Include USB printers in printer list as "provisional" devices.

chrome/browser/ui/webui/print_preview/extension_printer_handler.cc

Index: chrome/browser/ui/webui/print_preview/extension_printer_handler.cc
diff --git a/chrome/browser/ui/webui/print_preview/extension_printer_handler.cc b/chrome/browser/ui/webui/print_preview/extension_printer_handler.cc
index 3236e3ecda46426e5261994ef313b501b8fbc0f7..b5d2feb599b3dad353f8883f1fc3c6e4f3a5f7fb 100644
--- a/chrome/browser/ui/webui/print_preview/extension_printer_handler.cc
+++ b/chrome/browser/ui/webui/print_preview/extension_printer_handler.cc
@@ -18,12 +18,29 @@
 #include "chrome/browser/local_discovery/pwg_raster_converter.h"
 #include "components/cloud_devices/common/cloud_device_description.h"
 #include "components/cloud_devices/common/printer_description.h"
+#include "device/core/device_client.h"
+#include "device/usb/usb_device.h"
+#include "device/usb/usb_service.h"
+#include "extensions/browser/api/device_permissions_manager.h"
 #include "extensions/browser/api/printer_provider/printer_provider_api.h"
 #include "extensions/browser/api/printer_provider/printer_provider_api_factory.h"
 #include "extensions/browser/api/printer_provider/printer_provider_print_job.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/common/api/printer_provider/usb_printer_manifest_data.h"
+#include "extensions/common/permissions/permissions_data.h"
+#include "extensions/common/permissions/usb_device_permission.h"
+#include "extensions/common/permissions/usb_device_permission_data.h"
+#include "extensions/common/value_builder.h"
 #include "printing/pdf_render_settings.h"
 #include "printing/pwg_raster_settings.h"
 
+using device::UsbDevice;
+using extensions::DevicePermissionsManager;
+using extensions::DictionaryBuilder;
+using extensions::Extension;
+using extensions::ExtensionRegistry;
+using extensions::ListBuilder;
+using extensions::UsbPrinterManifestData;
 using local_discovery::PWGRasterConverter;
 
 namespace {
@@ -94,6 +111,30 @@ void ExtensionPrinterHandler::StartGetPrinters(
                      weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
+void ExtensionPrinterHandler::StartGetUsbPrinters(
+    const GetUsbPrintersCallback& callback) {
+  bool extensions_support_usb_devices = false;
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser_context_);
+  for (const auto& extension : registry->enabled_extensions()) {
+    if (UsbPrinterManifestData::Get(extension.get()) &&
+        extension->permissions_data() &&
+        extension->permissions_data()->HasAPIPermission(
+            extensions::APIPermission::kPrinterProvider) &&
+        extension->permissions_data()->HasAPIPermission(
+            extensions::APIPermission::kUsb)) {

[tbarzic, 2015/05/27 18:24:33]

Maybe check that the extension has required event listener (otherwise, these
filters are irrelevant)?

[Reilly Grant (use Gerrit), 2015/05/28 21:45:00]

I think that starts to get to be a lot of properties to check. Should we just
look for an onGetUsbPrinterInfoRequested handler, or
onGetPrinterCapabilitiesRequested and onPrintRequested as well? I think these
two permissions are the relevant ones for an app being able to declare a set of
supported USB printers.

+      extensions_support_usb_devices = true;
+    }
+  }
+
+  if (extensions_support_usb_devices) {
+    device::UsbService* service = device::DeviceClient::Get()->GetUsbService();
+    DCHECK(service);
+    service->GetDevices(
+        base::Bind(&ExtensionPrinterHandler::OnUsbDevicesEnumerated,
+                   weak_ptr_factory_.GetWeakPtr(), callback));
+  }
+}
+
 void ExtensionPrinterHandler::StartGetCapability(
     const std::string& destination_id,
     const PrinterHandler::GetCapabilityCallback& callback) {
@@ -208,3 +249,68 @@ void ExtensionPrinterHandler::WrapPrintCallback(
     const std::string& status) {
   callback.Run(success, status);
 }
+
+void ExtensionPrinterHandler::OnUsbDevicesEnumerated(
+    const GetUsbPrintersCallback& callback,
+    const std::vector<scoped_refptr<UsbDevice>>& devices) {
+  std::map<scoped_refptr<UsbDevice>,
+           std::vector<scoped_refptr<const Extension>>> result_map;
+
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser_context_);
+  DevicePermissionsManager* permissions_manager =

[tbarzic, 2015/05/27 18:24:33]

can this logic be moved somewhere under
extensions/browser/api/printer_provider/? Maybe create a new file,
supported_usb_printers_enumerator or something?

[tbarzic, 2015/05/28 00:30:21]

you can ignore this one :)

+      DevicePermissionsManager::Get(browser_context_);
+
+  for (const auto& extension : registry->enabled_extensions()) {
+    const UsbPrinterManifestData* manifest_data =
+        UsbPrinterManifestData::Get(extension.get());
+    const extensions::DevicePermissions* device_permissions =
+        permissions_manager->GetForExtension(extension->id());
+
+    if (!manifest_data || !extension->permissions_data() ||
+        !extension->permissions_data()->HasAPIPermission(
+            extensions::APIPermission::kPrinterProvider) ||
+        !extension->permissions_data()->HasAPIPermission(
+            extensions::APIPermission::kUsb)) {
+      continue;
+    }
+
+    for (const auto& device : devices) {
+      if (manifest_data->SupportsDevice(device)) {
+        extensions::UsbDevicePermission::CheckParam param(
+            device->vendor_id(),
+            device->product_id(),
+            extensions::UsbDevicePermissionData::UNSPECIFIED_INTERFACE);
+        if (device_permissions->FindUsbDeviceEntry(device) ||
+            extension->permissions_data()->CheckAPIPermissionWithParam(
+                extensions::APIPermission::kUsbDevice, &param)) {
+          // Skip devices the extension already has permission to access.
+          continue;
+        }
+
+        result_map[device].push_back(extension);
+      }
+    }
+  }
+
+  ListBuilder printer_list;
+  for (const auto& map_entry : result_map) {
+    ListBuilder extension_list;
+    for (const scoped_refptr<const Extension>& extension : map_entry.second) {
+      extension_list.Append(DictionaryBuilder()
+                                .Set("extensionId", extension->id())
+                                .Set("extensionName", extension->name()));
+    }
+
+    const scoped_refptr<UsbDevice>& device = map_entry.first;
+    printer_list.Append(
+        DictionaryBuilder()
+            .Set("name", DevicePermissionsManager::GetPermissionMessage(
+                             device->vendor_id(), device->product_id(),
+                             device->manufacturer_string(),
+                             device->product_string(), base::string16(), false))
+            .Set("usbDevice", static_cast<int>(device->unique_id()))
+            .Set("extensions", extension_list.Pass()));
+  }
+
+  callback.Run(*printer_list.Build().get());
+}