Add Raster PDF to Image

 # Changelog
 
+## 3.0.2
+
+- Add Raster PDF to Image
+
 ## 3.0.1
 
 - Add a link to the Web example

@@ -109,7 +109,7 @@ await Printing.layoutPdf(
    ```java
    defaultConfig {
        ...
-       minSdkVersion 19  // <-- Change this line to 19 or more
+       minSdkVersion 21  // <-- Change this line to 21 or more
        ...
    }
    ```

@@ -18,11 +18,15 @@ package net.nfet.flutter.printing;
 
 import android.content.Context;
 import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.Matrix;
+import android.graphics.pdf.PdfRenderer;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.CancellationSignal;
-import android.os.Environment;
+import android.os.Handler;
+import android.os.Looper;
 import android.os.ParcelFileDescriptor;
 import android.print.PageRange;
 import android.print.PdfConvert;
@@ -32,16 +36,20 @@ import android.print.PrintDocumentInfo;
 import android.print.PrintJob;
 import android.print.PrintJobInfo;
 import android.print.PrintManager;
+import android.util.Log;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
 import androidx.core.content.FileProvider;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.ByteBuffer;
 import java.util.HashMap;
 
 /**
@@ -71,6 +79,7 @@ public class PrintingJob extends PrintDocumentAdapter {
         result.put("canPrint", true);
         result.put("canConvertHtml", true);
         result.put("canShare", true);
+        result.put("canRaster", true);
         return result;
     }
 
@@ -240,4 +249,79 @@ public class PrintingJob extends PrintDocumentAdapter {
         // Content layout reflow is complete
         callback.onLayoutFinished(info, true);
     }
+
+    void rasterPdf(final byte[] data, final int[] pages, final Double scale) {
+        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
+            Log.e("PDF", "PDF Raster available since Android 5.0 Lollipop (API 21)");
+            printing.onPageRasterEnd(this);
+            return;
+        }
+
+        Thread thread = new Thread(new Runnable() {
+            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
+            @Override
+            public void run() {
+                try {
+                    File file = File.createTempFile("printing", null, null);
+                    FileOutputStream oStream = new FileOutputStream(file);
+                    oStream.write(data);
+                    oStream.close();
+
+                    FileInputStream iStream = new FileInputStream(file);
+                    ParcelFileDescriptor parcelFD = ParcelFileDescriptor.dup(iStream.getFD());
+                    PdfRenderer renderer = new PdfRenderer(parcelFD);
+
+                    if (!file.delete()) {
+                        Log.e("PDF", "Unable to delete temporary file");
+                    }
+
+                    final int pageCount = pages != null ? pages.length : renderer.getPageCount();
+                    for (int i = 0; i < pageCount; i++) {
+                        PdfRenderer.Page page = renderer.openPage(pages == null ? i : pages[i]);
+
+                        final int width = Double.valueOf(page.getWidth() * scale).intValue();
+                        final int height = Double.valueOf(page.getHeight() * scale).intValue();
+                        int stride = width * 4;
+
+                        Matrix transform = new Matrix();
+                        transform.setScale(scale.floatValue(), scale.floatValue());
+
+                        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+
+                        page.render(
+                                bitmap, null, transform, PdfRenderer.Page.RENDER_MODE_FOR_PRINT);
+
+                        page.close();
+
+                        final ByteBuffer buf = ByteBuffer.allocate(stride * height);
+                        bitmap.copyPixelsToBuffer(buf);
+                        bitmap.recycle();
+
+                        new Handler(Looper.getMainLooper()).post(new Runnable() {
+                            @Override
+                            public void run() {
+                                printing.onPageRasterized(
+                                        PrintingJob.this, buf.array(), width, height);
+                            }
+                        });
+                    }
+
+                    renderer.close();
+                    iStream.close();
+
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+
+                new Handler(Looper.getMainLooper()).post(new Runnable() {
+                    @Override
+                    public void run() {
+                        printing.onPageRasterEnd(PrintingJob.this);
+                    }
+                });
+            }
+        });
+
+        thread.start();
+    }
 }

@@ -125,6 +125,16 @@ public class PrintingPlugin implements MethodCallHandler {
                 result.success(PrintingJob.printingInfo());
                 break;
             }
+            case "rasterPdf": {
+                final byte[] document = call.argument("doc");
+                final int[] pages = call.argument("pages");
+                Double scale = call.argument("scale");
+                final PrintingJob printJob =
+                        new PrintingJob(activity, this, (int) call.argument("job"));
+                printJob.rasterPdf(document, pages, scale);
+                result.success(1);
+                break;
+            }
             default:
                 result.notImplemented();
                 break;
@@ -194,4 +204,22 @@ public class PrintingPlugin implements MethodCallHandler {
 
         channel.invokeMethod("onHtmlError", args);
     }
+
+    /// send pdf to raster data result to flutter
+    void onPageRasterized(PrintingJob printJob, byte[] imageData, int width, int height) {
+        HashMap<String, Object> args = new HashMap<>();
+        args.put("image", imageData);
+        args.put("width", width);
+        args.put("height", height);
+        args.put("job", printJob.index);
+
+        channel.invokeMethod("onPageRasterized", args);
+    }
+
+    void onPageRasterEnd(PrintingJob printJob) {
+        HashMap<String, Object> args = new HashMap<>();
+        args.put("job", printJob.index);
+
+        channel.invokeMethod("onPageRasterEnd", args);
+    }
 }

@@ -34,7 +34,7 @@ android {
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.example.example"
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 28
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

+import 'package:flutter/material.dart';
+
+class ImageViewer extends StatelessWidget {
+  const ImageViewer({this.images});
+
+  final List<ImageProvider> images;
+
+  Widget buildImage(BuildContext context, ImageProvider image) {
+    return Card(
+        margin: const EdgeInsets.all(10),
+        child: FittedBox(
+          child: Image(image: image),
+        ));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Document as Images'),
+      ),
+      body: ListView.builder(
+        itemCount: images.length,
+        itemBuilder: (BuildContext context, int index) =>
+            buildImage(context, images[index]),
+      ),
+    );
+  }
+}

@@ -15,6 +15,7 @@ import 'package:pdf/widgets.dart' as pdf;
 import 'package:printing/printing.dart';
 
 import 'document.dart';
+import 'image_viewer.dart';
 import 'viewer.dart';
 
 void main() {
@@ -82,6 +83,22 @@ class MyAppState extends State<MyApp> {
     );
   }
 
+  Future<void> _rasterToImage() async {
+    final List<int> doc = (await generateDocument(PdfPageFormat.a4)).save();
+
+    final List<ImageProvider> images = <ImageProvider>[];
+
+    await for (PdfRaster page in Printing.raster(doc)) {
+      images.add(PdfRasterImage(page));
+    }
+
+    Navigator.push<dynamic>(
+      context,
+      MaterialPageRoute<dynamic>(
+          builder: (BuildContext context) => ImageViewer(images: images)),
+    );
+  }
+
   Future<void> _pickPrinter() async {
     print('Pick printer ...');
 
@@ -243,6 +260,11 @@ class MyAppState extends State<MyApp> {
                 RaisedButton(
                     child: const Text('Save to file'), onPressed: _saveAsFile),
                 RaisedButton(
+                  child: const Text('Raster to Image'),
+                  onPressed:
+                      printingInfo?.canRaster ?? false ? _rasterToImage : null,
+                ),
+                RaisedButton(
                   child: const Text('Print Html'),
                   onPressed:
                       printingInfo?.canConvertHtml ?? false ? _printHtml : null,

@@ -231,6 +231,41 @@ public class PrintJob: UIPrintPageRenderer, UIPrintInteractionControllerDelegate
         controller.present(animated: true, completionHandler: pickPrinterCompletionHandler)
     }
 
+    public func rasterPdf(data: Data, pages: [Int]?, scale: CGFloat) {
+        let provider = CGDataProvider(data: data as CFData)!
+        let document = CGPDFDocument(provider)!
+
+        DispatchQueue.global().async {
+            let pageCount = document.numberOfPages
+
+            for pageNum in pages ?? Array(0 ... pageCount - 1) {
+                guard let page = document.page(at: pageNum + 1) else { continue }
+                let rect = page.getBoxRect(.mediaBox)
+                let width = Int(rect.width * scale)
+                let height = Int(rect.height * scale)
+                let stride = width * 4
+                var data = Data(repeating: 0, count: stride * height)
+
+                data.withUnsafeMutableBytes { (ptr: UnsafeMutablePointer<UInt8>) in
+                    let rgb = CGColorSpaceCreateDeviceRGB()
+                    let context = CGContext(data: ptr, width: width, height: height, bitsPerComponent: 8, bytesPerRow: stride, space: rgb, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
+                    if context != nil {
+                        context!.scaleBy(x: scale, y: scale)
+                        context!.drawPDFPage(page)
+                    }
+                }
+
+                DispatchQueue.main.sync {
+                    self.printing.onPageRasterized(printJob: self, imageData: data, width: width, height: height)
+                }
+            }
+
+            DispatchQueue.main.sync {
+                self.printing.onPageRasterEnd(printJob: self)
+            }
+        }
+    }
+
     public static func printingInfo() -> NSDictionary {
         let data: NSDictionary = [
             "directPrint": true,
@@ -238,6 +273,7 @@ public class PrintJob: UIPrintPageRenderer, UIPrintInteractionControllerDelegate
             "canPrint": true,
             "canConvertHtml": true,
             "canShare": true,
+            "canRaster": true,
         ]
         return data
     }

@@ -111,6 +111,15 @@ public class PrintingPlugin: NSObject, FlutterPlugin {
             ))
         } else if call.method == "printingInfo" {
             result(PrintJob.printingInfo())
+        } else if call.method == "rasterPdf" {
+            let doc = args["doc"] as! FlutterStandardTypedData
+            let pages = args["pages"] as? [Int]
+            let scale = CGFloat((args["scale"] as! NSNumber).floatValue)
+            let printJob = PrintJob(printing: self, index: args["job"] as! Int)
+            printJob.rasterPdf(data: doc.data,
+                               pages: pages,
+                               scale: scale)
+            result(NSNumber(value: 1))
         } else {
             result(FlutterMethodNotImplemented)
         }
@@ -165,4 +174,22 @@ public class PrintingPlugin: NSObject, FlutterPlugin {
         ]
         channel.invokeMethod("onHtmlError", arguments: data)
     }
+
+    /// send pdf to raster data result to flutter
+    public func onPageRasterized(printJob: PrintJob, imageData: Data, width: Int, height: Int) {
+        let data: NSDictionary = [
+            "image": FlutterStandardTypedData(bytes: imageData),
+            "width": width,
+            "height": height,
+            "job": printJob.index,
+        ]
+        channel.invokeMethod("onPageRasterized", arguments: data)
+    }
+
+    public func onPageRasterEnd(printJob: PrintJob) {
+        let data: NSDictionary = [
+            "job": printJob.index,
+        ]
+        channel.invokeMethod("onPageRasterEnd", arguments: data)
+    }
 }

@@ -31,4 +31,5 @@ part 'src/print_job.dart';
 part 'src/printer.dart';
 part 'src/printing.dart';
 part 'src/printing_info.dart';
+part 'src/raster.dart';
 part 'src/widgets.dart';

@@ -21,11 +21,13 @@ class _PrintJob {
     this.onLayout,
     this.onHtmlRendered,
     this.onCompleted,
+    this.onPageRasterized,
   });
 
   final LayoutCallback onLayout;
   final Completer<List<int>> onHtmlRendered;
   final Completer<bool> onCompleted;
+  final StreamController<PdfRaster> onPageRasterized;
 
   int index;
 }

@@ -68,6 +68,20 @@ mixin Printing {
         final _PrintJob job = _printJobs[call.arguments['job']];
         job.onHtmlRendered.completeError(call.arguments['error']);
         break;
+      case 'onPageRasterized':
+        final _PrintJob job = _printJobs[call.arguments['job']];
+        final PdfRaster raster = PdfRaster._(
+          call.arguments['width'],
+          call.arguments['height'],
+          call.arguments['image'],
+        );
+        job.onPageRasterized.add(raster);
+        break;
+      case 'onPageRasterEnd':
+        final _PrintJob job = _printJobs[call.arguments['job']];
+        job.onPageRasterized.close();
+        _printJobs.remove(job.index);
+        break;
     }
   }
 
@@ -273,4 +287,26 @@ mixin Printing {
 
     return PrintingInfo.fromMap(result);
   }
+
+  static Stream<PdfRaster> raster(
+    List<int> document, {
+    List<int> pages,
+    double dpi = PdfPageFormat.inch,
+  }) {
+    _channel.setMethodCallHandler(_handleMethod);
+
+    final _PrintJob job = _newPrintJob(_PrintJob(
+      onPageRasterized: StreamController<PdfRaster>(),
+    ));
+
+    final Map<String, dynamic> params = <String, dynamic>{
+      'doc': Uint8List.fromList(document),
+      'pages': pages,
+      'scale': dpi / PdfPageFormat.inch,
+      'job': job.index,
+    };
+
+    _channel.invokeMethod<void>('rasterPdf', params);
+    return job.onPageRasterized.stream;
+  }
 }

@@ -23,6 +23,7 @@ class PrintingInfo {
         canPrint: map['canPrint'],
         canConvertHtml: map['canConvertHtml'],
         canShare: map['canShare'],
+        canRaster: map['canRaster'],
       );
 
   const PrintingInfo._({
@@ -31,11 +32,13 @@ class PrintingInfo {
     this.canPrint = false,
     this.canConvertHtml = false,
     this.canShare = false,
+    this.canRaster = false,
   })  : assert(directPrint != null),
         assert(dynamicLayout != null),
         assert(canPrint != null),
         assert(canConvertHtml != null),
-        assert(canShare != null);
+        assert(canShare != null),
+        assert(canRaster != null);
 
   static const PrintingInfo unavailable = PrintingInfo._();
 
@@ -44,4 +47,5 @@ class PrintingInfo {
   final bool canPrint;
   final bool canConvertHtml;
   final bool canShare;
+  final bool canRaster;
 }

+/*
+ * 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 printing;
+
+class PdfRaster {
+  PdfRaster._(
+    this.width,
+    this.height,
+    this.pixels,
+  );
+
+  final int width;
+  final int height;
+  final Uint8List pixels;
+
+  @override
+  String toString() => 'Image ${width}x$height ${pixels.lengthInBytes} bytes';
+
+  /// Decode RGBA raw image to dart:ui Image
+  Future<ui.Image> toImage() {
+    final Completer<ui.Image> comp = Completer<ui.Image>();
+    ui.decodeImageFromPixels(
+      pixels,
+      width,
+      height,
+      ui.PixelFormat.rgba8888,
+      (ui.Image image) => comp.complete(image),
+    );
+    return comp.future;
+  }
+
+  /// Convert to a PNG image
+  Future<Uint8List> toPng() async {
+    final ui.Image image = await toImage();
+    final ByteData data =
+        await image.toByteData(format: ui.ImageByteFormat.png);
+    return data.buffer.asUint8List();
+  }
+}
+
+class PdfRasterImage extends ImageProvider<PdfRaster> {
+  PdfRasterImage(this.raster);
+
+  final PdfRaster raster;
+
+  Future<ImageInfo> _loadAsync() async {
+    final ui.Image uiImage = await raster.toImage();
+    return ImageInfo(image: uiImage, scale: 1);
+  }
+
+  @override
+  ImageStreamCompleter load(PdfRaster key, DecoderCallback decode) {
+    return OneFrameImageStreamCompleter(_loadAsync());
+  }
+
+  @override
+  Future<PdfRaster> obtainKey(ImageConfiguration configuration) async {
+    return raster;
+  }
+}

@@ -168,6 +168,41 @@ public class PrintJob: NSView, NSSharingServicePickerDelegate {
         result(NSNumber(value: 1))
     }
 
+    public func rasterPdf(data: Data, pages: [Int]?, scale: CGFloat) {
+        let provider = CGDataProvider(data: data as CFData)!
+        let document = CGPDFDocument(provider)!
+
+        DispatchQueue.global().async {
+            let pageCount = document.numberOfPages
+
+            for pageNum in pages ?? Array(0 ... pageCount - 1) {
+                guard let page = document.page(at: pageNum + 1) else { continue }
+                let rect = page.getBoxRect(.mediaBox)
+                let width = Int(rect.width * scale)
+                let height = Int(rect.height * scale)
+                let stride = width * 4
+                var data = Data(repeating: 0, count: stride * height)
+
+                data.withUnsafeMutableBytes { (ptr: UnsafeMutablePointer<UInt8>) in
+                    let rgb = CGColorSpaceCreateDeviceRGB()
+                    let context = CGContext(data: ptr, width: width, height: height, bitsPerComponent: 8, bytesPerRow: stride, space: rgb, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
+                    if context != nil {
+                        context!.scaleBy(x: scale, y: scale)
+                        context!.drawPDFPage(page)
+                    }
+                }
+
+                DispatchQueue.main.sync {
+                    self.printing.onPageRasterized(printJob: self, imageData: data, width: width, height: height)
+                }
+            }
+
+            DispatchQueue.main.sync {
+                self.printing.onPageRasterEnd(printJob: self)
+            }
+        }
+    }
+
     public static func printingInfo() -> NSDictionary {
         let data: NSDictionary = [
             "directPrint": false,
@@ -175,6 +210,7 @@ public class PrintJob: NSView, NSSharingServicePickerDelegate {
             "canPrint": true,
             "canConvertHtml": true,
             "canShare": true,
+            "canRaster": true,
         ]
         return data
     }

@@ -111,6 +111,15 @@ public class PrintingPlugin: NSObject, FlutterPlugin {
 //            ))
         } else if call.method == "printingInfo" {
             result(PrintJob.printingInfo())
+        } else if call.method == "rasterPdf" {
+            let doc = args["doc"] as! FlutterStandardTypedData
+            let pages = args["pages"] as? [Int]
+            let scale = CGFloat((args["scale"] as! NSNumber).floatValue)
+            let printJob = PrintJob(printing: self, index: args["job"] as! Int)
+            printJob.rasterPdf(data: doc.data,
+                               pages: pages,
+                               scale: scale)
+            result(NSNumber(value: 1))
         } else {
             result(FlutterMethodNotImplemented)
         }
@@ -165,4 +174,22 @@ public class PrintingPlugin: NSObject, FlutterPlugin {
         ]
         channel.invokeMethod("onHtmlError", arguments: data)
     }
+
+    /// send pdf to raster data result to flutter
+    public func onPageRasterized(printJob: PrintJob, imageData: Data, width: Int, height: Int) {
+        let data: NSDictionary = [
+            "image": FlutterStandardTypedData(bytes: imageData),
+            "width": width,
+            "height": height,
+            "job": printJob.index,
+        ]
+        channel.invokeMethod("onPageRasterized", arguments: data)
+    }
+
+    public func onPageRasterEnd(printJob: PrintJob) {
+        let data: NSDictionary = [
+            "job": printJob.index,
+        ]
+        channel.invokeMethod("onPageRasterEnd", arguments: data)
+    }
 }

@@ -4,7 +4,7 @@ description: Plugin that allows Flutter apps to generate and print documents to
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/printing
 repository: https://github.com/DavBfr/dart_pdf
 issue_tracker: https://github.com/DavBfr/dart_pdf/issues
-version: 3.0.1
+version: 3.0.2
 
 environment:
   sdk: ">=2.3.0 <3.0.0"