RenderSkinNinePatch.cpp revision e370de1d415855eb14e8f917acf5217c5ab5a2f9 
1/*
2 * Copyright (C) 2011 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#include "config.h"
18
19#include "RenderSkinNinePatch.h"
20#include "NinePatchPeeker.h"
21#include "SkCanvas.h"
22#include "SkImageDecoder.h"
23#include "SkNinePatch.h"
24#include "SkRect.h"
25#include "SkStream.h"
26#include "SkTemplates.h"
27#include <utils/Asset.h>
28#include <utils/AssetManager.h>
29#include <utils/Log.h>
30#include <utils/ResourceTypes.h>
31
32class SkPaint;
33class SkRegion;
34
35using namespace android;
36
37extern void NinePatch_Draw(SkCanvas* canvas, const SkRect& bounds,
38        const SkBitmap& bitmap, const Res_png_9patch& chunk,
39        const SkPaint* paint, SkRegion** outRegion);
40
41bool RenderSkinNinePatch::decodeAsset(AssetManager* am, const char* filename, NinePatch* ninepatch) {
42    Asset* asset = am->open(filename, android::Asset::ACCESS_BUFFER);
43    if (!asset) {
44        asset = am->openNonAsset(filename, android::Asset::ACCESS_BUFFER);
45        if (!asset) {
46            return false;
47        }
48    }
49
50    SkImageDecoder::Mode mode = SkImageDecoder::kDecodePixels_Mode;
51    SkBitmap::Config prefConfig = SkBitmap::kNo_Config;
52    SkMemoryStream stream(asset->getBuffer(false), asset->getLength());
53    SkImageDecoder* decoder = SkImageDecoder::Factory(&stream);
54    if (!decoder) {
55        asset->close();
56        LOGE("RenderSkinNinePatch::Failed to create an image decoder");
57        return false;
58    }
59
60    decoder->setSampleSize(1);
61    decoder->setDitherImage(true);
62    decoder->setPreferQualityOverSpeed(false);
63
64    NinePatchPeeker peeker(decoder);
65
66    SkAutoTDelete<SkImageDecoder> add(decoder);
67
68    decoder->setPeeker(&peeker);
69    if (!decoder->decode(&stream, &ninepatch->m_bitmap, prefConfig, mode, true)) {
70        asset->close();
71        LOGE("RenderSkinNinePatch::Failed to decode nine patch asset");
72        return false;
73    }
74
75    asset->close();
76    if (!peeker.fPatchIsValid) {
77        LOGE("RenderSkinNinePatch::Patch data not valid");
78        return false;
79    }
80    void** data = &ninepatch->m_serializedPatchData;
81    *data = malloc(peeker.fPatch->serializedSize());
82    peeker.fPatch->serialize(*data);
83    return true;
84}
85
86void RenderSkinNinePatch::DrawNinePatch(SkCanvas* canvas, const SkRect& bounds,
87                                        const NinePatch& patch) {
88    Res_png_9patch* data = Res_png_9patch::deserialize(patch.m_serializedPatchData);
89
90    // if the NinePatch is bigger than the destination on a given axis the default
91    // decoder will not stretch properly, therefore we fall back to skia's decoder
92    // which if needed will down-sample and draw the bitmap as best as possible.
93    if (patch.m_bitmap.width() >= bounds.width() || patch.m_bitmap.height() >= bounds.height()) {
94
95        SkPaint defaultPaint;
96        // matches default dither in NinePatchDrawable.java.
97        defaultPaint.setDither(true);
98        SkNinePatch::DrawMesh(canvas, bounds, patch.m_bitmap,
99                              data->xDivs, data->numXDivs,
100                              data->yDivs, data->numYDivs,
101                              &defaultPaint);
102    } else {
103        NinePatch_Draw(canvas, bounds, patch.m_bitmap, *data, 0, 0);
104    }
105}
106