1 /* 2 * Copyright (C) 2013 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 com.android.inputmethod.latin.utils; 18 19 import android.graphics.Paint; 20 import android.graphics.Rect; 21 import android.graphics.Typeface; 22 import android.util.SparseArray; 23 24 public final class TypefaceUtils { 25 private static final char[] KEY_LABEL_REFERENCE_CHAR = { 'M' }; 26 private static final char[] KEY_NUMERIC_HINT_LABEL_REFERENCE_CHAR = { '8' }; 27 28 private TypefaceUtils() { 29 // This utility class is not publicly instantiable. 30 } 31 32 // This sparse array caches key label text height in pixel indexed by key label text size. 33 private static final SparseArray<Float> sTextHeightCache = new SparseArray<>(); 34 // Working variable for the following method. 35 private static final Rect sTextHeightBounds = new Rect(); 36 37 private static float getCharHeight(final char[] referenceChar, final Paint paint) { 38 final int key = getCharGeometryCacheKey(referenceChar[0], paint); 39 synchronized (sTextHeightCache) { 40 final Float cachedValue = sTextHeightCache.get(key); 41 if (cachedValue != null) { 42 return cachedValue; 43 } 44 45 paint.getTextBounds(referenceChar, 0, 1, sTextHeightBounds); 46 final float height = sTextHeightBounds.height(); 47 sTextHeightCache.put(key, height); 48 return height; 49 } 50 } 51 52 // This sparse array caches key label text width in pixel indexed by key label text size. 53 private static final SparseArray<Float> sTextWidthCache = new SparseArray<>(); 54 // Working variable for the following method. 55 private static final Rect sTextWidthBounds = new Rect(); 56 57 private static float getCharWidth(final char[] referenceChar, final Paint paint) { 58 final int key = getCharGeometryCacheKey(referenceChar[0], paint); 59 synchronized (sTextWidthCache) { 60 final Float cachedValue = sTextWidthCache.get(key); 61 if (cachedValue != null) { 62 return cachedValue; 63 } 64 65 paint.getTextBounds(referenceChar, 0, 1, sTextWidthBounds); 66 final float width = sTextWidthBounds.width(); 67 sTextWidthCache.put(key, width); 68 return width; 69 } 70 } 71 72 private static int getCharGeometryCacheKey(final char referenceChar, final Paint paint) { 73 final int labelSize = (int)paint.getTextSize(); 74 final Typeface face = paint.getTypeface(); 75 final int codePointOffset = referenceChar << 15; 76 if (face == Typeface.DEFAULT) { 77 return codePointOffset + labelSize; 78 } else if (face == Typeface.DEFAULT_BOLD) { 79 return codePointOffset + labelSize + 0x1000; 80 } else if (face == Typeface.MONOSPACE) { 81 return codePointOffset + labelSize + 0x2000; 82 } else { 83 return codePointOffset + labelSize; 84 } 85 } 86 87 public static float getReferenceCharHeight(final Paint paint) { 88 return getCharHeight(KEY_LABEL_REFERENCE_CHAR, paint); 89 } 90 91 public static float getReferenceCharWidth(final Paint paint) { 92 return getCharWidth(KEY_LABEL_REFERENCE_CHAR, paint); 93 } 94 95 public static float getReferenceDigitWidth(final Paint paint) { 96 return getCharWidth(KEY_NUMERIC_HINT_LABEL_REFERENCE_CHAR, paint); 97 } 98 99 // Working variable for the following method. 100 private static final Rect sStringWidthBounds = new Rect(); 101 102 public static float getStringWidth(final String string, final Paint paint) { 103 synchronized (sStringWidthBounds) { 104 paint.getTextBounds(string, 0, string.length(), sStringWidthBounds); 105 return sStringWidthBounds.width(); 106 } 107 } 108 } 109
