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 17 package android.text.style; 18 19 import android.annotation.IntRange; 20 import android.annotation.NonNull; 21 import android.annotation.Nullable; 22 import android.graphics.Canvas; 23 import android.graphics.Paint; 24 import android.text.TextPaint; 25 26 public abstract class ReplacementSpan extends MetricAffectingSpan { 27 28 private CharSequence mContentDescription = null; 29 30 /** 31 * Returns the width of the span. Extending classes can set the height of the span by updating 32 * attributes of {@link android.graphics.Paint.FontMetricsInt}. If the span covers the whole 33 * text, and the height is not set, 34 * {@link #draw(Canvas, CharSequence, int, int, float, int, int, int, Paint)} will not be 35 * called for the span. 36 * 37 * @param paint Paint instance. 38 * @param text Current text. 39 * @param start Start character index for span. 40 * @param end End character index for span. 41 * @param fm Font metrics, can be null. 42 * @return Width of the span. 43 */ getSize(@onNull Paint paint, CharSequence text, @IntRange(from = 0) int start, @IntRange(from = 0) int end, @Nullable Paint.FontMetricsInt fm)44 public abstract int getSize(@NonNull Paint paint, CharSequence text, 45 @IntRange(from = 0) int start, @IntRange(from = 0) int end, 46 @Nullable Paint.FontMetricsInt fm); 47 48 /** 49 * Draws the span into the canvas. 50 * 51 * @param canvas Canvas into which the span should be rendered. 52 * @param text Current text. 53 * @param start Start character index for span. 54 * @param end End character index for span. 55 * @param x Edge of the replacement closest to the leading margin. 56 * @param top Top of the line. 57 * @param y Baseline. 58 * @param bottom Bottom of the line. 59 * @param paint Paint instance. 60 */ draw(@onNull Canvas canvas, CharSequence text, @IntRange(from = 0) int start, @IntRange(from = 0) int end, float x, int top, int y, int bottom, @NonNull Paint paint)61 public abstract void draw(@NonNull Canvas canvas, CharSequence text, 62 @IntRange(from = 0) int start, @IntRange(from = 0) int end, float x, 63 int top, int y, int bottom, @NonNull Paint paint); 64 65 /** 66 * Gets a brief description of this ReplacementSpan for use in accessibility support. 67 * 68 * @return The content description. 69 */ 70 @Nullable getContentDescription()71 public CharSequence getContentDescription() { 72 return mContentDescription; 73 } 74 75 /** 76 * Sets the specific content description into ReplacementSpan. 77 * ReplacementSpans are shared with accessibility services, 78 * but only the content description is available from them. 79 * 80 * @param contentDescription content description. The default value is null. 81 */ setContentDescription(@ullable CharSequence contentDescription)82 public void setContentDescription(@Nullable CharSequence contentDescription) { 83 mContentDescription = contentDescription; 84 } 85 86 /** 87 * This method does nothing, since ReplacementSpans are measured 88 * explicitly instead of affecting Paint properties. 89 */ updateMeasureState(TextPaint p)90 public void updateMeasureState(TextPaint p) { } 91 92 /** 93 * This method does nothing, since ReplacementSpans are drawn 94 * explicitly instead of affecting Paint properties. 95 */ updateDrawState(TextPaint ds)96 public void updateDrawState(TextPaint ds) { } 97 } 98