add PNG/ANSIImage element.

README.md

@@ -172,6 +172,7 @@ screen.render();
   - [Terminal](#terminal-from-box)
   - [Image](#image-from-box)
   - [Layout](#layout-from-element)
+  - [PNG](#png-from-box)
 
 ### Other
 
@@ -1384,11 +1385,13 @@ terminals.
 ##### Methods:
 
 - inherits all from Box.
-- __setImage(img, callback)__ - set the image in the box to a new path.
-- __clearImage(callback)__ - clear the current image.
-- __imageSize(img, callback)__ - get the size of an image file in pixels.
-- __termSize(callback)__ - get the size of the terminal in pixels.
-- __getPixelRatio(callback)__ - get the pixel to cell ratio for the terminal.
+- __setImage(img, [callback])__ - set the image in the box to a new path.
+- __clearImage([callback])__ - clear the current image.
+- __imageSize(img, [callback])__ - get the size of an image file in pixels.
+- __termSize([callback])__ - get the size of the terminal in pixels.
+- __getPixelRatio([callback])__ - get the pixel to cell ratio for the terminal.
+- _Note:_ All methods above can be synchronous as long as the host version of
+  node supports `spawnSync`.
 
 
 #### Layout (from Element)
@@ -1565,6 +1568,68 @@ for (var i = 0; i < 10; i++) {
 ```
 
 
+#### PNG (from Box)
+
+Convert any `.png` file (or `.gif`, see below) to an ANSI image and display it
+as an element. This differs from the `Image` element in that it uses blessed's
+internal PNG parser and does not require external dependencies.
+
+Blessed uses an internal from-scratch PNG reader because no other javascript
+PNG reader supports Adam7 interlaced images (much less pass the png test
+suite).
+
+The blessed PNG reader supports adam7 deinterlacing, animation (APNG), all
+color types, bit depths 1-32, alpha, alpha palettes, and outputs scaled bitmaps
+(cellmaps) in blessed for efficient rendering to the screen buffer. It also
+uses some code from libcaca/libcucul to add density ASCII characters in order
+to give the image more detail in the terminal.
+
+If a corrupt PNG or a non-PNG is passed in, blessed will display error text in
+the element.
+
+`.gif` files are also supported via a javascript implementation (they are
+internally converted to bitmaps and fed to the PNG renderer). Any other image
+format is support only if the user has imagemagick (`convert` and `identify`)
+installed.
+
+##### Options:
+
+- inherits all from Box.
+- __file__ - URL or path to PNG file. can also be a buffer.
+- __scale__ - scale cellmap down (`0-1.0`) from its original pixel width/height
+  (default: `1.0`).
+- __width/height__ - this differs from other element's `width` or `height` in
+  that only one of them is needed: blessed will maintain the aspect ratio of
+  the image as it scales down to the proper number of cells. __NOTE__: PNG's
+  are always automatically shrunken to size (based on scale) if a `width` or
+  `height` is not given.
+- __ascii__ - add various "density" ASCII characters over the rendering to give
+  the image more detail, similar to libcaca/libcucul (the library mplayer uses
+  to display videos in the terminal).
+- __animate__ - whether to animate if the image is an APNG. if false, only
+  display the first frame or IDAT (default: `true`).
+
+##### Properties:
+
+- inherits all from Box.
+- __img__ - image object from the png reader.
+- __img.width__ - pixel width.
+- __img.height__ - pixel height.
+- __img.bmp__ - image bitmap.
+- __img.cellmap__ - image cellmap (bitmap scaled down to cell size).
+
+##### Events:
+
+- inherits all from Box.
+
+##### Methods:
+
+- inherits all from Box.
+- __setImage(file)__ - set the image in the box to a new path. file can be a
+  path, url, or buffer.
+- __clearImage()__ - clear the image.
+
+
 ### Other
 
 

lib/widget.js

@@ -36,7 +36,8 @@ widget.classes = [
   'ListTable',
   'Terminal',
   'Image',
-  'Layout'
+  'Layout',
+  'PNG'
 ];
 
 widget.classes.forEach(function(name) {

lib/widgets/png.js

@@ -0,0 +1,142 @@
+/**
+ * png.js - render PNGs as ANSI
+ * Copyright (c) 2013-2015, Christopher Jeffrey and contributors (MIT License).
+ * https://github.com/chjj/blessed
+ */
+
+/**
+ * Modules
+ */
+
+var cp = require('child_process')
+  , path = require('path')
+  , fs = require('fs');
+
+var helpers = require('../helpers');
+var colors = require('../colors');
+
+var Node = require('./node');
+var Box = require('./box');
+
+var tng = require('../../vendor/tng');
+
+/**
+ * PNG
+ */
+
+function PNG(options) {
+  var self = this;
+
+  if (!(this instanceof Node)) {
+    return new PNG(options);
+  }
+
+  options = options || {};
+  options.shrink = true;
+
+  Box.call(this, options);
+
+  this.scale = this.options.scale || 1.0;
+  this.options.animate = this.options.animate !== false;
+  this._noFill = true;
+
+  if (this.options.file) {
+    this.setImage(this.options.file);
+  }
+
+  this.screen.on('prerender', function() {
+    var lpos = self.lpos;
+    if (!lpos) return;
+    // prevent image from blending with itself if there are alpha channels
+    self.screen.clearRegion(lpos.xi, lpos.xl, lpos.yi, lpos.yl);
+  });
+}
+
+PNG.prototype.__proto__ = Box.prototype;
+
+PNG.prototype.type = 'png';
+
+PNG.curl = function(url) {
+  try {
+    return cp.execFileSync('curl',
+      ['-s', '-A', '', url],
+      { stdio: ['ignore', 'pipe', 'ignore'] });
+  } catch (e) {
+    ;
+  }
+  try {
+    return cp.execFileSync('wget',
+      ['-U', '', '-O', '-', url],
+      { stdio: ['ignore', 'pipe', 'ignore'] });
+  } catch (e) {
+    ;
+  }
+  throw new Error('curl or wget failed.');
+};
+
+PNG.prototype.setImage = function(file) {
+  var self = this;
+  if (/^https?:/.test(file)) {
+    file = PNG.curl(file);
+  }
+  this.file = file;
+  var width = this.position.width;
+  var height = this.position.height;
+  if (width != null) {
+    width = this.width;
+  }
+  if (height != null) {
+    height = this.height;
+  }
+  try {
+    this.setContent('');
+    this.img = tng(this.file, {
+      colors: colors,
+      cellmapWidth: width,
+      cellmapHeight: height,
+      cellmapScale: this.scale,
+      ascii: this.options.ascii
+    });
+    if (width == null || height == null) {
+      this.width = this.img.cellmap[0].length;
+      this.height = this.img.cellmap.length;
+    }
+    if (this.img.frames && this.options.animate) {
+      this.img.play(function(bmp, cellmap) {
+        self.cellmap = cellmap;
+        self.screen.render();
+      });
+    } else {
+      self.cellmap = self.img.cellmap;
+    }
+  } catch (e) {
+    this.setContent('PNG Error: ' + e.message);
+    this.img = null;
+    this.cellmap = null;
+  }
+};
+
+PNG.prototype.clearImage = function() {
+  this.setContent('');
+  this.img = null;
+  this.cellmap = null;
+};
+
+PNG.prototype.render = function() {
+  var self = this;
+
+  var coords = this._render();
+  if (!coords) return;
+
+  if (this.img) {
+    this.img.renderElement(this.cellmap, this);
+  }
+
+  return coords;
+};
+
+/**
+ * Expose
+ */
+
+module.exports = PNG;

test/widget-png.js

@@ -0,0 +1,69 @@
+var blessed = require('../');
+var fs = require('fs');
+
+var screen = blessed.screen({
+  tput: true,
+  smartCSR: true,
+  dump: __dirname + '/logs/png.log'
+});
+
+var box = blessed.box({
+  parent: screen,
+  left: 4,
+  top: 3,
+  width: 10,
+  height: 6,
+  border: 'line',
+  style: {
+    bg: 'green'
+  },
+  content: 'Lorem ipsum doler',
+  align: 'center'
+});
+
+var file = process.argv[2];
+var testImage = __dirname + '/test-image.png';
+var spinfox = __dirname + '/spinfox.png';
+
+// XXX I'm not sure of the license of this file,
+// so I'm not going to redistribute it in the repo.
+var url = 'https://people.mozilla.org/~dolske/apng/spinfox.png';
+
+if (!file) {
+  try {
+    if (!fs.existsSync(spinfox)) {
+      var buf = blessed.png.curl(url);
+      fs.writeFileSync(spinfox, buf);
+    }
+    file = spinfox;
+  } catch (e) {
+    file = testImage;
+  }
+}
+
+var png = blessed.png({
+  parent: screen,
+  // border: 'line',
+  width: 20,
+  height: 19,
+  top: 2,
+  left: 0,
+  file: file,
+  ascii: false,
+  draggable: true
+});
+
+screen.render();
+
+screen.key('q', function() {
+  process.exit(0);
+});
+
+var timeout = setInterval(function() {
+  png.left++;
+  screen.render();
+}, 100);
+
+png.on('mousedown', function() {
+  clearInterval(timeout);
+});

vendor/tng/.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+debug.log
+png.json

vendor/tng/.npmignore

@@ -0,0 +1,6 @@
+.git*
+test/
+img/
+node_modules/
+debug.log
+png.json

vendor/tng/LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2015, Christopher Jeffrey
+https://github.com/chjj/tng
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

vendor/tng/README.md

@@ -0,0 +1,39 @@
+# tng
+
+A full-featured PNG renderer for the terminal, built for [blessed][blessed].
+
+![tng](https://raw.githubusercontent.com/chjj/blessed/master/img/demo.png)
+
+Convert any `.png` file (or `.gif`, see below) to an ANSI image and display it
+as an element or ANSI text.
+
+Blessed uses an internal from-scratch PNG reader because no other javascript
+PNG reader supports Adam7 interlaced images (much less pass the png test
+suite).
+
+The blessed PNG reader supports adam7 deinterlacing, animation (APNG), all
+color types, bit depths 1-32, alpha, alpha palettes, and outputs scaled bitmaps
+(cellmaps) in blessed for efficient rendering to the screen buffer. It also
+uses some code from libcaca/libcucul to add density ASCII characters in order
+to give the image more detail in the terminal.
+
+`.gif` files are also supported via a javascript implementation (they are
+internally converted to bitmaps and fed to the PNG renderer). Any other image
+format is support only if the user has imagemagick (`convert` and `identify`)
+installed.
+
+
+## Contribution and License Agreement
+
+If you contribute code to this project, you are implicitly allowing your code
+to be distributed under the MIT license. You are also implicitly verifying that
+all code is your original work. `</legalese>`
+
+
+## License
+
+Copyright (c) 2015, Christopher Jeffrey. (MIT License)
+
+See LICENSE for more info.
+
+[blessed]: https://github.com/chjj/blessed

vendor/tng/index.js

@@ -0,0 +1 @@
+module.exports = require('./lib/tng.js');

vendor/tng/lib/gif.js

@@ -0,0 +1,399 @@
+/**
+ * gif.js - gif reader for tng
+ * Copyright (c) 2015, Christopher Jeffrey (MIT License).
+ * https://github.com/chjj/tng
+ */
+
+var fs = require('fs')
+  , cp = require('child_process')
+  , path = require('path')
+  , assert = require('assert');
+
+/**
+ * GIF
+ */
+
+function GIF(file, options) {
+  var info = {}
+    , p = 0
+    , buf
+    , i
+    , total
+    , sig
+    , desc
+    , img
+    , ext
+    , label
+    , size;
+
+  if (!file) throw new Error('no file');
+
+  options = options || {};
+
+  if (Buffer.isBuffer(file)) {
+    buf = file;
+    file = null;
+  } else {
+    file = path.resolve(process.cwd(), file);
+    buf = fs.readFileSync(file);
+  }
+
+  sig = buf.slice(0, 6).toString('ascii');
+  if (sig !== 'GIF87a' && sig !== 'GIF89a') {
+    throw new Error('bad header: ' + sig);
+  }
+
+  info.screenWidth = buf.readUInt16LE(6);
+  info.screenHeight = buf.readUInt16LE(8);
+
+  info.flags = buf.readUInt8(10);
+  info.gct = !!(info.flags & 0x80);
+  info.gctsize = (info.flags & 0x07) + 1;
+
+  info.bgIndex = buf.readUInt8(11);
+  info.aspect = buf.readUInt8(12);
+  p += 13;
+
+  if (info.gct) {
+    info.colors = [];
+    total = 1 << info.gctsize;
+    for (i = 0; i < total; i++, p += 3) {
+      info.colors.push([buf[p], buf[p + 1], buf[p + 2], 255]);
+    }
+  }
+
+  info.images = [];
+  info.extensions = [];
+
+  try {
+    while (p < buf.length) {
+      desc = buf.readUInt8(p);
+      p += 1;
+      if (desc === 0x2c) {
+        img = {};
+
+        img.left = buf.readUInt16LE(p);
+        p += 2;
+        img.top = buf.readUInt16LE(p);
+        p += 2;
+
+        img.width = buf.readUInt16LE(p);
+        p += 2;
+        img.height = buf.readUInt16LE(p);
+        p += 2;
+
+        img.flags = buf.readUInt8(p);
+        p += 1;
+
+        img.lct = !!(img.flags & 0x80);
+        img.ilace = !!(img.flags & 0x40);
+        img.lctsize = (img.flags & 0x07) + 1;
+
+        if (img.lct) {
+          img.lcolors = [];
+          total = 1 << img.lctsize;
+          for (i = 0; i < total; i++, p += 3) {
+            img.lcolors.push([buf[p], buf[p + 1], buf[p + 2], 255]);
+          }
+        }
+
+        img.codeSize = buf.readUInt8(p);
+        p += 1;
+
+        img.size = buf.readUInt8(p);
+        p += 1;
+
+        img.lzw = [buf.slice(p, p + img.size)];
+        p += img.size;
+
+        while (buf[p] !== 0x00) {
+          // Some gifs screw up their size.
+          // XXX Same for all subblocks?
+          if (buf[p] === 0x3b) {
+            p--;
+            break;
+          }
+          size = buf.readUInt8(p);
+          p += 1;
+          img.lzw.push(buf.slice(p, p + size));
+          p += size;
+        }
+
+        assert.equal(buf.readUInt8(p), 0x00);
+        p += 1;
+
+        info.images.push(img);
+      } else if (desc === 0x21) {
+        // Extensions:
+        // http://www.w3.org/Graphics/GIF/spec-gif89a.txt
+        ext = {};
+        label = buf.readUInt8(p);
+        p += 1;
+        ext.label = label;
+        if (label === 0xf9) {
+          size = buf.readUInt8(p);
+          assert.equal(size, 0x04);
+          p += 1;
+          ext.fields = buf.readUInt8(p);
+          ext.disposeMethod = (ext.fields >> 2) & 0x07;
+          ext.useTransparent = !!(ext.fields & 0x01);
+          p += 1;
+          ext.delay = buf.readUInt16LE(p);
+          p += 2;
+          ext.transparentColor = buf.readUInt8(p);
+          p += 1;
+          while (buf[p] !== 0x00) {
+            size = buf.readUInt8(p);
+            p += 1;
+            p += size;
+          }
+          assert.equal(buf.readUInt8(p), 0x00);
+          p += 1;
+          info.delay = ext.delay;
+          info.transparentColor = ext.transparentColor;
+          info.disposeMethod = ext.disposeMethod;
+          info.useTransparent = ext.useTransparent;
+        } else if (label === 0xff) {
+          size = buf.readUInt8(p);
+          p += 1;
+          ext.id = buf.slice(p, p + 8).toString('ascii');
+          p += 8;
+          ext.auth = buf.slice(p, p + 3).toString('ascii');
+          p += 3;
+          ext.data = [];
+          while (buf[p] !== 0x00) {
+            size = buf.readUInt8(p);
+            p += 1;
+            ext.data.push(buf.slice(p, p + size));
+            p += size;
+          }
+          // http://graphcomp.com/info/specs/ani_gif.html
+          if (ext.id === 'NETSCAPE' && ext.auth === '2.0') {
+            assert.equal(ext.data[0].readUInt8(0), 0x01);
+            ext.numPlays = ext.data[0].readUInt16LE(1);
+            info.numPlays = ext.numPlays;
+          }
+          assert.equal(buf.readUInt8(p), 0x00);
+          p += 1;
+        } else {
+          ext.data = [];
+          while (buf[p] !== 0x00) {
+            size = buf.readUInt8(p);
+            p += 1;
+            ext.data.push(buf.slice(p, p + size));
+            p += size;
+          }
+          assert.equal(buf.readUInt8(p), 0x00);
+          p += 1;
+        }
+        info.extensions.push(ext);
+      } else if (desc === 0x3b) {
+        break;
+      } else if (p === buf.length - 1) {
+        // } else if (desc === 0x00 && p === buf.length - 1) {
+        break;
+      } else {
+        throw new Error('unknown block');
+      }
+    }
+  } catch (e) {
+    if (options.debug) {
+      throw e;
+    }
+  }
+
+  info.images = info.images.map(function(img) {
+    img.lzw = new Buffer(img.lzw.reduce(function(out, data) {
+      return out.concat(Array.prototype.slice.call(data));
+    }, []));
+
+    try {
+      img.data = decompress(img.lzw, img.codeSize);
+    } catch (e) {
+      if (options.debug) throw e;
+      return;
+    }
+
+    var interlacing = [
+      [ 0, 8 ],
+      [ 4, 8 ],
+      [ 2, 4 ],
+      [ 1, 2 ],
+      [ 0, 0 ]
+    ];
+
+    var table = img.lcolors || info.colors
+      , row = 0
+      , col = 0
+      , ilp = 0
+      , p = 0
+      , b
+      , idx
+      , i
+      , y
+      , x
+      , line
+      , pixel;
+
+    img.samples = [];
+    // Rewritten version of:
+    // https://github.com/lbv/ka-cs-programs/blob/master/lib/gif-reader.js
+    for (;;) {
+      b = img.data[p++];
+      if (b == null) break;
+      idx = (row * img.width + col) * 4;
+      if (!table[b]) {
+        if (options.debug) throw new Error('bad samples');
+        table[b] = [0, 0, 0, 0];
+      }
+      img.samples[idx] = table[b][0];
+      img.samples[idx + 1] = table[b][1];
+      img.samples[idx + 2] = table[b][2];
+      img.samples[idx + 3] = table[b][3];
+      if (info.useTransparent && b === info.transparentColor) {
+        img.samples[idx + 3] = 0;
+      }
+      if (++col >= img.width) {
+        col = 0;
+        if (img.ilace) {
+          row += interlacing[ilp][1];
+          if (row >= img.height) {
+            row = interlacing[++ilp][0];
+          }
+        } else {
+          row++;
+        }
+      }
+    }
+
+    img.pixels = [];
+    for (i = 0; i < img.samples.length; i += 4) {
+      img.pixels.push(img.samples.slice(i, i + 4));
+    }
+
+    img.bmp = [];
+    for (y = 0, p = 0; y < img.height; y++) {
+      line = [];
+      for (x = 0; x < img.width; x++) {
+        pixel = img.pixels[p++];
+        if (!pixel) {
+          if (options.debug) throw new Error('no pixel');
+          line.push({ r: 0, g: 0, b: 0, a: 0 });
+          continue;
+        }
+        line.push({ r: pixel[0], g: pixel[1], b: pixel[2], a: pixel[3] });
+      }
+      img.bmp.push(line);
+    }
+
+    return img;
+  }, this).filter(Boolean);
+
+  if (!info.images.length) {
+    throw new Error('no image data or bad decompress');
+  }
+
+  return info;
+}
+
+// Rewritten version of:
+// https://github.com/lbv/ka-cs-programs/blob/master/lib/gif-reader.js
+function decompress(input, codeSize) {
+  var bitDepth = codeSize + 1
+    , CC = 1 << codeSize
+    , EOI = CC + 1
+    , stack = []
+    , table = []
+    , ntable = 0
+    , oldCode = null
+    , buffer = 0
+    , nbuffer = 0
+    , p = 0
+    , buf = []
+    , bits
+    , read
+    , ans
+    , n
+    , code
+    , i
+    , K
+    , b
+    , maxElem;
+
+  for (;;) {
+    if (stack.length === 0) {
+      bits = bitDepth;
+      read = 0;
+      ans = 0;
+      while (read < bits) {
+        if (nbuffer === 0) {
+          if (p >= input.length) return buf;
+          buffer = input[p++];
+          nbuffer = 8;
+        }
+        n = Math.min(bits - read, nbuffer);
+        ans |= (buffer & ((1 << n) - 1)) << read;
+        read += n;
+        nbuffer -= n;
+        buffer >>= n;
+      }
+      code = ans;
+
+      if (code === EOI) {
+        break;
+      }
+
+      if (code === CC) {
+        table = [];
+        for (i = 0; i < CC; ++i) {
+          table[i] = [i, -1, i];
+        }
+        bitDepth = codeSize + 1;
+        maxElem = 1 << bitDepth;
+        ntable = CC + 2;
+        oldCode = null;
+        continue;
+      }
+
+      if (oldCode === null) {
+        oldCode = code;
+        buf.push(table[code][0]);
+        continue;
+      }
+
+      if (code < ntable) {
+        for (i = code; i >= 0; i = table[i][1]) {
+          stack.push(table[i][0]);
+        }
+        table[ntable++] = [
+          table[code][2],
+          oldCode,
+          table[oldCode][2]
+        ];
+      } else {
+        K = table[oldCode][2];
+        table[ntable++] = [K, oldCode, K];
+        for (i = code; i >= 0; i = table[i][1]) {
+          stack.push(table[i][0]);
+        }
+      }
+
+      oldCode = code;
+      if (ntable === maxElem) {
+        maxElem = 1 << (++bitDepth);
+        if (bitDepth > 12) bitDepth = 12;
+      }
+    }
+    b = stack.pop();
+    if (b == null) break;
+    buf.push(b);
+  }
+
+  return buf;
+}
+
+/**
+ * Expose
+ */
+
+module.exports = GIF;

vendor/tng/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "tng",
+  "description": "A full-featured PNG renderer for the terminal.",
+  "author": "Christopher Jeffrey",
+  "version": "0.0.1",
+  "main": "./lib/tng.js",
+  "bin": "./test/index.js",
+  "preferGlobal": false,
+  "repository": "git://github.com/chjj/tng.git",
+  "homepage": "https://github.com/chjj/tng",
+  "bugs": { "url": "http://github.com/chjj/tng/issues" },
+  "keywords": ["png", "gif", "image", "terminal", "term", "tty", "tui"],
+  "tags": ["png", "gif", "image", "terminal", "term", "tty", "tui"],
+  "peerDependencies": {
+    "blessed": ">=0.1.61"
+  }
+}