support custom page sizes for document builder #147

page size custom is not supported for the document builder so a new overload which supports user defined page sizes is provided.

src/UglyToad.PdfPig.Tests/Writer/PdfDocumentBuilderTests.cs

@@ -25,6 +25,34 @@
             Assert.EndsWith("%%EOF", str);
         }
 
+        [Fact]
+        public void CanCreateSingleCustomPageSize()
+        {
+            var builder = new PdfDocumentBuilder();
+
+            var page = builder.AddPage(120, 250);
+
+            var font = builder.AddStandard14Font(Standard14Font.Helvetica);
+
+            page.AddText("Small page.", 12, new PdfPoint(25, 200), font);
+
+            var bytes = builder.Build();
+
+            WriteFile(nameof(CanCreateSingleCustomPageSize), bytes);
+
+            using (var document = PdfDocument.Open(bytes, ParsingOptions.LenientParsingOff))
+            {
+                Assert.Equal(1, document.NumberOfPages);
+
+                var page1 = document.GetPage(1);
+
+                Assert.Equal(120, page1.Width);
+                Assert.Equal(250, page1.Height);
+
+                Assert.Equal("Small page.", page1.Text);
+            }
+        }
+
         [Fact]
         public void CanReadSingleBlankPage()
         {

src/UglyToad.PdfPig/Writer/PdfDocumentBuilder.cs

@@ -33,7 +33,8 @@
         public DocumentInformationBuilder DocumentInformation { get; } = new DocumentInformationBuilder();
 
         /// <summary>
-        /// The current page builders in the document and the corresponding 1 indexed page numbers. Use <see cref="AddPage"/> to add a new page.
+        /// The current page builders in the document and the corresponding 1 indexed page numbers. Use <see cref="AddPage(double,double)"/>
+        /// or <see cref="AddPage(PageSize,bool)"/> to add a new page.
         /// </summary>
         public IReadOnlyDictionary<int, PdfPageBuilder> Pages => pages;
 
@@ -136,19 +137,19 @@
         /// <summary>
         /// Add a new page with the specified size, this page will be included in the output when <see cref="Build"/> is called.
         /// </summary>
-        /// <param name="size">The size of the page to add.</param>
+        /// <param name="width">The width of the page in points.</param>
-        /// <param name="isPortrait">Whether the page is in portait or landscape orientation.</param>
+        /// <param name="height">The height of the page in points.</param>
         /// <returns>A builder for editing the new page.</returns>
-        public PdfPageBuilder AddPage(PageSize size, bool isPortrait = true)
+        public PdfPageBuilder AddPage(double width, double height)
         {
-            if (!size.TryGetPdfRectangle(out var rectangle))
+            if (width < 0)
             {
-                throw new ArgumentException($"No rectangle found for Page Size {size}.");
+                throw new ArgumentOutOfRangeException(nameof(width), $"Width cannot be negative, got: {width}.");
             }
 
-            if (!isPortrait)
+            if (height < 0)
             {
-                rectangle = new PdfRectangle(0, 0, rectangle.Height, rectangle.Width);
+                throw new ArgumentOutOfRangeException(nameof(height), $"Height cannot be negative, got: {height}.");
             }
 
             PdfPageBuilder builder = null;
@@ -166,12 +167,39 @@
                 builder = new PdfPageBuilder(pages.Count + 1, this);
             }
 
-            builder.PageSize = rectangle;
+            builder.PageSize = new PdfRectangle(0, 0, width, height);
             pages[builder.PageNumber] = builder;
 
             return builder;
         }
 
+        /// <summary>
+        /// Add a new page with the specified size, this page will be included in the output when <see cref="Build"/> is called.
+        /// </summary>
+        /// <param name="size">The size of the page to add.</param>
+        /// <param name="isPortrait">Whether the page is in portait or landscape orientation.</param>
+        /// <returns>A builder for editing the new page.</returns>
+        public PdfPageBuilder AddPage(PageSize size, bool isPortrait = true)
+        {
+            if (size == PageSize.Custom)
+            {
+                throw new ArgumentException($"Cannot use ${nameof(PageSize.Custom)} for ${nameof(AddPage)} using the ${nameof(PageSize)} enum, call the overload with width and height instead.",
+                    nameof(size));
+            }
+
+            if (!size.TryGetPdfRectangle(out var rectangle))
+            {
+                throw new ArgumentException($"No rectangle found for Page Size {size}.");
+            }
+
+            if (!isPortrait)
+            {
+                return AddPage(rectangle.Height, rectangle.Width);
+            }
+
+            return AddPage(rectangle.Width, rectangle.Height);
+        }
+
         /// <summary>
         /// Builds a PDF document from the current content of this builder and its pages.
         /// </summary>