Add soft mask

@@ -15,6 +15,7 @@
 - Automatically calculate Shape() bounding box
 - Improve gradient functions
 - Add blend mode
+- Add soft mask
 
 ## 1.12.0
 

@@ -37,5 +37,6 @@ export 'src/point.dart';
 export 'src/rect.dart';
 export 'src/shading.dart';
 export 'src/signature.dart';
+export 'src/smask.dart';
 export 'src/ttf_parser.dart';
 export 'src/ttffont.dart';

@@ -21,6 +21,8 @@ import 'package:meta/meta.dart';
 import 'data_types.dart';
 import 'document.dart';
 import 'object.dart';
+import 'smask.dart';
+
 enum PdfBlendMode {
   /// Selects the source colour, ignoring the backdrop
   normal,
@@ -81,7 +83,7 @@ enum PdfBlendMode {
 @immutable
 class PdfGraphicState {
   /// Create a new graphic state
-  const PdfGraphicState({this.opacity, this.blendMode});
+  const PdfGraphicState({this.opacity, this.blendMode, this.softMask});
 
   /// The opacity to apply to this graphic state
   final double opacity;
@@ -89,6 +91,8 @@ class PdfGraphicState {
   /// The current blend mode to be used
   final PdfBlendMode blendMode;
 
+  final PdfSoftMask softMask;
+
   PdfDict output() {
     final params = PdfDict();
 
@@ -99,11 +103,14 @@ class PdfGraphicState {
 
     if (blendMode != null) {
       final bm = blendMode.toString();
-      print(bm);
       params['/BM'] =
           PdfName('/' + bm.substring(13, 14).toUpperCase() + bm.substring(14));
     }
 
+    if (softMask != null) {
+      params['/SMask'] = softMask.output();
+    }
+
     return params;
   }
 
@@ -112,7 +119,9 @@ class PdfGraphicState {
     if (!(other is PdfGraphicState)) {
       return false;
     }
-    return other.opacity == opacity;
+    return other.opacity == opacity &&
+        other.blendMode == blendMode &&
+        other.softMask == softMask;
   }
 
   @override

+/*
+ * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General  License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+import 'package:meta/meta.dart';
+import 'package:pdf/pdf.dart';
+
+import 'data_types.dart';
+import 'document.dart';
+import 'graphic_stream.dart';
+import 'graphics.dart';
+import 'rect.dart';
+
+class PdfSoftMask {
+  PdfSoftMask(this.document,
+      {@required PdfRect boundingBox,
+      bool isolated = false,
+      bool knockout = false,
+      bool invert = false})
+      : assert(boundingBox != null),
+        assert(isolated != null),
+        assert(knockout != null),
+        assert(invert != null) {
+    _mask = PdfGraphicXObject(document);
+    _mask.params['/BBox'] = PdfArray.fromNum([
+      boundingBox.x,
+      boundingBox.y,
+      boundingBox.width,
+      boundingBox.height,
+    ]);
+    if (isolated) {
+      _mask.params['/I'] = const PdfBool(true);
+    }
+    if (knockout) {
+      _mask.params['/K'] = const PdfBool(true);
+    }
+    _graphics = PdfGraphics(_mask, _mask.buf);
+
+    if (invert) {
+      _tr = PdfFunction(
+        document,
+        data: [255, 0],
+      );
+    }
+  }
+
+  final PdfDocument document;
+
+  PdfGraphicXObject _mask;
+
+  PdfGraphics _graphics;
+
+  PdfGraphics getGraphics() => _graphics;
+
+  PdfBaseFunction _tr;
+
+  PdfDict output() {
+    final params = PdfDict({
+      '/S': const PdfName('/Luminosity'),
+      '/G': _mask.ref(),
+    });
+
+    if (_tr != null) {
+      params['/TR'] = _tr.ref();
+    }
+
+    return params;
+  }
+}

@@ -21,7 +21,9 @@ import 'object_stream.dart';
 class PdfXObject extends PdfObjectStream {
   PdfXObject(PdfDocument pdfDocument, String subtype, {bool isBinary = false})
       : super(pdfDocument, type: '/XObject', isBinary: isBinary) {
-    params['/Subtype'] = PdfName(subtype);
+    if (subtype != null) {
+      params['/Subtype'] = PdfName(subtype);
+    }
   }
 
   String get name => 'X$objser';