// 从xml中得到GifView的句柄
GifView gif2 = (GifView) findViewById(R.id.gif2);
// 设置Gif图片源
gif2.setGifImage(R.drawable.gif2);
// 添加监听器
gif2.setOnClickListener(this);
// 设置显示的大小，拉伸或者压缩
gif2.setShowDimension(etc.getWidth(), etc.getWidth() + 50);
// 设置加载方式：先加载后显示、边加载边显示、只显示第一帧再显示
gif2.setGifImageType(GifImageType.COVER);public interface GifAction {
/**
* gif解码观察者
* @param parseStatus 解码是否成功，成功会为true
* @param frameIndex 当前解码的第几帧，当全部解码成功后，这里为-1
*/
public void parseOk(boolean parseStatus,int frameIndex);
}public class GifFrame {
/**
* 构造函数
* @param im 图片
* @param del 延时
*/
public GifFrame(Bitmap im, int del) {
image = im;
delay = del;
}
/**图片*/
public Bitmap image;
/**延时*/
public int delay;
/**下一帧*/
public GifFrame nextFrame = null;
}
public class GifDecoder extends Thread{
/**状态：正在解码中*/
public static final int STATUS_PARSING = 0;
/**状态：图片格式错误*/
public static final int STATUS_FORMAT_ERROR = 1;
/**状态：打开失败*/
public static final int STATUS_OPEN_ERROR = 2;
/**状态：解码成功*/
public static final int STATUS_FINISH = -1;
private InputStream in;
private int status; public int width; // full image width
public int height; // full image height
private boolean gctFlag; // global color table used
private int gctSize; // size of global color table
private int loopCount = 1; // iterations; 0 = repeat forever private int[] gct; // global color table
private int[] lct; // local color table
private int[] act; // active color table private int bgIndex; // background color index
private int bgColor; // background color
private int lastBgColor; // previous bg color
private int pixelAspect; // pixel aspect ratio private boolean lctFlag; // local color table flag
private boolean interlace; // interlace flag
private int lctSize; // local color table size private int ix, iy, iw, ih; // current image rectangle
private int lrx, lry, lrw, lrh;
private Bitmap image; // current frame
private Bitmap lastImage; // previous frame
private GifFrame currentFrame = null; private boolean isShow = false;
private byte[] block = new byte[256]; // current data block
private int blockSize = 0; // block size // last graphic control extension info
private int dispose = 0;
// 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
private int lastDispose = 0;
private boolean transparency = false; // use transparent color
private int delay = 0; // delay in milliseconds
private int transIndex; // transparent color index private static final int MaxStackSize = 4096;
// max decoder pixel stack size // LZW decoder working arrays
private short[] prefix;
private byte[] suffix;
private byte[] pixelStack;
private byte[] pixels; private GifFrame gifFrame; // frames read from current file
private int frameCount; private GifAction action = null;
private byte[] gifData = null;
public GifDecoder(byte[] data,GifAction act){
gifData = data;
action = act;
}
public GifDecoder(InputStream is,GifAction act){
in = is;
action = act;
}
public void run(){
if(in != null){
readStream();
}else if(gifData != null){
readByte();
}
}
/**
* 释放资源
*/
public void free(){
GifFrame fg = gifFrame;
while(fg != null){
fg.image = null;
fg = null;
gifFrame = gifFrame.nextFrame;
fg = gifFrame;
}
if(in != null){
try{
in.close();
}catch(Exception ex){}
in = null;
}
gifData = null;
}
/**
* 当前状态
* @return
*/
public int getStatus(){
return status;
}
/**
* 解码是否成功，成功返回true
* @return 成功返回true，否则返回false
*/
public boolean parseOk(){
return status == STATUS_FINISH;
}
/**
* 取某帧的延时时间
* @param n 第几帧
* @return 延时时间，毫秒
*/
public int getDelay(int n) {
delay = -1;
if ((n >= 0) && (n < frameCount)) {
// delay = ((GifFrame) frames.elementAt(n)).delay;
GifFrame f = getFrame(n);
if (f != null)
delay = f.delay;
}
return delay;
}
/**
* 取所有帧的延时时间
* @return
*/
public int[] getDelays(){
GifFrame f = gifFrame;
int[] d = new int[frameCount];
int i = 0;
while(f != null && i < frameCount){
d[i] = f.delay;
f = f.nextFrame;
i++;
}
return d;
}
/**
* 取总帧 数
* @return 图片的总帧数
*/
public int getFrameCount() {
return frameCount;
} /**
* 取第一帧图片
* @return
*/
public Bitmap getImage() {
return getFrameImage(0);
} public int getLoopCount() {
return loopCount;
} private void setPixels() {
int[] dest = new int[width * height];
// fill in starting image contents based on last image's dispose code
if (lastDispose > 0) {
if (lastDispose == 3) {
// use image before last
int n = frameCount - 2;
if (n > 0) {
lastImage = getFrameImage(n - 1);
} else {
lastImage = null;
}
}
if (lastImage != null) {
lastImage.getPixels(dest, 0, width, 0, 0, width, height);
// copy pixels
if (lastDispose == 2) {
// fill last image rect area with background color
int c = 0;
if (!transparency) {
c = lastBgColor;
}
for (int i = 0; i < lrh; i++) {
int n1 = (lry + i) * width + lrx;
int n2 = n1 + lrw;
for (int k = n1; k < n2; k++) {
dest[k] = c;
}
}
}
}
} // copy each source line to the appropriate place in the destination
int pass = 1;
int inc = 8;
int iline = 0;
for (int i = 0; i < ih; i++) {
int line = i;
if (interlace) {
if (iline >= ih) {
pass++;
switch (pass) {
case 2:
iline = 4;
break;
case 3:
iline = 2;
inc = 4;
break;
case 4:
iline = 1;
inc = 2;
}
}
line = iline;
iline += inc;
}
line += iy;
if (line < height) {
int k = line * width;
int dx = k + ix; // start of line in dest
int dlim = dx + iw; // end of dest line
if ((k + width) < dlim) {
dlim = k + width; // past dest edge
}
int sx = i * iw; // start of line in source
while (dx < dlim) {
// map color and insert in destination
int index = ((int) pixels[sx++]) & 0xff;
int c = act[index];
if (c != 0) {
dest[dx] = c;
}
dx++;
}
}
}
image = Bitmap.createBitmap(dest, width, height, Config.ARGB_4444);
} /**
* 取第几帧的图片
* @param n 帧数
* @return 可画的图片，如果没有此帧或者出错，返回null
*/
public Bitmap getFrameImage(int n) {
GifFrame frame = getFrame(n);
if (frame == null)
return null;
else
return frame.image;
} /**
* 取当前帧图片
* @return 当前帧可画的图片
*/
public GifFrame getCurrentFrame(){
return currentFrame;
}
/**
* 取第几帧，每帧包含了可画的图片和延时时间
* @param n 帧数
* @return
*/
public GifFrame getFrame(int n) {
GifFrame frame = gifFrame;
int i = 0;
while (frame != null) {
if (i == n) {
return frame;
} else {
frame = frame.nextFrame;
}
i++;
}
return null;
} /**
* 重置，进行本操作后，会直接到第一帧
*/
public void reset(){
currentFrame = gifFrame;
}
/**
* 下一帧，进行本操作后，通过getCurrentFrame得到的是下一帧
* @return 返回下一帧
*/
public GifFrame next() {
if(isShow == false){
isShow = true;
return gifFrame;
}else{
if(status == STATUS_PARSING){
if(currentFrame.nextFrame != null)
currentFrame = currentFrame.nextFrame;
//currentFrame = gifFrame;
}else{
currentFrame = currentFrame.nextFrame;
if (currentFrame == null) {
currentFrame = gifFrame;
}
}
return currentFrame;
}
} private int readByte(){
in = new ByteArrayInputStream(gifData);
gifData = null;
return readStream();
}
// public int read(byte[] data){
// InputStream is = new ByteArrayInputStream(data);
// return read(is);
// }
private int readStream(){
init();
if(in != null){
readHeader();
if(!err()){
readContents();
if(frameCount < 0){
status = STATUS_FORMAT_ERROR;
action.parseOk(false,-1);
}else{
status = STATUS_FINISH;
action.parseOk(true,-1);
}
}
try {
in.close();
} catch (Exception e) {
e.printStackTrace();
}
}else {
status = STATUS_OPEN_ERROR;
action.parseOk(false,-1);
}
return status;
} private void decodeImageData() {
int NullCode = -1;
int npix = iw * ih;
int available, clear, code_mask, code_size, end_of_information, in_code, old_code, bits, code, count, i, datum, data_size, first, top, bi, pi; if ((pixels == null) || (pixels.length < npix)) {
pixels = new byte[npix]; // allocate new pixel array
}
if (prefix == null) {
prefix = new short[MaxStackSize];
}
if (suffix == null) {
suffix = new byte[MaxStackSize];
}
if (pixelStack == null) {
pixelStack = new byte[MaxStackSize + 1];
}
// Initialize GIF data stream decoder.
data_size = read();
clear = 1 << data_size;
end_of_information = clear + 1;
available = clear + 2;
old_code = NullCode;
code_size = data_size + 1;
code_mask = (1 << code_size) - 1;
for (code = 0; code < clear; code++) {
prefix[code] = 0;
suffix[code] = (byte) code;
} // Decode GIF pixel stream.
datum = bits = count = first = top = pi = bi = 0;
for (i = 0; i < npix;) {
if (top == 0) {
if (bits < code_size) {
// Load bytes until there are enough bits for a code.
if (count == 0) {
// Read a new data block.
count = readBlock();
if (count <= 0) {
break;
}
bi = 0;
}
datum += (((int) block[bi]) & 0xff) << bits;
bits += 8;
bi++;
count--;
continue;
}
// Get the next code.
code = datum & code_mask;
datum >>= code_size;
bits -= code_size; // Interpret the code
if ((code > available) || (code == end_of_information)) {
break;
}
if (code == clear) {
// Reset decoder.
code_size = data_size + 1;
code_mask = (1 << code_size) - 1;
available = clear + 2;
old_code = NullCode;
continue;
}
if (old_code == NullCode) {
pixelStack[top++] = suffix[code];
old_code = code;
first = code;
continue;
}
in_code = code;
if (code == available) {
pixelStack[top++] = (byte) first;
code = old_code;
}
while (code > clear) {
pixelStack[top++] = suffix[code];
code = prefix[code];
}
first = ((int) suffix[code]) & 0xff;
// Add a new string to the string table,
if (available >= MaxStackSize) {
break;
}
pixelStack[top++] = (byte) first;
prefix[available] = (short) old_code;
suffix[available] = (byte) first;
available++;
if (((available & code_mask) == 0)
&& (available < MaxStackSize)) {
code_size++;
code_mask += available;
}
old_code = in_code;
} // Pop a pixel off the pixel stack.
top--;
pixels[pi++] = pixelStack[top];
i++;
}
for (i = pi; i < npix; i++) {
pixels[i] = 0; // clear missing pixels
}
} private boolean err() {
return status != STATUS_PARSING;
} private void init() {
status = STATUS_PARSING;
frameCount = 0;
gifFrame = null;
gct = null;
lct = null;
} private int read() {
int curByte = 0;
try {
curByte = in.read();
} catch (Exception e) {
status = STATUS_FORMAT_ERROR;
}
return curByte;
}
private int readBlock() {
blockSize = read();
int n = 0;
if (blockSize > 0) {
try {
int count = 0;
while (n < blockSize) {
count = in.read(block, n, blockSize - n);
if (count == -1) {
break;
}
n += count;
}
} catch (Exception e) {
e.printStackTrace();
}
if (n < blockSize) {
status = STATUS_FORMAT_ERROR;
}
}
return n;
} private int[] readColorTable(int ncolors) {
int nbytes = 3 * ncolors;
int[] tab = null;
byte[] c = new byte[nbytes];
int n = 0;
try {
n = in.read(c);
} catch (Exception e) {
e.printStackTrace();
}
if (n < nbytes) {
status = STATUS_FORMAT_ERROR;
} else {
tab = new int[256]; // max size to avoid bounds checks
int i = 0;
int j = 0;
while (i < ncolors) {
int r = ((int) c[j++]) & 0xff;
int g = ((int) c[j++]) & 0xff;
int b = ((int) c[j++]) & 0xff;
tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b;
}
}
return tab;
} private void readContents() {
// read GIF file content blocks
boolean done = false;
while (!(done || err())) {
int code = read();
switch (code) {
case 0x2C: // image separator
readImage();
break;
case 0x21: // extension
code = read();
switch (code) {
case 0xf9: // graphics control extension
readGraphicControlExt();
break;
case 0xff: // application extension
readBlock();
String app = "";
for (int i = 0; i < 11; i++) {
app += (char) block[i];
}
if (app.equals("NETSCAPE2.0")) {
readNetscapeExt();
} else {
skip(); // don't care
}
break;
default: // uninteresting extension
skip();
}
break;
case 0x3b: // terminator
done = true;
break;
case 0x00: // bad byte, but keep going and see what happens
break;
default:
status = STATUS_FORMAT_ERROR;
}
}
} private void readGraphicControlExt() {
read(); // block size
int packed = read(); // packed fields
dispose = (packed & 0x1c) >> 2; // disposal method
if (dispose == 0) {
dispose = 1; // elect to keep old image if discretionary
}
transparency = (packed & 1) != 0;
delay = readShort() * 10; // delay in milliseconds
transIndex = read(); // transparent color index
read(); // block terminator
} private void readHeader() {
String id = "";
for (int i = 0; i < 6; i++) {
id += (char) read();
}
if (!id.startsWith("GIF")) {
status = STATUS_FORMAT_ERROR;
return;
}
readLSD();
if (gctFlag && !err()) {
gct = readColorTable(gctSize);
bgColor = gct[bgIndex];
}
} private void readImage() {
ix = readShort(); // (sub)image position & size
iy = readShort();
iw = readShort();
ih = readShort();
int packed = read();
lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
interlace = (packed & 0x40) != 0; // 2 - interlace flag
// 3 - sort flag
// 4-5 - reserved
lctSize = 2 << (packed & 7); // 6-8 - local color table size
if (lctFlag) {
lct = readColorTable(lctSize); // read table
act = lct; // make local table active
} else {
act = gct; // make global table active
if (bgIndex == transIndex) {
bgColor = 0;
}
}
int save = 0;
if (transparency) {
save = act[transIndex];
act[transIndex] = 0; // set transparent color if specified
}
if (act == null) {
status = STATUS_FORMAT_ERROR; // no color table defined
}
if (err()) {
return;
}
decodeImageData(); // decode pixel data
skip();
if (err()) {
return;
}
frameCount++;
// create new image to receive frame data
image = Bitmap.createBitmap(width, height, Config.ARGB_4444);
// createImage(width, height);
setPixels(); // transfer pixel data to image
if (gifFrame == null) {
gifFrame = new GifFrame(image, delay);
currentFrame = gifFrame;
} else {
GifFrame f = gifFrame;
while(f.nextFrame != null){
f = f.nextFrame;
}
f.nextFrame = new GifFrame(image, delay);
}
// frames.addElement(new GifFrame(image, delay)); // add image to frame
// list
if (transparency) {
act[transIndex] = save;
}
resetFrame();
action.parseOk(true, frameCount);
} private void readLSD() {
// logical screen size
width = readShort();
height = readShort();
// packed fields
int packed = read();
gctFlag = (packed & 0x80) != 0; // 1 : global color table flag
// 2-4 : color resolution
// 5 : gct sort flag
gctSize = 2 << (packed & 7); // 6-8 : gct size
bgIndex = read(); // background color index
pixelAspect = read(); // pixel aspect ratio
} private void readNetscapeExt() {
do {
readBlock();
if (block[0] == 1) {
// loop count sub-block
int b1 = ((int) block[1]) & 0xff;
int b2 = ((int) block[2]) & 0xff;
loopCount = (b2 << 8) | b1;
}
} while ((blockSize > 0) && !err());
} private int readShort() {
// read 16-bit value, LSB first
return read() | (read() << 8);
} private void resetFrame() {
lastDispose = dispose;
lrx = ix;
lry = iy;
lrw = iw;
lrh = ih;
lastImage = image;
lastBgColor = bgColor;
dispose = 0;
transparency = false;
delay = 0;
lct = null;
} /**
* Skips variable length blocks up to and including next zero length block.
*/
private void skip() {
do {
readBlock();
} while ((blockSize > 0) && !err());
}
}
public class GifView extends View implements GifAction{
/**gif解码器*/
private GifDecoder gifDecoder = null;
/**当前要画的帧的图*/
private Bitmap currentImage = null;
private boolean isRun = true;
private boolean pause = false;
private int showWidth = -1;
private int showHeight = -1;
private Rect rect = null;
private DrawThread drawThread = null;
private GifImageType animationType = GifImageType.SYNC_DECODER;
/**
* 解码过程中，Gif动画显示的方式<br>
* 如果图片较大，那么解码过程会比较长，这个解码过程中，gif如何显示
* @author liao
*
*/
public enum GifImageType{
/**
* 在解码过程中，不显示图片，直到解码全部成功后，再显示
*/
WAIT_FINISH (0),
/**
* 和解码过程同步，解码进行到哪里，图片显示到哪里
*/
SYNC_DECODER (1),
/**
* 在解码过程中，只显示第一帧图片
*/
COVER (2);
GifImageType(int i){
nativeInt = i;
}
final int nativeInt;
}
public GifView(Context context) {
super(context);
}
public GifView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public GifView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
/**
* 设置图片，并开始解码
* @param gif 要设置的图片
*/
private void setGifDecoderImage(byte[] gif){
if(gifDecoder != null){
gifDecoder.free();
gifDecoder = null;
}
gifDecoder = new GifDecoder(gif,this);
gifDecoder.start();
}
/**
* 设置图片，开始解码
* @param is 要设置的图片
*/
private void setGifDecoderImage(InputStream is){
if(gifDecoder != null){
gifDecoder.free();
gifDecoder= null;
}
gifDecoder = new GifDecoder(is,this);
gifDecoder.start();
}
/**
* 以字节数据形式设置gif图片
* @param gif 图片
*/
public void setGifImage(byte[] gif){
setGifDecoderImage(gif);
}
/**
* 以字节流形式设置gif图片
* @param is 图片
*/
public void setGifImage(InputStream is){
setGifDecoderImage(is);
}
/**
* 以资源形式设置gif图片
* @param resId gif图片的资源ID
*/
public void setGifImage(int resId){
Resources r = this.getResources();
InputStream is = r.openRawResource(resId);
setGifDecoderImage(is);
}
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(gifDecoder == null)
return;
if(currentImage == null){
currentImage = gifDecoder.getImage();
}
if(currentImage == null){
return;
}
int saveCount = canvas.getSaveCount();
canvas.save();
canvas.translate(getPaddingLeft(), getPaddingTop());
if(showWidth == -1){
canvas.drawBitmap(currentImage, 0, 0,null);
}else{
canvas.drawBitmap(currentImage, null, rect, null);
}
canvas.restoreToCount(saveCount);
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int pleft = getPaddingLeft();
int pright = getPaddingRight();
int ptop = getPaddingTop();
int pbottom = getPaddingBottom(); int widthSize;
int heightSize;
int w;
int h;
if(gifDecoder == null){
w = 1;
h = 1;
}else{
w = gifDecoder.width;
h = gifDecoder.height;
}
w += pleft + pright;
h += ptop + pbottom;
w = Math.max(w, getSuggestedMinimumWidth());
h = Math.max(h, getSuggestedMinimumHeight()); widthSize = resolveSize(w, widthMeasureSpec);
heightSize = resolveSize(h, heightMeasureSpec);
setMeasuredDimension(widthSize, heightSize);
}
/**
* 只显示第一帧图片<br>
* 调用本方法后，gif不会显示动画，只会显示gif的第一帧图
*/
public void showCover(){
if(gifDecoder == null)
return;
pause = true;
currentImage = gifDecoder.getImage();
invalidate();
}
/**
* 继续显示动画<br>
* 本方法在调用showCover后，会让动画继续显示，如果没有调用showCover方法，则没有任何效果
*/
public void showAnimation(){
if(pause){
pause = false;
}
}
/**
* 设置gif在解码过程中的显示方式<br>
* <strong>本方法只能在setGifImage方法之前设置，否则设置无效</strong>
* @param type 显示方式
*/
public void setGifImageType(GifImageType type){
if(gifDecoder == null)
animationType = type;
}
/**
* 设置要显示的图片的大小<br>
* 当设置了图片大小 之后，会按照设置的大小来显示gif（按设置后的大小来进行拉伸或压缩）
* @param width 要显示的图片宽
* @param height 要显示的图片高
*/
public void setShowDimension(int width,int height){
if(width > 0 && height > 0){
showWidth = width;
showHeight = height;
rect = new Rect();
rect.left = 0;
rect.top = 0;
rect.right = width;
rect.bottom = height;
}
}
public void parseOk(boolean parseStatus,int frameIndex){
if(parseStatus){
if(gifDecoder != null){
switch(animationType){
case WAIT_FINISH:
if(frameIndex == -1){
if(gifDecoder.getFrameCount() > 1){ //当帧数大于1时，启动动画线程
DrawThread dt = new DrawThread();
dt.start();
}else{
reDraw();
}
}
break;
case COVER:
if(frameIndex == 1){
currentImage = gifDecoder.getImage();
reDraw();
}else if(frameIndex == -1){
if(gifDecoder.getFrameCount() > 1){
if(drawThread == null){
drawThread = new DrawThread();
drawThread.start();
}
}else{
reDraw();
}
}
break;
case SYNC_DECODER:
if(frameIndex == 1){
currentImage = gifDecoder.getImage();
reDraw();
}else if(frameIndex == -1){
reDraw();
}else{
if(drawThread == null){
drawThread = new DrawThread();
drawThread.start();
}
}
break;
}
}else{
Log.e("gif","parse error");
}
}
}
private void reDraw(){
if(redrawHandler != null){
Message msg = redrawHandler.obtainMessage();
redrawHandler.sendMessage(msg);
}
}
private Handler redrawHandler = new Handler(){
public void handleMessage(Message msg) {
invalidate();
}
};
/**
* 动画线程
* @author liao
*
*/
private class DrawThread extends Thread{
public void run(){
if(gifDecoder == null){
return;
}
while(isRun){
if(pause == false){
//if(gifDecoder.parseOk()){
GifFrame frame = gifDecoder.next();
currentImage = frame.image;
long sp = frame.delay;
if(redrawHandler != null){
Message msg = redrawHandler.obtainMessage();
redrawHandler.sendMessage(msg);
SystemClock.sleep(sp);
}else{
break;
}
// }else{
// currentImage = gifDecoder.getImage();
// break;
// }
}else{
SystemClock.sleep(10);
}
}
}
}
}本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
