Use default margin in example

@@ -69,6 +69,15 @@ class PdfPageFormat {
   PdfPageFormat get portrait =>
       height >= width ? this : copyWith(width: height, height: width);
 
+  PdfPageFormat applyMargin(
+          {double left, double top, double right, double bottom}) =>
+      copyWith(
+        marginLeft: math.max(marginLeft, left),
+        marginTop: math.max(marginTop, top),
+        marginRight: math.max(marginRight, right),
+        marginBottom: math.max(marginBottom, bottom),
+      );
+
   @override
   String toString() {
     return "${width}x$height";

@@ -3,21 +3,90 @@ import 'dart:async';
 
 import 'package:pdf/pdf.dart';
 
-Future<PdfDocument> generateDocument() async {
+Future<PdfDocument> generateDocument(PdfPageFormat format) async {
   final pdf = PdfDocument(deflate: zlib.encode);
-  final page = PdfPage(pdf, pageFormat: PdfPageFormat.a4);
+  final page = PdfPage(pdf,
+      pageFormat: format.applyMargin(
+          left: 2.0 * PdfPageFormat.cm,
+          top: 2.0 * PdfPageFormat.cm,
+          right: 2.0 * PdfPageFormat.cm,
+          bottom: 2.0 * PdfPageFormat.cm));
   final g = page.getGraphics();
   final font = PdfFont.helvetica(pdf);
-  final top = page.pageFormat.height;
+  final top = page.pageFormat.height - page.pageFormat.marginTop;
+
+  g.setColor(PdfColor.orange);
+  g.drawRect(
+      page.pageFormat.marginLeft,
+      page.pageFormat.marginBottom,
+      page.pageFormat.width -
+          page.pageFormat.marginRight -
+          page.pageFormat.marginLeft,
+      page.pageFormat.height -
+          page.pageFormat.marginTop -
+          page.pageFormat.marginBottom);
+  g.strokePath();
 
   g.setColor(PdfColor(0.0, 1.0, 1.0));
-  g.drawRect(50.0 * PdfPageFormat.mm, top - 80.0 * PdfPageFormat.mm,
-      100.0 * PdfPageFormat.mm, 50.0 * PdfPageFormat.mm);
+  g.drawRRect(
+    50.0 * PdfPageFormat.mm,
+    top - 80.0 * PdfPageFormat.mm,
+    100.0 * PdfPageFormat.mm,
+    50.0 * PdfPageFormat.mm,
+    20.0,
+    20.0,
+  );
   g.fillPath();
 
   g.setColor(PdfColor(0.3, 0.3, 0.3));
-  g.drawString(font, 12.0, "Hello World!", 10.0 * PdfPageFormat.mm,
+  g.drawString(
+      font,
+      12.0,
+      "Hello World!",
+      page.pageFormat.marginLeft + 10.0 * PdfPageFormat.mm,
       top - 10.0 * PdfPageFormat.mm);
 
+  {
+    final page = PdfPage(pdf,
+        pageFormat: format.applyMargin(
+            left: 2.0 * PdfPageFormat.cm,
+            top: 2.0 * PdfPageFormat.cm,
+            right: 2.0 * PdfPageFormat.cm,
+            bottom: 2.0 * PdfPageFormat.cm));
+    final g = page.getGraphics();
+    final font = PdfFont.helvetica(pdf);
+    final top = page.pageFormat.height - page.pageFormat.marginTop;
+
+    g.setColor(PdfColor.orange);
+    g.drawRect(
+        page.pageFormat.marginLeft,
+        page.pageFormat.marginBottom,
+        page.pageFormat.width -
+            page.pageFormat.marginRight -
+            page.pageFormat.marginLeft,
+        page.pageFormat.height -
+            page.pageFormat.marginTop -
+            page.pageFormat.marginBottom);
+    g.strokePath();
+
+    g.setColor(PdfColor(0.0, 1.0, 1.0));
+    g.drawRRect(
+      50.0 * PdfPageFormat.mm,
+      top - 80.0 * PdfPageFormat.mm,
+      100.0 * PdfPageFormat.mm,
+      50.0 * PdfPageFormat.mm,
+      20.0,
+      20.0,
+    );
+    g.fillPath();
+
+    g.setColor(PdfColor(0.3, 0.3, 0.3));
+    g.drawString(
+        font,
+        12.0,
+        "Hello World!",
+        page.pageFormat.marginLeft + 10.0 * PdfPageFormat.mm,
+        top - 10.0 * PdfPageFormat.mm);
+  }
   return pdf;
 }

@@ -25,13 +25,13 @@ class MyAppState extends State<MyApp> {
 
   void _printPdf() async {
     print("Print ...");
-    final pdf = await generateDocument();
+    final pdf = await generateDocument(PdfPageFormat.a4);
     Printing.printPdf(document: pdf);
   }
 
   void _sharePdf() async {
     print("Share ...");
-    final pdf = await generateDocument();
+    final pdf = await generateDocument(PdfPageFormat.a4);
 
     // Calculate the widget center for iPad sharing popup position
     final RenderBox referenceBox =
@@ -46,7 +46,6 @@ class MyAppState extends State<MyApp> {
   }
 
   Future<void> _printScreen() async {
-    const margin = 10.0 * PdfPageFormat.mm;
     final pdf = PdfDocument(deflate: zlib.encode);
     final page = PdfPage(pdf, pageFormat: PdfPageFormat.a4);
     final g = page.getGraphics();
@@ -58,8 +57,12 @@ class MyAppState extends State<MyApp> {
     print("Print Screen ${im.width}x${im.height} ...");
 
     // Center the image
-    final w = page.pageFormat.width - margin * 2.0;
-    final h = page.pageFormat.height - margin * 2.0;
+    final w = page.pageFormat.width -
+        page.pageFormat.marginLeft -
+        page.pageFormat.marginRight;
+    final h = page.pageFormat.height -
+        page.pageFormat.marginTop -
+        page.pageFormat.marginBottom;
     double iw, ih;
     if (im.width.toDouble() / im.height.toDouble() < 1.0) {
       ih = h;
@@ -71,8 +74,15 @@ class MyAppState extends State<MyApp> {
 
     PdfImage image = PdfImage(pdf,
         image: bytes.buffer.asUint8List(), width: im.width, height: im.height);
-    g.drawImage(image, margin + (w - iw) / 2.0,
-        page.pageFormat.height - margin - ih - (h - ih) / 2.0, iw, ih);
+    g.drawImage(
+        image,
+        page.pageFormat.marginLeft + (w - iw) / 2.0,
+        page.pageFormat.height -
+            page.pageFormat.marginTop -
+            ih -
+            (h - ih) / 2.0,
+        iw,
+        ih);
 
     Printing.printPdf(document: pdf);
   }

@@ -2,11 +2,13 @@ import 'dart:io';
 
 import 'package:flutter_test/flutter_test.dart';
 
+import 'package:pdf/pdf.dart';
+
 import 'package:printing_example/document.dart';
 
 void main() {
   testWidgets('Generate the Pdf document', (WidgetTester tester) async {
-    final pdf = await generateDocument();
+    final pdf = await generateDocument(PdfPageFormat.a4);
     var file = File('document.pdf');
     file.writeAsBytesSync(pdf.save());
   });