src/ash/wm/header_painter.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/wm/header_painter.h"
   6
   7 #include <vector>
   8
   9 #include "ash/ash_constants.h"
  10 #include "ash/root_window_controller.h"
  11 #include "ash/root_window_settings.h"
  12 #include "ash/shell.h"
  13 #include "ash/shell_window_ids.h"
  14 #include "ash/wm/caption_buttons/frame_caption_button_container_view.h"
  15 #include "ash/wm/window_state.h"
  16 #include "ash/wm/window_util.h"
  17 #include "base/logging.h"  // DCHECK
  18 #include "grit/ash_resources.h"
  19 #include "third_party/skia/include/core/SkCanvas.h"
  20 #include "third_party/skia/include/core/SkColor.h"
  21 #include "third_party/skia/include/core/SkPaint.h"
  22 #include "third_party/skia/include/core/SkPath.h"
  23 #include "ui/aura/client/aura_constants.h"
  24 #include "ui/aura/env.h"
  25 #include "ui/aura/window.h"
  26 #include "ui/base/hit_test.h"
  27 #include "ui/base/layout.h"
  28 #include "ui/base/resource/resource_bundle.h"
  29 #include "ui/base/theme_provider.h"
  30 #include "ui/gfx/animation/slide_animation.h"
  31 #include "ui/gfx/canvas.h"
  32 #include "ui/gfx/font.h"
  33 #include "ui/gfx/image/image.h"
  34 #include "ui/gfx/screen.h"
  35 #include "ui/gfx/skia_util.h"
  36 #include "ui/views/widget/widget.h"
  37 #include "ui/views/widget/widget_delegate.h"
  38
  39 using aura::RootWindow;
  40 using aura::Window;
  41 using views::Widget;
  42
  43 namespace {
  44 // Space between left edge of window and popup window icon.
  45 const int kIconOffsetX = 9;
  46 // Height and width of window icon.
  47 const int kIconSize = 16;
  48 // Space between the title text and the caption buttons.
  49 const int kTitleLogoSpacing = 5;
  50 // Space between window icon and title text.
  51 const int kTitleIconOffsetX = 5;
  52 // Space between window edge and title text, when there is no icon.
  53 const int kTitleNoIconOffsetX = 8;
  54 // Color for the non-maximized window title text.
  55 const SkColor kNonMaximizedWindowTitleTextColor = SkColorSetRGB(40, 40, 40);
  56 // Color for the maximized window title text.
  57 const SkColor kMaximizedWindowTitleTextColor = SK_ColorWHITE;
  58 // Size of header/content separator line below the header image.
  59 const int kHeaderContentSeparatorSize = 1;
  60 // Color of header bottom edge line.
  61 const SkColor kHeaderContentSeparatorColor = SkColorSetRGB(128, 128, 128);
  62 // In the pre-Ash era the web content area had a frame along the left edge, so
  63 // user-generated theme images for the new tab page assume they are shifted
  64 // right relative to the header.  Now that we have removed the left edge frame
  65 // we need to copy the theme image for the window header from a few pixels
  66 // inset to preserve alignment with the NTP image, or else we'll break a bunch
  67 // of existing themes.  We do something similar on OS X for the same reason.
  68 const int kThemeFrameImageInsetX = 5;
  69 // Duration of crossfade animation for activating and deactivating frame.
  70 const int kActivationCrossfadeDurationMs = 200;
  71 // Alpha/opacity value for fully-opaque headers.
  72 const int kFullyOpaque = 255;
  73
  74 // A flag to enable/disable solo window header.
  75 bool solo_window_header_enabled = true;
  76
  77 // Tiles an image into an area, rounding the top corners. Samples |image|
  78 // starting |image_inset_x| pixels from the left of the image.
  79 void TileRoundRect(gfx::Canvas* canvas,
  80                    const gfx::ImageSkia& image,
  81                    const SkPaint& paint,
  82                    const gfx::Rect& bounds,
  83                    int top_left_corner_radius,
  84                    int top_right_corner_radius,
  85                    int image_inset_x) {
  86   SkRect rect = gfx::RectToSkRect(bounds);
  87   const SkScalar kTopLeftRadius = SkIntToScalar(top_left_corner_radius);
  88   const SkScalar kTopRightRadius = SkIntToScalar(top_right_corner_radius);
  89   SkScalar radii[8] = {
  90       kTopLeftRadius, kTopLeftRadius,  // top-left
  91       kTopRightRadius, kTopRightRadius,  // top-right
  92       0, 0,   // bottom-right
  93       0, 0};  // bottom-left
  94   SkPath path;
  95   path.addRoundRect(rect, radii, SkPath::kCW_Direction);
  96   canvas->DrawImageInPath(image, -image_inset_x, 0, path, paint);
  97 }
  98
  99 // Tiles |frame_image| and |frame_overlay_image| into an area, rounding the top
 100 // corners.
 101 void PaintFrameImagesInRoundRect(gfx::Canvas* canvas,
 102                                  const gfx::ImageSkia* frame_image,
 103                                  const gfx::ImageSkia* frame_overlay_image,
 104                                  const SkPaint& paint,
 105                                  const gfx::Rect& bounds,
 106                                  int corner_radius,
 107                                  int image_inset_x) {
 108   SkXfermode::Mode normal_mode;
 109   SkXfermode::AsMode(NULL, &normal_mode);
 110
 111   // If |paint| is using an unusual SkXfermode::Mode (this is the case while
 112   // crossfading), we must create a new canvas to overlay |frame_image| and
 113   // |frame_overlay_image| using |normal_mode| and then paint the result
 114   // using the unusual mode. We try to avoid this because creating a new
 115   // browser-width canvas is expensive.
 116   bool fast_path = (!frame_overlay_image ||
 117       SkXfermode::IsMode(paint.getXfermode(), normal_mode));
 118   if (fast_path) {
 119     TileRoundRect(canvas, *frame_image, paint, bounds, corner_radius,
 120         corner_radius, image_inset_x);
 121
 122     if (frame_overlay_image) {
 123       // Adjust |bounds| such that |frame_overlay_image| is not tiled.
 124       gfx::Rect overlay_bounds = bounds;
 125       overlay_bounds.Intersect(
 126           gfx::Rect(bounds.origin(), frame_overlay_image->size()));
 127       int top_left_corner_radius = corner_radius;
 128       int top_right_corner_radius = corner_radius;
 129       if (overlay_bounds.width() < bounds.width() - corner_radius)
 130         top_right_corner_radius = 0;
 131       TileRoundRect(canvas, *frame_overlay_image, paint, overlay_bounds,
 132           top_left_corner_radius, top_right_corner_radius, 0);
 133     }
 134   } else {
 135     gfx::Canvas temporary_canvas(bounds.size(), canvas->image_scale(), false);
 136     temporary_canvas.TileImageInt(*frame_image,
 137                                   image_inset_x, 0,
 138                                   0, 0,
 139                                   bounds.width(), bounds.height());
 140     temporary_canvas.DrawImageInt(*frame_overlay_image, 0, 0);
 141     TileRoundRect(canvas, gfx::ImageSkia(temporary_canvas.ExtractImageRep()),
 142         paint, bounds, corner_radius, corner_radius, 0);
 143   }
 144 }
 145
 146 // Returns true if |child| and all ancestors are visible. Useful to ensure that
 147 // a window is individually visible and is not part of a hidden workspace.
 148 bool IsVisibleToRoot(Window* child) {
 149   for (Window* window = child; window; window = window->parent()) {
 150     // We must use TargetVisibility() because windows animate in and out and
 151     // IsVisible() also tracks the layer visibility state.
 152     if (!window->TargetVisibility())
 153       return false;
 154   }
 155   return true;
 156 }
 157
 158 // Returns true if |window| is a "normal" window for purposes of solo window
 159 // computations. Returns false for windows that are:
 160 // * Not drawn (for example, DragDropTracker uses one for mouse capture)
 161 // * Modal alerts (it looks odd for headers to change when an alert opens)
 162 // * Constrained windows (ditto)
 163 bool IsSoloWindowHeaderCandidate(aura::Window* window) {
 164   return window &&
 165       window->type() == aura::client::WINDOW_TYPE_NORMAL &&
 166       window->layer() &&
 167       window->layer()->type() != ui::LAYER_NOT_DRAWN &&
 168       window->GetProperty(aura::client::kModalKey) == ui::MODAL_TYPE_NONE &&
 169       !window->GetProperty(ash::kConstrainedWindowKey);
 170 }
 171
 172 // Returns a list of windows in |root_window|| that potentially could have
 173 // a transparent solo-window header.
 174 std::vector<Window*> GetWindowsForSoloHeaderUpdate(Window* root_window) {
 175   std::vector<Window*> windows;
 176   // Avoid memory allocations for typical window counts.
 177   windows.reserve(16);
 178   // Collect windows from the desktop.
 179   Window* desktop = ash::Shell::GetContainer(
 180       root_window, ash::internal::kShellWindowId_DefaultContainer);
 181   windows.insert(windows.end(),
 182                  desktop->children().begin(),
 183                  desktop->children().end());
 184   // Collect "always on top" windows.
 185   Window* top_container =
 186       ash::Shell::GetContainer(
 187           root_window, ash::internal::kShellWindowId_AlwaysOnTopContainer);
 188   windows.insert(windows.end(),
 189                  top_container->children().begin(),
 190                  top_container->children().end());
 191   return windows;
 192 }
 193 }  // namespace
 194
 195 namespace ash {
 196
 197 // static
 198 int HeaderPainter::kActiveWindowOpacity = 255;  // 1.0
 199 int HeaderPainter::kInactiveWindowOpacity = 255;  // 1.0
 200 int HeaderPainter::kSoloWindowOpacity = 77;  // 0.3
 201
 202 ///////////////////////////////////////////////////////////////////////////////
 203 // HeaderPainter, public:
 204
 205 HeaderPainter::HeaderPainter()
 206     : frame_(NULL),
 207       header_view_(NULL),
 208       window_icon_(NULL),
 209       caption_button_container_(NULL),
 210       window_(NULL),
 211       header_height_(0),
 212       top_left_corner_(NULL),
 213       top_edge_(NULL),
 214       top_right_corner_(NULL),
 215       header_left_edge_(NULL),
 216       header_right_edge_(NULL),
 217       previous_theme_frame_id_(0),
 218       previous_theme_frame_overlay_id_(0),
 219       previous_opacity_(0),
 220       crossfade_theme_frame_id_(0),
 221       crossfade_theme_frame_overlay_id_(0),
 222       crossfade_opacity_(0) {}
 223
 224 HeaderPainter::~HeaderPainter() {
 225   // Sometimes we are destroyed before the window closes, so ensure we clean up.
 226   if (window_) {
 227     window_->RemoveObserver(this);
 228     wm::GetWindowState(window_)->RemoveObserver(this);
 229   }
 230 }
 231
 232 void HeaderPainter::Init(
 233     views::Widget* frame,
 234     views::View* header_view,
 235     views::View* window_icon,
 236     FrameCaptionButtonContainerView* caption_button_container) {
 237   DCHECK(frame);
 238   DCHECK(header_view);
 239   // window_icon may be NULL.
 240   DCHECK(caption_button_container);
 241   frame_ = frame;
 242   header_view_ = header_view;
 243   window_icon_ = window_icon;
 244   caption_button_container_ = caption_button_container;
 245
 246   // Window frame image parts.
 247   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
 248   top_left_corner_ =
 249       rb.GetImageNamed(IDR_AURA_WINDOW_HEADER_SHADE_TOP_LEFT).ToImageSkia();
 250   top_edge_ =
 251       rb.GetImageNamed(IDR_AURA_WINDOW_HEADER_SHADE_TOP).ToImageSkia();
 252   top_right_corner_ =
 253       rb.GetImageNamed(IDR_AURA_WINDOW_HEADER_SHADE_TOP_RIGHT).ToImageSkia();
 254   header_left_edge_ =
 255       rb.GetImageNamed(IDR_AURA_WINDOW_HEADER_SHADE_LEFT).ToImageSkia();
 256   header_right_edge_ =
 257       rb.GetImageNamed(IDR_AURA_WINDOW_HEADER_SHADE_RIGHT).ToImageSkia();
 258
 259   window_ = frame->GetNativeWindow();
 260
 261   // Observer removes itself in OnWindowDestroying() below, or in the destructor
 262   // if we go away before the window.
 263   window_->AddObserver(this);
 264   wm::GetWindowState(window_)->AddObserver(this);
 265
 266   // Solo-window header updates are handled by the WorkspaceLayoutManager when
 267   // this window is added to the desktop.
 268 }
 269
 270 // static
 271 void HeaderPainter::SetSoloWindowHeadersEnabled(bool enabled) {
 272   solo_window_header_enabled = enabled;
 273 }
 274
 275 // static
 276 void HeaderPainter::UpdateSoloWindowHeader(Window* root_window) {
 277   // Use a separate function here so callers outside of HeaderPainter don't need
 278   // to know about "ignorable_window".
 279   UpdateSoloWindowInRoot(root_window, NULL /* ignorable_window */);
 280 }
 281
 282 // static
 283 gfx::Rect HeaderPainter::GetBoundsForClientView(
 284     int header_height,
 285     const gfx::Rect& window_bounds) {
 286   gfx::Rect client_bounds(window_bounds);
 287   client_bounds.Inset(0, header_height, 0, 0);
 288   return client_bounds;
 289 }
 290
 291 // static
 292 gfx::Rect HeaderPainter::GetWindowBoundsForClientBounds(
 293       int header_height,
 294       const gfx::Rect& client_bounds) {
 295   gfx::Rect window_bounds(client_bounds);
 296   window_bounds.Inset(0, -header_height, 0, 0);
 297   if (window_bounds.y() < 0)
 298     window_bounds.set_y(0);
 299   return window_bounds;
 300 }
 301
 302 int HeaderPainter::NonClientHitTest(const gfx::Point& point) const {
 303   gfx::Point point_in_header_view(point);
 304   views::View::ConvertPointFromWidget(header_view_, &point_in_header_view);
 305   if (!GetHeaderLocalBounds().Contains(point_in_header_view))
 306     return HTNOWHERE;
 307   if (caption_button_container_->visible()) {
 308     gfx::Point point_in_caption_button_container(point);
 309     views::View::ConvertPointFromWidget(caption_button_container_,
 310         &point_in_caption_button_container);
 311     int component = caption_button_container_->NonClientHitTest(
 312         point_in_caption_button_container);
 313     if (component != HTNOWHERE)
 314       return component;
 315   }
 316   // Caption is a safe default.
 317   return HTCAPTION;
 318 }
 319
 320 int HeaderPainter::GetMinimumHeaderWidth() const {
 321   // Ensure we have enough space for the window icon and buttons. We allow
 322   // the title string to collapse to zero width.
 323   return GetTitleOffsetX() +
 324       caption_button_container_->GetMinimumSize().width();
 325 }
 326
 327 int HeaderPainter::GetRightInset() const {
 328   return caption_button_container_->GetPreferredSize().width();
 329 }
 330
 331 int HeaderPainter::GetThemeBackgroundXInset() const {
 332   return kThemeFrameImageInsetX;
 333 }
 334
 335 bool HeaderPainter::ShouldUseMinimalHeaderStyle(Themed header_themed) const {
 336   // Use the minimalistic header style whenever |frame_| is maximized or
 337   // fullscreen EXCEPT:
 338   // - If the user has installed a theme with custom images for the header.
 339   // - For windows which are not tracked by the workspace code (which are used
 340   //   for tab dragging).
 341   return (frame_->IsMaximized() || frame_->IsFullscreen()) &&
 342       header_themed == THEMED_NO &&
 343       wm::GetWindowState(frame_->GetNativeWindow())->tracked_by_workspace();
 344 }
 345
 346 void HeaderPainter::PaintHeader(gfx::Canvas* canvas,
 347                                 HeaderMode header_mode,
 348                                 int theme_frame_id,
 349                                 int theme_frame_overlay_id) {
 350   bool initial_paint = (previous_theme_frame_id_ == 0);
 351   if (!initial_paint &&
 352       (previous_theme_frame_id_ != theme_frame_id ||
 353        previous_theme_frame_overlay_id_ != theme_frame_overlay_id)) {
 354     aura::Window* parent = frame_->GetNativeWindow()->parent();
 355     // Don't animate the header if the parent (a workspace) is already
 356     // animating. Doing so results in continually painting during the animation
 357     // and gives a slower frame rate.
 358     // TODO(sky): expose a better way to determine this rather than assuming
 359     // the parent is a workspace.
 360     bool parent_animating = parent &&
 361         (parent->layer()->GetAnimator()->IsAnimatingProperty(
 362             ui::LayerAnimationElement::OPACITY) ||
 363          parent->layer()->GetAnimator()->IsAnimatingProperty(
 364              ui::LayerAnimationElement::VISIBILITY));
 365     if (!parent_animating) {
 366       crossfade_animation_.reset(new gfx::SlideAnimation(this));
 367       crossfade_theme_frame_id_ = previous_theme_frame_id_;
 368       crossfade_theme_frame_overlay_id_ = previous_theme_frame_overlay_id_;
 369       crossfade_opacity_ = previous_opacity_;
 370       crossfade_animation_->SetSlideDuration(kActivationCrossfadeDurationMs);
 371       crossfade_animation_->Show();
 372     } else {
 373       crossfade_animation_.reset();
 374     }
 375   }
 376
 377   int opacity =
 378       GetHeaderOpacity(header_mode, theme_frame_id, theme_frame_overlay_id);
 379   ui::ThemeProvider* theme_provider = frame_->GetThemeProvider();
 380   gfx::ImageSkia* theme_frame = theme_provider->GetImageSkiaNamed(
 381       theme_frame_id);
 382   gfx::ImageSkia* theme_frame_overlay = NULL;
 383   if (theme_frame_overlay_id != 0) {
 384     theme_frame_overlay = theme_provider->GetImageSkiaNamed(
 385         theme_frame_overlay_id);
 386   }
 387
 388   int corner_radius = GetHeaderCornerRadius();
 389   SkPaint paint;
 390
 391   if (crossfade_animation_.get() && crossfade_animation_->is_animating()) {
 392     gfx::ImageSkia* crossfade_theme_frame =
 393         theme_provider->GetImageSkiaNamed(crossfade_theme_frame_id_);
 394     gfx::ImageSkia* crossfade_theme_frame_overlay = NULL;
 395     if (crossfade_theme_frame_overlay_id_ != 0) {
 396       crossfade_theme_frame_overlay = theme_provider->GetImageSkiaNamed(
 397           crossfade_theme_frame_overlay_id_);
 398     }
 399     if (!crossfade_theme_frame ||
 400         (crossfade_theme_frame_overlay_id_ != 0 &&
 401          !crossfade_theme_frame_overlay)) {
 402       // Reset the animation. This case occurs when the user switches the theme
 403       // that they are using.
 404       crossfade_animation_.reset();
 405       paint.setAlpha(opacity);
 406     } else {
 407       double current_value = crossfade_animation_->GetCurrentValue();
 408       int old_alpha = (1 - current_value) * crossfade_opacity_;
 409       int new_alpha = current_value * opacity;
 410
 411       // Draw the old header background, clipping the corners to be rounded.
 412       paint.setAlpha(old_alpha);
 413       paint.setXfermodeMode(SkXfermode::kPlus_Mode);
 414       PaintFrameImagesInRoundRect(canvas,
 415                                   crossfade_theme_frame,
 416                                   crossfade_theme_frame_overlay,
 417                                   paint,
 418                                   GetHeaderLocalBounds(),
 419                                   corner_radius,
 420                                   GetThemeBackgroundXInset());
 421
 422       paint.setAlpha(new_alpha);
 423     }
 424   } else {
 425     paint.setAlpha(opacity);
 426   }
 427
 428   // Draw the header background, clipping the corners to be rounded.
 429   PaintFrameImagesInRoundRect(canvas,
 430                               theme_frame,
 431                               theme_frame_overlay,
 432                               paint,
 433                               GetHeaderLocalBounds(),
 434                               corner_radius,
 435                               GetThemeBackgroundXInset());
 436
 437   previous_theme_frame_id_ = theme_frame_id;
 438   previous_theme_frame_overlay_id_ = theme_frame_overlay_id;
 439   previous_opacity_ = opacity;
 440
 441   // We don't need the extra lightness in the edges when we're at the top edge
 442   // of the screen or when the header's corners are not rounded.
 443   //
 444   // TODO(sky): this isn't quite right. What we really want is a method that
 445   // returns bounds ignoring transforms on certain windows (such as workspaces)
 446   // and is relative to the root.
 447   if (frame_->GetNativeWindow()->bounds().y() == 0 || corner_radius == 0)
 448     return;
 449
 450   // Draw the top corners and edge.
 451   int top_left_width = top_left_corner_->width();
 452   int top_left_height = top_left_corner_->height();
 453   canvas->DrawImageInt(*top_left_corner_,
 454                        0, 0, top_left_width, top_left_height,
 455                        0, 0, top_left_width, top_left_height,
 456                        false);
 457   canvas->TileImageInt(*top_edge_,
 458       top_left_width,
 459       0,
 460       header_view_->width() - top_left_width - top_right_corner_->width(),
 461       top_edge_->height());
 462   int top_right_height = top_right_corner_->height();
 463   canvas->DrawImageInt(*top_right_corner_,
 464                        0, 0,
 465                        top_right_corner_->width(), top_right_height,
 466                        header_view_->width() - top_right_corner_->width(), 0,
 467                        top_right_corner_->width(), top_right_height,
 468                        false);
 469
 470   // Header left edge.
 471   int header_left_height = theme_frame->height() - top_left_height;
 472   canvas->TileImageInt(*header_left_edge_,
 473                        0, top_left_height,
 474                        header_left_edge_->width(), header_left_height);
 475
 476   // Header right edge.
 477   int header_right_height = theme_frame->height() - top_right_height;
 478   canvas->TileImageInt(*header_right_edge_,
 479                        header_view_->width() - header_right_edge_->width(),
 480                        top_right_height,
 481                        header_right_edge_->width(),
 482                        header_right_height);
 483
 484   // We don't draw edges around the content area.  Web content goes flush
 485   // to the edge of the window.
 486 }
 487
 488 void HeaderPainter::PaintHeaderContentSeparator(gfx::Canvas* canvas) {
 489   canvas->FillRect(gfx::Rect(0,
 490                              header_height_ - kHeaderContentSeparatorSize,
 491                              header_view_->width(),
 492                              kHeaderContentSeparatorSize),
 493                    kHeaderContentSeparatorColor);
 494 }
 495
 496 int HeaderPainter::HeaderContentSeparatorSize() const {
 497   return kHeaderContentSeparatorSize;
 498 }
 499
 500 void HeaderPainter::PaintTitleBar(gfx::Canvas* canvas,
 501                                   const gfx::Font& title_font) {
 502   // The window icon is painted by its own views::View.
 503   views::WidgetDelegate* delegate = frame_->widget_delegate();
 504   if (delegate && delegate->ShouldShowWindowTitle()) {
 505     gfx::Rect title_bounds = GetTitleBounds(title_font);
 506     SkColor title_color = frame_->IsMaximized() ?
 507         kMaximizedWindowTitleTextColor : kNonMaximizedWindowTitleTextColor;
 508     canvas->DrawStringInt(delegate->GetWindowTitle(),
 509                           title_font,
 510                           title_color,
 511                           header_view_->GetMirroredXForRect(title_bounds),
 512                           title_bounds.y(),
 513                           title_bounds.width(),
 514                           title_bounds.height(),
 515                           gfx::Canvas::NO_SUBPIXEL_RENDERING);
 516   }
 517 }
 518
 519 void HeaderPainter::LayoutHeader(bool shorter_layout) {
 520   caption_button_container_->set_header_style(shorter_layout ?
 521       FrameCaptionButtonContainerView::HEADER_STYLE_SHORT :
 522       FrameCaptionButtonContainerView::HEADER_STYLE_TALL);
 523   caption_button_container_->Layout();
 524
 525   gfx::Size caption_button_container_size =
 526       caption_button_container_->GetPreferredSize();
 527   caption_button_container_->SetBounds(
 528       header_view_->width() - caption_button_container_size.width(),
 529       0,
 530       caption_button_container_size.width(),
 531       caption_button_container_size.height());
 532
 533   if (window_icon_) {
 534     // Vertically center the window icon with respect to the caption button
 535     // container.
 536     int icon_offset_y =
 537         GetCaptionButtonContainerCenterY() - window_icon_->height() / 2;
 538     window_icon_->SetBounds(kIconOffsetX, icon_offset_y, kIconSize, kIconSize);
 539   }
 540 }
 541
 542 void HeaderPainter::SchedulePaintForTitle(const gfx::Font& title_font) {
 543   header_view_->SchedulePaintInRect(GetTitleBounds(title_font));
 544 }
 545
 546 void HeaderPainter::OnThemeChanged() {
 547   // We do not cache the images for |previous_theme_frame_id_| and
 548   // |previous_theme_frame_overlay_id_|. Changing the theme changes the images
 549   // returned from ui::ThemeProvider for |previous_theme_frame_id_|
 550   // and |previous_theme_frame_overlay_id_|. Reset the image ids to prevent
 551   // starting a crossfade animation with these images.
 552   previous_theme_frame_id_ = 0;
 553   previous_theme_frame_overlay_id_ = 0;
 554
 555   if (crossfade_animation_.get() && crossfade_animation_->is_animating()) {
 556     crossfade_animation_.reset();
 557     header_view_->SchedulePaintInRect(GetHeaderLocalBounds());
 558   }
 559 }
 560
 561 ///////////////////////////////////////////////////////////////////////////////
 562 // WindowStateObserver overrides:
 563 void HeaderPainter::OnTrackedByWorkspaceChanged(wm::WindowState* window_state,
 564                                                 bool old) {
 565   // When 'TrackedByWorkspace' changes, we are going to paint the header
 566   // differently. Schedule a paint to ensure everything is updated correctly.
 567   if (window_state->tracked_by_workspace())
 568     header_view_->SchedulePaint();
 569 }
 570
 571 ///////////////////////////////////////////////////////////////////////////////
 572 // aura::WindowObserver overrides:
 573
 574 void HeaderPainter::OnWindowVisibilityChanged(aura::Window* window,
 575                                               bool visible) {
 576   // OnWindowVisibilityChanged can be called for the child windows of |window_|.
 577   if (window != window_)
 578     return;
 579
 580   // Window visibility change may trigger the change of window solo-ness in a
 581   // different window.
 582   UpdateSoloWindowInRoot(window_->GetRootWindow(), visible ? NULL : window_);
 583 }
 584
 585 void HeaderPainter::OnWindowDestroying(aura::Window* destroying) {
 586   DCHECK_EQ(window_, destroying);
 587
 588   // Must be removed here and not in the destructor, as the aura::Window is
 589   // already destroyed when our destructor runs.
 590   window_->RemoveObserver(this);
 591   wm::GetWindowState(window_)->RemoveObserver(this);
 592
 593   // If we have two or more windows open and we close this one, we might trigger
 594   // the solo window appearance for another window.
 595   UpdateSoloWindowInRoot(window_->GetRootWindow(), window_);
 596
 597   window_ = NULL;
 598 }
 599
 600 void HeaderPainter::OnWindowBoundsChanged(aura::Window* window,
 601                                          const gfx::Rect& old_bounds,
 602                                          const gfx::Rect& new_bounds) {
 603   // TODO(sky): this isn't quite right. What we really want is a method that
 604   // returns bounds ignoring transforms on certain windows (such as workspaces).
 605   if ((!frame_->IsMaximized() && !frame_->IsFullscreen()) &&
 606       ((old_bounds.y() == 0 && new_bounds.y() != 0) ||
 607        (old_bounds.y() != 0 && new_bounds.y() == 0))) {
 608     SchedulePaintForHeader();
 609   }
 610 }
 611
 612 void HeaderPainter::OnWindowAddedToRootWindow(aura::Window* window) {
 613   // Needs to trigger the window appearance change if the window moves across
 614   // root windows and a solo window is already in the new root.
 615   UpdateSoloWindowInRoot(window->GetRootWindow(), NULL /* ignore_window */);
 616 }
 617
 618 void HeaderPainter::OnWindowRemovingFromRootWindow(aura::Window* window) {
 619   // Needs to trigger the window appearance change if the window moves across
 620   // root windows and only one window is left in the previous root.  Because
 621   // |window| is not yet moved, |window| has to be ignored.
 622   UpdateSoloWindowInRoot(window->GetRootWindow(), window);
 623 }
 624
 625 ///////////////////////////////////////////////////////////////////////////////
 626 // gfx::AnimationDelegate overrides:
 627
 628 void HeaderPainter::AnimationProgressed(const gfx::Animation* animation) {
 629   header_view_->SchedulePaintInRect(GetHeaderLocalBounds());
 630 }
 631
 632 ///////////////////////////////////////////////////////////////////////////////
 633 // HeaderPainter, private:
 634
 635 gfx::Rect HeaderPainter::GetHeaderLocalBounds() const {
 636   return gfx::Rect(header_view_->width(), header_height_);
 637 }
 638
 639 int HeaderPainter::GetTitleOffsetX() const {
 640   return window_icon_ ?
 641       window_icon_->bounds().right() + kTitleIconOffsetX :
 642       kTitleNoIconOffsetX;
 643 }
 644
 645 int HeaderPainter::GetCaptionButtonContainerCenterY() const {
 646   return caption_button_container_->y() +
 647       caption_button_container_->height() / 2;
 648 }
 649
 650 int HeaderPainter::GetHeaderCornerRadius() const {
 651   // Use square corners for maximized and fullscreen windows when they are
 652   // tracked by the workspace code. (Windows which are not tracked by the
 653   // workspace code are used for tab dragging.)
 654   bool square_corners = ((frame_->IsMaximized() || frame_->IsFullscreen())) &&
 655       wm::GetWindowState(frame_->GetNativeWindow())->tracked_by_workspace();
 656   const int kCornerRadius = 2;
 657   return square_corners ? 0 : kCornerRadius;
 658 }
 659
 660 int HeaderPainter::GetHeaderOpacity(
 661     HeaderMode header_mode,
 662     int theme_frame_id,
 663     int theme_frame_overlay_id) const {
 664   // User-provided themes are painted fully opaque.
 665   ui::ThemeProvider* theme_provider = frame_->GetThemeProvider();
 666   if (theme_provider->HasCustomImage(theme_frame_id) ||
 667       (theme_frame_overlay_id != 0 &&
 668        theme_provider->HasCustomImage(theme_frame_overlay_id))) {
 669     return kFullyOpaque;
 670   }
 671
 672   // The header is fully opaque when using the minimalistic header style.
 673   if (ShouldUseMinimalHeaderStyle(THEMED_NO))
 674     return kFullyOpaque;
 675
 676   // Single browser window is very transparent.
 677   if (UseSoloWindowHeader())
 678     return kSoloWindowOpacity;
 679
 680   // Otherwise, change transparency based on window activation status.
 681   if (header_mode == ACTIVE)
 682     return kActiveWindowOpacity;
 683   return kInactiveWindowOpacity;
 684 }
 685
 686 bool HeaderPainter::UseSoloWindowHeader() const {
 687   if (!solo_window_header_enabled)
 688     return false;
 689   // Don't use transparent headers for panels, pop-ups, etc.
 690   if (!IsSoloWindowHeaderCandidate(window_))
 691     return false;
 692   aura::Window* root = window_->GetRootWindow();
 693   // Don't recompute every time, as it would require many window property
 694   // lookups.
 695   return internal::GetRootWindowSettings(root)->solo_window_header;
 696 }
 697
 698 // static
 699 bool HeaderPainter::UseSoloWindowHeaderInRoot(Window* root_window,
 700                                               Window* ignore_window) {
 701   int visible_window_count = 0;
 702   std::vector<Window*> windows = GetWindowsForSoloHeaderUpdate(root_window);
 703   for (std::vector<Window*>::const_iterator it = windows.begin();
 704        it != windows.end();
 705        ++it) {
 706     Window* window = *it;
 707     // Various sorts of windows "don't count" for this computation.
 708     if (ignore_window == window ||
 709         !IsSoloWindowHeaderCandidate(window) ||
 710         !IsVisibleToRoot(window))
 711       continue;
 712     if (wm::GetWindowState(window)->IsMaximized())
 713       return false;
 714     ++visible_window_count;
 715     if (visible_window_count > 1)
 716       return false;
 717   }
 718   // Count must be tested because all windows might be "don't count" windows
 719   // in the loop above.
 720   return visible_window_count == 1;
 721 }
 722
 723 // static
 724 void HeaderPainter::UpdateSoloWindowInRoot(Window* root,
 725                                            Window* ignore_window) {
 726 #if defined(OS_WIN)
 727   // Non-Ash Windows doesn't do solo-window counting for transparency effects,
 728   // as the desktop background and window frames are managed by the OS.
 729   if (!ash::Shell::HasInstance())
 730     return;
 731 #endif
 732   if (!root)
 733     return;
 734   internal::RootWindowSettings* root_window_settings =
 735       internal::GetRootWindowSettings(root);
 736   bool old_solo_header = root_window_settings->solo_window_header;
 737   bool new_solo_header = UseSoloWindowHeaderInRoot(root, ignore_window);
 738   if (old_solo_header == new_solo_header)
 739     return;
 740   root_window_settings->solo_window_header = new_solo_header;
 741
 742   // Invalidate all the window frames in the desktop. There should only be
 743   // a few.
 744   std::vector<Window*> windows = GetWindowsForSoloHeaderUpdate(root);
 745   for (std::vector<Window*>::const_iterator it = windows.begin();
 746        it != windows.end();
 747        ++it) {
 748     Widget* widget = Widget::GetWidgetForNativeWindow(*it);
 749     if (widget && widget->non_client_view())
 750       widget->non_client_view()->SchedulePaint();
 751   }
 752 }
 753
 754 void HeaderPainter::SchedulePaintForHeader() {
 755   int top_left_height = top_left_corner_->height();
 756   int top_right_height = top_right_corner_->height();
 757   header_view_->SchedulePaintInRect(
 758       gfx::Rect(0, 0, header_view_->width(),
 759                 std::max(top_left_height, top_right_height)));
 760 }
 761
 762 gfx::Rect HeaderPainter::GetTitleBounds(const gfx::Font& title_font) {
 763   int title_x = GetTitleOffsetX();
 764   // Center the text with respect to the caption button container. This way it
 765   // adapts to the caption button height and aligns exactly with the window
 766   // icon. Don't use |window_icon_| for this computation as it may be NULL.
 767   int title_y = GetCaptionButtonContainerCenterY() - title_font.GetHeight() / 2;
 768   return gfx::Rect(
 769       title_x,
 770       std::max(0, title_y),
 771       std::max(0, caption_button_container_->x() - kTitleLogoSpacing - title_x),
 772       title_font.GetHeight());
 773 }
 774
 775 }  // namespace ash