scanning: Support JPG file format in ScanService

Implement conversion from PNG to JPG image format when requested by user
on scanning UI. Add unit tests to verify functionality.

Bug: b:161237869
Change-Id: I8d21a0d7ddff0ddb3635b45b133f3869ec3e61cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2507574
Commit-Queue: Kyra Moed <kmoed@google.com>
Reviewed-by: Jesse Schettler <jschettler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823330}

chrome/browser/chromeos/scanning/scan_service.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/scanning/scan_service.h"
 
+#include <cstdint>
 #include <utility>
 
 #include "base/bind.h"
@@ -15,6 +16,8 @@
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/scanning/lorgnette_scanner_manager.h"
 #include "chrome/browser/chromeos/scanning/scanning_type_converters.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_util.h"
 
 namespace chromeos {
 
@@ -25,6 +28,22 @@ namespace mojo_ipc = scanning::mojom;
 // Path to the active user's "My files" folder.
 constexpr char kActiveUserMyFilesPath[] = "/home/chronos/user/MyFiles";
 
+// The conversion quality when converting from PNG to JPG.
+constexpr int kJpgQuality = 100;
+
+// Converts |png_img| to JPG.
+std::string PngToJpg(const std::string& png_img) {
+  std::vector<uint8_t> jpg_img;
+  const gfx::Image img = gfx::Image::CreateFrom1xPNGBytes(
+      reinterpret_cast<const unsigned char*>(png_img.c_str()), png_img.size());
+  if (!gfx::JPEG1xEncodedDataFromImage(img, kJpgQuality, &jpg_img)) {
+    LOG(ERROR) << "Failed to convert image from PNG to JPG.";
+    return "";
+  }
+
+  return std::string(jpg_img.begin(), jpg_img.end());
+}
+
 }  // namespace
 
 ScanService::ScanService(LorgnetteScannerManager* lorgnette_scanner_manager,
@@ -132,18 +151,30 @@ void ScanService::OnPageReceived(const base::FilePath& scan_to_path,
                                  const mojo_ipc::FileType file_type,
                                  std::string scanned_image,
                                  uint32_t page_number) {
-  // TODO(jschettler): Add support for converting the scanned image to other
-  // file types.
-  if (file_type != mojo_ipc::FileType::kPng) {
-    LOG(ERROR) << "Selected file type not supported.";
-    save_failed_ = true;
-    return;
+  std::string filename;
+  std::string file_ext;
+  switch (file_type) {
+    case mojo_ipc::FileType::kPng:
+      file_ext = "png";
+      break;
+    case mojo_ipc::FileType::kJpg:
+      file_ext = "jpg";
+      scanned_image = PngToJpg(scanned_image);
+      if (scanned_image == "") {
+        save_failed_ = true;
+        return;
+      }
+      break;
+    default:
+      LOG(ERROR) << "Selected file type not supported.";
+      save_failed_ = true;
+      return;
   }
 
-  const std::string filename = base::StringPrintf(
-      "scan_%02d%02d%02d-%02d%02d%02d_%d.png", start_time_.year,
+  filename = base::StringPrintf(
+      "scan_%02d%02d%02d-%02d%02d%02d_%d.%s", start_time_.year,
       start_time_.month, start_time_.day_of_month, start_time_.hour,
-      start_time_.minute, start_time_.second, page_number);
+      start_time_.minute, start_time_.second, page_number, file_ext.c_str());
   const auto file_path = scan_to_path.Append(filename);
   if (!base::WriteFile(file_path, scanned_image)) {
     LOG(ERROR) << "Failed to save scanned image: " << file_path.value().c_str();

chrome/browser/chromeos/scanning/scan_service_unittest.cc

@@ -4,8 +4,11 @@
 
 #include "chrome/browser/chromeos/scanning/scan_service.h"
 
+#include <map>
+#include <string>
 #include <vector>
 
+#include "base/containers/flat_set.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ -222,19 +225,24 @@ TEST_F(ScanServiceTest, Scan) {
   base::Time::Exploded scan_time;
   // Since we're using mock time, this is deterministic.
   base::Time::Now().LocalExplode(&scan_time);
-  base::FilePath saved_scan_path = temp_dir_.GetPath().Append(
-      base::StringPrintf("scan_%02d%02d%02d-%02d%02d%02d_1.png", scan_time.year,
-                         scan_time.month, scan_time.day_of_month,
-                         scan_time.hour, scan_time.minute, scan_time.second));
-  EXPECT_FALSE(base::PathExists(saved_scan_path));
 
-  // Saving scanned images is currently only supported for the PNG file type.
   scan_service_.SetMyFilesPathForTesting(temp_dir_.GetPath());
   mojo_ipc::ScanSettings settings;
   settings.scan_to_path = temp_dir_.GetPath();
-  settings.file_type = mojo_ipc::FileType::kPng;
-  EXPECT_TRUE(Scan(scanners[0]->id, settings.Clone()));
-  EXPECT_TRUE(base::PathExists(saved_scan_path));
+  std::map<std::string, mojo_ipc::FileType> file_types = {
+      {"png", mojo_ipc::FileType::kPng}, {"jpg", mojo_ipc::FileType::kJpg}};
+  base::FilePath saved_scan_path;
+  for (const auto& type : file_types) {
+    saved_scan_path = temp_dir_.GetPath().Append(base::StringPrintf(
+        "scan_%02d%02d%02d-%02d%02d%02d_1.%s", scan_time.year, scan_time.month,
+        scan_time.day_of_month, scan_time.hour, scan_time.minute,
+        scan_time.second, type.first.c_str()));
+    EXPECT_FALSE(base::PathExists(saved_scan_path));
+
+    settings.file_type = type.second;
+    EXPECT_TRUE(Scan(scanners[0]->id, settings.Clone()));
+    EXPECT_TRUE(base::PathExists(saved_scan_path));
+  }
 }
 
 }  // namespace chromeos

chromeos/components/scanning/resources/scanning_app.js

@@ -26,7 +26,7 @@ import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bun
 
 import {getScanService} from './mojo_interface_provider.js';
 import {ScannerArr} from './scanning_app_types.js';
-import {colorModeFromString, pageSizeFromString, tokenToString} from './scanning_app_util.js';
+import {colorModeFromString, fileTypeFromString, pageSizeFromString, tokenToString} from './scanning_app_util.js';
 
 /**
  * The default save directory for completed scans.
@@ -227,10 +227,10 @@ Polymer({
       return;
     }
 
-    // TODO(jschettler): Remove this once ScanService supports other file types.
-    if (this.selectedFileType !==
-        chromeos.scanning.mojom.FileType.kPng.toString()) {
-      this.statusText_ = 'PNG is the only supported file type.';
+    // TODO(jschettler): Remove this once ScanService supports PDF.
+    if (this.selectedFileType ==
+        chromeos.scanning.mojom.FileType.kPdf.toString()) {
+      this.statusText_ = 'PDF is not a supported file type.';
       return;
     }
 
@@ -238,12 +238,10 @@ Polymer({
     this.settingsDisabled_ = true;
     this.scanButtonDisabled_ = true;
 
-    // TODO(jschettler): Use the selected file type when ScanService supports
-    // it.
     const settings = {
       'sourceName': this.selectedSource,
       'scanToPath': {'path': this.selectedFilePath},
-      'fileType': chromeos.scanning.mojom.FileType.kPng,
+      'fileType': fileTypeFromString(this.selectedFileType),
       'colorMode': colorModeFromString(this.selectedColorMode),
       'pageSize': pageSizeFromString(this.selectedPageSize),
       'resolutionDpi': Number(this.selectedResolution),

chromeos/components/scanning/resources/scanning_app_util.js

@@ -24,6 +24,26 @@ export function colorModeFromString(colorModeString) {
   }
 }
 
+/**
+ * Converts a chromeos.scanning.mojom.FileType string to the corresponding
+ * enum value.
+ * @param {string} fileTypeString
+ * @return {chromeos.scanning.mojom.FileType}
+ */
+export function fileTypeFromString(fileTypeString) {
+  switch (fileTypeString) {
+    case chromeos.scanning.mojom.FileType.kJpg.toString():
+      return chromeos.scanning.mojom.FileType.kJpg;
+    case chromeos.scanning.mojom.FileType.kPdf.toString():
+      return chromeos.scanning.mojom.FileType.kPdf;
+    case chromeos.scanning.mojom.FileType.kPng.toString():
+      return chromeos.scanning.mojom.FileType.kPng;
+    default:
+      assertNotReached();
+      return chromeos.scanning.mojom.FileType.kPdf;
+  }
+}
+
 /**
  * Converts a chromeos.scanning.mojom.ColorMode to a string that can be
  * displayed in the color mode dropdown.