pjs/layout/generic/nsHTMLReflowState.h

516 строки
21 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* struct containing the input to nsIFrame::Reflow */
#ifndef nsHTMLReflowState_h___
#define nsHTMLReflowState_h___
#include "nsMargin.h"
#include "nsStyleCoord.h"
#include "nsIFrame.h"
class nsPresContext;
class nsIRenderingContext;
class nsFloatManager;
class nsLineLayout;
class nsIPercentHeightObserver;
struct nsStyleDisplay;
struct nsStyleVisibility;
struct nsStylePosition;
struct nsStyleBorder;
struct nsStyleMargin;
struct nsStylePadding;
struct nsStyleText;
struct nsHypotheticalBox;
template <class NumericType>
NumericType
NS_CSS_MINMAX(NumericType aValue, NumericType aMinValue, NumericType aMaxValue)
{
NumericType result = aValue;
if (aMaxValue < result)
result = aMaxValue;
if (aMinValue > result)
result = aMinValue;
return result;
}
/**
* Constant used to indicate an unconstrained size.
*
* @see #Reflow()
*/
#define NS_UNCONSTRAINEDSIZE NS_MAXSIZE
/**
* CSS Frame type. Included as part of the reflow state.
*/
typedef PRUint32 nsCSSFrameType;
#define NS_CSS_FRAME_TYPE_UNKNOWN 0
#define NS_CSS_FRAME_TYPE_INLINE 1
#define NS_CSS_FRAME_TYPE_BLOCK 2 /* block-level in normal flow */
#define NS_CSS_FRAME_TYPE_FLOATING 3
#define NS_CSS_FRAME_TYPE_ABSOLUTE 4
#define NS_CSS_FRAME_TYPE_INTERNAL_TABLE 5 /* row group frame, row frame, cell frame, ... */
/**
* Bit-flag that indicates whether the element is replaced. Applies to inline,
* block-level, floating, and absolutely positioned elements
*/
#define NS_CSS_FRAME_TYPE_REPLACED 0x08000
/**
* Bit-flag that indicates that the element is replaced and contains a block
* (eg some form controls). Applies to inline, block-level, floating, and
* absolutely positioned elements. Mutually exclusive with
* NS_CSS_FRAME_TYPE_REPLACED.
*/
#define NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK 0x10000
/**
* Helper macros for telling whether items are replaced
*/
#define NS_FRAME_IS_REPLACED_NOBLOCK(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED == ((_ft) & NS_CSS_FRAME_TYPE_REPLACED))
#define NS_FRAME_IS_REPLACED(_ft) \
(NS_FRAME_IS_REPLACED_NOBLOCK(_ft) || \
NS_FRAME_IS_REPLACED_CONTAINS_BLOCK(_ft))
#define NS_FRAME_REPLACED(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED | (_ft))
#define NS_FRAME_IS_REPLACED_CONTAINS_BLOCK(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK == \
((_ft) & NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK))
#define NS_FRAME_REPLACED_CONTAINS_BLOCK(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK | (_ft))
/**
* A macro to extract the type. Masks off the 'replaced' bit-flag
*/
#define NS_FRAME_GET_TYPE(_ft) \
((_ft) & ~(NS_CSS_FRAME_TYPE_REPLACED | \
NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK))
#define NS_INTRINSICSIZE NS_UNCONSTRAINEDSIZE
#define NS_AUTOHEIGHT NS_UNCONSTRAINEDSIZE
#define NS_AUTOMARGIN NS_UNCONSTRAINEDSIZE
#define NS_AUTOOFFSET NS_UNCONSTRAINEDSIZE
// NOTE: there are assumptions all over that these have the same value, namely NS_UNCONSTRAINEDSIZE
// if any are changed to be a value other than NS_UNCONSTRAINEDSIZE
// at least update AdjustComputedHeight/Width and test ad nauseum
// A base class of nsHTMLReflowState that computes only the padding,
// border, and margin, since those values are needed more often.
struct nsCSSOffsetState {
public:
// the frame being reflowed
nsIFrame* frame;
// rendering context to use for measurement
nsIRenderingContext* rendContext;
// Computed margin values
nsMargin mComputedMargin;
// Cached copy of the border + padding values
nsMargin mComputedBorderPadding;
// Computed padding values
nsMargin mComputedPadding;
// Callers using this constructor must call InitOffsets on their own.
nsCSSOffsetState(nsIFrame *aFrame, nsIRenderingContext *aRenderingContext)
: frame(aFrame)
, rendContext(aRenderingContext)
{
}
nsCSSOffsetState(nsIFrame *aFrame, nsIRenderingContext *aRenderingContext,
nscoord aContainingBlockWidth)
: frame(aFrame)
, rendContext(aRenderingContext)
{
InitOffsets(aContainingBlockWidth);
}
// Destructor for usedPaddingProperty
static void DestroyMarginFunc(void* aFrame,
nsIAtom* aPropertyName,
void* aPropertyValue,
void* aDtorData);
private:
// Computes margin values from the specified margin style information, and
// fills in the mComputedMargin member
void ComputeMargin(nscoord aContainingBlockWidth);
// Computes padding values from the specified padding style information, and
// fills in the mComputedPadding member
void ComputePadding(nscoord aContainingBlockWidth);
protected:
void InitOffsets(nscoord aContainingBlockWidth,
const nsMargin *aBorder = nsnull,
const nsMargin *aPadding = nsnull);
/*
* Convert nsStyleCoord to nscoord when percentages depend on the
* containing block width, and enumerated values are for width,
* min-width, or max-width. Does not handle auto widths.
*/
inline nscoord ComputeWidthValue(nscoord aContainingBlockWidth,
nscoord aContentEdgeToBoxSizing,
nscoord aBoxSizingToMarginEdge,
const nsStyleCoord& aCoord);
// same as previous, but using mComputedBorderPadding, mComputedPadding,
// and mComputedMargin
nscoord ComputeWidthValue(nscoord aContainingBlockWidth,
PRUint8 aBoxSizing,
const nsStyleCoord& aCoord);
};
/**
* State passed to a frame during reflow or intrinsic size calculation.
*
* XXX Refactor so only a base class (nsSizingState?) is used for intrinsic
* size calculation.
*
* @see nsIFrame#Reflow()
*/
struct nsHTMLReflowState : public nsCSSOffsetState {
// the reflow states are linked together. this is the pointer to the
// parent's reflow state
const nsHTMLReflowState* parentReflowState;
// the available width in which to reflow the frame. The space
// represents the amount of room for the frame's border, padding,
// and content area (not the margin area. The parent frame deals
// with the child frame's margins). The frame size you choose should
// fit within the available width.
nscoord availableWidth;
// A value of NS_UNCONSTRAINEDSIZE for the available height means
// you can choose whatever size you want. In galley mode the
// available height is always NS_UNCONSTRAINEDSIZE, and only page
// mode or multi-column layout involves a constrained height. The
// element's the top border and padding, and content, must fit. If the
// element is complete after reflow then its bottom border, padding
// and margin (and similar for its complete ancestors) will need to
// fit in this height.
nscoord availableHeight;
// The type of frame, from css's perspective. This value is
// initialized by the Init method below.
nsCSSFrameType mFrameType;
// pointer to the float manager associated with this area
nsFloatManager* mFloatManager;
// The amount the in-flow position of the block is moving vertically relative
// to its previous in-flow position (i.e. the amount the line containing the
// block is moving).
// This should be zero for anything which is not a block outside, and it
// should be zero for anything which has a non-block parent.
// The intended use of this value is to allow the accurate determination
// of the potential impact of a float
// This takes on an arbitrary value the first time a block is reflowed
nscoord mBlockDelta;
// LineLayout object (only for inline reflow; set to NULL otherwise)
nsLineLayout* mLineLayout;
// The appropriate reflow state for the containing block (for
// percentage widths, etc.) of this reflow state's frame.
const nsHTMLReflowState *mCBReflowState;
private:
// The computed width specifies the frame's content area width, and it does
// not apply to inline non-replaced elements
//
// For replaced inline frames, a value of NS_INTRINSICSIZE means you should
// use your intrinsic width as the computed width
//
// For block-level frames, the computed width is based on the width of the
// containing block, the margin/border/padding areas, and the min/max width.
nscoord mComputedWidth;
// The computed height specifies the frame's content height, and it does
// not apply to inline non-replaced elements
//
// For replaced inline frames, a value of NS_INTRINSICSIZE means you should
// use your intrinsic height as the computed height
//
// For non-replaced block-level frames in the flow and floated, a value of
// NS_AUTOHEIGHT means you choose a height to shrink wrap around the normal
// flow child frames. The height must be within the limit of the min/max
// height if there is such a limit
//
// For replaced block-level frames, a value of NS_INTRINSICSIZE
// means you use your intrinsic height as the computed height
nscoord mComputedHeight;
public:
// Computed values for 'left/top/right/bottom' offsets. Only applies to
// 'positioned' elements
nsMargin mComputedOffsets;
// Computed values for 'min-width/max-width' and 'min-height/max-height'
// XXXldb The width ones here should go; they should be needed only
// internally.
nscoord mComputedMinWidth, mComputedMaxWidth;
nscoord mComputedMinHeight, mComputedMaxHeight;
// Cached pointers to the various style structs used during intialization
const nsStyleDisplay* mStyleDisplay;
const nsStyleVisibility* mStyleVisibility;
const nsStylePosition* mStylePosition;
const nsStyleBorder* mStyleBorder;
const nsStyleMargin* mStyleMargin;
const nsStylePadding* mStylePadding;
const nsStyleText* mStyleText;
// a frame (e.g. nsTableCellFrame) which may need to generate a special
// reflow for percent height calculations
nsIPercentHeightObserver* mPercentHeightObserver;
// CSS margin collapsing sometimes requires us to reflow
// optimistically assuming that margins collapse to see if clearance
// is required. When we discover that clearance is required, we
// store the frame in which clearance was discovered to the location
// requested here.
nsIFrame** mDiscoveredClearance;
// This value keeps track of how deeply nested a given reflow state
// is from the top of the frame tree.
PRInt16 mReflowDepth;
struct ReflowStateFlags {
PRUint16 mSpecialHeightReflow:1; // used by tables to communicate special reflow (in process) to handle
// percent height frames inside cells which may not have computed heights
PRUint16 mNextInFlowUntouched:1; // nothing in the frame's next-in-flow (or its descendants)
// is changing
PRUint16 mIsTopOfPage:1; // is the current context at the top of a page?
PRUint16 mBlinks:1; // Keep track of text-decoration: blink
PRUint16 mHasClearance:1; // Block has clearance
PRUint16 mAssumingHScrollbar:1; // parent frame is an nsIScrollableFrame and it
// is assuming a horizontal scrollbar
PRUint16 mAssumingVScrollbar:1; // parent frame is an nsIScrollableFrame and it
// is assuming a vertical scrollbar
PRUint16 mHResize:1; // Is frame (a) not dirty and (b) a
// different width than before?
PRUint16 mVResize:1; // Is frame (a) not dirty and (b) a
// different height than before or
// (potentially) in a context where
// percent heights have a different
// basis?
PRUint16 mTableIsSplittable:1; // tables are splittable, this should happen only inside a page
// and never insider a column frame
PRUint16 mHeightDependsOnAncestorCell:1; // Does frame height depend on
// an ancestor table-cell?
} mFlags;
// Note: The copy constructor is written by the compiler automatically. You
// can use that and then override specific values if you want, or you can
// call Init as desired...
// Initialize a <b>root</b> reflow state with a rendering context to
// use for measuring things.
nsHTMLReflowState(nsPresContext* aPresContext,
nsIFrame* aFrame,
nsIRenderingContext* aRenderingContext,
const nsSize& aAvailableSpace);
// Initialize a reflow state for a child frames reflow. Some state
// is copied from the parent reflow state; the remaining state is
// computed.
nsHTMLReflowState(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace,
// These two are used by absolute positioning code
// to override default containing block w & h:
nscoord aContainingBlockWidth = -1,
nscoord aContainingBlockHeight = -1,
PRBool aInit = PR_TRUE);
// This method initializes various data members. It is automatically
// called by the various constructors
void Init(nsPresContext* aPresContext,
nscoord aContainingBlockWidth = -1,
nscoord aContainingBlockHeight = -1,
const nsMargin* aBorder = nsnull,
const nsMargin* aPadding = nsnull);
/**
* Find the content width of the containing block of aReflowState
*/
static nscoord
GetContainingBlockContentWidth(const nsHTMLReflowState* aReflowState);
/**
* Find the containing block of aFrame. This may return null if
* there isn't one (but that should really only happen for root
* frames).
*/
static nsIFrame* GetContainingBlockFor(const nsIFrame* aFrame);
/**
* Calculate the raw line-height property for the given frame. The return
* value will be >= 0.
*/
static nscoord CalcLineHeight(nsIFrame* aFrame)
{
return CalcLineHeight(aFrame->GetStyleContext());
}
/**
* Same as above, but doesn't need a frame.
*/
static nscoord CalcLineHeight(nsStyleContext* aStyleContext);
void ComputeContainingBlockRectangle(nsPresContext* aPresContext,
const nsHTMLReflowState* aContainingBlockRS,
nscoord& aContainingBlockWidth,
nscoord& aContainingBlockHeight);
/**
* Apply the mComputed(Min/Max)(Width/Height) values to the content
* size computed so far. If a passed-in pointer is null, we skip
* adjusting that dimension.
*/
void ApplyMinMaxConstraints(nscoord* aContentWidth, nscoord* aContentHeight) const;
PRBool ShouldReflowAllKids() const {
// Note that we could make a stronger optimization for mVResize if
// we use it in a ShouldReflowChild test that replaces the current
// checks of NS_FRAME_IS_DIRTY | NS_FRAME_HAS_DIRTY_CHILDREN, if it
// were tested there along with NS_FRAME_CONTAINS_RELATIVE_HEIGHT.
// This would need to be combined with a slight change in which
// frames NS_FRAME_CONTAINS_RELATIVE_HEIGHT is marked on.
return (frame->GetStateBits() & NS_FRAME_IS_DIRTY) ||
mFlags.mHResize ||
(mFlags.mVResize &&
(frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT));
}
nscoord ComputedWidth() const { return mComputedWidth; }
// This method doesn't apply min/max computed widths to the value passed in.
void SetComputedWidth(nscoord aComputedWidth);
nscoord ComputedHeight() const { return mComputedHeight; }
// This method doesn't apply min/max computed heights to the value passed in.
void SetComputedHeight(nscoord aComputedHeight);
void SetComputedHeightWithoutResettingResizeFlags(nscoord aComputedHeight) {
// Viewport frames reset the computed height on a copy of their reflow
// state when reflowing fixed-pos kids. In that case we actually don't
// want to mess with the resize flags, because comparing the frame's rect
// to the munged computed width is pointless.
mComputedHeight = aComputedHeight;
}
void SetTruncated(const nsHTMLReflowMetrics& aMetrics, nsReflowStatus* aStatus) const;
PRBool WillReflowAgainForClearance() const {
return mDiscoveredClearance && *mDiscoveredClearance;
}
protected:
void InitFrameType();
void InitCBReflowState();
void InitResizeFlags(nsPresContext* aPresContext);
void InitConstraints(nsPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsMargin* aBorder,
const nsMargin* aPadding);
// Returns the nearest containing block or block frame (whether or not
// it is a containing block) for the specified frame. Also returns
// the left edge and width of the containing block's content area.
// These are returned in the coordinate space of the containing block.
nsIFrame* GetHypotheticalBoxContainer(nsIFrame* aFrame,
nscoord& aCBLeftEdge,
nscoord& aCBWidth);
void CalculateHypotheticalBox(nsPresContext* aPresContext,
nsIFrame* aPlaceholderFrame,
nsIFrame* aContainingBlock,
nscoord aBlockLeftContentEdge,
nscoord aBlockContentWidth,
const nsHTMLReflowState* cbrs,
nsHypotheticalBox& aHypotheticalBox);
void InitAbsoluteConstraints(nsPresContext* aPresContext,
const nsHTMLReflowState* cbrs,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight);
void ComputeRelativeOffsets(const nsHTMLReflowState* cbrs,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
nsPresContext* aPresContext);
// Calculates the computed values for the 'min-Width', 'max-Width',
// 'min-Height', and 'max-Height' properties, and stores them in the assorted
// data members
void ComputeMinMaxValues(nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsHTMLReflowState* aContainingBlockRS);
void CalculateHorizBorderPaddingMargin(nscoord aContainingBlockWidth,
nscoord* aInsideBoxSizing,
nscoord* aOutsideBoxSizing);
void CalculateBlockSideMargins(nscoord aAvailWidth,
nscoord aComputedWidth);
};
#endif /* nsHTMLReflowState_h___ */