本文主要是介绍TextView图文混排Gif，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
1.gif解析器
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;import java.io.InputStream;
import java.util.Vector;public class GifDecoder {/*** File read status: No errors.*/public static final int STATUS_OK = 0;/*** File read status: Error decoding file (may be partially decoded)*/public static final int STATUS_FORMAT_ERROR = 1;/*** File read status: Unable to open source.*/public static final int STATUS_OPEN_ERROR = 2;/** max decoder pixel stack size */protected static final int MAX_STACK_SIZE = 4096;protected InputStream in;protected int status;protected int width; // full image widthprotected int height; // full image heightprotected boolean gctFlag; // global color table usedprotected int gctSize; // size of global color tableprotected int loopCount = 1; // iterations; 0 = repeat foreverprotected int[] gct; // global color tableprotected int[] lct; // local color tableprotected int[] act; // active color tableprotected int bgIndex; // background color indexprotected int bgColor; // background colorprotected int lastBgColor; // previous bg colorprotected int pixelAspect; // pixel aspect ratioprotected boolean lctFlag; // local color table flagprotected boolean interlace; // interlace flagprotected int lctSize; // local color table sizeprotected int ix, iy, iw, ih; // current image rectangleprotected int lrx, lry, lrw, lrh;protected Bitmap image; // current frameprotected Bitmap lastBitmap; // previous frameprotected byte[] block = new byte[256]; // current data blockprotected int blockSize = 0; // block size last graphic control extension infoprotected int dispose = 0; // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prevprotected int lastDispose = 0;protected boolean transparency = false; // use transparent colorprotected int delay = 0; // delay in millisecondsprotected int transIndex; // transparent color index// LZW decoder working arraysprotected short[] prefix;protected byte[] suffix;protected byte[] pixelStack;protected byte[] pixels;protected Vector<GifFrame> frames; // frames read from current fileprotected int frameCount;private static class GifFrame {public GifFrame(Bitmap im, int del) {image = im;delay = del;}public Bitmap image;public int delay;}/*** Gets display duration for specified frame.* * @param n* int index of frame* @return delay in milliseconds*/public int getDelay(int n) {delay = -1;if ((n >= 0) && (n < frameCount)) {delay = frames.elementAt(n).delay;}return delay;}/*** Gets the number of frames read from file.* * @return frame count*/public int getFrameCount() {return frameCount;}/*** Gets the first (or only) image read.* * @return BufferedBitmap containing first frame, or null if none.*/public Bitmap getBitmap() {return getFrame(0);}/*** Gets the "Netscape" iteration count, if any. A count of 0 means repeat indefinitiely.* * @return iteration count if one was specified, else 1.*/public int getLoopCount() {return loopCount;}/*** Creates new frame image from current data (and previous frames as specified by their disposition codes).*/protected void setPixels() {// expose destination image's pixels as int arrayint[] dest = new int[width * height];// fill in starting image contents based on last image's dispose codeif (lastDispose > 0) {if (lastDispose == 3) {// use image before lastint n = frameCount - 2;if (n > 0) {lastBitmap = getFrame(n - 1);} else {lastBitmap = null;}}if (lastBitmap != null) {lastBitmap.getPixels(dest, 0, width, 0, 0, width, height);// copy pixelsif (lastDispose == 2) {// fill last image rect area with background colorint 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 destinationint 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;break;default:break;}}line = iline;iline += inc;}line += iy;if (line < height) {int k = line * width;int dx = k + ix; // start of line in destint dlim = dx + iw; // end of dest lineif ((k + width) < dlim) {dlim = k + width; // past dest edge}int sx = i * iw; // start of line in sourcewhile (dx < dlim) {// map color and insert in destinationint 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);}/*** Gets the image contents of frame n.* * @return BufferedBitmap representation of frame, or null if n is invalid.*/public Bitmap getFrame(int n) {if (frameCount <= 0)return null;n = n % frameCount;return ((GifFrame) frames.elementAt(n)).image;}/*** Reads GIF image from stream* * @param is* containing GIF file.* @return read status code (0 = no errors)*/public int read(InputStream is) {init();if (is != null) {in = is;readHeader();if (!err()) {readContents();if (frameCount < 0) {status = STATUS_FORMAT_ERROR;}}} else {status = STATUS_OPEN_ERROR;}try {is.close();} catch (Exception e) {}return status;}/*** Decodes LZW image data into pixel array. Adapted from John Cristy's BitmapMagick.*/protected void decodeBitmapData() {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[MAX_STACK_SIZE];}if (suffix == null) {suffix = new byte[MAX_STACK_SIZE];}if (pixelStack == null) {pixelStack = new byte[MAX_STACK_SIZE + 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; // XXX ArrayIndexOutOfBoundsExceptionsuffix[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 codeif ((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 >= MAX_STACK_SIZE) {break;}pixelStack[top++] = (byte) first;prefix[available] = (short) old_code;suffix[available] = (byte) first;available++;if (((available & code_mask) == 0) && (available < MAX_STACK_SIZE)) {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}}/*** Returns true if an error was encountered during reading/decoding*/protected boolean err() {return status != STATUS_OK;}/*** Initializes or re-initializes reader*/protected void init() {status = STATUS_OK;frameCount = 0;frames = new Vector<GifFrame>();gct = null;lct = null;}/*** Reads a single byte from the input stream.*/protected int read() {int curByte = 0;try {curByte = in.read();} catch (Exception e) {status = STATUS_FORMAT_ERROR;}return curByte;}/*** Reads next variable length block from input.* * @return number of bytes stored in "buffer"*/protected 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;}/*** Reads color table as 256 RGB integer values* * @param ncolors* int number of colors to read* @return int array containing 256 colors (packed ARGB with full alpha)*/protected 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 checksint 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;}/*** Main file parser. Reads GIF content blocks.*/protected void readContents() {// read GIF file content blocksboolean done = false;while (!(done || err())) {int code = read();switch (code) {case 0x2C: // image separatorreadBitmap();break;case 0x21: // extensioncode = read();switch (code) {case 0xf9: // graphics control extensionreadGraphicControlExt();break;case 0xff: // application extensionreadBlock();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;case 0xfe:// comment extensionskip();break;case 0x01:// plain text extensionskip();break;default: // uninteresting extensionskip();}break;case 0x3b: // terminatordone = true;break;case 0x00: // bad byte, but keep going and see what happens break;default:status = STATUS_FORMAT_ERROR;}}}/*** Reads Graphics Control Extension values*/protected void readGraphicControlExt() {read(); // block sizeint packed = read(); // packed fieldsdispose = (packed & 0x1c) >> 2; // disposal methodif (dispose == 0) {dispose = 1; // elect to keep old image if discretionary}transparency = (packed & 1) != 0;delay = readShort() * 10; // delay in millisecondstransIndex = read(); // transparent color indexread(); // block terminator}/*** Reads GIF file header information.*/protected 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];}}/*** Reads next frame image*/protected void readBitmap() {ix = readShort(); // (sub)image position & sizeiy = readShort();iw = readShort();ih = readShort();int packed = read();lctFlag = (packed & 0x80) != 0; // 1 - local color table flag interlacelctSize = (int) Math.pow(2, (packed & 0x07) + 1);// 3 - sort flag// 4-5 - reserved lctSize = 2 << (packed & 7); // 6-8 - local color// table sizeinterlace = (packed & 0x40) != 0;if (lctFlag) {lct = readColorTable(lctSize); // read tableact = lct; // make local table active} else {act = gct; // make global table activeif (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;}decodeBitmapData(); // decode pixel dataskip();if (err()) {return;}frameCount++;// create new image to receive frame dataimage = Bitmap.createBitmap(width, height, Config.ARGB_4444);setPixels(); // transfer pixel data to imageframes.addElement(new GifFrame(image, delay)); // add image to frame// listif (transparency) {act[transIndex] = save;}resetFrame();}/*** Reads Logical Screen Descriptor*/protected void readLSD() {// logical screen sizewidth = readShort();height = readShort();// packed fieldsint packed = read();gctFlag = (packed & 0x80) != 0; // 1 : global color table flag// 2-4 : color resolution// 5 : gct sort flaggctSize = 2 << (packed & 7); // 6-8 : gct sizebgIndex = read(); // background color indexpixelAspect = read(); // pixel aspect ratio}/*** Reads Netscape extenstion to obtain iteration count*/protected void readNetscapeExt() {do {readBlock();if (block[0] == 1) {// loop count sub-blockint b1 = ((int) block[1]) & 0xff;int b2 = ((int) block[2]) & 0xff;loopCount = (b2 << 8) | b1;}} while ((blockSize > 0) && !err());}/*** Reads next 16-bit value, LSB first*/protected int readShort() {// read 16-bit value, LSB firstreturn read() | (read() << 8);}/*** Resets frame state for reading next image.*/protected void resetFrame() {lastDispose = dispose;lrx = ix;lry = iy;lrw = iw;lrh = ih;lastBitmap = image;lastBgColor = bgColor;dispose = 0;transparency = false;delay = 0;lct = null;}/*** Skips variable length blocks up to and including next zero length block.*/protected void skip() {do {readBlock();} while ((blockSize > 0) && !err());}
}
2.AnimatedGifDrawable 动画Drawable
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;import java.io.InputStream;/*** * @author tracyZhang https://github.com/TracyZhangLei* @since 2014-4-4**/public class AnimatedGifDrawable extends AnimationDrawable {private final Context context;private int mCurrentIndex = 0;private UpdateListener mListener;public AnimatedGifDrawable(Context context,InputStream source, UpdateListener listener) {mListener = listener;this.context = context;GifDecoder decoder = new GifDecoder();decoder.read(source);// Iterate through the gif frames, add each as animation framefor (int i = 0; i < decoder.getFrameCount(); i++) {Bitmap bitmap = decoder.getFrame(i);Matrix matrix = new Matrix();int width = bitmap.getWidth();int height = bitmap.getHeight();// 缩放图片的尺寸int i1 = dip2px(context, 28);float scaleWidth = (float) i1/width;float scaleHeight = (float) i1/height;matrix.postScale(scaleWidth, scaleHeight);Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,width, height, matrix, true);BitmapDrawable drawable = new BitmapDrawable(context.getResources(),resizedBitmap);// Explicitly set the bounds in order for the frames to displaydrawable.setBounds(0, 0, resizedBitmap.getWidth(), resizedBitmap.getHeight());addFrame(drawable, decoder.getDelay(i));if (i == 0) {// Also set the bounds for this container drawablesetBounds(0, 0, resizedBitmap.getWidth(), resizedBitmap.getHeight());}}}/*** Naive method to proceed to next frame. Also notifies listener.*/public void nextFrame() {mCurrentIndex = (mCurrentIndex + 1) % getNumberOfFrames();if (mListener != null) mListener.update();}/*** Return display duration for current frame*/public int getFrameDuration() {return getDuration(mCurrentIndex);}/*** Return drawable for current frame*/public Drawable getDrawable() {return getFrame(mCurrentIndex);}/*** Interface to notify listener to update/redraw * Can't figure out how to invalidate the drawable (or span in which it sits) itself to force redraw*/public interface UpdateListener {void update();}/*** dip转换px** @param context* @param dpValue* @return float*/public static int dip2px(Context context, float dpValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (dpValue * scale + 0.5f);}
}
3.AnimatedImageSpan 将字符串中指定文字转换成图片
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.text.style.DynamicDrawableSpan;/*** * @author tracyZhang https://github.com/TracyZhangLei* @since 2014-4-4**/
public class AnimatedImageSpan extends DynamicDrawableSpan {private Drawable mDrawable;public AnimatedImageSpan(Drawable d) {super();mDrawable = d;// Use handler for 'ticks' to proceed to next frame final Handler mHandler = new Handler();mHandler.post(new Runnable() {public void run() {((AnimatedGifDrawable)mDrawable).nextFrame();// Set next with a delay depending on the duration for this frame mHandler.postDelayed(this, ((AnimatedGifDrawable)mDrawable).getFrameDuration());}});}/** Return current frame from animated drawable. Also acts as replacement for super.getCachedDrawable(),* since we can't cache the 'image' of an animated image.*/@Overridepublic Drawable getDrawable() {return ((AnimatedGifDrawable)mDrawable).getDrawable();}/** Copy-paste of super.getSize(...) but use getDrawable() to get the image/frame to calculate the size,* in stead of the cached drawable.*/@Overridepublic int getSize(Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) {Drawable d = getDrawable();Rect rect = d.getBounds();if (fm != null) {fm.ascent = -rect.bottom; fm.descent = 0; fm.top = fm.ascent;fm.bottom = 0;}return rect.right;}/** Copy-paste of super.draw(...) but use getDrawable() to get the image/frame to draw, in stead of* the cached drawable.*/@Overridepublic void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {Drawable b = getDrawable();canvas.save();int transY = bottom - b.getBounds().bottom;if (mVerticalAlignment == ALIGN_BASELINE) {transY -= paint.getFontMetricsInt().descent;}canvas.translate(x, transY);b.draw(canvas);canvas.restore();}}
4.使用方法
TextView gifTextview = (TextView) findViewById(R.id.gifTextview);SpannableStringBuilder stringBuilder = new SpannableStringBuilder();AssetManager am = getAssets();try {InputStream is = am.open("emo/anim_flag_hungary.gif");if (is == null) return;stringBuilder.append("anim_flag_hungary");stringBuilder.append("jkfsdjfksk哈哈");WeakReference<AnimatedImageSpan> localImageSpanRef = new WeakReference<>(new AnimatedImageSpan(new AnimatedGifDrawable(this, is, new AnimatedGifDrawable.UpdateListener(){@Overridepublic void update() {//update the textviewgifTextview.postInvalidate();}})));stringBuilder.setSpan(localImageSpanRef.get(), 0, stringBuilder.length()-"anim_flag_hungary".length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);gifTextview.setGravity(Gravity.CENTER_VERTICAL);gifTextview.setText(stringBuilder);is.close();} catch (IOException e) {e.printStackTrace();}
如果有不懂的，欢迎随时提问，你的支持是我前进的动力哦！
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