ash: Add a heads-up display to track touch-point states and positions.

ash/touch/touch_observer_hud.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 "ash/touch/touch_observer_hud.h"
+
+#include "ash/shell_window_ids.h"
+#include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
+#include "ui/aura/event.h"
+#include "ui/views/background.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/box_layout.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace internal {
+
+TouchObserverHUD::TouchObserverHUD() {
+  views::View* content = new views::View;
+  content->SetLayoutManager(new views::BoxLayout(
+      views::BoxLayout::kVertical, 0, 0, 0));
+
+  for (int i = 0; i < kMaxTouchPoints; ++i) {
+    touch_status_[i] = ui::ET_UNKNOWN;
+    touch_labels_[i] = new views::Label;
+    touch_labels_[i]->SetBackgroundColor(SkColorSetARGB(0, 255, 255, 255));
+    touch_labels_[i]->SetShadowColors(SK_ColorWHITE,
+                                      SK_ColorWHITE);
+    touch_labels_[i]->SetShadowOffset(1, 1);
+    touch_labels_[i]->SetVisible(false);
+    content->AddChildView(touch_labels_[i]);
+  }
+
+  widget_.reset(new views::Widget());
+  views::Widget::InitParams
+      params(views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+  params.transparent = true;
+  params.can_activate = false;
+  params.bounds = gfx::Rect(content->GetPreferredSize());
+  params.parent = Shell::GetInstance()->GetContainer(
+      internal::kShellWindowId_OverlayContainer);
+  widget_->Init(params);
+  widget_->SetContentsView(content);
+  widget_->StackAtTop();
+  widget_->Show();
+}
+
+TouchObserverHUD::~TouchObserverHUD() {}
+
+void TouchObserverHUD::UpdateTouchPointLabel(int index) {
+  const char* status = NULL;
+  switch (touch_status_[index]) {
+    case ui::ET_UNKNOWN:
+      status = " ";
+      break;
+    case ui::ET_TOUCH_PRESSED:
+      status = "P";
+      break;
+    case ui::ET_TOUCH_MOVED:
+      status = "M";
+      break;
+    case ui::ET_TOUCH_RELEASED:
+      status = "R";
+      break;
+    case ui::ET_TOUCH_CANCELLED:
+      status = "C";
+      break;
+    default:
+      status = "?";
+      break;
+  }
+  std::string string = base::StringPrintf("%2d: %s %s",
+      index, status, touch_positions_[index].ToString().c_str());
+  touch_labels_[index]->SetText(UTF8ToUTF16(string));
+}
+
+bool TouchObserverHUD::PreHandleKeyEvent(aura::Window* target,
+                                         aura::KeyEvent* event) {
+  return false;
+}
+
+bool TouchObserverHUD::PreHandleMouseEvent(aura::Window* target,
+                                           aura::MouseEvent* event) {
+  return false;
+}
+
+ui::TouchStatus TouchObserverHUD::PreHandleTouchEvent(
+    aura::Window* target,
+    aura::TouchEvent* event) {
+  if (event->touch_id() >= kMaxTouchPoints)
+    return ui::TOUCH_STATUS_UNKNOWN;
+
+  if (event->type() != ui::ET_TOUCH_CANCELLED)
+    touch_positions_[event->touch_id()] = event->root_location();
+  touch_status_[event->touch_id()] = event->type();
+  touch_labels_[event->touch_id()]->SetVisible(true);
+  UpdateTouchPointLabel(event->touch_id());
+
+  widget_->SetSize(widget_->GetContentsView()->GetPreferredSize());
+
+  return ui::TOUCH_STATUS_UNKNOWN;
+}
+
+ui::GestureStatus TouchObserverHUD::PreHandleGestureEvent(
+    aura::Window* target,
+    aura::GestureEvent* event) {
+  return ui::GESTURE_STATUS_UNKNOWN;
+}
+
+}  // namespace internal
+}  // namespace ash