MacViews a11y: Support the "Show menu" action in Textfield and Combobox.

ui/views/controls/combobox/combobox_unittest.cc

 // Copyright 2013 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 "ui/views/controls/combobox/combobox.h"
 
 #include <set>
 
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
+#include "ui/accessibility/ax_action_data.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/base/models/combobox_model.h"
 #include "ui/base/models/menu_model.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/dom/dom_code.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/events/test/event_generator.h"
@@ skipping 613 matching lines @@
   // With STYLE_NORMAL, the click event is ignored. Instead the menu is shwon.
   PressKey(ui::VKEY_SPACE);
   EXPECT_EQ(1, menu_show_count_);
   EXPECT_FALSE(listener.on_perform_action_called());
 
   ReleaseKey(ui::VKEY_SPACE);
   EXPECT_EQ(1, menu_show_count_);
   EXPECT_FALSE(listener.on_perform_action_called());
 }
 
+// Test that accessibility action events show the combobox dropdown.
+TEST_F(ComboboxTest, ShowViaAccessibleAction) {
+  InitCombobox(nullptr, Combobox::STYLE_NORMAL);
+
+  ui::AXActionData data;
+  data.action = ui::AX_ACTION_DO_DEFAULT;
+
+  EXPECT_EQ(0, menu_show_count_);
+  combobox_->HandleAccessibleAction(data);
+  EXPECT_EQ(1, menu_show_count_);

[msw, 2017/06/29 19:26:12]

nit: test handling the action while the menu is showing?

[tapted, 2017/06/30 06:04:47]

doing this requires an interactive_ui_test (menus are tricksy). 

Combobox::ShowDropDownMenu() has handling for ensuring the old menu is closed
for the non-accessible actions.

+
+  combobox_->SetEnabled(false);
+  combobox_->HandleAccessibleAction(data);
+  EXPECT_EQ(1, menu_show_count_);  // No change.
+
+  data.action = ui::AX_ACTION_BLUR;

[msw, 2017/06/29 19:26:12]

Should this also test AX_ACTION_SHOW_CONTEXT_MENU, and increment/decrement?

[tapted, 2017/06/30 06:04:47]

AX_ACTION_SHOW_CONTEXT_MENU was actually tested in earlier patchsets, but we
decided context menus should not be a concept that views comboboxes should
handle -- it should do nothing. (For <select> elements in webcontent
AX_ACTION_SHOW_CONTEXT_MENU should show the regular page context menu.)

Except, for Mac, we want to expose NSAccessibilityShowMenuAction since it's not
exclusively used for context menus on native controls. (if this is a bug on
other platforms we can explore in a follow-up)

I guess it doesn't hurt to send AX_ACTION_SHOW_CONTEXT_MENU anyway, and verify
there's no change (done). However, a control doesn't usually expect to see
requests to handle actions it didn't first expose in its AXNodeData.

increment/decrement aren't exposed as actions on native Cocoa controls, so I
haven't added handling for it.

+  combobox_->HandleAccessibleAction(data);

[msw, 2017/06/29 19:26:12]

Maybe test other actions, like blur, before disabling the combobox?

[tapted, 2017/06/30 06:04:47]

Done.

+  EXPECT_EQ(1, menu_show_count_);  // No change.
+}
+
 TEST_F(ComboboxTest, NotifyOnClickWithSpaceKeyActionStyle) {
   InitCombobox(nullptr, Combobox::STYLE_ACTION);
 
   TestComboboxListener listener;
   combobox_->set_listener(&listener);
 
   // With STYLE_ACTION, the click event is notified after releasing and the menu
   // is not shown. On Mac, the menu should be shown.
   PressKey(ui::VKEY_SPACE);
 #if defined(OS_MACOSX)
@@ skipping 261 matching lines @@
   EXPECT_EQ(ui::MenuModel::TYPE_COMMAND, menu_model->GetTypeAt(0));
   EXPECT_EQ(ui::MenuModel::TYPE_COMMAND, menu_model->GetTypeAt(1));
 
   EXPECT_EQ(ASCIIToUTF16("PEANUT BUTTER"), menu_model->GetLabelAt(0));
   EXPECT_EQ(ASCIIToUTF16("JELLY"), menu_model->GetLabelAt(1));
   EXPECT_FALSE(menu_model->IsVisibleAt(0));
   EXPECT_TRUE(menu_model->IsVisibleAt(1));
 }
 
 }  // namespace views