1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsILineIterator.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,133 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +#ifndef nsILineIterator_h___
1.9 +#define nsILineIterator_h___
1.10 +
1.11 +#include "nscore.h"
1.12 +#include "nsCoord.h"
1.13 +
1.14 +class nsIFrame;
1.15 +struct nsRect;
1.16 +
1.17 +// Line Flags (see GetLine below)
1.18 +
1.19 +// This bit is set when the line is wrapping up a block frame. When
1.20 +// clear, it means that the line contains inline elements.
1.21 +#define NS_LINE_FLAG_IS_BLOCK 0x1
1.22 +
1.23 +// This bit is set when the line ends in some sort of break.
1.24 +#define NS_LINE_FLAG_ENDS_IN_BREAK 0x4
1.25 +
1.26 +/**
1.27 + * Line iterator API.
1.28 + *
1.29 + * Lines are numbered from 0 to N, where 0 is the top line and N is
1.30 + * the bottom line.
1.31 + *
1.32 + * Obtain this interface from frames via nsIFrame::GetLineIterator.
1.33 + * When you are finished using the iterator, call DisposeLineIterator()
1.34 + * to destroy the iterator if appropriate.
1.35 + */
1.36 +class nsILineIterator
1.37 +{
1.38 +protected:
1.39 + ~nsILineIterator() { }
1.40 +
1.41 +public:
1.42 + virtual void DisposeLineIterator() = 0;
1.43 +
1.44 + /**
1.45 + * The number of lines in the block
1.46 + */
1.47 + virtual int32_t GetNumLines() = 0;
1.48 +
1.49 + /**
1.50 + * The prevailing direction of lines.
1.51 + *
1.52 + * @return true if the CSS direction property for the block is
1.53 + * "rtl", otherwise false
1.54 + */
1.55 + virtual bool GetDirection() = 0;
1.56 +
1.57 + // Return structural information about a line. aFirstFrameOnLine is
1.58 + // the first frame on the line and aNumFramesOnLine is the number of
1.59 + // frames that are on the line. If the line-number is invalid then
1.60 + // aFirstFrameOnLine will be nullptr and aNumFramesOnLine will be
1.61 + // zero.
1.62 + //
1.63 + // For valid line numbers, aLineBounds is set to the bounding box of
1.64 + // the line (which is based on the in-flow position of the frames on
1.65 + // the line; if a frame was moved because of relative positioning
1.66 + // then its coordinates may be outside the line bounds).
1.67 + //
1.68 + // In addition, aLineFlags will contain flag information about the
1.69 + // line.
1.70 + NS_IMETHOD GetLine(int32_t aLineNumber,
1.71 + nsIFrame** aFirstFrameOnLine,
1.72 + int32_t* aNumFramesOnLine,
1.73 + nsRect& aLineBounds,
1.74 + uint32_t* aLineFlags) = 0;
1.75 +
1.76 + /**
1.77 + * Given a frame that's a child of the block, find which line its on
1.78 + * and return that line index, as long as it's at least as big as
1.79 + * aStartLine. Returns -1 if the frame cannot be found on lines
1.80 + * starting with aStartLine.
1.81 + */
1.82 + virtual int32_t FindLineContaining(nsIFrame* aFrame,
1.83 + int32_t aStartLine = 0) = 0;
1.84 +
1.85 + // Given a line number and an X coordinate, find the frame on the
1.86 + // line that is nearest to the X coordinate. The
1.87 + // aXIsBeforeFirstFrame and aXIsAfterLastFrame flags are updated
1.88 + // appropriately.
1.89 + NS_IMETHOD FindFrameAt(int32_t aLineNumber,
1.90 + nscoord aX,
1.91 + nsIFrame** aFrameFound,
1.92 + bool* aXIsBeforeFirstFrame,
1.93 + bool* aXIsAfterLastFrame) = 0;
1.94 +
1.95 + // Give the line iterator implementor a chance todo something more complicated than
1.96 + // nsIFrame::GetNextSibling()
1.97 + NS_IMETHOD GetNextSiblingOnLine(nsIFrame*& aFrame, int32_t aLineNumber) = 0;
1.98 +
1.99 + // Check whether visual and logical order of frames within a line are identical.
1.100 + // If not, return the first and last visual frames
1.101 + NS_IMETHOD CheckLineOrder(int32_t aLine,
1.102 + bool *aIsReordered,
1.103 + nsIFrame **aFirstVisual,
1.104 + nsIFrame **aLastVisual) = 0;
1.105 +};
1.106 +
1.107 +class nsAutoLineIterator
1.108 +{
1.109 +public:
1.110 + nsAutoLineIterator() : mRawPtr(nullptr) { }
1.111 + nsAutoLineIterator(nsILineIterator *i) : mRawPtr(i) { }
1.112 +
1.113 + ~nsAutoLineIterator() {
1.114 + if (mRawPtr)
1.115 + mRawPtr->DisposeLineIterator();
1.116 + }
1.117 +
1.118 + operator nsILineIterator*() { return mRawPtr; }
1.119 + nsILineIterator* operator->() { return mRawPtr; }
1.120 +
1.121 + nsILineIterator* operator=(nsILineIterator* i) {
1.122 + if (i == mRawPtr)
1.123 + return i;
1.124 +
1.125 + if (mRawPtr)
1.126 + mRawPtr->DisposeLineIterator();
1.127 +
1.128 + mRawPtr = i;
1.129 + return i;
1.130 + }
1.131 +
1.132 +private:
1.133 + nsILineIterator* mRawPtr;
1.134 +};
1.135 +
1.136 +#endif /* nsILineIterator_h___ */
