Add PageTheme

@@ -4,6 +4,7 @@
 
 - Fix Transform.rotateBox
 - Add Watermark widget
+- Add PageTheme
 
 ## 1.3.19
 

@@ -37,6 +37,7 @@ part 'widgets/grid_view.dart';
 part 'widgets/image.dart';
 part 'widgets/multi_page.dart';
 part 'widgets/page.dart';
+part 'widgets/page_theme.dart';
 part 'widgets/placeholders.dart';
 part 'widgets/progress.dart';
 part 'widgets/stack.dart';

@@ -40,27 +40,31 @@ class _MultiPageInstance {
   const _MultiPageInstance(
       {@required this.context,
       @required this.constraints,
+      @required this.fullConstraints,
       @required this.offsetStart});
 
   final Context context;
   final BoxConstraints constraints;
+  final BoxConstraints fullConstraints;
   final double offsetStart;
 }
 
 class MultiPage extends Page {
   MultiPage(
-      {PdfPageFormat pageFormat = PdfPageFormat.a4,
+      {PageTheme pageTheme,
+      PdfPageFormat pageFormat,
       BuildListCallback build,
       this.crossAxisAlignment = CrossAxisAlignment.start,
       this.header,
       this.footer,
       Theme theme,
       this.maxPages = 20,
-      PageOrientation orientation = PageOrientation.natural,
+      PageOrientation orientation,
       EdgeInsets margin})
       : _buildList = build,
         assert(maxPages != null && maxPages > 0),
         super(
+            pageTheme: pageTheme,
             pageFormat: pageFormat,
             margin: margin,
             theme: theme,
@@ -88,6 +92,7 @@ class MultiPage extends Page {
           ..rotateZ(-math.pi / 2)
           ..translate(x - pageHeight + _margin.top - _margin.left,
               y + _margin.left - _margin.bottom));
+
       child.paint(context);
       context.canvas.restoreContext();
     } else {
@@ -112,6 +117,13 @@ class MultiPage extends Page {
         maxWidth: _mustRotate
             ? (pageFormat.height - _margin.vertical)
             : (pageFormat.width - _margin.horizontal));
+    final BoxConstraints fullConstraints = mustRotate
+        ? BoxConstraints(
+            maxWidth: pageFormat.height - _margin.vertical,
+            maxHeight: pageFormat.width - _margin.horizontal)
+        : BoxConstraints(
+            maxWidth: pageFormat.width - _margin.horizontal,
+            maxHeight: pageFormat.height - _margin.vertical);
     final Theme calculatedTheme = theme ?? document.theme ?? Theme.base();
     Context context;
     double offsetEnd;
@@ -149,6 +161,16 @@ class MultiPage extends Page {
           return true;
         }());
 
+        if (pageTheme.buildBackground != null) {
+          final Widget child = pageTheme.buildBackground(context);
+          if (child != null) {
+            child.layout(context, fullConstraints, parentUsesSize: false);
+            assert(child.box != null);
+            _paintChild(context, child, _margin.left, _margin.bottom,
+                pageFormat.height);
+          }
+        }
+
         offsetStart = pageHeight -
             (_mustRotate ? pageHeightMargin - margin.bottom : _margin.top);
         offsetEnd =
@@ -157,6 +179,7 @@ class MultiPage extends Page {
         _pages.add(_MultiPageInstance(
           context: context,
           constraints: constraints,
+          fullConstraints: fullConstraints,
           offsetStart: offsetStart,
         ));
 
@@ -262,6 +285,17 @@ class MultiPage extends Page {
               pageFormat.height);
         }
       }
+
+      if (pageTheme.buildForeground != null) {
+        final Widget child = pageTheme.buildForeground(page.context);
+        if (child != null) {
+          child.layout(page.context, page.fullConstraints,
+              parentUsesSize: false);
+          assert(child.box != null);
+          _paintChild(page.context, child, _margin.left, _margin.bottom,
+              pageFormat.height);
+        }
+      }
     }
   }
 }

@@ -23,51 +23,43 @@ enum PageOrientation { natural, landscape, portrait }
 
 class Page {
   Page(
-      {this.pageFormat = PdfPageFormat.standard,
+      {PageTheme pageTheme,
+      PdfPageFormat pageFormat,
       BuildCallback build,
-      this.theme,
-      this.orientation = PageOrientation.natural,
+      Theme theme,
+      PageOrientation orientation,
       EdgeInsets margin})
-      : assert(pageFormat != null),
-        _margin = margin,
+      : assert(
+            pageTheme == null ||
+                (pageFormat == null &&
+                    theme == null &&
+                    orientation == null &&
+                    margin == null),
+            'Don\'t set both pageTheme and other settings'),
+        pageTheme = pageTheme ??
+            PageTheme(
+              pageFormat: pageFormat,
+              orientation: orientation,
+              margin: margin,
+              theme: theme,
+            ),
         _build = build;
 
-  final PdfPageFormat pageFormat;
+  final PageTheme pageTheme;
 
-  final PageOrientation orientation;
+  PdfPageFormat get pageFormat => pageTheme.pageFormat;
 
-  final EdgeInsets _margin;
+  PageOrientation get orientation => pageTheme.orientation;
 
   final BuildCallback _build;
 
-  final Theme theme;
+  Theme get theme => pageTheme.theme;
 
-  bool get mustRotate =>
-      (orientation == PageOrientation.landscape &&
-          pageFormat.height > pageFormat.width) ||
-      (orientation == PageOrientation.portrait &&
-          pageFormat.width > pageFormat.height);
+  bool get mustRotate => pageTheme.mustRotate;
 
   PdfPage _pdfPage;
 
-  EdgeInsets get margin {
-    if (_margin != null) {
-      if (mustRotate) {
-        return EdgeInsets.fromLTRB(
-            _margin.bottom, _margin.left, _margin.top, _margin.right);
-      } else {
-        return _margin;
-      }
-    }
-
-    if (mustRotate) {
-      return EdgeInsets.fromLTRB(pageFormat.marginBottom, pageFormat.marginLeft,
-          pageFormat.marginTop, pageFormat.marginRight);
-    } else {
-      return EdgeInsets.fromLTRB(pageFormat.marginLeft, pageFormat.marginTop,
-          pageFormat.marginRight, pageFormat.marginBottom);
-    }
-  }
+  EdgeInsets get margin => pageTheme.margin;
 
   @protected
   void debugPaint(Context context) {
@@ -109,10 +101,26 @@ class Page {
       page: _pdfPage,
       canvas: canvas,
     ).inheritFrom(calculatedTheme);
+    if (pageTheme.buildBackground != null) {
+      final Widget child = pageTheme.buildBackground(context);
+      if (child != null) {
+        layout(child, context, constraints);
+        paint(child, context);
+      }
+    }
     if (_build != null) {
       final Widget child = _build(context);
-      layout(child, context, constraints);
-      paint(child, context);
+      if (child != null) {
+        layout(child, context, constraints);
+        paint(child, context);
+      }
+    }
+    if (pageTheme.buildForeground != null) {
+      final Widget child = pageTheme.buildForeground(context);
+      if (child != null) {
+        layout(child, context, constraints);
+        paint(child, context);
+      }
     }
   }
 

+/*
+ * 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;
+
+@immutable
+class PageTheme {
+  const PageTheme(
+      {PdfPageFormat pageFormat,
+      this.buildBackground,
+      this.buildForeground,
+      this.theme,
+      PageOrientation orientation,
+      EdgeInsets margin})
+      : pageFormat = pageFormat ?? PdfPageFormat.standard,
+        orientation = orientation ?? PageOrientation.natural,
+        _margin = margin;
+
+  final PdfPageFormat pageFormat;
+
+  final PageOrientation orientation;
+
+  final EdgeInsets _margin;
+
+  final BuildCallback buildBackground;
+
+  final BuildCallback buildForeground;
+
+  final Theme theme;
+
+  bool get mustRotate =>
+      (orientation == PageOrientation.landscape &&
+          pageFormat.height > pageFormat.width) ||
+      (orientation == PageOrientation.portrait &&
+          pageFormat.width > pageFormat.height);
+
+  EdgeInsets get margin {
+    if (_margin != null) {
+      if (mustRotate) {
+        return EdgeInsets.fromLTRB(
+            _margin.bottom, _margin.left, _margin.top, _margin.right);
+      } else {
+        return _margin;
+      }
+    }
+
+    if (mustRotate) {
+      return EdgeInsets.fromLTRB(pageFormat.marginBottom, pageFormat.marginLeft,
+          pageFormat.marginTop, pageFormat.marginRight);
+    } else {
+      return EdgeInsets.fromLTRB(pageFormat.marginLeft, pageFormat.marginTop,
+          pageFormat.marginRight, pageFormat.marginBottom);
+    }
+  }
+}

@@ -34,6 +34,7 @@ import 'widget_table_test.dart' as widget_table;
 import 'widget_test.dart' as widget;
 import 'widget_text_test.dart' as widget_text;
 import 'widget_theme_test.dart' as widget_theme;
+import 'widget_watermark_test.dart' as widget_watermark;
 import 'widget_wrap_test.dart' as widget_wrap;
 
 void main() {
@@ -54,6 +55,7 @@ void main() {
   widget_table.main();
   widget_text.main();
   widget_theme.main();
+  widget_watermark.main();
   widget_wrap.main();
   widget.main();
 }

+/*
+ * 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.
+ */
+
+import 'dart:io';
+
+import 'package:pdf/widgets.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Pdf Widgets Watermark', () {
+    Document.debug = true;
+    final Document pdf = Document();
+
+    final PageTheme pageTheme = PageTheme(
+      buildBackground: (Context context) => Watermark.text('DRAFT'),
+      buildForeground: (Context context) => Align(
+        alignment: Alignment.bottomLeft,
+        child: SizedBox(
+          width: 100,
+          height: 100,
+          child: PdfLogo(),
+        ),
+      ),
+    );
+
+    pdf.addPage(
+      Page(
+        pageTheme: pageTheme,
+        build: (Context context) => Center(
+          child: Text(
+            'Hello World',
+          ),
+        ),
+      ),
+    );
+
+    pdf.addPage(
+      MultiPage(
+        pageTheme: pageTheme,
+        build: (Context context) => List<Widget>.filled(
+          100,
+          Text(
+            'Hello World',
+          ),
+        ),
+      ),
+    );
+
+    final File file = File('widgets-watermark.pdf');
+    file.writeAsBytesSync(pdf.save());
+  });
+}