisiblePageIndexes.StartIndex )
- ( pageEndIndex - pageStartIndex );
if( ( remainingItemCount > 0 ) && ( this.GetMaxDesiredWidth() < this.AnimatedScrollInfo.ExtentWidth ) )
{
int itemCount = generator.ItemCount;
if( ( currentIndex >= 0 ) && ( currentIndex < itemCount ) )
{
position = generator.GeneratorPositionFromIndex( currentIndex );
using( generator.StartAt( position, direction, true ) )
{
while( ( remainingItemCount > 0 ) && ( currentIndex >= 0 ) && ( currentIndex < itemCount ) )
{
UIElement container = this.GenerateContainer( generator, currentIndex, measureInvalidated, true );
if( container == null )
break;
if( focusedElement == container )
{
focusedElement = null;
}
// The container is now part of the page layout. Add it to the list.
m_layoutedContainers.Add( new LayoutedContainerInfo( currentIndex, container ) );
m_layoutedContainersToRecycle.Remove( container );
unusedLayoutedContainers.Remove( container );
currentIndex += step;
remainingItemCount--;
}
}
}
}
}
m_layoutedContainers.Sort();
// Recycle the containers that have not been reused in the current page.
foreach( var container in unusedLayoutedContainers )
{
// We do not recycle the focused element!
if( container.IsKeyboardFocusWithin )
{
Debug.Assert( focusedElement == null );
focusedElement = container;
}
else
{
int index = generator.GetRealizedIndexForContainer( container );
this.RecycleContainer( generator, index, container );
m_layoutedContainersToRecycle.Add( container );
}
}
}
private void GenerateFocusedContainer(
ICustomItemContainerGenerator generator,
bool measureInvalidated,
UIElement focusedElement )
{
if( focusedElement == null )
return;
int index = generator.GetRealizedIndexForContainer( focusedElement );
if( index >= 0 )
{
if( measureInvalidated )
{
this.MeasureContainer( focusedElement );
}
m_layoutedContainers.Add( new LayoutedContainerInfo( index, focusedElement ) );
}
else
{
this.RecycleContainer( focusedElement );
}
}
private void RecycleUnusedStickyContainers(
ICustomItemContainerGenerator generator,
StickyContainerInfoList stickyContainers,
StickyContainerInfoList stickyContainersToExclude,
ref UIElement focusedElement )
{
for( int i = stickyContainers.Count - 1; i >= 0; i-- )
{
StickyContainerInfo stickyHeaderInfo = stickyContainers[ i ];
UIElement container = stickyHeaderInfo.Container;
if( m_layoutedContainers.ContainsContainer( container ) )
continue;
if( ( stickyContainersToExclude != null ) && ( stickyContainersToExclude.ContainsContainer( container ) ) )
continue;
if( container.IsKeyboardFocusWithin )
{
Debug.Assert( ( focusedElement == null ) || ( focusedElement == container ) );
focusedElement = container;
continue;
}
int index = generator.GetRealizedIndexForContainer( container );
this.RecycleContainer( generator, index, container );
stickyContainers.RemoveAt( i );
}
}
private void RecycleContainer( ICustomItemContainerGenerator generator, int containerIndex, UIElement container )
{
if( ( generator != null ) && ( containerIndex != -1 ) )
{
try
{
GeneratorPosition position = generator.GeneratorPositionFromIndex( containerIndex );
generator.Remove( position, 1 );
}
catch
{
Debug.Fail( "Unable to remove container for containerIndex " + containerIndex );
}
}
#if DEBUG
TableflowViewItemsHost.SetRealizedIndex( container, -1 );
#endif //DEBUG
TableflowViewItemsHost.ClearIsSticky( container );
container.ClearValue( UIElement.ClipProperty );
this.DisableElementNavigation( container );
this.FreeRowSelector( container );
m_layoutedContainersToRecycle.Add( container );
}
private void GenerateContainers(
ICustomItemContainerGenerator generator,
int pageStartIndex,
int pageEndIndex,
bool measureInvalidated,
ref UIElement focusedElement )
{
ScrollDirection scrollDirection = this.AnimatedScrollInfo.VerticalScrollingDirection;
GeneratorPosition position;
GeneratorDirection direction;
if( ( scrollDirection == ScrollDirection.Forward )
|| ( scrollDirection == ScrollDirection.None ) )
{
position = generator.GeneratorPositionFromIndex( pageStartIndex );
direction = GeneratorDirection.Forward;
}
else
{
position = generator.GeneratorPositionFromIndex( pageEndIndex );
direction = GeneratorDirection.Backward;
}
using( generator.StartAt( position, direction, true ) )
{
int currentIndex = ( direction == GeneratorDirection.Forward )
? pageStartIndex
: pageEndIndex;
while( ( direction == GeneratorDirection.Forward )
? ( currentIndex <= pageEndIndex )
: ( currentIndex >= pageStartIndex ) )
{
UIElement container = this.GenerateContainer( generator, currentIndex, measureInvalidated, true );
if( container == null )
return;
if( ( focusedElement != null ) && ( focusedElement == container ) )
{
focusedElement = null;
}
// The container is now part of the page layout. Add it to the list.
m_layoutedContainers.Add( new LayoutedContainerInfo( currentIndex, container ) );
m_layoutedContainersToRecycle.Remove( container );
currentIndex += ( direction == GeneratorDirection.Forward ) ? 1 : -1;
}
}
m_layoutedContainers.Sort();
}
private UIElement RecycleSafeContainers(
ICustomItemContainerGenerator generator,
int pageStartIndex,
int pageEndIndex )
{
if( m_lastVisiblePageIndexes == PageIndexes.Empty )
return this.RecycleContainers( generator, pageStartIndex, pageEndIndex );
if( m_lastVisiblePageIndexes.StartIndex == pageStartIndex )
return this.RecycleContainers( generator,
pageStartIndex,
Math.Max( pageEndIndex, m_lastVisiblePageIndexes.EndIndex ) );
if( m_lastVisiblePageIndexes.EndIndex == pageEndIndex )
return this.RecycleContainers( generator,
Math.Min( pageStartIndex, m_lastVisiblePageIndexes.StartIndex ),
pageEndIndex );
int itemCount = generator.ItemCount;
int threshold = Math.Max( 0,
( m_lastVisiblePageIndexes.EndIndex - m_lastVisiblePageIndexes.StartIndex ) -
( pageEndIndex - pageStartIndex ) );
int endIndex = Math.Min( pageEndIndex + threshold, itemCount - 1 );
if( endIndex < 0 )
return this.RecycleAllContainers( generator );
int startIndex = Math.Max( endIndex - threshold - ( pageEndIndex - pageStartIndex ), 0 );
return this.RecycleContainers( generator, startIndex, endIndex );
}
private UIElement GenerateContainer( ICustomItemContainerGenerator generator, int index, bool forceMeasure )
{
bool isNewlyRealized;
var container = ( UIElement )generator.GenerateNext( out isNewlyRealized );
if( container == null )
return null;
if( isNewlyRealized )
{
var collection = this.Children;
if( !collection.Contains( container ) )
{
collection.Add( container );
}
this.EnableElementNavigation( container );
KeyboardNavigation.SetTabIndex( container, index );
this.PrepareContainer( container );
this.MeasureContainer( container );
}
else if( forceMeasure )
{
this.MeasureContainer( container );
}
return container;
}
private UIElement RecycleContainers(
ICustomItemContainerGenerator generator,
int pageStartIndex,
int pageEndIndex )
{
UIElement focusedElement = null;
for( int i = m_layoutedContainers.Count - 1; i >= 0; i-- )
{
var container = m_layoutedContainers[ i ].Container;
int index = generator.GetRealizedIndexForContainer( container );
// If the container's index is now out of view, recycle that container.
if( ( index < pageStartIndex ) || ( index > pageEndIndex ) )
{
// We do not recycle the focused element!
if( container.IsKeyboardFocusWithin )
{
focusedElement = container;
}
else
{
this.RecycleContainer( generator, index, container );
}
m_layoutedContainers.RemoveAt( i );
}
}
return focusedElement;
}
private void GenerateContainers(
ICustomItemContainerGenerator generator,
double pageHeight,
HashSet<UIElement> layoutedContainersToRecycle,
bool measureInvalidated,
ref PageIndexes pageIndexes,
out double containersHeight )
{
int currentIndex = pageIndexes.StartIndex;
GeneratorDirection direction;
if( currentIndex == -1 )
{
currentIndex = pageIndexes.EndIndex;
Debug.Assert( currentIndex != -1 );
direction = GeneratorDirection.Backward;
}
else
{
direction = GeneratorDirection.Forward;
}
int startIndex = currentIndex;
int endIndex = currentIndex;
containersHeight = 0d;
GeneratorPosition position;
position = generator.GeneratorPositionFromIndex( currentIndex );
int itemCount = generator.ItemCount;
using( generator.StartAt( position, direction, true ) )
{
while( ( ( direction == GeneratorDirection.Forward )
? ( currentIndex < itemCount ) : ( currentIndex >= 0 ) ) && ( pageHeight > 0 ) )
{
UIElement container = this.GenerateContainer( generator, currentIndex, measureInvalidated );
if( container == null )
break;
double containerHeight = container.DesiredSize.Height;
m_layoutedContainers.Add( new LayoutedContainerInfo( currentIndex, container ) );
layoutedContainersToRecycle.Remove( container );
m_layoutedContainersToRecycle.Remove( container );
if( ( direction == GeneratorDirection.Backward ) && ( ( pageHeight - containerHeight ) < 0 ) )
{
// We do not want to recycle the container since it will cause a re-invalidation of the measure and
// may cause an infinit loop. This case has been observed with a MaxHeight set on the DataGridControl.
break;
}
pageHeight -= containerHeight;
containersHeight += containerHeight;
endIndex = currentIndex;
currentIndex += ( direction == GeneratorDirection.Forward ) ? 1 : -1;
}
}
if( pageHeight > 0 )
{
if( direction == GeneratorDirection.Forward )
{
direction = GeneratorDirection.Backward;
}
else
{
direction = GeneratorDirection.Forward;
}
DataGridContext dataGridContext = DataGridControl.GetDataGridContext( this );
if( ( direction == GeneratorDirection.Forward ) || ( ( dataGridContext == null ) || ( TableView.GetAutoFillLastPage( dataGridContext ) ) ) )
{
currentIndex = ( direction == GeneratorDirection.Forward ) ? startIndex + 1 : startIndex - 1;
if( ( direction == GeneratorDirection.Forward ) ? ( currentIndex < itemCount ) : ( currentIndex >= 0 ) )
{
position = generator.GeneratorPositionFromIndex( currentIndex );
using( generator.StartAt( position, direction, true ) )
{
// If we still have more space, try to get more container to fill up the page.
while( ( ( direction == GeneratorDirection.Forward ) ?
( currentIndex < itemCount ) : ( currentIndex >= 0 ) ) && ( pageHeight > 0 ) )
{
UIElement container = this.GenerateContainer( generator, currentIndex, measureInvalidated );
if( container == null )
break;
double containerHeight = container.DesiredSize.Height;
pageHeight -= containerHeight;
m_layoutedContainers.Add( new LayoutedContainerInfo( currentIndex, container ) );
layoutedContainersToRecycle.Remove( container );
m_layoutedContainersToRecycle.Remove( container );
if( ( direction == GeneratorDirection.Backward ) && ( pageHeight < 0 ) )
{
// We do not want to recycle the container since it will cause a re-invalidation of the measure and
// may cause an infinit loop. This case has been observed with a MaxHeight set on the DataGridControl.
break;
}
containersHeight += containerHeight;
startIndex = currentIndex;
currentIndex += ( direction == GeneratorDirection.Forward ) ? 1 : -1;
}
}
}
}
}
m_layoutedContainers.Sort();
if( startIndex > endIndex )
{
pageIndexes = new PageIndexes( endIndex, startIndex );
}
else
{
pageIndexes = new PageIndexes( startIndex, endIndex );
}
}
private void RecycleContainer( ICustomItemContainerGenerator generator, LayoutedContainerInfo containerInfo )
{
Debug.Assert( containerInfo != null );
var index = containerInfo.RealizedIndex;
if( ( generator != null ) && ( index >= 0 ) )
{
try
{
var position = generator.GeneratorPositionFromIndex( index );
generator.Remove( position, 1 );
}
catch
{
Debug.Fail( "Unable to remove container for containerIndex " + index );
}
}
this.ClearContainer( containerInfo.Container );
}
private void TrySafeRecycleContainer( ICustomItemContainerGenerator generator, int containerIndex, UIElement container )
{
int newIndex = -1;
if( ( generator != null ) && ( containerIndex != -1 ) )
{
GeneratorPosition position = generator.GeneratorPositionFromIndex( containerIndex );
if( ( position.Index != -1 ) && ( position.Offset == 0 ) )
{
newIndex = containerIndex;
}
}
this.RecycleContainer( generator, newIndex, container );
}
private void RecycleContainer( ICustomItemContainerGenerator generator, int containerIndex, UIElement container )
{
if( ( generator != null ) && ( containerIndex != -1 ) )
{
try
{
GeneratorPosition position = generator.GeneratorPositionFromIndex( containerIndex );
generator.Remove( position, 1 );
}
catch
{
Debug.Fail( "Unable to remove container for containerIndex " + containerIndex );
}
}
this.DisableElementNavigation( container );
this.FreeRowSelector( container );
}
private void RecycleContainers(
HashSet<UIElement> layoutedContainersToRecycle,
ICustomItemContainerGenerator generator )
{
foreach( UIElement containerToRecycle in layoutedContainersToRecycle )
{
this.RecycleContainer( generator, generator.GetRealizedIndexForContainer( containerToRecycle ), containerToRecycle );
}
}
private void GenerateStickyFooters( ICustomItemContainerGenerator generator, bool measureInvalidated, ref UIElement focusedElement )
{
if( !this.AreFootersStickyCache && !this.AreGroupFootersStickyCache )
{
this.RecycleUnusedStickyContainers( generator, m_stickyFooters, null, ref focusedElement );
m_stickyFooters.Clear();
return;
}
CustomItemContainerGenerator customGenerator = ( CustomItemContainerGenerator )generator;
int numberOfContainerChecked = 0;
StickyContainerInfoList newStickyFooters = new StickyContainerInfoList();
int layoutedContainerCount = m_layoutedContainers.Count;
if( layoutedContainerCount > 0 )
{
// We must not generate sticky footers if the last container is not even at the bottom of the view!
LayoutedContainerInfo bottomMostContainerInfo = m_layoutedContainers[ layoutedContainerCount - 1 ];
double bottomMostContainerOffset = this.GetContainerOffsetFromIndex( bottomMostContainerInfo.RealizedIndex );
if( ( bottomMostContainerOffset + m_containerHeight ) >= m_viewportHeight )
{
for( int i = layoutedContainerCount - 1; i >= 0; i-- )
{
LayoutedContainerInfo layoutedContainerInfo = m_layoutedContainers[ i ];
UIElement layoutedContainer = layoutedContainerInfo.Container;
// For each visible container, we must find what footers should be sticky for it.
List<StickyContainerGenerated> stickyFooters =
customGenerator.GenerateStickyFooters( layoutedContainer, this.AreFootersStickyCache, this.AreGroupFootersStickyCache );
stickyFooters.Sort( StickyContainerGeneratedReverseComparer.Singleton );
// For each sticky headers returned, we must get the index of the last container
// that could need that container to be sticky.
foreach( StickyContainerGenerated stickyFooterInfo in stickyFooters )
{
UIElement stickyContainer = ( UIElement )stickyFooterInfo.StickyContainer;
if( newStickyFooters.ContainsContainer( stickyContainer ) )
continue;
int firstContainerIndex = customGenerator.GetFirstHoldingContainerIndexForStickyFooter( stickyContainer );
StickyContainerInfo stickyContainerInfo = new StickyContainerInfo( stickyContainer, stickyFooterInfo.Index, firstContainerIndex );
newStickyFooters.Add( stickyContainerInfo );
if( focusedElement == stickyContainer )
{
focusedElement = null;
}
this.HandleGeneratedStickyContainerPreparation( stickyFooterInfo, measureInvalidated );
}
// We only need to find the sticky footers for one
// more element than what is already sticky.
int visibleStickyFootersCount = ( int )Math.Ceiling( ( this.AnimatedScrollInfo.ViewportHeight - this.GetStickyFootersRegionHeight( newStickyFooters ) ) / m_containerHeight );
if( ( ++numberOfContainerChecked - visibleStickyFootersCount ) >= 1 )
break;
}
}
}
foreach( StickyContainerInfo stickyFooterInfo in newStickyFooters )
{
int indexOf = m_layoutedContainers.IndexOfContainer( stickyFooterInfo.Container );
if( indexOf > -1 )
{
m_layoutedContainers.RemoveAt( indexOf );
}
}
this.RecycleUnusedStickyContainers( generator, m_stickyFooters, newStickyFooters, ref focusedElement );
m_stickyFooters.Clear();
m_stickyFooters.AddRange( newStickyFooters );
m_stickyFooters.Sort( StickyContainerInfoReverseComparer.Singleton );
}
private UIElement RecycleAllContainers( ICustomItemContainerGenerator generator )
{
return this.RecycleContainers( generator, -1, -1 );
}
private UIElement GenerateContainer(
ICustomItemContainerGenerator generator,
int index,
bool measureInvalidated,
bool delayDataContext )
{
bool isNewlyRealized;
UIElement container = ( UIElement )generator.GenerateNext( out isNewlyRealized );
if( container != null )
{
if( isNewlyRealized )
{
if( !this.Children.Contains( container ) )
{
this.Children.Add( container );
}
this.EnableElementNavigation( container );
KeyboardNavigation.SetTabIndex( container, index );
}
this.HandleGeneratedContainerPreparation( container, index, isNewlyRealized, delayDataContext );
if( ( isNewlyRealized ) || ( measureInvalidated ) )
{
this.MeasureContainer( container );
}
}
return container;
}
private UIElement RecycleContainers(
ICustomItemContainerGenerator generator,
int pageStartIndex,
int pageEndIndex )
{
UIElement focusedElement = null;
for( int i = 0; i < m_layoutedContainers.Count; i++ )
{
LayoutedContainerInfo layoutedContainerInfo = m_layoutedContainers[ i ];
UIElement container = layoutedContainerInfo.Container;
// We do not recycle the focused element!
if( container.IsKeyboardFocusWithin )
{
focusedElement = container;
continue;
}
int index = generator.GetRealizedIndexForContainer( container );
// If the container's index is now out of view, recycle that container.
if( ( index < pageStartIndex ) || ( index > pageEndIndex ) )
{
this.RecycleContainer( generator, index, container );
m_layoutedContainersToRecycle.Add( container );
}
}
m_layoutedContainers.Clear();
return focusedElement;
}