Layers (OCG) Manipulation - Sample Code

1//---------------------------------------------------------------------------------------
2// Copyright (c) 2001-2023 by Apryse Software Inc. All Rights Reserved.
3// Consult legal.txt regarding legal and license information.
4//---------------------------------------------------------------------------------------
5(exports => {
6  exports.runPDFLayersTest = () => {
7    const PDFNet = exports.Core.PDFNet;
8
9    // A utility function used to add new Content Groups (Layers) to the document.
10    const CreateLayer = async (doc, layerName) => {
11      await PDFNet.startDeallocateStack();
12      const grp = await PDFNet.OCG.create(doc, layerName);
13      let cfg = await doc.getOCGConfig();
14      if (cfg == null) {
15        cfg = await PDFNet.OCGConfig.create(doc, true);
16        cfg.setName('Default');
17      }
18
19      // Add the new OCG to the list of layers that should appear in PDF viewer GUI.
20      let layerOrderArray = await cfg.getOrder();
21      if (layerOrderArray == null) {
22        layerOrderArray = await doc.createIndirectArray();
23        cfg.setOrder(layerOrderArray);
24      }
25      const grpSDFObj = await grp.getSDFObj();
26      layerOrderArray.pushBack(grpSDFObj);
27
28      await PDFNet.endDeallocateStack();
29      return grp;
30    };
31
32    // Creates some content (3 images) and associate them with the image layer
33    const CreateGroup1 = async (doc, layer) => {
34      await PDFNet.startDeallocateStack();
35      const writer = await PDFNet.ElementWriter.create();
36      writer.begin(doc);
37
38      // Create an Image that can be reused in the document or on the same page.
39      const nullEncoderHints = new PDFNet.Obj('0');
40      const img = await PDFNet.Image.createFromURL(doc, '../TestFiles/peppers.jpg', nullEncoderHints);
41
42      const builder = await PDFNet.ElementBuilder.create();
43      const imgWidth = await img.getImageWidth();
44      const imgHeight = await img.getImageHeight();
45      const imgMatrix = new PDFNet.Matrix2D(imgWidth / 2, -145, 20, imgHeight / 2, 200, 150);
46      const element = await builder.createImageFromMatrix(img, imgMatrix);
47      writer.writePlacedElement(element);
48
49      const gstate = await element.getGState(); // use the same image (just change its matrix)
50      gstate.setTransform(200, 0, 0, 300, 50, 450);
51      writer.writePlacedElement(element);
52
53      // use the same image again (just change its matrix).
54      writer.writePlacedElement(await builder.createImageScaled(img, 300, 600, 200, -150));
55
56      const grpObj = await writer.end();
57
58      // Indicate that this form (content group) belongs to the given layer (OCG).
59      grpObj.putName('Subtype', 'Form');
60      grpObj.put('OC', layer);
61      grpObj.putRect('BBox', 0, 0, 1000, 1000); // Set the clip box for the content.
62      await PDFNet.endDeallocateStack();
63
64      return grpObj;
65    };
66
67    const CreateGroup2 = async (doc, layer) => {
68      await PDFNet.startDeallocateStack();
69      const writer = await PDFNet.ElementWriter.create();
70      writer.begin(doc);
71
72      // Create a path object in the shape of a heart.
73      const builder = await PDFNet.ElementBuilder.create();
74      builder.pathBegin(); // start constructing the path
75      builder.moveTo(306, 396);
76      builder.curveTo(681, 771, 399.75, 864.75, 306, 771);
77      builder.curveTo(212.25, 864.75, -69, 771, 306, 396);
78      builder.closePath();
79      const element = await builder.pathEnd(); // the path geometry is now specified.
80
81      // Set the path FILL color space and color.
82      element.setPathFill(true);
83      const gstate = await element.getGState();
84      const CMYKSpace = await PDFNet.ColorSpace.createDeviceCMYK();
85      gstate.setFillColorSpace(CMYKSpace);
86      const cyanColorPt = await PDFNet.ColorPt.init(1, 0, 0, 0); // CMYK
87      gstate.setFillColorWithColorPt(cyanColorPt); // cyan
88
89      // Set the path STROKE color space and color.
90      element.setPathStroke(true);
91      const RGBSpace = await PDFNet.ColorSpace.createDeviceRGB();
92      gstate.setStrokeColorSpace(RGBSpace);
93      const redColorPt = await PDFNet.ColorPt.init(1, 0, 0); // RGB
94      gstate.setStrokeColorWithColorPt(redColorPt); // red
95      gstate.setLineWidth(20);
96
97      gstate.setTransform(0.5, 0, 0, 0.5, 280, 300);
98
99      writer.writeElement(element);
100
101      const grpObj = await writer.end();
102
103      // Indicate that this form (content group) belongs to the given layer (OCG).
104      grpObj.putName('Subtype', 'Form');
105      grpObj.put('OC', layer);
106      grpObj.putRect('BBox', 0, 0, 1000, 1000); // Set the clip box for the content.
107
108      await PDFNet.endDeallocateStack();
109      return grpObj;
110    };
111
112    const CreateGroup3 = async (doc, layer) => {
113      await PDFNet.startDeallocateStack();
114      const writer = await PDFNet.ElementWriter.create();
115      writer.begin(doc);
116
117      const builder = await PDFNet.ElementBuilder.create();
118
119      // Begin writing a block of text
120      const textFont = await PDFNet.Font.create(doc, PDFNet.Font.StandardType1Font.e_times_roman);
121      let element = await builder.createTextBeginWithFont(textFont, 120);
122      writer.writeElement(element);
123
124      element = await builder.createNewTextRun('A text layer!');
125
126      // Rotate text 45 degrees, than translate 180 pts horizontally and 100 pts vertically.
127      const transform = await PDFNet.Matrix2D.createRotationMatrix(-45 * (3.1415 / 180.0));
128      await transform.concat(1, 0, 0, 1, 180, 100);
129      await element.setTextMatrix(transform);
130
131      await writer.writeElement(element);
132      await writer.writeElement(await builder.createTextEnd());
133
134      const grpObj = await writer.end();
135
136      // Indicate that this form (content group) belongs to the given layer (OCG).
137      grpObj.putName('Subtype', 'Form');
138      grpObj.put('OC', layer);
139      grpObj.putRect('BBox', 0, 0, 1000, 1000); // Set the clip box for the content.
140      await PDFNet.endDeallocateStack();
141      return grpObj;
142    };
143
144    const main = async () => {
145      console.log('Beginning Test');
146      let doc = null;
147      // Here we output a pdf document with layers.
148      try {
149        doc = await PDFNet.PDFDoc.create();
150        doc.initSecurityHandler();
151        doc.lock();
152        console.log('PDFNet and PDF document initialized and locked');
153
154        const imageLayer = await CreateLayer(doc, 'Image Layer');
155        const textLayer = await CreateLayer(doc, 'Text Layer');
156        const vectorLayer = await CreateLayer(doc, 'Vector Layer');
157
158        const page = await doc.pageCreate();
159
160        const builder = await PDFNet.ElementBuilder.create();
161        const writer = await PDFNet.ElementWriter.create();
162        writer.beginOnPage(page);
163
164        const groupObj = await CreateGroup1(doc, await imageLayer.getSDFObj());
165        let element = await builder.createFormFromStream(groupObj);
166        writer.writeElement(element);
167
168        const groupObj2 = await CreateGroup2(doc, await vectorLayer.getSDFObj());
169        element = await builder.createFormFromStream(groupObj2);
170        writer.writeElement(element);
171
172        // eslint-disable-next-line no-constant-condition
173        if (false) {
174          // A bit more advanced example of how to create an OCMD text layer that
175          // is visible only if text, image and path layers are all 'ON'.
176          // An example of how to set 'Visibility Policy' in OCMD.
177          const ocgs = doc.createIndirectArray();
178          ocgs.pushBack(await imageLayer.getSDFObj());
179          ocgs.pushBack(await vectorLayer.getSDFObj());
180          ocgs.PushBack(await textLayer.getSDFObj());
181          const textOcmd = await PDFNet.OCMD.create(doc, ocgs, PDFNet.OCMD.VisibilityPolicyType.e_AllOn);
182          element = await builder.createFormFromStream(await CreateGroup3(doc, await textOcmd.getSDFObj()));
183        } else {
184          // let SDFObj = await textLayer.getSDFObj();
185          element = await builder.createFormFromStream(await CreateGroup3(doc, await textLayer.getSDFObj()));
186        }
187        writer.writeElement(element);
188
189        // Add some content to the page that does not belong to any layer...
190        // In this case this is a rectangle representing the page border.
191        element = await builder.createRect(0, 0, await page.getPageWidth(), await page.getPageHeight());
192        element.setPathFill(false);
193        element.setPathStroke(true);
194        const elementGState = await element.getGState();
195        elementGState.setLineWidth(40);
196        writer.writeElement(element);
197
198        writer.end(); // save changes to the current page
199        doc.pagePushBack(page);
200
201        // Set the default viewing preference to display 'Layer' tab.
202        const prefs = await doc.getViewPrefs();
203        prefs.setPageMode(PDFNet.PDFDocViewPrefs.PageMode.e_UseOC);
204
205        const docbuf = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_linearized);
206        saveBufferAsPDFDoc(docbuf, 'pdf_layers.pdf');
207        console.log('done example 1');
208      } catch (err) {
209        console.log(err.stack);
210      }
211
212      // Here we output the individual layers as png files.
213      try {
214        // we are still using the doc from the previous section.
215        if (!(await doc.hasOC())) {
216          console.log("The document does not contain 'Optional Content'");
217        } else {
218          const initCfg = await doc.getOCGConfig();
219          const ctx = await PDFNet.OCGContext.createFromConfig(initCfg);
220
221          const pdfdraw = await PDFNet.PDFDraw.create();
222          pdfdraw.setImageSize(1000, 1000);
223          pdfdraw.setOCGContext(ctx);
224
225          const page = await doc.getPage(1);
226
227          const firstPageBuffer = await pdfdraw.exportStream(page);
228          saveBufferAsPNG(firstPageBuffer, 'pdf_layers_default.png');
229
230          ctx.setNonOCDrawing(false);
231
232          const ocgs = await doc.getOCGs();
233          if (ocgs !== null) {
234            let i;
235            const sz = await ocgs.size();
236            for (i = 0; i < sz; ++i) {
237              const ocg = await PDFNet.OCG.createFromObj(await ocgs.getAt(i));
238              ctx.resetStates(false);
239              ctx.setState(ocg, true);
240              let fname = 'pdf_layers_';
241              fname += await ocg.getName();
242              fname += '.png';
243              const pageBuffer = await pdfdraw.exportStream(page);
244              saveBufferAsPNG(pageBuffer, fname);
245            }
246          }
247
248          // Now draw content that is not part of any layer...
249          ctx.setNonOCDrawing(true);
250          ctx.setOCDrawMode(PDFNet.OCGContext.OCDrawMode.e_NoOC);
251          const nonLayerBuffer = await pdfdraw.exportStream(page);
252          saveBufferAsPNG(nonLayerBuffer, 'pdf_layers_non_oc.png');
253        }
254
255        console.log('done');
256      } catch (err) {
257        console.log(err.stack);
258      }
259    };
260    // add your own license key as the second parameter, e.g. PDFNet.runWithCleanup(main, 'YOUR_LICENSE_KEY')
261    PDFNet.runWithCleanup(main);
262  };
263})(window);
264// eslint-disable-next-line spaced-comment
265//# sourceURL=PDFLayersTest.js