| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "device/hid/hid_report_descriptor.h" |
| |
| #include "base/stl_util.h" |
| |
| namespace device { |
| |
| HidReportDescriptor::HidReportDescriptor(const uint8_t* bytes, size_t size) { |
| size_t header_index = 0; |
| HidReportDescriptorItem* item = NULL; |
| while (header_index < size) { |
| item = new HidReportDescriptorItem(&bytes[header_index], item); |
| items_.push_back(linked_ptr<HidReportDescriptorItem>(item)); |
| header_index += item->GetSize(); |
| } |
| } |
| |
| HidReportDescriptor::~HidReportDescriptor() {} |
| |
| void HidReportDescriptor::GetTopLevelCollections( |
| std::vector<HidUsageAndPage>* topLevelCollections) { |
| DCHECK(topLevelCollections); |
| STLClearObject(topLevelCollections); |
| |
| for (std::vector<linked_ptr<HidReportDescriptorItem> >::const_iterator |
| items_iter = items().begin(); |
| items_iter != items().end(); |
| ++items_iter) { |
| linked_ptr<HidReportDescriptorItem> item = *items_iter; |
| |
| bool isTopLevelCollection = |
| item->tag() == HidReportDescriptorItem::kTagCollection && |
| item->parent() == NULL; |
| |
| if (isTopLevelCollection) { |
| uint16_t collection_usage = 0; |
| HidUsageAndPage::Page collection_usage_page = |
| HidUsageAndPage::kPageUndefined; |
| |
| HidReportDescriptorItem* usage = item->previous(); |
| if (usage && usage->tag() == HidReportDescriptorItem::kTagUsage) { |
| collection_usage = usage->GetShortData(); |
| } |
| |
| HidReportDescriptorItem* usage_page = usage->previous(); |
| if (usage_page && |
| usage_page->tag() == HidReportDescriptorItem::kTagUsagePage) { |
| collection_usage_page = |
| (HidUsageAndPage::Page)usage_page->GetShortData(); |
| } |
| |
| topLevelCollections->push_back( |
| HidUsageAndPage(collection_usage, collection_usage_page)); |
| } |
| } |
| } |
| |
| } // namespace device |