ElementBuilder

1//
2// Copyright (c) 2001-2020 by PDFTron Systems Inc. All Rights Reserved.
3//
4
5using System;
6using System.IO;
7using System.Threading.Tasks;
8using Windows.Foundation;
9
10using pdftron.Common;
11using pdftron.Filters;
12using pdftron.PDF;
13using pdftron.SDF;
14
15using PDFNetUniversalSamples.ViewModels;
16
17namespace PDFNetSamples
18{
19    public sealed class ElementBuilderTest : Sample
20    {
21        public ElementBuilderTest() :
22            base("ElementBuilder", "Illustrates how to use PDFNet page writing API, how to embed fonts and images and how to copy graphical elements from one page to another.")
23        {
24        }
25
26        public override IAsyncAction RunAsync()
27        {
28            return Task.Run(new System.Action(async () => {
29                WriteLine("--------------------------------");
30                WriteLine("Starting ElementBuilder Test...");
31                WriteLine("--------------------------------\n");
32            
33                try
34                {
35                    PDFDoc doc = new PDFDoc();
36
37                    ElementBuilder eb = new ElementBuilder();		// ElementBuilder is used to build new Element objects
38                    ElementWriter writer = new ElementWriter();	// ElementWriter is used to write Elements to the page	
39
40                    // Start a new page ------------------------------------
41                    // Position an image stream on several places on the page
42                    pdftron.PDF.Page page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 612, 794));
43
44                    writer.Begin(page);	// begin writing to this page
45
46                    // Create an Image that can be reused multiple times in the document or 
47                    // multiple on the same page.
48
49                    MappedFile img_file = new MappedFile(Path.Combine(InputPath, "peppers.jpg"));
50                    FilterReader img_data = new FilterReader(img_file);
51                    pdftron.PDF.Image img = pdftron.PDF.Image.Create(new SDFDoc(doc), img_data, 400, 600, 8, ColorSpace.CreateDeviceRGB(), pdftron.PDF.ImageInputFilter.e_jpeg);
52
53                    Element element = eb.CreateImage(img, new Matrix2D(200, -145, 20, 300, 200, 150));
54                    writer.WritePlacedElement(element);
55
56                    GState gstate = element.GetGState();	// use the same image (just change its matrix)
57                    gstate.SetTransform(200, 0, 0, 300, 50, 450);
58                    writer.WritePlacedElement(element);
59
60                    // use the same image again (just change its matrix).
61                    writer.WritePlacedElement(eb.CreateImage(img, 300, 600, 200, -150));
62                
63                    writer.End();  // save changes to the current page
64                    doc.PagePushBack(page);
65
66                    // Start a new page ------------------------------------
67                    // Construct and draw a path object using different styles
68                    page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 612, 794));
69
70                    writer.Begin(page);	// begin writing to this page
71                    eb.Reset(); 		// Reset GState to default
72
73                    eb.PathBegin();		// start constructing the path				                            
74                    eb.MoveTo(306, 396);
75                    eb.CurveTo(681, 771, 399.75, 864.75, 306, 771);
76                    eb.CurveTo(212.25, 864.75, -69, 771, 306, 396);
77                    eb.ClosePath();
78                    element = eb.PathEnd();			// the path is now finished
79                    element.SetPathFill(true);		// the path should be filled
80
81                    // Set the path color space and color
82                    gstate = element.GetGState();
83                    gstate.SetFillColorSpace(ColorSpace.CreateDeviceCMYK());
84                    gstate.SetFillColor(new ColorPt(1, 0, 0, 0));  // cyan
85                    gstate.SetTransform(0.5, 0, 0, 0.5, -20, 300);
86                    writer.WritePlacedElement(element);
87
88                    // Draw the same path using a different stroke color
89                    element.SetPathStroke(true);		// this path is should be filled and stroked
90                    gstate.SetFillColor(new ColorPt(0, 0, 1, 0));  // yellow
91                    gstate.SetStrokeColorSpace(ColorSpace.CreateDeviceRGB());
92                    gstate.SetStrokeColor(new ColorPt(1, 0, 0));  // red
93                    gstate.SetTransform(0.5, 0, 0, 0.5, 280, 300);
94                    gstate.SetLineWidth(20);
95                    writer.WritePlacedElement(element);
96
97                    // Draw the same path with with a given dash pattern
98                    element.SetPathFill(false);	// this path is should be only stroked
99                    gstate.SetStrokeColor(new ColorPt(0, 0, 1));  // blue
100                    gstate.SetTransform(0.5, 0, 0, 0.5, 280, 0);
101                    double[] dash_pattern = { 30 };
102                    gstate.SetDashPattern(dash_pattern, 0);
103                    writer.WritePlacedElement(element);
104
105                    // Use the path as a clipping path
106                    writer.WriteElement(eb.CreateGroupBegin());	// Save the graphics state
107                    // Start constructing a new path (the old path was lost when we created 
108                    // a new Element using CreateGroupBegin()).
109                    eb.PathBegin();
110                    eb.MoveTo(306, 396);
111                    eb.CurveTo(681, 771, 399.75, 864.75, 306, 771);
112                    eb.CurveTo(212.25, 864.75, -69, 771, 306, 396);
113                    eb.ClosePath();
114                    element = eb.PathEnd();	// path is now built
115                    element.SetPathClip(true);	// this path is a clipping path
116                    element.SetPathStroke(true);		// this path is should be filled and stroked
117                    gstate = element.GetGState();
118                    gstate.SetTransform(0.5, 0, 0, 0.5, -20, 0);
119                    writer.WriteElement(element);
120                    writer.WriteElement(eb.CreateImage(img, 100, 300, 400, 600));
121                    writer.WriteElement(eb.CreateGroupEnd());	// Restore the graphics state
122
123                    writer.End();  // save changes to the current page
124                    doc.PagePushBack(page);
125
126                    // Start a new page ------------------------------------
127                    page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 612, 794));
128
129                    writer.Begin(page);	// begin writing to this page
130                    eb.Reset(); 		// Reset GState to default
131
132                    // Begin writing a block of text
133                    element = eb.CreateTextBegin(Font.Create(doc.GetSDFDoc(), FontStandardType1Font.e_times_roman), 12);
134                    writer.WriteElement(element);
135
136                    string data = "Hello World!";
137                    element = eb.CreateTextRun(data);
138                    element.SetTextMatrix(10, 0, 0, 10, 0, 600);
139                    element.GetGState().SetLeading(15);		 // Set the spacing between lines
140                    writer.WriteElement(element);
141
142                    writer.WriteElement(eb.CreateTextNewLine());  // New line
143
144                    element = eb.CreateTextRun(data);
145                    gstate = element.GetGState();
146                    gstate.SetTextRenderMode(GStateTextRenderingMode.e_stroke_text);
147                    gstate.SetCharSpacing(-1.25);
148                    gstate.SetWordSpacing(-1.25);
149                    writer.WriteElement(element);
150
151                    writer.WriteElement(eb.CreateTextNewLine());  // New line
152
153                    element = eb.CreateTextRun(data);
154                    gstate = element.GetGState();
155                    gstate.SetCharSpacing(0);
156                    gstate.SetWordSpacing(0);
157                    gstate.SetLineWidth(3);
158                    gstate.SetTextRenderMode(GStateTextRenderingMode.e_fill_stroke_text);
159                    gstate.SetStrokeColorSpace(ColorSpace.CreateDeviceRGB());
160                    gstate.SetStrokeColor(new ColorPt(1, 0, 0));	// red
161                    gstate.SetFillColorSpace(ColorSpace.CreateDeviceCMYK());
162                    gstate.SetFillColor(new ColorPt(1, 0, 0, 0));	// cyan
163                    writer.WriteElement(element);
164
165                    writer.WriteElement(eb.CreateTextNewLine());  // New line
166
167                    // Set text as a clipping path to the image.
168                    element = eb.CreateTextRun(data);
169                    gstate = element.GetGState();
170                    gstate.SetTextRenderMode(GStateTextRenderingMode.e_clip_text);
171                    writer.WriteElement(element);
172
173                    // Finish the block of text
174                    writer.WriteElement(eb.CreateTextEnd());
175
176                    // Draw an image that will be clipped by the above text
177                    writer.WriteElement(eb.CreateImage(img, 10, 100, 1300, 720));
178
179                    writer.End();  // save changes to the current page
180                    doc.PagePushBack(page);
181
182                    // Start a new page ------------------------------------
183                    //
184                    // The example illustrates how to embed the external font in a PDF document. 
185                    // The example also shows how ElementReader can be used to copy and modify 
186                    // Elements between pages.
187
188                    ElementReader reader = new ElementReader();
189
190                    // Start reading Elements from the last page. We will copy all Elements to 
191                    // a new page but will modify the font associated with text.
192                    reader.Begin(doc.GetPage(doc.GetPageCount()));
193
194                    page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 1300, 794));
195
196                    writer.Begin(page);	// begin writing to this page
197                    eb.Reset(); 		// Reset GState to default
198
199                    // Embed an external font in the document.
200                    Font font = Font.CreateTrueTypeFont(doc, Path.Combine(InputPath, "font.ttf"));
201
202                    while ((element = reader.Next()) != null) 	// Read page contents
203                    {
204                        if (element.GetType() == ElementType.e_text)
205                        {
206                            element.GetGState().SetFont(font, 12);
207                        }
208
209                        writer.WriteElement(element);
210                    }
211
212                    reader.End();
213                    writer.End();  // save changes to the current page
214
215                    doc.PagePushBack(page);
216
217                    // Start a new page ------------------------------------
218                    //
219                    // The example illustrates how to embed the external font in a PDF document. 
220                    // The example also shows how ElementReader can be used to copy and modify 
221                    // Elements between pages.
222
223                    // Start reading Elements from the last page. We will copy all Elements to 
224                    // a new page but will modify the font associated with text.
225                    reader.Begin(doc.GetPage(doc.GetPageCount()));
226
227                    page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 1300, 794));
228
229                    writer.Begin(page);	// begin writing to this page
230                    eb.Reset(); 		// Reset GState to default
231
232                    // Embed an external font in the document.
233                    Font font2 = Font.CreateType1Font(doc, Path.Combine(InputPath, "Misc-Fixed.pfa"));
234
235                    while ((element = reader.Next()) != null) 	// Read page contents
236                    {
237                        if (element.GetType() == ElementType.e_text)
238                        {
239                            element.GetGState().SetFont(font2, 12);
240                        }
241                        writer.WriteElement(element);
242                    }
243
244                    reader.End();
245                    writer.End();  // save changes to the current page
246                    doc.PagePushBack(page);
247
248
249                    // Start a new page ------------------------------------
250                    page = doc.PageCreate();
251                    writer.Begin(page);	// begin writing to this page
252                    eb.Reset(); 		// Reset GState to default
253
254                    // Begin writing a block of text
255                    //System.Drawing.Font sys_font = new System.Drawing.Font("Comic Sans MS", 12);
256                    //Font my_font = Font.CreateTrueTypeFont(doc, sys_font, false, false);
257                    Font my_font = Font.Create(doc, pdftron.PDF.FontStandardType1Font.e_times_roman);
258                    element = eb.CreateTextBegin(my_font, 12);
259                    element.SetTextMatrix(1.5, 0, 0, 1.5, 50, 600);
260                    element.GetGState().SetLeading(15);	// Set the spacing between lines
261                    writer.WriteElement(element);
262
263                    string para = "A PDF text object consists of operators that can show " +
264                    "text strings, move the text position, and set text state and certain " +
265                    "other parameters. In addition, there are three parameters that are " +
266                    "defined only within a text object and do not persist from one text " +
267                    "object to the next: Tm, the text matrix, Tlm, the text line matrix, " +
268                    "Trm, the text rendering matrix, actually just an intermediate result " +
269                    "that combines the effects of text state parameters, the text matrix " +
270                    "(Tm), and the current transformation matrix";
271
272                    int para_end = para.Length;
273                    int text_run = 0;
274                    int text_run_end;
275
276                    double para_width = 300; // paragraph width is 300 units
277                    double cur_width = 0;
278
279                    while (text_run < para_end)
280                    {
281                        text_run_end = para.IndexOf(' ', text_run);
282                        if (text_run_end < 0)
283                            text_run_end = para_end - 1;
284
285                        string text = para.Substring(text_run, text_run_end - text_run + 1);
286                        element = eb.CreateTextRun(text);
287                        if (cur_width + element.GetTextLength() < para_width)
288                        {
289                            writer.WriteElement(element);
290                            cur_width += element.GetTextLength();
291                        }
292                        else
293                        {
294                            writer.WriteElement(eb.CreateTextNewLine());  // New line
295                            text = para.Substring(text_run, text_run_end - text_run + 1);
296                            element = eb.CreateTextRun(text);
297                            cur_width = element.GetTextLength();
298                            writer.WriteElement(element);
299                        }
300
301                        text_run = text_run_end + 1;
302                    }
303
304                    // Draw the same strings using direct content output...
305                    writer.Flush();  // flush pending Element writing operations.
306
307                    // You can also write page content directly to the content stream using 
308                    // ElementWriter.WriteString(...) and ElementWriter.WriteBuffer(...) methods.
309                    // Note that if you are planning to use these functions you need to be familiar
310                    // with PDF page content operators (see Appendix A in PDF Reference Manual). 
311                    // Because it is easy to make mistakes during direct output we recommend that 
312                    // you use ElementBuilder and Element interface instead.
313                    writer.WriteString("T* T* T* "); // New Lines 
314                    writer.WriteElement(eb.CreateTextNewLine());
315                    writer.WriteString("(Direct output to PDF page content stream:) Tj  T* ");
316                    writer.WriteString("(AWAY) Tj T* ");
317                    writer.WriteString("[(A)140(W)140(A)115(Y again)] TJ ");
318
319                    // Finish the block of text
320                    writer.WriteElement(eb.CreateTextEnd());
321
322                    writer.End();  // save changes to the current page
323                    doc.PagePushBack(page);
324
325
326                    // Transparency sample ----------------------------------
327
328                    // Start a new page -------------------------------------
329                    page = doc.PageCreate();
330                    writer.Begin(page);	// begin writing to this page
331                    eb.Reset();			// Reset the GState to default
332
333                    // Write some transparent text at the bottom of the page.
334                    element = eb.CreateTextBegin(Font.Create(doc.GetSDFDoc(), FontStandardType1Font.e_times_roman), 100);
335
336                    // Set the text knockout attribute. Text knockout must be set outside of 
337                    // the text group.
338                    gstate = element.GetGState();
339                    gstate.SetTextKnockout(false);
340                    gstate.SetBlendMode(GStateBlendMode.e_bl_difference);
341                    writer.WriteElement(element);
342
343                    element = eb.CreateTextRun("Transparency");
344                    element.SetTextMatrix(1, 0, 0, 1, 30, 30);
345                    gstate = element.GetGState();
346                    gstate.SetFillColorSpace(ColorSpace.CreateDeviceCMYK());
347                    gstate.SetFillColor(new ColorPt(1, 0, 0, 0));
348
349                    gstate.SetFillOpacity(0.5);
350                    writer.WriteElement(element);
351
352                    // Write the same text on top the old; shifted by 3 points
353                    element.SetTextMatrix(1, 0, 0, 1, 33, 33);
354                    gstate.SetFillColor(new ColorPt(0, 1, 0, 0));
355                    gstate.SetFillOpacity(0.5);
356
357                    writer.WriteElement(element);
358                    writer.WriteElement(eb.CreateTextEnd());
359
360                    // Draw three overlapping transparent circles.
361                    eb.PathBegin();		// start constructing the path
362                    eb.MoveTo(459.223, 505.646);
363                    eb.CurveTo(459.223, 415.841, 389.85, 343.04, 304.273, 343.04);
364                    eb.CurveTo(218.697, 343.04, 149.324, 415.841, 149.324, 505.646);
365                    eb.CurveTo(149.324, 595.45, 218.697, 668.25, 304.273, 668.25);
366                    eb.CurveTo(389.85, 668.25, 459.223, 595.45, 459.223, 505.646);
367                    element = eb.PathEnd();
368                    element.SetPathFill(true);
369
370                    gstate = element.GetGState();
371                    gstate.SetFillColorSpace(ColorSpace.CreateDeviceRGB());
372                    gstate.SetFillColor(new ColorPt(0, 0, 1));                     // Blue Circle
373
374                    gstate.SetBlendMode(GStateBlendMode.e_bl_normal);
375                    gstate.SetFillOpacity(0.5);
376                    writer.WriteElement(element);
377
378                    // Translate relative to the Blue Circle
379                    gstate.SetTransform(1, 0, 0, 1, 113, -185);
380                    gstate.SetFillColor(new ColorPt(0, 1, 0));                     // Green Circle
381                    gstate.SetFillOpacity(0.5);
382                    writer.WriteElement(element);
383
384                    // Translate relative to the Green Circle
385                    gstate.SetTransform(1, 0, 0, 1, -220, 0);
386                    gstate.SetFillColor(new ColorPt(1, 0, 0));                     // Red Circle
387                    gstate.SetFillOpacity(0.5);
388                    writer.WriteElement(element);
389
390                    writer.End();  // save changes to the current page
391                    doc.PagePushBack(page);
392
393                    // End page ------------------------------------
394
395                    String output_file_path = Path.Combine(OutputPath, "element_builder.pdf");
396                    await doc.SaveAsync(output_file_path, SDFDocSaveOptions.e_remove_unused);
397                    doc.Destroy();
398                    WriteLine("Done. Result saved in " + output_file_path);
399                    await AddFileToOutputList(output_file_path).ConfigureAwait(false);
400                }
401                catch (Exception e)
402                {
403                    WriteLine(GetExceptionMessage(e));
404                }
405
406                WriteLine("\n--------------------------------");
407                WriteLine("Done ElementBuilder Test.");
408                WriteLine("--------------------------------\n");
409            })).AsAsyncAction();
410        }
411    }
412}