pt 1 in reviving the android build (copied from pm 28a1, wish me luck)

mobile/android/base/java/org/mozilla/gecko/PrintHelper.java

@@ -0,0 +1,124 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko;
+
+import org.mozilla.gecko.AppConstants.Versions;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.util.GeckoRequest;
+import org.mozilla.gecko.util.IOUtils;
+import org.mozilla.gecko.util.NativeJSObject;
+import org.mozilla.gecko.util.ThreadUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.os.CancellationSignal;
+import android.os.ParcelFileDescriptor;
+import android.print.PrintAttributes;
+import android.print.PrintDocumentAdapter;
+import android.print.PrintDocumentAdapter.LayoutResultCallback;
+import android.print.PrintDocumentAdapter.WriteResultCallback;
+import android.print.PrintDocumentInfo;
+import android.print.PrintManager;
+import android.print.PageRange;
+import android.util.Log;
+
+public class PrintHelper {
+    private static final String LOGTAG = "GeckoPrintUtils";
+
+    public static void printPDF(final Context context) {
+        GeckoAppShell.sendRequestToGecko(new GeckoRequest("Print:PDF", new JSONObject()) {
+            @Override
+            public void onResponse(NativeJSObject nativeJSObject) {
+                final String filePath = nativeJSObject.getString("file");
+                final String title = nativeJSObject.getString("title");
+                finish(context, filePath, title);
+            }
+
+            @Override
+            public void onError(NativeJSObject error) {
+                // Gecko didn't respond due to state change, javascript error, etc.
+                Log.d(LOGTAG, "No response from Gecko on request to generate a PDF");
+            }
+
+            private void finish(final Context context, final String filePath, final String title) {
+                PrintManager printManager = (PrintManager) context.getSystemService(Context.PRINT_SERVICE);
+                String jobName = title;
+
+                // The adapter methods are all called on the UI thread by the PrintManager. Put the heavyweight code
+                // in onWrite on the background thread.
+                PrintDocumentAdapter pda = new PrintDocumentAdapter() {
+                    @Override
+                    public void onWrite(final PageRange[] pages, final ParcelFileDescriptor destination, final CancellationSignal cancellationSignal, final WriteResultCallback callback) {
+                        ThreadUtils.postToBackgroundThread(new Runnable() {
+                            @Override
+                            public void run() {
+                                InputStream input = null;
+                                OutputStream output = null;
+
+                                try {
+                                    File pdfFile = new File(filePath);
+                                    input = new FileInputStream(pdfFile);
+                                    output = new FileOutputStream(destination.getFileDescriptor());
+
+                                    byte[] buf = new byte[8192];
+                                    int bytesRead;
+                                    while ((bytesRead = input.read(buf)) > 0) {
+                                        output.write(buf, 0, bytesRead);
+                                    }
+
+                                    callback.onWriteFinished(new PageRange[] { PageRange.ALL_PAGES });
+                                } catch (FileNotFoundException ee) {
+                                    Log.d(LOGTAG, "Unable to find the temporary PDF file.");
+                                } catch (IOException ioe) {
+                                    Log.e(LOGTAG, "IOException while transferring temporary PDF file: ", ioe);
+                                } finally {
+                                    IOUtils.safeStreamClose(input);
+                                    IOUtils.safeStreamClose(output);
+                                }
+                            }
+                        });
+                    }
+
+                    @Override
+                    public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes, CancellationSignal cancellationSignal, LayoutResultCallback callback, Bundle extras) {
+                        if (cancellationSignal.isCanceled()) {
+                            callback.onLayoutCancelled();
+                            return;
+                        }
+
+                        PrintDocumentInfo pdi = new PrintDocumentInfo.Builder(filePath).setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT).build();
+                        callback.onLayoutFinished(pdi, true);
+                    }
+
+                    @Override
+                    public void onFinish() {
+                        // Remove the temporary file when the printing system is finished.
+                        try {
+                            File pdfFile = new File(filePath);
+                            pdfFile.delete();
+                        } catch (NullPointerException npe) {
+                            // Silence the exception. We only want to delete a real file. We don't
+                            // care if the file doesn't exist.
+                        }
+                    }
+                };
+
+                printManager.print(jobName, pda, null);
+            }
+        });
+    }
+}