Add Hyperlink widgets

@@ -5,6 +5,7 @@
 * Improve MultiPage Widget
 * Convert GridView to a SpanningWidget
 * Add all Material Colors
+* Add Hyperlink widgets
 
 # 1.3.3
 * Fix a bug with the RichText Widget

@@ -41,6 +41,7 @@ part 'src/formxobject.dart';
 part 'src/graphics.dart';
 part 'src/image.dart';
 part 'src/info.dart';
+part 'src/names.dart';
 part 'src/object.dart';
 part 'src/object_stream.dart';
 part 'src/outline.dart';

@@ -24,7 +24,9 @@ class PdfAnnot extends PdfObject {
       @required this.subtype,
       this.dest,
       this.destRect,
-      this.border})
+      this.border,
+      this.url,
+      this.name})
       : super(pdfPage.pdfDocument, type ?? '/Annot') {
     pdfPage.annotations.add(this);
   }
@@ -56,6 +58,18 @@ class PdfAnnot extends PdfObject {
           destRect: destRect,
           border: border);
 
+  /// Creates an external link annotation
+  factory PdfAnnot.urlLink(PdfPage pdfPage,
+          {@required PdfRect rect, @required String dest, PdfBorder border}) =>
+      PdfAnnot._create(pdfPage,
+          subtype: '/Link', srcRect: rect, url: dest, border: border);
+
+  /// Creates a link annotation to a named destination
+  factory PdfAnnot.namedLink(PdfPage pdfPage,
+          {@required PdfRect rect, @required String dest, PdfBorder border}) =>
+      PdfAnnot._create(pdfPage,
+          subtype: '/Link', srcRect: rect, name: dest, border: border);
+
   /// The subtype of the outline, ie text, note, etc
   final String subtype;
 
@@ -75,6 +89,12 @@ class PdfAnnot extends PdfObject {
   /// the border for this annotation
   final PdfBorder border;
 
+  /// The external url for a link
+  final String url;
+
+  /// The internal name for a link
+  final String name;
+
   /// Output the annotation
   ///
   /// @param os OutputStream to send the object to
@@ -83,8 +103,9 @@ class PdfAnnot extends PdfObject {
     super._prepare();
 
     params['/Subtype'] = PdfStream.string(subtype);
-    params['/Rect'] = PdfStream.string(
-        '[${srcRect.left} ${srcRect.bottom} ${srcRect.right} ${srcRect.top}]');
+    params['/Rect'] = PdfStream()
+      ..putNumArray(
+          <double>[srcRect.left, srcRect.bottom, srcRect.right, srcRect.top]);
 
     // handle the border
     if (border == null) {
@@ -97,15 +118,35 @@ class PdfAnnot extends PdfObject {
     if (subtype == '/Text') {
       params['/Contents'] = PdfStream()..putLiteral(content);
     } else if (subtype == '/Link') {
+      if (url != null) {
+        params['/A'] = PdfStream()
+          ..putDictionary(<String, PdfStream>{
+            '/S': PdfStream()..putString('/URI'),
+            '/URI': PdfStream()..putText(url),
+          });
+      } else if (name != null) {
+        params['/A'] = PdfStream()
+          ..putDictionary(<String, PdfStream>{
+            '/S': PdfStream()..putString('/GoTo'),
+            '/D': PdfStream()..putText(name),
+          });
+      } else {
         final List<PdfStream> dests = <PdfStream>[];
         dests.add(dest.ref());
         if (destRect == null)
           dests.add(PdfStream.string('/Fit'));
         else {
-        dests.add(PdfStream.string(
-            '/FitR ${destRect.left} ${destRect.bottom} ${destRect.right} ${destRect.top}'));
+          dests.add(PdfStream.string('/FitR '));
+          dests.add(PdfStream()
+            ..putNumList(<double>[
+              destRect.left,
+              destRect.bottom,
+              destRect.right,
+              destRect.top
+            ]));
         }
         params['/Dest'] = PdfStream.array(dests);
       }
     }
+  }
 }

@@ -22,7 +22,8 @@ class PdfCatalog extends PdfObject {
   /// @param pdfPageList The [PdfPageList] object that's the root of the documents page tree
   /// @param pagemode How the document should appear when opened.
   /// Allowed values are usenone, useoutlines, usethumbs or fullscreen.
-  PdfCatalog(PdfDocument pdfDocument, this.pdfPageList, this.pageMode)
+  PdfCatalog(
+      PdfDocument pdfDocument, this.pdfPageList, this.pageMode, this.names)
       : super(pdfDocument, '/Catalog');
 
   /// The pages of the document
@@ -34,6 +35,9 @@ class PdfCatalog extends PdfObject {
   /// The initial page mode
   final PdfPageMode pageMode;
 
+  /// The initial page mode
+  final PdfNames names;
+
   /// @param os OutputStream to send the object to
   @override
   void _prepare() {
@@ -46,6 +50,9 @@ class PdfCatalog extends PdfObject {
       params['/Outlines'] = outlines.ref();
     }
 
+    // the Names object
+    params['/Names'] = names.ref();
+
     // the /PageMode setting
     params['/PageMode'] =
         PdfStream.string(PdfDocument._PdfPageModes[pageMode.index]);

@@ -89,9 +89,9 @@ class PDFBorder extends PdfBorder {
 
 @deprecated
 class PDFCatalog extends PdfCatalog {
-  PDFCatalog(
-      PdfDocument pdfDocument, PdfPageList pdfPageList, PdfPageMode pageMode)
-      : super(pdfDocument, pdfPageList, pageMode);
+  PDFCatalog(PdfDocument pdfDocument, PdfPageList pdfPageList,
+      PdfPageMode pageMode, PdfNames names)
+      : super(pdfDocument, pdfPageList, pageMode, names);
 }
 
 @deprecated

@@ -51,7 +51,8 @@ class PdfDocument {
 
     // Now create some standard objects
     pdfPageList = PdfPageList(this);
-    catalog = PdfCatalog(this, pdfPageList, pageMode);
+    pdfNames = PdfNames(this);
+    catalog = PdfCatalog(this, pdfPageList, pageMode, pdfNames);
   }
 
   /// This is used to allocate objects a unique serial number in the document.
@@ -70,6 +71,9 @@ class PdfDocument {
   /// This is the Pages object, which is required by each Pdf Document
   PdfPageList pdfPageList;
 
+  /// The name dictionary
+  PdfNames pdfNames;
+
   /// This is the Outline object, which is optional
   PdfOutline _outline;
 

+/*
+ * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+part of pdf;
+
+class PdfNames extends PdfObject {
+  /// This constructs a Pdf Name object
+  PdfNames(PdfDocument pdfDocument) : super(pdfDocument);
+
+  final List<PdfStream> _dests = <PdfStream>[];
+
+  void addDest(
+    String name,
+    PdfPage page, {
+    double posX,
+    double posY,
+    double posZ,
+  }) {
+    assert(page.pdfDocument == pdfDocument);
+    assert(name != null);
+
+    _dests.add(PdfStream()..putText(name));
+    _dests.add(PdfStream()
+      ..putDictionary(<String, PdfStream>{
+        '/D': PdfStream()
+          ..putArray(<PdfStream>[
+            page.ref(),
+            PdfStream.string('/XYZ'),
+            posX == null ? PdfStream.string('null') : PdfStream.num(posX),
+            posY == null ? PdfStream.string('null') : PdfStream.num(posY),
+            posZ == null ? PdfStream.string('null') : PdfStream.num(posZ),
+          ]),
+      }));
+  }
+
+  @override
+  void _prepare() {
+    super._prepare();
+
+    params['/Dests'] = PdfStream()
+      ..putDictionary(<String, PdfStream>{
+        '/Names': PdfStream()..putArray(_dests),
+      });
+  }
+}

@@ -23,6 +23,7 @@ import 'package:meta/meta.dart';
 import 'package:pdf/pdf.dart';
 import 'package:vector_math/vector_math_64.dart';
 
+part 'widgets/annotations.dart';
 part 'widgets/basic.dart';
 part 'widgets/clip.dart';
 part 'widgets/container.dart';

+/*
+ * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+part of widget;
+
+class Anchor extends SingleChildWidget {
+  Anchor({Widget child, @required this.name, this.description})
+      : assert(name != null),
+        super(child: child);
+
+  final String name;
+
+  final String description;
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+
+    final Matrix4 mat = context.canvas.getTransform();
+    final Vector3 lt = mat.transform3(Vector3(box.left, box.bottom, 0));
+    context.document.pdfNames.addDest(name, context.page, posY: lt.y);
+
+    if (description != null) {
+      final Vector3 rb = mat.transform3(Vector3(box.right, box.top, 0));
+      final PdfRect ibox = PdfRect.fromLTRB(lt.x, lt.y, rb.x, rb.y);
+      PdfAnnot.text(context.page, content: description, rect: ibox);
+    }
+  }
+}
+
+class _Annotation extends SingleChildWidget {
+  _Annotation({Widget child}) : super(child: child);
+
+  @override
+  void debugPaint(Context context) {
+    context.canvas
+      ..setFillColor(PdfColors.pink)
+      ..drawRect(box.x, box.y, box.width, box.height)
+      ..fillPath();
+  }
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
+}
+
+class Link extends _Annotation {
+  Link({@required Widget child, this.destination})
+      : assert(child != null),
+        super(child: child);
+
+  final String destination;
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+
+    if (destination != null) {
+      final Matrix4 mat = context.canvas.getTransform();
+      final Vector3 lt = mat.transform3(Vector3(box.left, box.bottom, 0));
+      final Vector3 rb = mat.transform3(Vector3(box.right, box.top, 0));
+      final PdfRect ibox = PdfRect.fromLTRB(lt.x, lt.y, rb.x, rb.y);
+      PdfAnnot.namedLink(
+        context.page,
+        rect: ibox,
+        dest: destination,
+      );
+    }
+  }
+}
+
+class UrlLink extends _Annotation {
+  UrlLink({@required Widget child, @required this.destination})
+      : assert(child != null),
+        assert(destination != null),
+        super(child: child);
+
+  final String destination;
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+
+    final Matrix4 mat = context.canvas.getTransform();
+    final Vector3 lt = mat.transform3(Vector3(box.left, box.bottom, 0));
+    final Vector3 rb = mat.transform3(Vector3(box.right, box.top, 0));
+    final PdfRect ibox = PdfRect.fromLTRB(lt.x, lt.y, rb.x, rb.y);
+    PdfAnnot.urlLink(
+      context.page,
+      rect: ibox,
+      dest: destination,
+    );
+  }
+}

@@ -36,6 +36,12 @@ void main() {
     g.drawRect(100, 150, 50, 50);
     g.strokePath();
 
+    PdfAnnot.urlLink(page,
+        rect: const PdfRect(100, 250, 50, 50),
+        dest: 'https://github.com/DavBfr/dart_pdf/');
+    g.drawRect(100, 250, 50, 50);
+    g.strokePath();
+
     final File file = File('annotations.pdf');
     file.writeAsBytesSync(pdf.save());
   });

@@ -51,7 +51,10 @@ void main() {
                           width: 2)),
                   child: Text('Hello World',
                       textScaleFactor: 2, textAlign: TextAlign.center)),
-              Align(alignment: Alignment.topLeft, child: Text('Left align')),
+              Align(
+                  alignment: Alignment.topLeft,
+                  child:
+                      Link(destination: 'anchor', child: Text('Left align'))),
               Padding(padding: const EdgeInsets.all(5)),
               Row(
                   mainAxisAlignment: MainAxisAlignment.spaceEvenly,
@@ -133,6 +136,7 @@ void main() {
                 <String>['York Steak House', 'Outi Vuorinen', 'Finland'],
                 <String>['Weathervane', 'Else Jeremiassen', 'Iceland'],
               ]),
+              Anchor(name: 'anchor', child: Text('Anchor')),
             ]));
 
     pdf.addPage(Page(
@@ -172,7 +176,13 @@ void main() {
                             ),
                           ],
                         ),
-                      ))
+                      )),
+                  Positioned(
+                      right: 10,
+                      bottom: 10,
+                      child: UrlLink(
+                          child: Text('dart_pdf'),
+                          destination: 'https://github.com/DavBfr/dart_pdf/'))
                 ])));
 
     final File file = File('widgets.pdf');