Laser tool blocks events from propagating.

ash/common/system/chromeos/palette/tools/laser_pointer_view.cc

-// Copyright 2016 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/common/system/chromeos/palette/tools/laser_pointer_view.h"
-
-#include <memory>
-
-#include "ash/common/shell_window_ids.h"
-#include "ash/common/wm_root_window_controller.h"
-#include "ash/common/wm_shell.h"
-#include "ash/common/wm_window.h"
-#include "third_party/skia/include/core/SkColor.h"
-#include "third_party/skia/include/core/SkPaint.h"
-#include "ui/gfx/canvas.h"
-
-namespace ash {
-namespace {
-
-const double kPointInitialRadius = 5;
-const double kPointFinalRadius = 0.25;
-const int kPointInitialOpacity = 200;
-const int kPointFinalOpacity = 0;
-const SkColor kPointColor = SkColorSetRGB(255, 0, 0);
-
-float DistanceBetweenPoints(const gfx::Point& point1,
-                            const gfx::Point& point2) {
-  return (point1 - point2).Length();
-}
-
-double LinearInterpolate(double initial_value,
-                         double final_value,
-                         double progress) {
-  return initial_value + (final_value - initial_value) * progress;
-}
-
-}  // namespace
-
-////////////////////////////////////////////////////////////////////////////////
-
-// LaserPointerView
-LaserPointerView::LaserPointerView(base::TimeDelta life_duration)
-    : laser_points_(life_duration) {
-  widget_.reset(new views::Widget);
-  views::Widget::InitParams params;
-  params.type = views::Widget::InitParams::TYPE_WINDOW_FRAMELESS;
-  params.name = "LaserOverlay";
-  params.accept_events = false;
-  params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
-  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
-  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
-  WmShell::Get()
-      ->GetRootWindowForNewWindows()
-      ->GetRootWindowController()
-      ->ConfigureWidgetInitParamsForContainer(
-          widget_.get(), kShellWindowId_OverlayContainer, &params);
-  widget_->Init(params);
-  widget_->Show();
-  widget_->SetContentsView(this);
-  set_owned_by_client();
-}
-
-LaserPointerView::~LaserPointerView() {}
-
-void LaserPointerView::Stop() {
-  laser_points_.Clear();
-  SchedulePaint();
-}
-
-void LaserPointerView::AddNewPoint(const gfx::Point& new_point) {
-  laser_points_.AddPoint(new_point);
-  // Expand the bounding box so that it includes the radius of the points on the
-  // edges.
-  gfx::Rect bounding_box;
-  bounding_box = laser_points_.GetBoundingBox();
-  bounding_box.Offset(-kPointInitialRadius, -kPointInitialRadius);
-  bounding_box.set_width(bounding_box.width() + (kPointInitialRadius * 2));
-  bounding_box.set_height(bounding_box.height() + (kPointInitialRadius * 2));
-  widget_->SetBounds(bounding_box);
-  SchedulePaint();
-}
-
-void LaserPointerView::OnPaint(gfx::Canvas* canvas) {
-  if (laser_points_.IsEmpty())
-    return;
-
-  SkPaint paint;
-  paint.setStyle(SkPaint::kStroke_Style);
-  paint.setAntiAlias(true);
-  paint.setStrokeJoin(SkPaint::kBevel_Join);
-
-  base::Time oldest = laser_points_.GetOldest().creation_time;
-  base::Time newest = laser_points_.GetNewest().creation_time;
-  gfx::Point previous_point = laser_points_.GetOldest().location;
-  gfx::Point current_point;
-  gfx::Rect widget_bounds = widget_->GetWindowBoundsInScreen();
-  int num_points_ = laser_points_.GetNumberOfPoints();
-  int point_count = 0;
-  for (const LaserPointerPoints::LaserPoint& point :
-       laser_points_.laser_points()) {
-    // relative_time is a value between [0,1] where 0 means the point is about
-    // to be removed and 1 means that the point was just added.
-    double relative_time = 1.0;
-    if (oldest != newest) {
-      relative_time = 1.0 - ((point.creation_time - oldest).InMillisecondsF() /
-                             (newest - oldest).InMillisecondsF());
-    }
-
-    // Set the radius and opacity based on the distance.
-    double radius = LinearInterpolate(kPointInitialRadius, kPointFinalRadius,
-                                      relative_time);
-
-    gfx::Vector2d center = point.location - widget_bounds.origin();
-    current_point = gfx::Point(center.x(), center.y());
-
-    // If we draw laser_points_ that are within a stroke width of each other,
-    // the result will be very jagged, unless we are on the last point, then we
-    // draw regardless.
-    point_count++;
-    float distance_threshold = float{radius * 2};
-    if (DistanceBetweenPoints(previous_point, current_point) <=
-            distance_threshold &&
-        point_count != num_points_) {
-      continue;
-    }
-
-    int opacity =
-        int{LinearInterpolate(double{kPointInitialOpacity},
-                              double{kPointFinalOpacity}, relative_time)};
-    paint.setColor(SkColorSetA(kPointColor, opacity));
-    paint.setStrokeWidth(radius * 2);
-    canvas->DrawLine(previous_point, current_point, paint);
-    previous_point = current_point;
-  }
-  paint.setColor(SkColorSetA(kPointColor, kPointInitialOpacity));
-  paint.setStyle(SkPaint::kFill_Style);
-  canvas->DrawCircle(current_point, kPointInitialRadius, paint);
-}
-}  // namespace ash