1
2 /*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8 #include "ReaderView.h"
9 #include "SkGPipe.h"
10 #include "SkCanvas.h"
11
12 #include <stdio.h>
13
14 #define FILE_PATH "/Users/yangsu/Code/test/test.a"
ReaderView()15 ReaderView::ReaderView() {
16 fBGColor = 0xFFDDDDDD;
17 fFilePos = 0;
18 fBufferBitmaps[0].setConfig(SkBitmap::kARGB_8888_Config, 640, 480);
19 fBufferBitmaps[0].allocPixels(NULL);
20 fBufferBitmaps[1].setConfig(SkBitmap::kARGB_8888_Config, 640, 480);
21 fBufferBitmaps[1].allocPixels(NULL);
22 fFront = 0;
23 fBack = 1;
24 }
25
draw(SkCanvas * canvas)26 void ReaderView::draw(SkCanvas* canvas) {
27 canvas->drawColor(fBGColor);
28
29 SkAutoCanvasRestore acr(canvas, true);
30
31 //Create a temporary canvas and reader object that draws into the back
32 //bitmap so that the incremental changes or incomplete reads are not shown
33 //on screen
34 SkCanvas bufferCanvas(fBufferBitmaps[fBack]);
35 SkGPipeReader reader(&bufferCanvas);
36
37 //The file specified by FILE_PATH MUST exist
38 FILE* f = fopen(FILE_PATH, "rb");
39 SkASSERT(f != NULL);
40
41 fseek(f, 0, SEEK_END);
42 int size = ftell(f) * sizeof(char);
43 if (size <= fFilePos) {
44 fFilePos = 0;
45 }
46
47 //Resume from the last read location
48 fseek(f, fFilePos, SEEK_SET);
49 int toBeRead = size - fFilePos;
50 if (size > 0 && toBeRead > 0) {
51 void* block = sk_malloc_throw(toBeRead);
52 fread(block, 1, toBeRead, f);
53
54 size_t bytesRead;
55 SkGPipeReader::Status fStatus = reader.playback(block, toBeRead, &bytesRead);
56 SkASSERT(SkGPipeReader::kError_Status != fStatus);
57 SkASSERT(toBeRead >= bytesRead);
58
59 //if the reader reaches a done verb, a frame is complete.
60 //Update the file location and swap the front and back bitmaps to show
61 //the new frame
62 if (SkGPipeReader::kDone_Status == fStatus) {
63 fFilePos += bytesRead;
64 fFront = fFront ^ 0x1;
65 fBack = fBack ^ 0x1;
66 }
67 sk_free(block);
68 }
69
70 fclose(f);
71
72 //the front bitmap is always drawn
73 canvas->drawBitmap(fBufferBitmaps[fFront], 0, 0, NULL);
74 this->inval(NULL);
75 }
76