|
public InvalidateInRoot ( |
||
| rect | ||
| return | void | |
/// <summary>
/// Overriden since, if our old Height is zero, the base method will assume the box is new and does
/// not need invalidate, since it's container will figure its new area. But the root has no container,
/// so we handle this special case here.
/// </summary>
internal override bool Relayout(LayoutInfo transform, Dictionary <Box, Rectangle> fixupMap,
LayoutCallbacks lcb)
{
var oldHeight = Height;
var result = base.Relayout(transform, fixupMap, lcb);
if (oldHeight == 0 && Height != 0)
{
lcb.InvalidateInRoot(InvalidateRect);
}
if (Height != oldHeight)
{
RaiseSizeChanged();
}
return(result);
}
/// <summary>
///When the contents of a box changes, and its size consequently might change, something
///needs to be done about the layout of that box and all its containers.
///The process begins by constructing a FixupMap, which contains the changed box and all
///its parents, each recording (against the box as a key) the invalidate rectangle appropriate
///to the old box layout.
///We then pass this to the Relayout method of the root box.
///By default, any box which finds itself in the map, or which has never been laid out
///(its height is zero), does a full normal layout, and invalidates its old (if any)
///rectangle. It can't invalidate its new rectangle, because at the point where relayout
///is called, the parent box may not have finalized the new position of the child...
///so return true if the parent needs to invalidate the new position.
///Relayout should not be used in cases where the available width may have changed, as this
///could affect the layout of boxes that are not in the map.
///Note that, if the box moves, invalidating its new size at its old position, or vice versa,
///may not do much good. If it moves, the containing box must do appropriate extra
///invalidating.
///Some boxes, notably VwDivBox, may not need to relayout all their children, or even to
///invalidate all their own contents. This can be an important optimization, but must be
///done with care to ensure that what is actually drawn is always correct.
/// </summary>
internal virtual bool Relayout(LayoutInfo transform, Dictionary <Box, Rectangle> fixupMap, LayoutCallbacks lcb)
{
if (Height == 0)
{
// Never been laid out. Can't need to invalidate, before or after.
Layout(transform);
return(false);
}
Rectangle invalidRect;
if (fixupMap.TryGetValue(this, out invalidRect))
{
lcb.InvalidateInRoot(invalidRect);
Layout(transform);
return(true);
}
// Previously laid-out box unaffected by current events. Do nothing, caller need not invalidate unless moved.
return(false);
}
/// <summary>
/// Keep in sync with PileBox.Layout.
/// It's important to optimize relayout of DivBox, because they can be very large, and often the height
/// of a child does not actually change. Also, this is currently the implementation inherited by root box,
/// and the boolean returned from Relayout on the root is ignored; this routine must accomplish all needed
/// layout itself.
/// We override here rather than on PileBox because non-div piles are typically small and laying out the whole
/// thing is not too expensive, while it is harder to predict how changes (e.g., in width) might affect parents.
/// The parents of Divs can only be divs.
/// </summary>
internal override bool Relayout(LayoutInfo transform, Dictionary <Box, Rectangle> fixupMap, LayoutCallbacks lcb)
{
if (Height == 0)
{
// brand new box, needs full layout but not invalidate, since it never has been visible.
Layout(transform);
return(false);
}
Rectangle oldLocation;
if (!fixupMap.TryGetValue(this, out oldLocation))
{
return(false); // unchanged, this box does not need to be re-laid out or invalidated.
}
var left = GapLeading(transform);
var top = GapTop(transform);
var rightGap = GapTrailing(transform);
var maxWidth = 0;
int oldHeight = Height;
int oldWidth = Width;
var topInvalidate = int.MaxValue;
int prevBoxOldBottom = 0;
var childTransform = transform.WithMaxWidthOffsetBy(transform.MaxWidth - left - rightGap, Left, Top);
Box prevBox = null;
for (var box = FirstBox; box != null; box = box.Next)
{
int oldBottom = box.Bottom; // before it is moved or resized (but may be spuriously 0 for new box)
bool needsInvalidate = box.Relayout(childTransform, fixupMap, lcb);
top = AdjustTopForMargins(top, transform, prevBox, box);
// Now figure whether we need to start invalidating based on moved boxes.
// If this box moved, we need to invalidate from its top down...or even from its old
// top, since the preceding box may have shrunk, without this one changing internally.
if (box.Top != top) // test this before we add height to top.
{
topInvalidate = Math.Min(topInvalidate, Math.Min(top, prevBoxOldBottom));
box.Top = top;
}
box.Left = left;
top += box.Height;
maxWidth = Math.Max(maxWidth, box.Width);
// assumes our top will not move; if it does, everything gets invalidated, so this is only wasted.
if (needsInvalidate)
{
lcb.InvalidateInRoot(box.InvalidateRect);
}
// The Math.Max prevents us adjusting it downwards for a new box, which originally had zero top
// and height.
prevBoxOldBottom = Math.Max(prevBoxOldBottom, oldBottom);
prevBox = box;
}
Height = top + GapBottom(transform);
Width = maxWidth + left + rightGap;
if (oldWidth != Width)
{
// The new invalidate rect may not be strictly right, but in the unlikley event that this
// box moves, its parent will invalidate its new location again.
lcb.InvalidateInRoot(oldLocation);
lcb.InvalidateInRoot(InvalidateRect);
return(false);
}
// Even if none of the tops moved, if our height changed, we need to invalidate the difference area.
if (Height != oldHeight)
{
topInvalidate = Math.Min(topInvalidate, Math.Min(Height, oldHeight));
}
if (topInvalidate != int.MaxValue)
{
var bottomInvalidate = Math.Max(Height, oldHeight);
// if our top moves, the whole box will get invalidated. Assuming it doesn't,
// oldLocation needs it, adjusted for the bit that didn't move at the top, and possibly
// to account for getting bigger at the bottom.
var invalidate = new Rectangle(oldLocation.Left, oldLocation.Top + topInvalidate, oldLocation.Width,
bottomInvalidate - topInvalidate + Box.InvalidateMargin * 2);
lcb.InvalidateInRoot(invalidate);
}
return(false);
}
/// <summary>
/// Overriden since, if our old Height is zero, the base method will assume the box is new and does
/// not need invalidate, since it's container will figure its new area. But the root has no container,
/// so we handle this special case here.
/// </summary>
internal override bool Relayout(LayoutInfo transform, Dictionary<Box, Rectangle> fixupMap,
LayoutCallbacks lcb)
{
var oldHeight = Height;
var result = base.Relayout(transform, fixupMap, lcb);
if (oldHeight == 0 && Height != 0)
lcb.InvalidateInRoot(InvalidateRect);
if (Height != oldHeight)
RaiseSizeChanged();
return result;
}
/// <summary>
///When the contents of a box changes, and its size consequently might change, something
///needs to be done about the layout of that box and all its containers.
///The process begins by constructing a FixupMap, which contains the changed box and all
///its parents, each recording (against the box as a key) the invalidate rectangle appropriate
///to the old box layout.
///We then pass this to the Relayout method of the root box.
///By default, any box which finds itself in the map, or which has never been laid out
///(its height is zero), does a full normal layout, and invalidates its old (if any)
///rectangle. It can't invalidate its new rectangle, because at the point where relayout
///is called, the parent box may not have finalized the new position of the child...
///so return true if the parent needs to invalidate the new position.
///Relayout should not be used in cases where the available width may have changed, as this
///could affect the layout of boxes that are not in the map.
///Note that, if the box moves, invalidating its new size at its old position, or vice versa,
///may not do much good. If it moves, the containing box must do appropriate extra
///invalidating.
///Some boxes, notably VwDivBox, may not need to relayout all their children, or even to
///invalidate all their own contents. This can be an important optimization, but must be
///done with care to ensure that what is actually drawn is always correct.
/// </summary>
internal virtual bool Relayout(LayoutInfo transform, Dictionary<Box, Rectangle> fixupMap, LayoutCallbacks lcb)
{
if (Height == 0)
{
// Never been laid out. Can't need to invalidate, before or after.
Layout(transform);
return false;
}
Rectangle invalidRect;
if (fixupMap.TryGetValue(this, out invalidRect))
{
lcb.InvalidateInRoot(invalidRect);
Layout(transform);
return true;
}
// Previously laid-out box unaffected by current events. Do nothing, caller need not invalidate unless moved.
return false;
}
/// <summary>
/// Keep in sync with PileBox.Layout.
/// It's important to optimize relayout of DivBox, because they can be very large, and often the height
/// of a child does not actually change. Also, this is currently the implementation inherited by root box,
/// and the boolean returned from Relayout on the root is ignored; this routine must accomplish all needed
/// layout itself.
/// We override here rather than on PileBox because non-div piles are typically small and laying out the whole
/// thing is not too expensive, while it is harder to predict how changes (e.g., in width) might affect parents.
/// The parents of Divs can only be divs.
/// </summary>
internal override bool Relayout(LayoutInfo transform, Dictionary<Box, Rectangle> fixupMap, LayoutCallbacks lcb)
{
if (Height == 0)
{
// brand new box, needs full layout but not invalidate, since it never has been visible.
Layout(transform);
return false;
}
Rectangle oldLocation;
if (!fixupMap.TryGetValue(this, out oldLocation))
return false; // unchanged, this box does not need to be re-laid out or invalidated.
var left = GapLeading(transform);
var top = GapTop(transform);
var rightGap = GapTrailing(transform);
var maxWidth = 0;
int oldHeight = Height;
int oldWidth = Width;
var topInvalidate = int.MaxValue;
int prevBoxOldBottom = 0;
var childTransform = transform.WithMaxWidthOffsetBy(transform.MaxWidth - left - rightGap, Left, Top);
Box prevBox = null;
for (var box = FirstBox; box != null; box = box.Next)
{
int oldBottom = box.Bottom; // before it is moved or resized (but may be spuriously 0 for new box)
bool needsInvalidate = box.Relayout(childTransform, fixupMap, lcb);
top = AdjustTopForMargins(top, transform, prevBox, box);
// Now figure whether we need to start invalidating based on moved boxes.
// If this box moved, we need to invalidate from its top down...or even from its old
// top, since the preceding box may have shrunk, without this one changing internally.
if (box.Top != top) // test this before we add height to top.
{
topInvalidate = Math.Min(topInvalidate, Math.Min(top, prevBoxOldBottom));
box.Top = top;
}
box.Left = left;
top += box.Height;
maxWidth = Math.Max(maxWidth, box.Width);
// assumes our top will not move; if it does, everything gets invalidated, so this is only wasted.
if (needsInvalidate)
lcb.InvalidateInRoot(box.InvalidateRect);
// The Math.Max prevents us adjusting it downwards for a new box, which originally had zero top
// and height.
prevBoxOldBottom = Math.Max(prevBoxOldBottom, oldBottom);
prevBox = box;
}
Height = top + GapBottom(transform);
Width = maxWidth + left + rightGap;
if (oldWidth != Width)
{
// The new invalidate rect may not be strictly right, but in the unlikley event that this
// box moves, its parent will invalidate its new location again.
lcb.InvalidateInRoot(oldLocation);
lcb.InvalidateInRoot(InvalidateRect);
return false;
}
// Even if none of the tops moved, if our height changed, we need to invalidate the difference area.
if (Height != oldHeight)
topInvalidate = Math.Min(topInvalidate, Math.Min(Height, oldHeight));
if (topInvalidate != int.MaxValue)
{
var bottomInvalidate = Math.Max(Height, oldHeight);
// if our top moves, the whole box will get invalidated. Assuming it doesn't,
// oldLocation needs it, adjusted for the bit that didn't move at the top, and possibly
// to account for getting bigger at the bottom.
var invalidate = new Rectangle(oldLocation.Left, oldLocation.Top + topInvalidate, oldLocation.Width,
bottomInvalidate - topInvalidate + Box.InvalidateMargin*2);
lcb.InvalidateInRoot(invalidate);
}
return false;
}