1/*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.text;
18
19/**
20 * This is the interface for text that has markup objects attached to
21 * ranges of it.  Not all text classes have mutable markup or text;
22 * see {@link Spannable} for mutable markup and {@link Editable} for
23 * mutable text.
24 */
25public interface Spanned
26extends CharSequence
27{
28    /**
29     * Bitmask of bits that are relevent for controlling point/mark behavior
30     * of spans.
31     */
32    public static final int SPAN_POINT_MARK_MASK = 0x33;
33
34    /**
35     * 0-length spans with type SPAN_MARK_MARK behave like text marks:
36     * they remain at their original offset when text is inserted
37     * at that offset.
38     */
39    public static final int SPAN_MARK_MARK =   0x11;
40    /**
41     * SPAN_MARK_POINT is a synonym for {@link #SPAN_INCLUSIVE_INCLUSIVE}.
42     */
43    public static final int SPAN_MARK_POINT =  0x12;
44    /**
45     * SPAN_POINT_MARK is a synonym for {@link #SPAN_EXCLUSIVE_EXCLUSIVE}.
46     */
47    public static final int SPAN_POINT_MARK =  0x21;
48
49    /**
50     * 0-length spans with type SPAN_POINT_POINT behave like cursors:
51     * they are pushed forward by the length of the insertion when text
52     * is inserted at their offset.
53     */
54    public static final int SPAN_POINT_POINT = 0x22;
55
56    /**
57     * SPAN_PARAGRAPH behaves like SPAN_INCLUSIVE_EXCLUSIVE
58     * (SPAN_MARK_MARK), except that if either end of the span is
59     * at the end of the buffer, that end behaves like _POINT
60     * instead (so SPAN_INCLUSIVE_INCLUSIVE if it starts in the
61     * middle and ends at the end, or SPAN_EXCLUSIVE_INCLUSIVE
62     * if it both starts and ends at the end).
63     * <p>
64     * Its endpoints must be the start or end of the buffer or
65     * immediately after a \n character, and if the \n
66     * that anchors it is deleted, the endpoint is pulled to the
67     * next \n that follows in the buffer (or to the end of
68     * the buffer).
69     */
70    public static final int SPAN_PARAGRAPH =   0x33;
71
72    /**
73     * Non-0-length spans of type SPAN_INCLUSIVE_EXCLUSIVE expand
74     * to include text inserted at their starting point but not at their
75     * ending point.  When 0-length, they behave like marks.
76     */
77    public static final int SPAN_INCLUSIVE_EXCLUSIVE = SPAN_MARK_MARK;
78
79    /**
80     * Spans of type SPAN_INCLUSIVE_INCLUSIVE expand
81     * to include text inserted at either their starting or ending point.
82     */
83    public static final int SPAN_INCLUSIVE_INCLUSIVE = SPAN_MARK_POINT;
84
85    /**
86     * Spans of type SPAN_EXCLUSIVE_EXCLUSIVE do not expand
87     * to include text inserted at either their starting or ending point.
88     * They can never have a length of 0 and are automatically removed
89     * from the buffer if all the text they cover is removed.
90     */
91    public static final int SPAN_EXCLUSIVE_EXCLUSIVE = SPAN_POINT_MARK;
92
93    /**
94     * Non-0-length spans of type SPAN_INCLUSIVE_EXCLUSIVE expand
95     * to include text inserted at their ending point but not at their
96     * starting point.  When 0-length, they behave like points.
97     */
98    public static final int SPAN_EXCLUSIVE_INCLUSIVE = SPAN_POINT_POINT;
99
100    /**
101     * This flag is set on spans that are being used to apply temporary
102     * styling information on the composing text of an input method, so that
103     * they can be found and removed when the composing text is being
104     * replaced.
105     */
106    public static final int SPAN_COMPOSING = 0x100;
107
108    /**
109     * This flag will be set for intermediate span changes, meaning there
110     * is guaranteed to be another change following it.  Typically it is
111     * used for {@link Selection} which automatically uses this with the first
112     * offset it sets when updating the selection.
113     */
114    public static final int SPAN_INTERMEDIATE = 0x200;
115
116    /**
117     * The bits numbered SPAN_USER_SHIFT and above are available
118     * for callers to use to store scalar data associated with their
119     * span object.
120     */
121    public static final int SPAN_USER_SHIFT = 24;
122    /**
123     * The bits specified by the SPAN_USER bitfield are available
124     * for callers to use to store scalar data associated with their
125     * span object.
126     */
127    public static final int SPAN_USER = 0xFFFFFFFF << SPAN_USER_SHIFT;
128
129    /**
130     * The bits numbered just above SPAN_PRIORITY_SHIFT determine the order
131     * of change notifications -- higher numbers go first.  You probably
132     * don't need to set this; it is used so that when text changes, the
133     * text layout gets the chance to update itself before any other
134     * callbacks can inquire about the layout of the text.
135     */
136    public static final int SPAN_PRIORITY_SHIFT = 16;
137    /**
138     * The bits specified by the SPAN_PRIORITY bitmap determine the order
139     * of change notifications -- higher numbers go first.  You probably
140     * don't need to set this; it is used so that when text changes, the
141     * text layout gets the chance to update itself before any other
142     * callbacks can inquire about the layout of the text.
143     */
144    public static final int SPAN_PRIORITY = 0xFF << SPAN_PRIORITY_SHIFT;
145
146    /**
147     * Return an array of the markup objects attached to the specified
148     * slice of this CharSequence and whose type is the specified type
149     * or a subclass of it.  Specify Object.class for the type if you
150     * want all the objects regardless of type.
151     */
152    public <T> T[] getSpans(int start, int end, Class<T> type);
153
154    /**
155     * Return the beginning of the range of text to which the specified
156     * markup object is attached, or -1 if the object is not attached.
157     */
158    public int getSpanStart(Object tag);
159
160    /**
161     * Return the end of the range of text to which the specified
162     * markup object is attached, or -1 if the object is not attached.
163     */
164    public int getSpanEnd(Object tag);
165
166    /**
167     * Return the flags that were specified when {@link Spannable#setSpan} was
168     * used to attach the specified markup object, or 0 if the specified
169     * object has not been attached.
170     */
171    public int getSpanFlags(Object tag);
172
173    /**
174     * Return the first offset greater than or equal to <code>start</code>
175     * where a markup object of class <code>type</code> begins or ends,
176     * or <code>limit</code> if there are no starts or ends greater than or
177     * equal to <code>start</code> but less than <code>limit</code>.  Specify
178     * <code>null</code> or Object.class for the type if you want every
179     * transition regardless of type.
180     */
181    public int nextSpanTransition(int start, int limit, Class type);
182}
183