Keyboard Lock Host implementation

components/keyboard_lock/platform_key_hook_x11.cc

Index: components/keyboard_lock/platform_key_hook_x11.cc
diff --git a/components/keyboard_lock/platform_key_hook_x11.cc b/components/keyboard_lock/platform_key_hook_x11.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0c832569ca0985412f7e32b6f6384a105189aca2
--- /dev/null
+++ b/components/keyboard_lock/platform_key_hook_x11.cc
@@ -0,0 +1,107 @@
+// Copyright 2017 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 "components/keyboard_lock/platform_key_hook.h"
+
+#include <X11/Xlib.h>
+#undef Status
+
+#include <unordered_set>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/macros.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "components/keyboard_lock/platform_key_event_filter.h"
+#include "ui/aura/window.h"
+#include "ui/aura/window_tree_host.h"
+#include "ui/base/x/x11_window_event_manager.h"
+#include "ui/events/platform/x11/x11_event_source.h"
+#include "ui/gfx/x/x11_error_tracker.h"
+#include "ui/gfx/x/x11_types.h"
+
+namespace keyboard_lock {
+
+namespace {
+
+const unsigned int kSingleStates[] = { ShiftMask,
+                                       LockMask,
+                                       ControlMask,
+                                       Mod1Mask,
+                                       Mod2Mask,
+                                       Mod3Mask,
+                                       Mod4Mask,
+                                       Mod5Mask };
+
+std::vector<int> all_states;
+
+void InitializeStates() {
+  if (!all_states.empty()) {
+    return;
+  }
+
+  std::unordered_set<int> states {
+      kSingleStates, kSingleStates + arraysize(kSingleStates) };
+  for (size_t i = 0; i < arraysize(kSingleStates); i++) {
+    std::vector<int> new_states;
+    for (auto state : states) {
+      for (size_t j = 0; j < arraysize(kSingleStates); j++) {
+        new_states.push_back(state | kSingleStates[j]);
+      }
+    }
+    states.insert(new_states.begin(), new_states.end());
+  }
+
+  all_states = std::vector<int> { states.begin(), states.end() };
+}
+
+}  // namespace
+
+PlatformKeyHook::PlatformKeyHook(Browser* owner, KeyEventFilter* filter)
+    : owner_(owner),
+      filter_(filter) {
+  DCHECK(owner_);
+  ui::X11EventSource::GetInstance()->set_platform_key_event_filter(&filter_);
+}
+
+PlatformKeyHook::~PlatformKeyHook() = default;
+
+bool PlatformKeyHook::RegisterKey(const std::vector<ui::KeyboardCode>& codes) {
+  InitializeStates();
+  gfx::X11ErrorTracker x11_error_tracker;
+  Display* display = gfx::GetXDisplay();
+  if (owner_->window() == nullptr ||
+      owner_->window()->GetNativeWindow() == nullptr ||
+      owner_->window()->GetNativeWindow()->GetHost() == nullptr) {
+    LOG(ERROR) << "No native window found.";
+    // This should not happen in production, JavaScript cannot be executed
+    // before CreateBrowserWindow().
+    return false;
+  }
+  const Window root =
+      owner_->window()->GetNativeWindow()->GetHost()->GetAcceleratedWidget();
+  for (ui::KeyboardCode code : codes) {
+    for (auto state : all_states) {
+      XGrabKey(display, code, state, root, False, GrabModeAsync, GrabModeAsync);
+    }
+  }
+  return true;
+}
+
+bool PlatformKeyHook::UnregisterKey(
+    const std::vector<ui::KeyboardCode>& codes) {
+  InitializeStates();
+  gfx::X11ErrorTracker x11_error_tracker;
+  Display* display = gfx::GetXDisplay();
+  const Window root = DefaultRootWindow(display);
+  for (ui::KeyboardCode code : codes) {
+    for (auto state : all_states) {
+      XUngrabKey(display, code, state, root);
+    }
+  }
+  return true;
+}
+
+}  // namespace keyboard_lock