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). 85 */ 86 public static final int SPAN_PARAGRAPH = 0x33; 87 88 /** 89 * Non-0-length spans of type SPAN_INCLUSIVE_EXCLUSIVE expand 90 * to include text inserted at their starting point but not at their 91 * ending point. When 0-length, they behave like marks. 92 */ 93 public static final int SPAN_INCLUSIVE_EXCLUSIVE = SPAN_MARK_MARK; 94 95 /** 96 * Spans of type SPAN_INCLUSIVE_INCLUSIVE expand 97 * to include text inserted at either their starting or ending point. 98 */ 99 public static final int SPAN_INCLUSIVE_INCLUSIVE = SPAN_MARK_POINT; 100 101 /** 102 * Spans of type SPAN_EXCLUSIVE_EXCLUSIVE do not expand 103 * to include text inserted at either their starting or ending point. 104 * They can never have a length of 0 and are automatically removed 105 * from the buffer if all the text they cover is removed. 106 */ 107 public static final int SPAN_EXCLUSIVE_EXCLUSIVE = SPAN_POINT_MARK; 108 109 /** 110 * Non-0-length spans of type SPAN_EXCLUSIVE_INCLUSIVE expand 111 * to include text inserted at their ending point but not at their 112 * starting point. When 0-length, they behave like points. 113 */ 114 public static final int SPAN_EXCLUSIVE_INCLUSIVE = SPAN_POINT_POINT; 115 116 /** 117 * This flag is set on spans that are being used to apply temporary 118 * styling information on the composing text of an input method, so that 119 * they can be found and removed when the composing text is being 120 * replaced. 121 */ 122 public static final int SPAN_COMPOSING = 0x100; 123 124 /** 125 * This flag will be set for intermediate span changes, meaning there 126 * is guaranteed to be another change following it. Typically it is 127 * used for {@link Selection} which automatically uses this with the first 128 * offset it sets when updating the selection. 129 */ 130 public static final int SPAN_INTERMEDIATE = 0x200; 131 132 /** 133 * The bits numbered SPAN_USER_SHIFT and above are available 134 * for callers to use to store scalar data associated with their 135 * span object. 136 */ 137 public static final int SPAN_USER_SHIFT = 24; 138 /** 139 * The bits specified by the SPAN_USER bitfield are available 140 * for callers to use to store scalar data associated with their 141 * span object. 142 */ 143 public static final int SPAN_USER = 0xFFFFFFFF << SPAN_USER_SHIFT; 144 145 /** 146 * The bits numbered just above SPAN_PRIORITY_SHIFT determine the order 147 * of change notifications -- higher numbers go first. You probably 148 * don't need to set this; it is used so that when text changes, the 149 * text layout gets the chance to update itself before any other 150 * callbacks can inquire about the layout of the text. 151 */ 152 public static final int SPAN_PRIORITY_SHIFT = 16; 153 /** 154 * The bits specified by the SPAN_PRIORITY bitmap determine the order 155 * of change notifications -- higher numbers go first. You probably 156 * don't need to set this; it is used so that when text changes, the 157 * text layout gets the chance to update itself before any other 158 * callbacks can inquire about the layout of the text. 159 */ 160 public static final int SPAN_PRIORITY = 0xFF << SPAN_PRIORITY_SHIFT; 161 162 /** 163 * Return an array of the markup objects attached to the specified 164 * slice of this CharSequence and whose type is the specified type 165 * or a subclass of it. Specify Object.class for the type if you 166 * want all the objects regardless of type. 167 */ 168 public <T> T[] getSpans(int start, int end, Class<T> type); 169 170 /** 171 * Return the beginning of the range of text to which the specified 172 * markup object is attached, or -1 if the object is not attached. 173 */ 174 public int getSpanStart(Object tag); 175 176 /** 177 * Return the end of the range of text to which the specified 178 * markup object is attached, or -1 if the object is not attached. 179 */ 180 public int getSpanEnd(Object tag); 181 182 /** 183 * Return the flags that were specified when {@link Spannable#setSpan} was 184 * used to attach the specified markup object, or 0 if the specified 185 * object has not been attached. 186 */ 187 public int getSpanFlags(Object tag); 188 189 /** 190 * Return the first offset greater than or equal to <code>start</code> 191 * where a markup object of class <code>type</code> begins or ends, 192 * or <code>limit</code> if there are no starts or ends greater than or 193 * equal to <code>start</code> but less than <code>limit</code>. Specify 194 * <code>null</code> or Object.class for the type if you want every 195 * transition regardless of type. 196 */ 197 public int nextSpanTransition(int start, int limit, Class type); 198} 199