1 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is Mozilla Communicator client code.
16 : *
17 : * The Initial Developer of the Original Code is
18 : * Netscape Communications Corporation.
19 : * Portions created by the Initial Developer are Copyright (C) 1998
20 : * the Initial Developer. All Rights Reserved.
21 : *
22 : * Contributor(s):
23 : *
24 : * Alternatively, the contents of this file may be used under the terms of
25 : * either of the GNU General Public License Version 2 or later (the "GPL"),
26 : * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 : * in which case the provisions of the GPL or the LGPL are applicable instead
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33 : * the provisions above, a recipient may use your version of this file under
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35 : *
36 : * ***** END LICENSE BLOCK ***** */
37 : #ifndef nsILineIterator_h___
38 : #define nsILineIterator_h___
39 :
40 : #include "nscore.h"
41 : #include "nsCoord.h"
42 :
43 : class nsIFrame;
44 : struct nsRect;
45 :
46 : // Line Flags (see GetLine below)
47 :
48 : // This bit is set when the line is wrapping up a block frame. When
49 : // clear, it means that the line contains inline elements.
50 : #define NS_LINE_FLAG_IS_BLOCK 0x1
51 :
52 : // This bit is set when the line ends in some sort of break.
53 : #define NS_LINE_FLAG_ENDS_IN_BREAK 0x4
54 :
55 : /**
56 : * Line iterator API.
57 : *
58 : * Lines are numbered from 0 to N, where 0 is the top line and N is
59 : * the bottom line.
60 : *
61 : * Obtain this interface from frames via nsIFrame::GetLineIterator.
62 : * When you are finished using the iterator, call DisposeLineIterator()
63 : * to destroy the iterator if appropriate.
64 : */
65 : class nsILineIterator
66 0 : {
67 : protected:
68 0 : ~nsILineIterator() { }
69 :
70 : public:
71 : virtual void DisposeLineIterator() = 0;
72 :
73 : /**
74 : * The number of lines in the block
75 : */
76 : virtual PRInt32 GetNumLines() = 0;
77 :
78 : /**
79 : * The prevailing direction of lines.
80 : *
81 : * @return true if the CSS direction property for the block is
82 : * "rtl", otherwise false
83 : */
84 : virtual bool GetDirection() = 0;
85 :
86 : // Return structural information about a line. aFirstFrameOnLine is
87 : // the first frame on the line and aNumFramesOnLine is the number of
88 : // frames that are on the line. If the line-number is invalid then
89 : // aFirstFrameOnLine will be nsnull and aNumFramesOnLine will be
90 : // zero.
91 : //
92 : // For valid line numbers, aLineBounds is set to the bounding box of
93 : // the line (which is based on the in-flow position of the frames on
94 : // the line; if a frame was moved because of relative positioning
95 : // then its coordinates may be outside the line bounds).
96 : //
97 : // In addition, aLineFlags will contain flag information about the
98 : // line.
99 : NS_IMETHOD GetLine(PRInt32 aLineNumber,
100 : nsIFrame** aFirstFrameOnLine,
101 : PRInt32* aNumFramesOnLine,
102 : nsRect& aLineBounds,
103 : PRUint32* aLineFlags) = 0;
104 :
105 : /**
106 : * Given a frame that's a child of the block, find which line its on
107 : * and return that line index, as long as it's at least as big as
108 : * aStartLine. Returns -1 if the frame cannot be found on lines
109 : * starting with aStartLine.
110 : */
111 : virtual PRInt32 FindLineContaining(nsIFrame* aFrame,
112 : PRInt32 aStartLine = 0) = 0;
113 :
114 : // Given a line number and an X coordinate, find the frame on the
115 : // line that is nearest to the X coordinate. The
116 : // aXIsBeforeFirstFrame and aXIsAfterLastFrame flags are updated
117 : // appropriately.
118 : NS_IMETHOD FindFrameAt(PRInt32 aLineNumber,
119 : nscoord aX,
120 : nsIFrame** aFrameFound,
121 : bool* aXIsBeforeFirstFrame,
122 : bool* aXIsAfterLastFrame) = 0;
123 :
124 : // Give the line iterator implementor a chance todo something more complicated than
125 : // nsIFrame::GetNextSibling()
126 : NS_IMETHOD GetNextSiblingOnLine(nsIFrame*& aFrame, PRInt32 aLineNumber) = 0;
127 :
128 : #ifdef IBMBIDI
129 : // Check whether visual and logical order of frames within a line are identical.
130 : // If not, return the first and last visual frames
131 : NS_IMETHOD CheckLineOrder(PRInt32 aLine,
132 : bool *aIsReordered,
133 : nsIFrame **aFirstVisual,
134 : nsIFrame **aLastVisual) = 0;
135 : #endif
136 : };
137 :
138 : class nsAutoLineIterator
139 : {
140 : public:
141 0 : nsAutoLineIterator() : mRawPtr(nsnull) { }
142 0 : nsAutoLineIterator(nsILineIterator *i) : mRawPtr(i) { }
143 :
144 0 : ~nsAutoLineIterator() {
145 0 : if (mRawPtr)
146 0 : mRawPtr->DisposeLineIterator();
147 0 : }
148 :
149 0 : operator nsILineIterator*() { return mRawPtr; }
150 0 : nsILineIterator* operator->() { return mRawPtr; }
151 :
152 0 : nsILineIterator* operator=(nsILineIterator* i) {
153 0 : if (i == mRawPtr)
154 0 : return i;
155 :
156 0 : if (mRawPtr)
157 0 : mRawPtr->DisposeLineIterator();
158 :
159 0 : mRawPtr = i;
160 0 : return i;
161 : }
162 :
163 : private:
164 : nsILineIterator* mRawPtr;
165 : };
166 :
167 : #endif /* nsILineIterator_h___ */
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