/// <summary>
/// Layout collection of views horizontally/vertically.
/// </summary>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- public class LinearLayoutManager : FlexibleView.LayoutManager
+ public partial class LinearLayoutManager : FlexibleViewLayoutManager
{
/// <summary>
/// Constant value: 0.
[EditorBrowsable(EditorBrowsableState.Never)]
public static readonly int INVALID_OFFSET = -2147483648;
- private static readonly float MAX_SCROLL_FACTOR = 1 / 3f;
-
- /// <summary>
- /// Current orientation.
- /// </summary>
- /// <since_tizen> 6 </since_tizen>
- /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
- [EditorBrowsable(EditorBrowsableState.Never)]
- protected int mOrientation;
+ private const float MAX_SCROLL_FACTOR = 1 / 3f;
internal OrientationHelper mOrientationHelper;
[EditorBrowsable(EditorBrowsableState.Never)]
public LinearLayoutManager(int orientation)
{
- mOrientation = orientation;
- mOrientationHelper = OrientationHelper.CreateOrientationHelper(this, mOrientation);
+ Orientation = orientation;
+ mOrientationHelper = OrientationHelper.CreateOrientationHelper(this, Orientation);
mLayoutState = new LayoutState();
mLayoutState.Offset = mOrientationHelper.GetStartAfterPadding();
}
/// <summary>
+ /// Current orientation.
+ /// </summary>
+ /// <since_tizen> 6 </since_tizen>
+ /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
+ [EditorBrowsable(EditorBrowsableState.Never)]
+ protected int Orientation { get; set; }
+
+ /// <summary>
/// Retrieves the first visible item position.
/// </summary>
/// <since_tizen> 6 </since_tizen>
{
get
{
- FlexibleView.ViewHolder child = FindFirstVisibleItemView();
+ FlexibleViewViewHolder child = FindFirstVisibleItemView();
return child == null ? NO_POSITION : child.LayoutPosition;
}
}
{
get
{
- FlexibleView.ViewHolder child = FindFirstCompleteVisibleItemView();
+ FlexibleViewViewHolder child = FindFirstCompleteVisibleItemView();
return child == null ? NO_POSITION : child.LayoutPosition;
}
}
{
get
{
- FlexibleView.ViewHolder child = FindLastVisibleItemView();
+ FlexibleViewViewHolder child = FindLastVisibleItemView();
return child == null ? NO_POSITION : child.LayoutPosition;
}
}
{
get
{
- FlexibleView.ViewHolder child = FindLastCompleteVisibleItemView();
+ FlexibleViewViewHolder child = FindLastCompleteVisibleItemView();
return child == null ? NO_POSITION : child.LayoutPosition;
}
}
[EditorBrowsable(EditorBrowsableState.Never)]
public override bool CanScrollHorizontally()
{
- return mOrientation == HORIZONTAL;
+ return Orientation == HORIZONTAL;
}
/// <summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public override bool CanScrollVertically()
{
- return mOrientation == VERTICAL;
+ return Orientation == VERTICAL;
}
/// <summary>
/// Lay out all relevant child views from the given adapter.
/// </summary>
/// <param name="recycler">Recycler to use for fetching potentially cached views for a position</param>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- public override void OnLayoutChildren(FlexibleView.Recycler recycler)
+ public override void OnLayoutChildren(FlexibleViewRecycler recycler)
{
mLayoutState.Recycle = false;
if (!mAnchorInfo.Valid || mPendingScrollPosition != NO_POSITION)
/// <param name="dx">distance to scroll in pixels. Y increases as scroll position approaches the top.</param>
/// <param name="recycler">Recycler to use for fetching potentially cached views for a position</param>
/// <param name="immediate">Specify if the scroll need animation</param>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- public override float ScrollHorizontallyBy(float dx, FlexibleView.Recycler recycler, bool immediate)
+ public override float ScrollHorizontallyBy(float dx, FlexibleViewRecycler recycler, bool immediate)
{
- if (mOrientation == VERTICAL)
+ if (Orientation == VERTICAL)
{
return 0;
}
/// <param name="dy">distance to scroll in pixels. Y increases as scroll position approaches the top.</param>
/// <param name="recycler">Recycler to use for fetching potentially cached views for a position</param>
/// <param name="immediate">Specify if the scroll need animation</param>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- public override float ScrollVerticallyBy(float dy, FlexibleView.Recycler recycler, bool immediate)
+ public override float ScrollVerticallyBy(float dy, FlexibleViewRecycler recycler, bool immediate)
{
- if (mOrientation == HORIZONTAL)
+ if (Orientation == HORIZONTAL)
{
return 0;
}
[EditorBrowsable(EditorBrowsableState.Never)]
public override float ComputeScrollOffset()
{
- FlexibleView.ViewHolder startChild = FindFirstVisibleItemView();
- FlexibleView.ViewHolder endChild = FindLastVisibleItemView();
+ FlexibleViewViewHolder startChild = FindFirstVisibleItemView();
+ FlexibleViewViewHolder endChild = FindLastVisibleItemView();
if (ChildCount == 0 || startChild == null || endChild == null)
{
return 0;
[EditorBrowsable(EditorBrowsableState.Never)]
public override float ComputeScrollExtent()
{
- FlexibleView.ViewHolder startChild = FindFirstVisibleItemView();
- FlexibleView.ViewHolder endChild = FindLastVisibleItemView();
+ FlexibleViewViewHolder startChild = FindFirstVisibleItemView();
+ FlexibleViewViewHolder endChild = FindLastVisibleItemView();
if (ChildCount == 0 || startChild == null || endChild == null)
{
return 0;
[EditorBrowsable(EditorBrowsableState.Never)]
public override float ComputeScrollRange()
{
- FlexibleView.ViewHolder startChild = FindFirstVisibleItemView();
- FlexibleView.ViewHolder endChild = FindLastVisibleItemView();
+ FlexibleViewViewHolder startChild = FindFirstVisibleItemView();
+ FlexibleViewViewHolder endChild = FindLastVisibleItemView();
if (ChildCount == 0 || startChild == null || endChild == null)
{
return 0;
mAnchorInfo.Reset();
}
- internal virtual void EnsureAnchorReady(FlexibleView.Recycler recycler, AnchorInfo anchorInfo, int itemDirection)
+ internal virtual void EnsureAnchorReady(FlexibleViewRecycler recycler, AnchorInfo anchorInfo, int itemDirection)
{
}
/// </summary>
/// <param name="position">The anchor adapter position</param>
/// <param name="direction">The direction.</param>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- protected override int GetNextPosition(int position, FlexibleView.LayoutManager.Direction direction)
+ protected override int GetNextPosition(int position, FlexibleViewLayoutManager.Direction direction)
{
- if (mOrientation == HORIZONTAL)
+ if (Orientation == HORIZONTAL)
{
switch (direction)
{
- case FlexibleView.LayoutManager.Direction.Left:
+ case FlexibleViewLayoutManager.Direction.Left:
if (position > 0)
{
return position - 1;
}
break;
- case FlexibleView.LayoutManager.Direction.Right:
+ case FlexibleViewLayoutManager.Direction.Right:
if (position < ItemCount - 1)
{
return position + 1;
{
switch (direction)
{
- case FlexibleView.LayoutManager.Direction.Up:
+ case FlexibleViewLayoutManager.Direction.Up:
if (position > 0)
{
return position - 1;
}
break;
- case FlexibleView.LayoutManager.Direction.Down:
+ case FlexibleViewLayoutManager.Direction.Down:
if (position < ItemCount - 1)
{
return position + 1;
/// <summary>
/// Retrieves the first visible item view.
/// </summary>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- protected override FlexibleView.ViewHolder FindFirstVisibleItemView()
+ protected override FlexibleViewViewHolder FindFirstVisibleItemView()
{
int childCount = ChildCount;
if (mShouldReverseLayout == false)
{
for (int i = 0; i < childCount; i++)
{
- FlexibleView.ViewHolder child = GetChildAt(i);
+ FlexibleViewViewHolder child = GetChildAt(i);
int end = (int)mOrientationHelper.GetViewHolderEnd(child);
if (end >= 0 && end < (int)mOrientationHelper.GetEnd())
{
{
for (int i = childCount - 1; i >= 0; i--)
{
- FlexibleView.ViewHolder child = GetChildAt(i);
+ FlexibleViewViewHolder child = GetChildAt(i);
int end = (int)mOrientationHelper.GetViewHolderEnd(child);
if (end >= 0 && end < (int)mOrientationHelper.GetEnd())
{
/// <summary>
/// Retrieves the last visible item view.
/// </summary>
- /// <since_tizen> 6 </since_tizen>
/// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
[EditorBrowsable(EditorBrowsableState.Never)]
- protected override FlexibleView.ViewHolder FindLastVisibleItemView()
+ protected override FlexibleViewViewHolder FindLastVisibleItemView()
{
int childCount = ChildCount;
if (mShouldReverseLayout == false)
{
for (int i = childCount - 1; i >= 0; i--)
{
- FlexibleView.ViewHolder child = GetChildAt(i);
+ FlexibleViewViewHolder child = GetChildAt(i);
int start = (int)mOrientationHelper.GetViewHolderStart(child);
if (start > 0 && start < (int)mOrientationHelper.GetEnd())
{
{
for (int i = 0; i < childCount; i++)
{
- FlexibleView.ViewHolder child = GetChildAt(i);
+ FlexibleViewViewHolder child = GetChildAt(i);
int start = (int)mOrientationHelper.GetViewHolderStart(child);
if (start > 0 && start < (int)mOrientationHelper.GetEnd())
{
}
return null;
}
-
- internal virtual void LayoutChunk(FlexibleView.Recycler recycler,
- LayoutState layoutState, LayoutChunkResult result)
- {
- FlexibleView.ViewHolder holder = layoutState.Next(recycler);
- if (holder == null)
- {
- // if we are laying out views in scrap, this may return null which means there is
- // no more items to layout.
- result.Finished = true;
- return;
- }
-
- if (mShouldReverseLayout == (layoutState.LayoutDirection == LayoutState.LAYOUT_START))
- AddView(holder);
- else
- AddView(holder, 0);
-
- result.Consumed = mOrientationHelper.GetViewHolderMeasurement(holder);
-
- float left, top, width, height;
- if (mOrientation == VERTICAL)
- {
- width = Width - PaddingLeft - PaddingRight;
- height = result.Consumed;
- left = PaddingLeft;
- if (layoutState.LayoutDirection == LayoutState.LAYOUT_END)
- {
- top = layoutState.Offset;
- }
- else
- {
- top = layoutState.Offset - height;
- }
- LayoutChild(holder, left, top, width, height);
- }
- else
- {
- width = result.Consumed;
- height = Height - PaddingTop - PaddingBottom;
- top = PaddingTop;
- if (layoutState.LayoutDirection == LayoutState.LAYOUT_END)
- {
- left = layoutState.Offset;
- }
- else
- {
- left = layoutState.Offset - width;
- }
- LayoutChild(holder, left, top, width, height);
- }
-
- result.Focusable = true;
- }
-
- internal override FlexibleView.ViewHolder OnFocusSearchFailed(FlexibleView.ViewHolder focused, FlexibleView.LayoutManager.Direction direction, FlexibleView.Recycler recycler)
- {
- if (ChildCount == 0)
- {
- return null;
- }
- int layoutDir = ConvertFocusDirectionToLayoutDirection(direction);
- if (layoutDir == LayoutState.INVALID_LAYOUT)
- {
- return null;
- }
- int maxScroll = (int)(MAX_SCROLL_FACTOR * mOrientationHelper.GetTotalSpace());
- UpdateLayoutState(layoutDir, maxScroll, false);
- mLayoutState.ScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
- mLayoutState.Recycle = false;
- Fill(recycler, mLayoutState, true, true);
-
- FlexibleView.ViewHolder nextFocus;
- if (layoutDir == LayoutState.LAYOUT_START)
- {
- nextFocus = GetChildAt(0);
- }
- else
- {
- nextFocus = GetChildAt(ChildCount - 1);
- }
- return nextFocus;
- }
-
-
- private void UpdateAnchorInfoForLayout(FlexibleView.Recycler recycler, AnchorInfo anchorInfo)
- {
- if (UpdateAnchorFromPendingData(anchorInfo))
- {
- return;
- }
-
- if (UpdateAnchorFromChildren(recycler, anchorInfo))
- {
- return;
- }
-
- anchorInfo.Position = FocusPosition != NO_POSITION ? FocusPosition : 0;
- anchorInfo.Coordinate = anchorInfo.LayoutFromEnd ? mOrientationHelper.GetEndAfterPadding() : mOrientationHelper.GetStartAfterPadding();
- }
-
-
- // If there is a pending scroll position or saved states, updates the anchor info from that
- // data and returns true
- private bool UpdateAnchorFromPendingData(AnchorInfo anchorInfo)
- {
- if (mPendingScrollPosition == NO_POSITION)
- {
- return false;
- }
- // validate scroll position
- if (mPendingScrollPosition < 0 || mPendingScrollPosition >= ItemCount)
- {
- mPendingScrollPosition = NO_POSITION;
- mPendingScrollPositionOffset = INVALID_OFFSET;
- return false;
- }
-
- anchorInfo.Position = mPendingScrollPosition;
-
- if (mPendingScrollPositionOffset == INVALID_OFFSET)
- {
- anchorInfo.Coordinate = anchorInfo.LayoutFromEnd ? mOrientationHelper.GetEndAfterPadding() : mOrientationHelper.GetStartAfterPadding();
- }
- else
- {
- if (mShouldReverseLayout)
- {
- anchorInfo.Coordinate = mOrientationHelper.GetEndAfterPadding()
- - mPendingScrollPositionOffset;
- }
- else
- {
- anchorInfo.Coordinate = mOrientationHelper.GetStartAfterPadding()
- + mPendingScrollPositionOffset;
- }
- }
-
- return true;
- }
-
- // Finds an anchor child from existing Views. Most of the time, this is the view closest to
- // start or end that has a valid position (e.g. not removed).
- // If a child has focus, it is given priority.
- private bool UpdateAnchorFromChildren(FlexibleView.Recycler recycler, AnchorInfo anchorInfo)
- {
- if (ChildCount == 0)
- {
- return false;
- }
-
- FlexibleView.ViewHolder anchorChild = FindFirstVisibleItemView();
- if (anchorChild == null)
- {
- Log.Error("flexibleview", $"exception occurs when updating anchor information!");
- anchorChild = GetChildAt(0);
- }
- anchorInfo.Position = anchorChild.LayoutPosition;
- anchorInfo.Coordinate = mOrientationHelper.GetViewHolderStart(anchorChild);
-
- return true;
- }
-
- // Converts a focusDirection to orientation.
- //
- // @param focusDirection One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
- // {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT},
- // {@link View#FOCUS_BACKWARD}, {@link View#FOCUS_FORWARD}
- // or 0 for not applicable
- // @return {@link LayoutState#LAYOUT_START} or {@link LayoutState#LAYOUT_END} if focus direction
- // is applicable to current state, {@link LayoutState#INVALID_LAYOUT} otherwise.
- private int ConvertFocusDirectionToLayoutDirection(FlexibleView.LayoutManager.Direction focusDirection)
- {
- switch (focusDirection)
- {
- case FlexibleView.LayoutManager.Direction.Up:
- return mOrientation == VERTICAL ? LayoutState.LAYOUT_START
- : LayoutState.INVALID_LAYOUT;
- case FlexibleView.LayoutManager.Direction.Down:
- return mOrientation == VERTICAL ? LayoutState.LAYOUT_END
- : LayoutState.INVALID_LAYOUT;
- case FlexibleView.LayoutManager.Direction.Left:
- return mOrientation == HORIZONTAL ? LayoutState.LAYOUT_START
- : LayoutState.INVALID_LAYOUT;
- case FlexibleView.LayoutManager.Direction.Right:
- return mOrientation == HORIZONTAL ? LayoutState.LAYOUT_END
- : LayoutState.INVALID_LAYOUT;
- default:
- return LayoutState.INVALID_LAYOUT;
- }
-
- }
-
-
- private float Fill(FlexibleView.Recycler recycler, LayoutState layoutState, bool stopOnFocusable, bool immediate)
- {
- float start = layoutState.Available;
-
- if (layoutState.ScrollingOffset != LayoutState.SCROLLING_OFFSET_NaN)
- {
- // TODO ugly bug fix. should not happen
- if (layoutState.Available < 0)
- {
- layoutState.ScrollingOffset += layoutState.Available;
- }
- if (immediate == true)
- {
- RecycleByLayoutState(recycler, layoutState, true);
- }
- }
- float remainingSpace = layoutState.Available + layoutState.Extra;
- LayoutChunkResult layoutChunkResult = mLayoutChunkResult;
- while ((remainingSpace > 0) && layoutState.HasMore(ItemCount))
- {
- layoutChunkResult.ResetInternal();
- LayoutChunk(recycler, layoutState, layoutChunkResult);
- if (layoutChunkResult.Finished)
- {
- break;
- }
- layoutState.Offset += layoutChunkResult.Consumed * layoutState.LayoutDirection;
-
- // Consume the available space if:
- // layoutChunk did not request to be ignored
- // OR we are laying out scrap children
- // OR we are not doing pre-layout
- if (!layoutChunkResult.IgnoreConsumed)
- {
- layoutState.Available -= layoutChunkResult.Consumed;
- // we keep a separate remaining space because mAvailable is important for recycling
- remainingSpace -= layoutChunkResult.Consumed;
- }
-
- if (layoutState.ScrollingOffset != LayoutState.SCROLLING_OFFSET_NaN)
- {
- layoutState.ScrollingOffset += layoutChunkResult.Consumed;
- if (layoutState.Available < 0)
- {
- layoutState.ScrollingOffset += layoutState.Available;
- }
- if (immediate == true)
- {
- RecycleByLayoutState(recycler, layoutState, true);
- }
- }
- if (stopOnFocusable && layoutChunkResult.Focusable)
- {
- break;
- }
- }
- if (immediate == false)
- {
- RecycleByLayoutState(recycler, layoutState, false);
- }
-
- return start - layoutState.Available;
- }
-
- private void Cache(FlexibleView.Recycler recycler, LayoutState layoutState, bool immediate, float scrolled = 0)
- {
- if (layoutState.LayoutDirection == LayoutState.LAYOUT_END)
- {
- // get the first child in the direction we are going
- FlexibleView.ViewHolder child = GetChildClosestToEnd();
- if (child != null)
- {
- if (child.ItemView.Focusable == false || mOrientationHelper.GetViewHolderEnd(child) + scrolled < mOrientationHelper.GetEnd())
- {
- layoutState.Available = MAX_SCROLL_FACTOR * mOrientationHelper.GetTotalSpace();
- layoutState.Extra = 0;
- layoutState.ScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
- layoutState.Recycle = false;
- Fill(recycler, layoutState, true, immediate);
- }
- }
- }
- else
- {
- FlexibleView.ViewHolder child = GetChildClosestToStart();
- if (child != null)
- {
- if (child.ItemView.Focusable == false || mOrientationHelper.GetViewHolderStart(child) + scrolled > 0)
- {
- layoutState.Available = MAX_SCROLL_FACTOR * mOrientationHelper.GetTotalSpace();
- layoutState.Extra = 0;
- layoutState.ScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
- layoutState.Recycle = false;
- Fill(recycler, layoutState, true, immediate);
- }
- }
- }
- }
-
- private void RecycleByLayoutState(FlexibleView.Recycler recycler, LayoutState layoutState, bool immediate)
- {
- if (!layoutState.Recycle)
- {
- return;
- }
- if (layoutState.LayoutDirection == LayoutState.LAYOUT_START)
- {
- RecycleViewsFromEnd(recycler, layoutState.ScrollingOffset, immediate);
- }
- else
- {
- RecycleViewsFromStart(recycler, layoutState.ScrollingOffset, immediate);
- }
- }
-
- private void RecycleViewsFromStart(FlexibleView.Recycler recycler, float dt, bool immediate)
- {
- if (dt < 0)
- {
- return;
- }
- // ignore padding, ViewGroup may not clip children.
- float limit = dt;
- int childCount = ChildCount;
- if (mShouldReverseLayout)
- {
- for (int i = childCount - 1; i >= 0; i--)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if (mOrientationHelper.GetViewHolderEnd(child) > limit)
- {
- // stop here
- RecycleChildren(recycler, childCount - 1, i, immediate);
- return;
- }
- }
- }
- else
- {
- for (int i = 0; i < childCount; i++)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if (mOrientationHelper.GetViewHolderEnd(child) > limit)
- {
- // stop here
- RecycleChildren(recycler, 0, i, immediate);
- return;
- }
- }
- }
- }
-
- private void RecycleViewsFromEnd(FlexibleView.Recycler recycler, float dt, bool immediate)
- {
- if (dt < 0)
- {
- return;
- }
- int childCount = ChildCount;
- float limit = mOrientationHelper.GetEnd() - dt;
- if (mShouldReverseLayout)
- {
- for (int i = 0; i < childCount; i++)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if (mOrientationHelper.GetViewHolderStart(child) < limit)
- {
- // stop here
- RecycleChildren(recycler, 0, i, immediate);
- return;
- }
- }
- }
- else
- {
- for (int i = childCount - 1; i >= 0; i--)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if (mOrientationHelper.GetViewHolderStart(child) < limit)
- {
- // stop here
- RecycleChildren(recycler, childCount - 1, i, immediate);
- return;
- }
- }
- }
- }
-
- private float ScrollBy(float dy, FlexibleView.Recycler recycler, bool immediate)
- {
- if (ChildCount == 0 || dy == 0)
- {
- return 0;
- }
- mLayoutState.Recycle = true;
- int layoutDirection = dy < 0 ? LayoutState.LAYOUT_END : LayoutState.LAYOUT_START;
- float absDy = Math.Abs(dy);
-
- UpdateLayoutState(layoutDirection, absDy, true);
-
- float consumed = mLayoutState.ScrollingOffset
- + Fill(recycler, mLayoutState, false, immediate);
-
- if (consumed < 0)
- {
- return 0;
- }
-
- float scrolled = absDy > consumed ? -layoutDirection * consumed : dy;
- Cache(recycler, mLayoutState, immediate, scrolled);
-
- mOrientationHelper.OffsetChildren(scrolled, immediate);
-
- return scrolled;
- }
-
- private void UpdateLayoutState(int layoutDirection, float requiredSpace, bool canUseExistingSpace)
- {
- mLayoutState.Extra = 0;
- mLayoutState.LayoutDirection = layoutDirection;
- float scrollingOffset = 0.0f;
- if (layoutDirection == LayoutState.LAYOUT_END)
- {
- mLayoutState.Extra += mOrientationHelper.GetEndPadding();
- // get the first child in the direction we are going
- FlexibleView.ViewHolder child = GetChildClosestToEnd();
- if (child != null)
- {
- // the direction in which we are traversing children
- mLayoutState.ItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_HEAD
- : LayoutState.ITEM_DIRECTION_TAIL;
- mLayoutState.CurrentPosition = child.LayoutPosition + mLayoutState.ItemDirection;
- mLayoutState.Offset = mOrientationHelper.GetViewHolderEnd(child);
- // calculate how much we can scroll without adding new children (independent of layout)
- scrollingOffset = mOrientationHelper.GetViewHolderEnd(child)
- - mOrientationHelper.GetEndAfterPadding();
- }
-
- }
- else
- {
- mLayoutState.Extra += mOrientationHelper.GetStartAfterPadding();
- FlexibleView.ViewHolder child = GetChildClosestToStart();
- if (child != null)
- {
- mLayoutState.ItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_TAIL
- : LayoutState.ITEM_DIRECTION_HEAD;
- mLayoutState.CurrentPosition = child.LayoutPosition + mLayoutState.ItemDirection;
- mLayoutState.Offset = mOrientationHelper.GetViewHolderStart(child);
- scrollingOffset = -mOrientationHelper.GetViewHolderStart(child)
- + mOrientationHelper.GetStartAfterPadding();
- }
- }
- mLayoutState.Available = requiredSpace;
- if (canUseExistingSpace)
- {
- mLayoutState.Available -= scrollingOffset;
- }
- mLayoutState.ScrollingOffset = scrollingOffset;
- }
-
- // Convenience method to find the child closes to start. Caller should check it has enough
- // children.
- //
- // @return The child closes to start of the layout from user's perspective.
- private FlexibleView.ViewHolder GetChildClosestToStart()
- {
- return GetChildAt(mShouldReverseLayout ? ChildCount - 1 : 0);
- }
-
- // Convenience method to find the child closes to end. Caller should check it has enough
- // children.
- //
- // @return The child closes to end of the layout from user's perspective.
- private FlexibleView.ViewHolder GetChildClosestToEnd()
- {
- return GetChildAt(mShouldReverseLayout ? 0 : ChildCount - 1);
- }
-
- private void UpdateLayoutStateToFillEnd(int itemPosition, float offset)
- {
- mLayoutState.Available = mOrientationHelper.GetEndAfterPadding() - offset;
- mLayoutState.ItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_HEAD :
- LayoutState.ITEM_DIRECTION_TAIL;
- mLayoutState.CurrentPosition = itemPosition;
- mLayoutState.LayoutDirection = LayoutState.LAYOUT_END;
- mLayoutState.Offset = offset;
- mLayoutState.ScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
- mLayoutState.Extra = mOrientationHelper.GetEndPadding();
-
- }
-
- private void UpdateLayoutStateToFillStart(int itemPosition, float offset)
- {
- mLayoutState.Available = offset - mOrientationHelper.GetStartAfterPadding();
- mLayoutState.CurrentPosition = itemPosition;
- mLayoutState.ItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_TAIL :
- LayoutState.ITEM_DIRECTION_HEAD;
- mLayoutState.LayoutDirection = LayoutState.LAYOUT_START;
- mLayoutState.Offset = offset;
- mLayoutState.ScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
- mLayoutState.Extra = mOrientationHelper.GetStartAfterPadding();
- }
-
- private FlexibleView.ViewHolder FindFirstCompleteVisibleItemView()
- {
- int childCount = ChildCount;
- if (mShouldReverseLayout == false)
- {
- for (int i = 0; i < childCount; i++)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- int start = (int)mOrientationHelper.GetViewHolderStart(child);
- if (start > 0 && start < (int)mOrientationHelper.GetEnd())
- {
- return child;
- }
- }
- }
- else
- {
- for (int i = childCount - 1; i >= 0; i--)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- int start = (int)mOrientationHelper.GetViewHolderStart(child);
- if (start > 0 && start < (int)mOrientationHelper.GetEnd())
- {
- return child;
- }
- }
- }
- return null;
- }
-
- private FlexibleView.ViewHolder FindLastCompleteVisibleItemView()
- {
- int childCount = ChildCount;
- if (mShouldReverseLayout == false)
- {
- for (int i = childCount - 1; i >= 0; i--)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if ((int)mOrientationHelper.GetViewHolderEnd(child) < (int)mOrientationHelper.GetEnd())
- {
- return child;
- }
- }
- }
- else
- {
- for (int i = 0; i < childCount; i++)
- {
- FlexibleView.ViewHolder child = GetChildAt(i);
- if ((int)mOrientationHelper.GetViewHolderEnd(child) < (int)mOrientationHelper.GetEnd())
- {
- return child;
- }
- }
- }
- return null;
- }
-
- // Helper class that keeps temporary state while {LayoutManager} is filling out the empty space.
- internal class LayoutState
- {
- public static readonly int LAYOUT_START = -1;
-
- public static readonly int LAYOUT_END = 1;
-
- public static readonly int INVALID_LAYOUT = -1000;
-
- public static readonly int ITEM_DIRECTION_HEAD = -1;
-
- public static readonly int ITEM_DIRECTION_TAIL = 1;
-
- public static readonly int SCROLLING_OFFSET_NaN = -10000;
-
- // We may not want to recycle children in some cases (e.g. layout)
- public bool Recycle = true;
-
- // Pixel offset where layout should start
- public float Offset;
-
- // Number of pixels that we should fill, in the layout direction.
- public float Available;
-
- // Current position on the adapter to get the next item.
- public int CurrentPosition;
-
- // Defines the direction in which the data adapter is traversed.
- // Should be {@link #ITEM_DIRECTION_HEAD} or {@link #ITEM_DIRECTION_TAIL}
- public int ItemDirection;
-
- // Defines the direction in which the layout is filled.
- // Should be {@link #LAYOUT_START} or {@link #LAYOUT_END}
- public int LayoutDirection;
-
- // Used when LayoutState is constructed in a scrolling state.
- // It should be set the amount of scrolling we can make without creating a new view.
- // Settings this is required for efficient view recycling.
- public float ScrollingOffset;
-
- // Used if you want to pre-layout items that are not yet visible.
- // The difference with {@link #mAvailable} is that, when recycling, distance laid out for
- // {@link #mExtra} is not considered to avoid recycling visible children.
- public float Extra = 0;
-
- // @return true if there are more items in the data adapter
- public bool HasMore(int itemCount)
- {
- return CurrentPosition >= 0 && CurrentPosition < itemCount;
- }
-
- // Gets the view for the next element that we should layout.
- // Also updates current item index to the next item, based on {@link #mItemDirection}
- //
- // @return The next element that we should layout.
- public FlexibleView.ViewHolder Next(FlexibleView.Recycler recycler)
- {
- FlexibleView.ViewHolder itemView = recycler.GetViewForPosition(CurrentPosition);
- CurrentPosition += ItemDirection;
-
- return itemView;
- }
- }
-
- internal class LayoutChunkResult
- {
- public float Consumed;
- public bool Finished;
- public bool IgnoreConsumed;
- public bool Focusable;
-
- public void ResetInternal()
- {
- Consumed = 0;
- Finished = false;
- IgnoreConsumed = false;
- Focusable = false;
- }
- }
-
- internal class AnchorInfo
- {
- public int Position;
- public float Coordinate;
- public bool LayoutFromEnd;
- public bool Valid;
-
- public void Reset()
- {
- Position = NO_POSITION;
- Coordinate = INVALID_OFFSET;
- LayoutFromEnd = false;
- Valid = false;
- }
-
- }
}
}
projects / platform / core / csapi / tizenfx.git / blobdiff