Improve PdfPoint and PdfRect

+# 1.1.1
+* Improve PdfPoint and PdfRect
+
 # 1.1.0
 # 1.1.0
 * Rename classes to satisfy Dart conventions
 * Rename classes to satisfy Dart conventions
 * Remove useless new and const keywords
 * Remove useless new and const keywords

@@ -30,6 +30,8 @@ class PdfPoint {
 
 
   const PdfPoint(this.x, this.y);
   const PdfPoint(this.x, this.y);
 
 
+  static const zero = PdfPoint(0.0, 0.0);
+
   @override
   @override
   String toString() => "PdfPoint($x, $y)";
   String toString() => "PdfPoint($x, $y)";
 }
 }

@@ -22,6 +22,8 @@ part of pdf;
 class PdfRect {
 class PdfRect {
   final double x, y, w, h;
   final double x, y, w, h;
 
 
+  static const zero = PdfRect(0.0, 0.0, 0.0, 0.0);
+
   const PdfRect(this.x, this.y, this.w, this.h);
   const PdfRect(this.x, this.y, this.w, this.h);
 
 
   factory PdfRect.fromLTRB(
   factory PdfRect.fromLTRB(
@@ -29,6 +31,10 @@ class PdfRect {
     return PdfRect(left, top, right - left, bottom - top);
     return PdfRect(left, top, right - left, bottom - top);
   }
   }
 
 
+  factory PdfRect.fromPoints(PdfPoint offset, PdfPoint size) {
+    return PdfRect(offset.x, offset.y, size.x, size.y);
+  }
+
   double get l => x;
   double get l => x;
   double get b => y;
   double get b => y;
   double get r => x + w;
   double get r => x + w;
@@ -36,4 +42,16 @@ class PdfRect {
 
 
   @override
   @override
   String toString() => "PdfRect($x, $y, $w, $h)";
   String toString() => "PdfRect($x, $y, $w, $h)";
+
+  PdfRect operator *(double factor) {
+    return PdfRect(x * factor, y * factor, w * factor, h * factor);
+  }
+
+  PdfPoint get offset => PdfPoint(x, y);
+  PdfPoint get size => PdfPoint(w, h);
+
+  PdfPoint get topLeft => PdfPoint(x, y);
+  PdfPoint get topRight => PdfPoint(r, y);
+  PdfPoint get bottomLeft => PdfPoint(x, t);
+  PdfPoint get bottomRight => PdfPoint(r, t);
 }
 }

@@ -2,7 +2,7 @@ name: pdf
 author: David PHAM-VAN <dev.nfet.net@gmail.com>
 author: David PHAM-VAN <dev.nfet.net@gmail.com>
 description: A pdf producer for Dart. It can create pdf files for both web or flutter.
 description: A pdf producer for Dart. It can create pdf files for both web or flutter.
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/pdf
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/pdf
-version: 1.1.0
+version: 1.1.1
 
 
 environment:
 environment:
   sdk: ">=1.8.0 <3.0.0"
   sdk: ">=1.8.0 <3.0.0"