Java tutorial
/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.text; /** * This is the interface for text that has markup objects attached to * ranges of it. Not all text classes have mutable markup or text; * see {@link Spannable} for mutable markup and {@link Editable} for * mutable text. */ public interface Spanned extends CharSequence { /** * Bitmask of bits that are relevent for controlling point/mark behavior * of spans. * * MARK and POINT are conceptually located <i>between</i> two adjacent characters. * A MARK is "attached" to the character before, while a POINT will stick to the character * after. The insertion cursor is conceptually located between the MARK and the POINT. * * As a result, inserting a new character between a MARK and a POINT will leave the MARK * unchanged, while the POINT will be shifted, now located after the inserted character and * still glued to the same character after it. * * Depending on whether the insertion happens at the beginning or the end of a span, the span * will hence be expanded to <i>include</i> the new character (when the span is using a MARK at * its beginning or a POINT at its end) or it will be <i>excluded</i>. * * Note that <i>before</i> and <i>after</i> here refer to offsets in the String, which are * independent from the visual representation of the text (left-to-right or right-to-left). */ public static final int SPAN_POINT_MARK_MASK = 0x33; /** * 0-length spans with type SPAN_MARK_MARK behave like text marks: * they remain at their original offset when text is inserted * at that offset. Conceptually, the text is added after the mark. */ public static final int SPAN_MARK_MARK = 0x11; /** * SPAN_MARK_POINT is a synonym for {@link #SPAN_INCLUSIVE_INCLUSIVE}. */ public static final int SPAN_MARK_POINT = 0x12; /** * SPAN_POINT_MARK is a synonym for {@link #SPAN_EXCLUSIVE_EXCLUSIVE}. */ public static final int SPAN_POINT_MARK = 0x21; /** * 0-length spans with type SPAN_POINT_POINT behave like cursors: * they are pushed forward by the length of the insertion when text * is inserted at their offset. * The text is conceptually inserted before the point. */ public static final int SPAN_POINT_POINT = 0x22; /** * SPAN_PARAGRAPH behaves like SPAN_INCLUSIVE_EXCLUSIVE * (SPAN_MARK_MARK), except that if either end of the span is * at the end of the buffer, that end behaves like _POINT * instead (so SPAN_INCLUSIVE_INCLUSIVE if it starts in the * middle and ends at the end, or SPAN_EXCLUSIVE_INCLUSIVE * if it both starts and ends at the end). * <p> * Its endpoints must be the start or end of the buffer or * immediately after a \n character, and if the \n * that anchors it is deleted, the endpoint is pulled to the * next \n that follows in the buffer (or to the end of * the buffer). If a span with SPAN_PARAGRAPH flag is pasted * into another text and the paragraph boundary constraint * is not satisfied, the span is discarded. */ public static final int SPAN_PARAGRAPH = 0x33; /** * Non-0-length spans of type SPAN_INCLUSIVE_EXCLUSIVE expand * to include text inserted at their starting point but not at their * ending point. When 0-length, they behave like marks. */ public static final int SPAN_INCLUSIVE_EXCLUSIVE = SPAN_MARK_MARK; /** * Spans of type SPAN_INCLUSIVE_INCLUSIVE expand * to include text inserted at either their starting or ending point. */ public static final int SPAN_INCLUSIVE_INCLUSIVE = SPAN_MARK_POINT; /** * Spans of type SPAN_EXCLUSIVE_EXCLUSIVE do not expand * to include text inserted at either their starting or ending point. * They can never have a length of 0 and are automatically removed * from the buffer if all the text they cover is removed. */ public static final int SPAN_EXCLUSIVE_EXCLUSIVE = SPAN_POINT_MARK; /** * Non-0-length spans of type SPAN_EXCLUSIVE_INCLUSIVE expand * to include text inserted at their ending point but not at their * starting point. When 0-length, they behave like points. */ public static final int SPAN_EXCLUSIVE_INCLUSIVE = SPAN_POINT_POINT; /** * This flag is set on spans that are being used to apply temporary * styling information on the composing text of an input method, so that * they can be found and removed when the composing text is being * replaced. */ public static final int SPAN_COMPOSING = 0x100; /** * This flag will be set for intermediate span changes, meaning there * is guaranteed to be another change following it. Typically it is * used for {@link Selection} which automatically uses this with the first * offset it sets when updating the selection. */ public static final int SPAN_INTERMEDIATE = 0x200; /** * The bits numbered SPAN_USER_SHIFT and above are available * for callers to use to store scalar data associated with their * span object. */ public static final int SPAN_USER_SHIFT = 24; /** * The bits specified by the SPAN_USER bitfield are available * for callers to use to store scalar data associated with their * span object. */ public static final int SPAN_USER = 0xFFFFFFFF << SPAN_USER_SHIFT; /** * The bits numbered just above SPAN_PRIORITY_SHIFT determine the order * of change notifications -- higher numbers go first. You probably * don't need to set this; it is used so that when text changes, the * text layout gets the chance to update itself before any other * callbacks can inquire about the layout of the text. */ public static final int SPAN_PRIORITY_SHIFT = 16; /** * The bits specified by the SPAN_PRIORITY bitmap determine the order * of change notifications -- higher numbers go first. You probably * don't need to set this; it is used so that when text changes, the * text layout gets the chance to update itself before any other * callbacks can inquire about the layout of the text. */ public static final int SPAN_PRIORITY = 0xFF << SPAN_PRIORITY_SHIFT; /** * Return an array of the markup objects attached to the specified * slice of this CharSequence and whose type is the specified type * or a subclass of it. Specify Object.class for the type if you * want all the objects regardless of type. */ public <T> T[] getSpans(int start, int end, Class<T> type); /** * Return the beginning of the range of text to which the specified * markup object is attached, or -1 if the object is not attached. */ public int getSpanStart(Object tag); /** * Return the end of the range of text to which the specified * markup object is attached, or -1 if the object is not attached. */ public int getSpanEnd(Object tag); /** * Return the flags that were specified when {@link Spannable#setSpan} was * used to attach the specified markup object, or 0 if the specified * object has not been attached. */ public int getSpanFlags(Object tag); /** * Return the first offset greater than <code>start</code> where a markup * object of class <code>type</code> begins or ends, or <code>limit</code> * if there are no starts or ends greater than <code>start</code> but less * than <code>limit</code>. Specify <code>null</code> or Object.class for * the type if you want every transition regardless of type. */ public int nextSpanTransition(int start, int limit, Class type); }