Added a class acting as a fake caret for accessibility.

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 85 matching lines @@
 #include "ui/touch_selection/touch_selection_controller.h"
 #include "ui/wm/public/activation_client.h"
 #include "ui/wm/public/scoped_tooltip_disabler.h"
 #include "ui/wm/public/tooltip_client.h"
 
 #if defined(OS_WIN)
 #include "base/time/time.h"
 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
 #include "content/browser/accessibility/browser_accessibility_win.h"
 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
+#include "ui/accessibility/platform/ax_fake_caret_win.h"
 #include "ui/base/win/hidden_window.h"
 #include "ui/base/win/osk_display_manager.h"
 #include "ui/base/win/osk_display_observer.h"
 #include "ui/display/win/screen_win.h"
 #include "ui/gfx/gdi_util.h"
 #endif
 
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS) && defined(USE_X11)
 #include "content/browser/accessibility/browser_accessibility_auralinux.h"
 #endif
@@ skipping 762 matching lines @@
 
 void RenderWidgetHostViewAura::UpdateMouseLockRegion() {
   RECT window_rect =
       display::Screen::GetScreen()
           ->DIPToScreenRectInWindow(window_, window_->GetBoundsInScreen())
           .ToRECT();
   ::ClipCursor(&window_rect);
 }
 
 void RenderWidgetHostViewAura::OnLegacyWindowDestroyed() {
-  legacy_render_widget_host_HWND_ = NULL;
+  ui::AXFakeCaretWin::Get()->SetTargetForNativeAccessibilityEvent(

[dmazzoni, 2017/04/21 21:06:30]

Hmmm, I wonder if it'd make more sense for each
HWND to just own its own instance of AXFakeCaretWin,
then you wouldn't need to do any of this. What do
you think?

+      gfx::kNullAcceleratedWidget);
+  legacy_render_widget_host_HWND_ = nullptr;
   legacy_window_destroyed_ = true;
 }
 #endif
 
 void RenderWidgetHostViewAura::DidCreateNewRendererCompositorFrameSink() {
   if (delegated_frame_host_)
     delegated_frame_host_->DidCreateNewRendererCompositorFrameSink();
 }
 
 void RenderWidgetHostViewAura::SubmitCompositorFrame(
@@ skipping 650 matching lines @@
   // in the dtor. However there may be cases where the window is destroyed
   // by Windows, i.e. the parent window is destroyed before the
   // RenderWidgetHostViewAura instance goes away etc. To avoid that we
   // destroy the LegacyRenderWidgetHostHWND instance here.
   if (legacy_render_widget_host_HWND_) {
     legacy_render_widget_host_HWND_->set_host(NULL);
     legacy_render_widget_host_HWND_->Destroy();
     // The Destroy call above will delete the LegacyRenderWidgetHostHWND
     // instance.
     legacy_render_widget_host_HWND_ = NULL;
+    ui::AXFakeCaretWin::Get()->SetTargetForNativeAccessibilityEvent(
+        gfx::kNullAcceleratedWidget);
   }
 #endif
 
   // Make sure that the input method no longer references to this object before
   // this object is removed from the root window (i.e. this object loses access
   // to the input method).
   DetachFromInputMethod();
 
   if (overscroll_controller_)
     overscroll_controller_->Reset();
@@ skipping 579 matching lines @@
     legacy_render_widget_host_HWND_->set_host(this);
     legacy_render_widget_host_HWND_->UpdateParent(GetHostWindowHWND());
     legacy_render_widget_host_HWND_->SetBounds(
         window_->GetBoundsInRootWindow());
     // There are cases where the parent window is created, made visible and
     // the associated RenderWidget is also visible before the
     // LegacyRenderWidgetHostHWND instace is created. Ensure that it is shown
     // here.
     if (!host_->is_hidden())
       legacy_render_widget_host_HWND_->Show();
+    ui::AXFakeCaretWin::Get()->SetTargetForNativeAccessibilityEvent(
+        legacy_render_widget_host_HWND_->hwnd());
   }
 }
 #endif
 
 void RenderWidgetHostViewAura::SchedulePaintIfNotInClip(
     const gfx::Rect& rect,
     const gfx::Rect& clip) {
   if (!clip.IsEmpty()) {
     gfx::Rect to_paint = gfx::SubtractRects(rect, clip);
     if (!to_paint.IsEmpty())
@@ skipping 158 matching lines @@
 void RenderWidgetHostViewAura::OnSelectionBoundsChanged(
     TextInputManager* text_input_manager,
     RenderWidgetHostViewBase* updated_view) {
   if (GetInputMethod())
     GetInputMethod()->OnCaretBoundsChanged(this);
 }
 
 void RenderWidgetHostViewAura::OnTextSelectionChanged(
     TextInputManager* text_input_manager,
     RenderWidgetHostViewBase* updated_view) {
-#if defined(USE_X11) && !defined(OS_CHROMEOS)
   if (!GetTextInputManager())
     return;
 
   // We obtain the TextSelection from focused RWH which is obtained from the
   // frame tree. BrowserPlugin-based guests' RWH is not part of the frame tree
   // and the focused RWH will be that of the embedder which is incorrect. In
   // this case we should use TextSelection for |this| since RWHV for guest
   // forwards text selection information to its platform view.
   RenderWidgetHostViewBase* focused_view =
       is_guest_view_hack_ ? this : GetFocusedWidget()
                                        ? GetFocusedWidget()->GetView()
                                        : nullptr;
 
   if (!focused_view)
     return;
 
+#if defined(USE_X11) && !defined(OS_CHROMEOS)
   const TextInputManager::TextSelection* selection =
       GetTextInputManager()->GetTextSelection(focused_view);
   if (selection->selected_text().length()) {
     // Set the CLIPBOARD_TYPE_SELECTION to the ui::Clipboard.
     ui::ScopedClipboardWriter clipboard_writer(ui::CLIPBOARD_TYPE_SELECTION);
     clipboard_writer.WriteText(selection->selected_text());
   }
-#endif  // defined(USE_X11) && !defined(OS_CHROMEOS)
+
+// #endif defined(USE_X11) && !defined(OS_CHROMEOS)
+#elif defined(OS_WIN)
+  // Some assistive software need to track the location of the caret.
+  if (!GetRenderWidgetHost())
+    return;
+
+  // Not using |GetCaretBounds| because it includes the whole of the selection,
+  // not just the focus.
+  const TextInputManager::SelectionRegion* region =
+      GetTextInputManager()->GetSelectionRegion(focused_view);
+  if (!region)
+    return;
+  gfx::Rect caret_rect = ConvertRectToScreen(gfx::Rect(
+      region->focus.edge_top_rounded().x(),
+      region->focus.edge_top_rounded().y(), 1, region->focus.GetHeight()));
+  ui::AXFakeCaretWin::Get()->MoveCaretTo(caret_rect);
+#endif  // defined(OS_WIN)
 }
 
 void RenderWidgetHostViewAura::SetPopupChild(
     RenderWidgetHostViewAura* popup_child_host_view) {
   popup_child_host_view_ = popup_child_host_view;
   event_handler_->SetPopupChild(
       popup_child_host_view,
       popup_child_host_view ? popup_child_host_view->event_handler() : nullptr);
 }
 
 void RenderWidgetHostViewAura::UpdateNeedsBeginFramesInternal() {
   if (!delegated_frame_host_)
     return;
   delegated_frame_host_->SetNeedsBeginFrames(needs_begin_frames_ ||
                                              needs_flush_input_);
 }
 
 }  // namespace content