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 * MARK and POINT are conceptually located <i>between</i> two adjacent characters. 33 * A MARK is "attached" to the character before, while a POINT will stick to the character 34 * after. The insertion cursor is conceptually located between the MARK and the POINT. 35 * 36 * As a result, inserting a new character between a MARK and a POINT will leave the MARK 37 * unchanged, while the POINT will be shifted, now located after the inserted character and 38 * still glued to the same character after it. 39 * 40 * Depending on whether the insertion happens at the beginning or the end of a span, the span 41 * will hence be expanded to <i>include</i> the new character (when the span is using a MARK at 42 * its beginning or a POINT at its end) or it will be <i>excluded</i>. 43 * 44 * Note that <i>before</i> and <i>after</i> here refer to offsets in the String, which are 45 * independent from the visual representation of the text (left-to-right or right-to-left). 46 */ 47 public static final int SPAN_POINT_MARK_MASK = 0x33; 48 49 /** 50 * 0-length spans with type SPAN_MARK_MARK behave like text marks: 51 * they remain at their original offset when text is inserted 52 * at that offset. Conceptually, the text is added after the mark. 53 */ 54 public static final int SPAN_MARK_MARK = 0x11; 55 /** 56 * SPAN_MARK_POINT is a synonym for {@link #SPAN_INCLUSIVE_INCLUSIVE}. 57 */ 58 public static final int SPAN_MARK_POINT = 0x12; 59 /** 60 * SPAN_POINT_MARK is a synonym for {@link #SPAN_EXCLUSIVE_EXCLUSIVE}. 61 */ 62 public static final int SPAN_POINT_MARK = 0x21; 63 64 /** 65 * 0-length spans with type SPAN_POINT_POINT behave like cursors: 66 * they are pushed forward by the length of the insertion when text 67 * is inserted at their offset. 68 * The text is conceptually inserted before the point. 69 */ 70 public static final int SPAN_POINT_POINT = 0x22; 71 72 /** 73 * SPAN_PARAGRAPH behaves like SPAN_INCLUSIVE_EXCLUSIVE 74 * (SPAN_MARK_MARK), except that if either end of the span is 75 * at the end of the buffer, that end behaves like _POINT 76 * instead (so SPAN_INCLUSIVE_INCLUSIVE if it starts in the 77 * middle and ends at the end, or SPAN_EXCLUSIVE_INCLUSIVE 78 * if it both starts and ends at the end). 79 * <p> 80 * Its endpoints must be the start or end of the buffer or 81 * immediately after a \n character, and if the \n 82 * that anchors it is deleted, the endpoint is pulled to the 83 * next \n that follows in the buffer (or to the end of 84 * the buffer). If a span with SPAN_PARAGRAPH flag is pasted 85 * into another text and the paragraph boundary constraint 86 * is not satisfied, the span is discarded. 87 */ 88 public static final int SPAN_PARAGRAPH = 0x33; 89 90 /** 91 * Non-0-length spans of type SPAN_INCLUSIVE_EXCLUSIVE expand 92 * to include text inserted at their starting point but not at their 93 * ending point. When 0-length, they behave like marks. 94 */ 95 public static final int SPAN_INCLUSIVE_EXCLUSIVE = SPAN_MARK_MARK; 96 97 /** 98 * Spans of type SPAN_INCLUSIVE_INCLUSIVE expand 99 * to include text inserted at either their starting or ending point. 100 */ 101 public static final int SPAN_INCLUSIVE_INCLUSIVE = SPAN_MARK_POINT; 102 103 /** 104 * Spans of type SPAN_EXCLUSIVE_EXCLUSIVE do not expand 105 * to include text inserted at either their starting or ending point. 106 * They can never have a length of 0 and are automatically removed 107 * from the buffer if all the text they cover is removed. 108 */ 109 public static final int SPAN_EXCLUSIVE_EXCLUSIVE = SPAN_POINT_MARK; 110 111 /** 112 * Non-0-length spans of type SPAN_EXCLUSIVE_INCLUSIVE expand 113 * to include text inserted at their ending point but not at their 114 * starting point. When 0-length, they behave like points. 115 */ 116 public static final int SPAN_EXCLUSIVE_INCLUSIVE = SPAN_POINT_POINT; 117 118 /** 119 * This flag is set on spans that are being used to apply temporary 120 * styling information on the composing text of an input method, so that 121 * they can be found and removed when the composing text is being 122 * replaced. 123 */ 124 public static final int SPAN_COMPOSING = 0x100; 125 126 /** 127 * This flag will be set for intermediate span changes, meaning there 128 * is guaranteed to be another change following it. Typically it is 129 * used for {@link Selection} which automatically uses this with the first 130 * offset it sets when updating the selection. 131 */ 132 public static final int SPAN_INTERMEDIATE = 0x200; 133 134 /** 135 * The bits numbered SPAN_USER_SHIFT and above are available 136 * for callers to use to store scalar data associated with their 137 * span object. 138 */ 139 public static final int SPAN_USER_SHIFT = 24; 140 /** 141 * The bits specified by the SPAN_USER bitfield are available 142 * for callers to use to store scalar data associated with their 143 * span object. 144 */ 145 public static final int SPAN_USER = 0xFFFFFFFF << SPAN_USER_SHIFT; 146 147 /** 148 * The bits numbered just above SPAN_PRIORITY_SHIFT determine the order 149 * of change notifications -- higher numbers go first. You probably 150 * don't need to set this; it is used so that when text changes, the 151 * text layout gets the chance to update itself before any other 152 * callbacks can inquire about the layout of the text. 153 */ 154 public static final int SPAN_PRIORITY_SHIFT = 16; 155 /** 156 * The bits specified by the SPAN_PRIORITY bitmap determine the order 157 * of change notifications -- higher numbers go first. You probably 158 * don't need to set this; it is used so that when text changes, the 159 * text layout gets the chance to update itself before any other 160 * callbacks can inquire about the layout of the text. 161 */ 162 public static final int SPAN_PRIORITY = 0xFF << SPAN_PRIORITY_SHIFT; 163 164 /** 165 * Return an array of the markup objects attached to the specified 166 * slice of this CharSequence and whose type is the specified type 167 * or a subclass of it. Specify Object.class for the type if you 168 * want all the objects regardless of type. 169 */ 170 public <T> T[] getSpans(int start, int end, Class<T> type); 171 172 /** 173 * Return the beginning of the range of text to which the specified 174 * markup object is attached, or -1 if the object is not attached. 175 */ 176 public int getSpanStart(Object tag); 177 178 /** 179 * Return the end of the range of text to which the specified 180 * markup object is attached, or -1 if the object is not attached. 181 */ 182 public int getSpanEnd(Object tag); 183 184 /** 185 * Return the flags that were specified when {@link Spannable#setSpan} was 186 * used to attach the specified markup object, or 0 if the specified 187 * object has not been attached. 188 */ 189 public int getSpanFlags(Object tag); 190 191 /** 192 * Return the first offset greater than <code>start</code> where a markup 193 * object of class <code>type</code> begins or ends, or <code>limit</code> 194 * if there are no starts or ends greater than <code>start</code> but less 195 * than <code>limit</code>. Specify <code>null</code> or Object.class for 196 * the type if you want every transition regardless of type. 197 */ 198 public int nextSpanTransition(int start, int limit, Class type); 199} 200