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#ifndef nsHTMLReflowState_h___
#define nsHTMLReflowState_h___
#include "nsMargin.h"
#include "nsStyleCoord.h"
class nsIFrame;
class nsPresContext;
class nsReflowPath;
class nsIRenderingContext;
class nsSpaceManager;
class nsLineLayout;
class nsIPercentHeightObserver;
struct nsStyleDisplay;
struct nsStyleVisibility;
struct nsStylePosition;
struct nsStyleBorder;
struct nsStyleMargin;
struct nsStylePadding;
struct nsStyleText;
struct nsHypotheticalBox;
/**
* Constant used to indicate an unconstrained size.
*
* @see #Reflow()
*/
#define NS_UNCONSTRAINEDSIZE NS_MAXSIZE
/**
* The reason the frame is being reflowed.
*
* XXX Should probably be a #define so it can be extended for specialized
* reflow interfaces...
*
* @see nsHTMLReflowState
*/
enum nsReflowReason {
eReflowReason_Initial = 0, // initial reflow of a newly created frame
eReflowReason_Incremental = 1, // an incremental change has occured. see the reflow command for details
eReflowReason_Resize = 2, // general request to determine a desired size
eReflowReason_StyleChange = 3, // request to reflow because of a style change. Note: you must reflow
// all your child frames
eReflowReason_Dirty = 4 // request to reflow because you and/or your children are dirty
};
/**
* 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 0x8000
/**
* Helper macros for telling whether items are replaced
*/
#define NS_FRAME_IS_REPLACED(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED == ((_ft) & NS_CSS_FRAME_TYPE_REPLACED))
#define NS_FRAME_REPLACED(_ft) \
(NS_CSS_FRAME_TYPE_REPLACED | (_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)
#define NS_INTRINSICSIZE NS_UNCONSTRAINEDSIZE
#define NS_SHRINKWRAPWIDTH 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
/**
* Reflow state passed to a frame during reflow.
*
* @see nsIFrame#Reflow()
*/
struct nsHTMLReflowState {
// the reflow states are linked together. this is the pointer to the
// parent's reflow state
const nsHTMLReflowState* parentReflowState;
// the frame being reflowed
nsIFrame* frame;
// the reason for the reflow
nsReflowReason reason;
// the incremental reflow path, when the reflow reason is
// eReflowReason_Incremental. Specifically, this corresponds to the
// portion of the incremental reflow path from `frame' down. Note
// that it is safe to assume that this is non-null: we maintain the
// invariant that it contains a valid nsReflowPath pointer when
// reason == eReflowReason_Incremental.
nsReflowPath *path;
// 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 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;
// rendering context to use for measurement
nsIRenderingContext* rendContext;
// The type of frame, from css's perspective. This value is
// initialized by the Init method below.
nsCSSFrameType mFrameType;
// pointer to the space manager associated with this area
nsSpaceManager* mSpaceManager;
// 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;
// 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.
// A value of NS_SHRINKWRAPWIDTH means that you should choose a width based
// on your content. The width may be as large as the specified maximum width
// (see mComputedMaxWidth).
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;
// Computed margin values
nsMargin mComputedMargin;
// Cached copy of the border values
nsMargin mComputedBorderPadding;
// Computed padding values
nsMargin mComputedPadding;
// 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'
nscoord mComputedMinWidth, mComputedMaxWidth;
nscoord mComputedMinHeight, mComputedMaxHeight;
// Compact margin available space
nscoord mCompactMarginWidth;
// 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;
// a frame (e.g. nsTableFrame) which initiates a special reflow for percent height calculations
nsIFrame* mPercentHeightReflowInitiator;
// 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 mVisualBidiFormControl:1; // Keep track of descendants of form controls on Visual Bidi pages
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
} mFlags;
#ifdef IBMBIDI
nscoord mRightEdge;
#endif
#ifdef DEBUG
// hook for attaching debug info (e.g. tables may attach a timer during reflow)
void* mDebugHook;
static const char* ReasonToString(nsReflowReason aReason);
#endif
// 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 root reflow state with a rendering context to
// use for measuring things.
nsHTMLReflowState(nsPresContext* aPresContext,
nsIFrame* aFrame,
nsReflowReason aReason,
nsIRenderingContext* aRenderingContext,
const nsSize& aAvailableSpace);
// Initialize a root reflow state for an incremental
// reflow.
nsHTMLReflowState(nsPresContext* aPresContext,
nsIFrame* aFrame,
nsReflowPath* aReflowPath,
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,
nsReflowReason aReason,
PRBool aInit = PR_TRUE);
// Same as the previous except that the reason is taken from the
// parent's reflow state.
nsHTMLReflowState(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace);
// Used when you want to override the default containing block
// width and height. Used by absolute positioning code
nsHTMLReflowState(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
nsReflowReason aReason);
// This method initializes various data members. It is automatically
// called by the various constructors
void Init(nsPresContext* aPresContext,
nscoord aContainingBlockWidth = -1,
nscoord aContainingBlockHeight = -1,
nsMargin* aBorder = nsnull,
nsMargin* aPadding = nsnull);
/**
* Find the content width of the containing block of aReflowState
*/
static nscoord
GetContainingBlockContentWidth(const nsHTMLReflowState* aReflowState);
/**
* Adjust content MEW take into account the settings of the CSS
* 'width', 'min-width' and 'max-width' properties.
*/
nscoord AdjustIntrinsicMinContentWidthForStyle(nscoord aWidth) const;
/**
* Adjust content maximum-width take into account the settings of
* the CSS 'width', 'min-width' and 'max-width' properties.
*/
nscoord AdjustIntrinsicContentWidthForStyle(nscoord aWidth) const;
/**
* 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);
/**
* Get the page box reflow state, starting from a frames
* parent reflow state (the parent reflow state may or may not end
* up being the containing block reflow state)
*/
static const nsHTMLReflowState*
GetPageBoxReflowState(const nsHTMLReflowState* aParentRS);
/**
* Compute the border plus padding for aFrame. If a
* percentage needs to be computed it will be computed by finding
* the containing block, use GetContainingBlockReflowState.
* aParentReflowState is aFrame's
* parent's reflow state. The resulting computed border plus padding
* is returned in aResult.
*/
static void ComputeBorderPaddingFor(nsIFrame* aFrame,
const nsHTMLReflowState* aParentRS,
nsMargin& aResult);
/**
* Calculate the raw line-height property for the given frame. The return
* value, if line-height was applied and is valid will be >= 0. Otherwise,
* the return value will be <0 which is illegal (CSS2 spec: section 10.8.1).
*/
static nscoord CalcLineHeight(nsPresContext* aPresContext,
nsIRenderingContext* aRenderingContext,
nsIFrame* aFrame);
void InitFrameType();
void ComputeContainingBlockRectangle(nsPresContext* aPresContext,
const nsHTMLReflowState* aContainingBlockRS,
nscoord& aContainingBlockWidth,
nscoord& aContainingBlockHeight);
void CalculateBlockSideMargins(nscoord aAvailWidth,
nscoord aComputedWidth);
/**
* 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;
protected:
void InitCBReflowState();
void InitConstraints(nsPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
nsMargin* aBorder,
nsMargin* aPadding);
void CalculateHypotheticalBox(nsPresContext* aPresContext,
nsIFrame* aPlaceholderFrame,
nsIFrame* aContainingBlock,
nsMargin& aBlockContentArea,
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);
void ComputeBlockBoxData(nsPresContext* aPresContext,
const nsHTMLReflowState* cbrs,
nsStyleUnit aWidthUnit,
nsStyleUnit aHeightUnit,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight);
void ComputeHorizontalValue(nscoord aContainingBlockWidth,
nsStyleUnit aUnit,
const nsStyleCoord& aCoord,
nscoord& aResult);
void ComputeVerticalValue(nscoord aContainingBlockHeight,
nsStyleUnit aUnit,
const nsStyleCoord& aCoord,
nscoord& aResult);
// Computes margin values from the specified margin style information, and
// fills in the mComputedMargin member
void ComputeMargin(nscoord aContainingBlockWidth,
const nsHTMLReflowState* aContainingBlockRS);
// Computes padding values from the specified padding style information, and
// fills in the mComputedPadding member
void ComputePadding(nscoord aContainingBlockWidth,
const nsHTMLReflowState* aContainingBlockRS);
// 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);
nscoord CalculateHorizBorderPaddingMargin(nscoord aContainingBlockWidth);
// Adjust Computed sizes for Min/Max Width and box-Sizing (if
// aAdjustForBoxSizing is true)
// - guarantees that the computed height/width will be non-negative
// If the value goes negative (because the padding or border is greater than
// the width/height and it is removed due to box sizing) then it is driven to 0
void AdjustComputedHeight(PRBool aAdjustForBoxSizing);
void AdjustComputedWidth(PRBool aAdjustForBoxSizing);
#ifdef IBMBIDI
/**
* Test whether the frame is a form control in a visual Bidi page.
* This is necessary for backwards-compatibility, because most visual
* pages use logical order for form controls so that they will
* display correctly on native widgets in OSs with Bidi support
* @param aPresContext the pres context
* @return whether the frame is a BIDI form control
*/
PRBool IsBidiFormControl(nsPresContext* aPresContext);
#endif
};
#endif /* nsHTMLReflowState_h___ */