Add optional clipping on Page

@@ -8,6 +8,7 @@
 - Fix warning in tests
 - Fix warning in example
 - Format Java code
+- Add optional clipping on Page
 
 ## 1.3.23
 

@@ -28,13 +28,15 @@ class Page {
       BuildCallback build,
       Theme theme,
       PageOrientation orientation,
-      EdgeInsets margin})
+      EdgeInsets margin,
+      bool clip = false})
       : assert(
             pageTheme == null ||
                 (pageFormat == null &&
                     theme == null &&
                     orientation == null &&
-                    margin == null),
+                    margin == null &&
+                    clip == false),
             'Don\'t set both pageTheme and other settings'),
         pageTheme = pageTheme ??
             PageTheme(
@@ -42,6 +44,7 @@ class Page {
               orientation: orientation,
               margin: margin,
               theme: theme,
+              clip: clip,
             ),
         _build = build;
 
@@ -152,6 +155,19 @@ class Page {
       return;
     }
 
+    if (pageTheme.clip) {
+      final EdgeInsets _margin = margin;
+      context.canvas
+        ..saveContext()
+        ..drawRect(
+          _margin.left,
+          _margin.bottom,
+          pageFormat.width - _margin.horizontal,
+          pageFormat.height - _margin.vertical,
+        )
+        ..clipPath();
+    }
+
     if (mustRotate) {
       final EdgeInsets _margin = margin;
       final Matrix4 mat = Matrix4.identity();
@@ -167,5 +183,9 @@ class Page {
     } else {
       child.paint(context);
     }
+
+    if (pageTheme.clip) {
+      context.canvas.restoreContext();
+    }
   }
 }

@@ -18,14 +18,15 @@ part of widget;
 
 @immutable
 class PageTheme {
-  const PageTheme(
-      {PdfPageFormat pageFormat,
+  const PageTheme({
+    PdfPageFormat pageFormat,
     this.buildBackground,
     this.buildForeground,
     this.theme,
     PageOrientation orientation,
-      EdgeInsets margin})
-      : pageFormat = pageFormat ?? PdfPageFormat.standard,
+    EdgeInsets margin,
+    this.clip = false,
+  })  : pageFormat = pageFormat ?? PdfPageFormat.standard,
         orientation = orientation ?? PageOrientation.natural,
         _margin = margin;
 
@@ -41,6 +42,8 @@ class PageTheme {
 
   final Theme theme;
 
+  final bool clip;
+
   bool get mustRotate =>
       (orientation == PageOrientation.landscape &&
           pageFormat.height > pageFormat.width) ||