Refactor on equality check function (foliojs#1280)

Avoidable 'if' statement

demo/testSpotColor.js

@@ -0,0 +1,50 @@
+var PDFDocument = require('../');
+
+var fs = require('fs');
+
+// Create a new PDFDocument
+var doc = new PDFDocument();
+
+doc.pipe(fs.createWriteStream('spotColor.pdf'));
+
+// Set some meta data
+doc.info['Title'] = 'Test Document for Sport Color';
+
+doc.info['Author'] = 'Nicola A.';
+
+
+// Register a font name for use later
+doc.registerFont('Palatino', 'fonts/PalatinoBold.ttf');
+
+// Set the font, draw some text, and embed an image
+doc
+  .font('Palatino')
+  .fontSize(18)
+  .text('Testing Spot Colors: MYFIRST_SPOT_COLOR, MYSECOND_SPOT_COLOR', 50, 50)
+  .fontSize(12)
+  .text('Check it out on Swatches palette', 50, 100)
+
+// Add another page
+// doc
+//   .addPage()
+//   .fontSize(25)
+//   .text('Here is some vector graphics...', 100, 100);
+
+doc.addSpotColor('MYFIRST_SPOT_COLOR', 0, 50, 0, 0);
+doc.addSpotColor('MYSECOND_SPOT_COLOR', 50, 0, 0, 0);
+
+
+// Draw a triangle and a circle
+doc
+  .moveTo(100, 150)
+  .lineTo(100, 250)
+  .lineTo(200, 250)
+  .stroke('MYFIRST_SPOT_COLOR');
+
+doc
+  .moveTo(200, 250)
+  .lineTo(100, 150)
+  .lineTo(200, 150)
+  .lineTo(200, 250)
+  .fillAndStroke('MYFIRST_SPOT_COLOR', 'MYSECOND_SPOT_COLOR');
+doc.end();

lib/document.js

@@ -328,6 +328,7 @@ Please pipe the document into a Node stream.\
   _finalize() {
     // generate xref
     const xRefOffset = this._offset;
+    this._putSpotColors();
     this._write('xref');
     this._write(`0 ${this._offsets.length + 1}`);
     this._write('0000000000 65535 f ');

lib/mixins/color.js

@@ -5,6 +5,8 @@ const { PDFGradient, PDFLinearGradient, PDFRadialGradient } = Gradient;
 const { PDFTilingPattern } = pattern;
 
 export default {
+  spotColors: {},
+  spotColorsCount: 0,
   initColor() {
     // The opacity dictionaries
     this._opacityRegistry = {};
@@ -38,6 +40,8 @@ export default {
         color = color.map(part => part / 100);
       }
       return color;
+    } else if (this.spotColors[color]) {
+      return color;
     }
 
     return null;
@@ -48,6 +52,9 @@ export default {
       color.apply(stroke);
       return true;
       // see if tiling pattern, decode & apply it it
+    } else if (typeof color === 'string') {
+      this.addContent(`/CS${this.spotColors[color].index} ${stroke ? 'CS' : 'cs'} 1 ${op}`);
+      return false;
     } else if (Array.isArray(color) && color[0] instanceof PDFTilingPattern) {
       color[0].apply(stroke, color[1]);
       return true;
@@ -163,6 +170,28 @@ export default {
 
   pattern(bbox, xStep, yStep, stream) {
     return new PDFTilingPattern(this, bbox, xStep, yStep, stream);
+  },
+
+  addSpotColor: function (name, C, M, Y, K) {
+    this._offsets.push(this._offset);
+    this.spotColors[name] = {
+      id: this._offsets.length,
+      index: ++this.spotColorsCount,
+      name: name,
+      values: [C, M, Y, K],
+    };
+  },
+  _putSpotColors: function () {
+    for (var item in this.spotColors) {
+      let output = '';
+      item = this.spotColors[item];
+      output += `${item.id} 0 obj \n`;
+      output += `[/Separation /${item.name} /DeviceCMYK << /Range [0 1 0 1 0 1 0 1] /C0 [0 0 0 0] /C1 [${
+          item.values.map(value => value / 100.0).join(' ')
+      }]  /FunctionType 2 /Domain [0 1] /N 1>>]`;
+      output += `\nendobj`;
+      this._write(output);
+    }
   }
 };
 

lib/object.js

@@ -40,7 +40,7 @@ class PDFObject {
   static convert(object, encryptFn = null) {
     // String literals are converted to the PDF name type
     if (typeof object === 'string') {
-      return `/${object}`;
+      return /^[\/\[\(\d].*/.test(object) ? object : '/' + object;
 
       // String objects are converted to PDF strings (UTF-16)
     } else if (object instanceof String) {

lib/page.js

@@ -157,6 +157,12 @@ class PDFPage {
 
   end() {
     this.dictionary.end();
+    this.resources.data.ColorSpace = {};
+    let i = 1;
+    for (let item in this.document.spotColors) {
+      item = this.document.spotColors[item];
+      this.resources.data.ColorSpace[`CS${i++}`] = `${item.id} 0 R`;
+    }
     this.resources.end();
     return this.content.end();
   }