MinikinUtils.cpp revision bad99183916ba2bac6659efc8a28273e344ba511 
1/*
2 * Copyright (C) 2014 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#include "MinikinUtils.h"
17
18#include "Paint.h"
19#include "SkPathMeasure.h"
20#include "Typeface.h"
21
22#include <cutils/log.h>
23#include <string>
24
25namespace android {
26
27FontStyle MinikinUtils::prepareMinikinPaint(MinikinPaint* minikinPaint, FontCollection** pFont,
28        const Paint* paint, Typeface* typeface) {
29    const Typeface* resolvedFace = Typeface::resolveDefault(typeface);
30    *pFont = resolvedFace->fFontCollection;
31    FontStyle resolved = resolvedFace->fStyle;
32
33    /* Prepare minikin FontStyle */
34    FontVariant minikinVariant = (paint->getFontVariant() == VARIANT_ELEGANT) ? VARIANT_ELEGANT
35            : VARIANT_COMPACT;
36    const uint32_t langListId = paint->getMinikinLangListId();
37    FontStyle minikinStyle(langListId, minikinVariant, resolved.getWeight(), resolved.getItalic());
38
39    /* Prepare minikin Paint */
40    // Note: it would be nice to handle fractional size values (it would improve smooth zoom
41    // behavior), but historically size has been treated as an int.
42    // TODO: explore whether to enable fractional sizes, possibly when linear text flag is set.
43    minikinPaint->size = (int)paint->getTextSize();
44    minikinPaint->scaleX = paint->getTextScaleX();
45    minikinPaint->skewX = paint->getTextSkewX();
46    minikinPaint->letterSpacing = paint->getLetterSpacing();
47    minikinPaint->paintFlags = MinikinFontSkia::packPaintFlags(paint);
48    minikinPaint->fontFeatureSettings = paint->getFontFeatureSettings();
49    minikinPaint->hyphenEdit = HyphenEdit(paint->getHyphenEdit());
50    return minikinStyle;
51}
52
53void MinikinUtils::doLayout(Layout* layout, const Paint* paint, int bidiFlags,
54        Typeface* typeface, const uint16_t* buf, size_t start, size_t count,
55        size_t bufSize) {
56    FontCollection *font;
57    MinikinPaint minikinPaint;
58    FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, &font, paint, typeface);
59    layout->setFontCollection(font);
60    layout->doLayout(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint);
61}
62
63float MinikinUtils::measureText(const Paint* paint, int bidiFlags, Typeface* typeface,
64        const uint16_t* buf, size_t start, size_t count, size_t bufSize, float *advances) {
65    FontCollection *font;
66    MinikinPaint minikinPaint;
67    FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, &font, paint, typeface);
68    return Layout::measureText(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint,
69            font, advances);
70}
71
72bool MinikinUtils::hasVariationSelector(Typeface* typeface, uint32_t codepoint, uint32_t vs) {
73    const Typeface* resolvedFace = Typeface::resolveDefault(typeface);
74    return resolvedFace->fFontCollection->hasVariationSelector(codepoint, vs);
75}
76
77float MinikinUtils::xOffsetForTextAlign(Paint* paint, const Layout& layout) {
78    switch (paint->getTextAlign()) {
79        case Paint::kCenter_Align:
80            return layout.getAdvance() * -0.5f;
81            break;
82        case Paint::kRight_Align:
83            return -layout.getAdvance();
84            break;
85        default:
86            break;
87    }
88    return 0;
89}
90
91float MinikinUtils::hOffsetForTextAlign(Paint* paint, const Layout& layout, const SkPath& path) {
92    float align = 0;
93    switch (paint->getTextAlign()) {
94        case Paint::kCenter_Align:
95            align = -0.5f;
96            break;
97        case Paint::kRight_Align:
98            align = -1;
99            break;
100        default:
101            return 0;
102    }
103    SkPathMeasure measure(path, false);
104    return align * (layout.getAdvance() - measure.getLength());
105}
106
107}
108