Merge pull request #85 from atom/frameless-window

Add frameless window support, fixes #72.

atom.gyp

@@ -139,6 +139,8 @@
       'common/api/atom_extensions.h',
       'common/api/object_life_monitor.cc',
       'common/api/object_life_monitor.h',
+      'common/draggable_region.cc',
+      'common/draggable_region.h',
       'common/node_bindings.cc',
       'common/node_bindings.h',
       'common/node_bindings_mac.cc',

browser/default_app/main.js

@@ -1,7 +1,14 @@
+var app = require('app');
 var argv = require('optimist').argv;
 var dialog = require('dialog');
 var path = require('path');
 
+// Quit when all windows are closed and no other one is listening to this.
+app.on('window-all-closed', function() {
+  if (app.listeners('window-all-closed').length == 1)
+    app.quit();
+});
+
 // Start the specified app if there is one specified in command line, otherwise
 // start the default app.
 if (argv._.length > 0) {
@@ -9,6 +16,7 @@ if (argv._.length > 0) {
     require(path.resolve(argv._[0]));
   } catch(e) {
     if (e.code == 'MODULE_NOT_FOUND') {
+      console.error(e.stack);
       console.error('Specified app is invalid');
       process.exit(1);
     } else {

browser/native_window.cc

@@ -39,10 +39,13 @@ namespace atom {
 NativeWindow::NativeWindow(content::WebContents* web_contents,
                            base::DictionaryValue* options)
     : content::WebContentsObserver(web_contents),
+      has_frame_(true),
       is_closed_(false),
       not_responding_(false),
       inspectable_web_contents_(
           brightray::InspectableWebContents::Create(web_contents)) {
+  options->GetBoolean(switches::kFrame, &has_frame_);
+
   web_contents->SetDelegate(this);
 
   WindowList::AddWindow(this);
@@ -298,6 +301,8 @@ bool NativeWindow::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP(NativeWindow, message)
     IPC_MESSAGE_HANDLER(AtomViewHostMsg_Message, OnRendererMessage)
     IPC_MESSAGE_HANDLER(AtomViewHostMsg_Message_Sync, OnRendererMessageSync)
+    IPC_MESSAGE_HANDLER(AtomViewHostMsg_UpdateDraggableRegions,
+                        UpdateDraggableRegions)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 

browser/native_window.h

@@ -38,6 +38,7 @@ class Size;
 namespace atom {
 
 class AtomJavaScriptDialogManager;
+struct DraggableRegion;
 
 class NativeWindow : public brightray::DefaultWebContentsDelegate,
                      public content::WebContentsObserver,
@@ -125,6 +126,10 @@ class NativeWindow : public brightray::DefaultWebContentsDelegate,
   void NotifyWindowClosed();
   void NotifyWindowBlur();
 
+  // Called when the window needs to update its draggable region.
+  virtual void UpdateDraggableRegions(
+      const std::vector<DraggableRegion>& regions) = 0;
+
   // Implementations of content::WebContentsDelegate.
   virtual void WebContentsCreated(content::WebContents* source_contents,
                                   int64 source_frame_id,
@@ -160,6 +165,9 @@ class NativeWindow : public brightray::DefaultWebContentsDelegate,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Whether window has standard frame.
+  bool has_frame_;
+
  private:
   void RendererUnresponsiveDelayed();
 

browser/native_window_mac.h

@@ -10,6 +10,8 @@
 #include "base/memory/scoped_ptr.h"
 #include "browser/native_window.h"
 
+class SkRegion;
+
 namespace atom {
 
 class NativeWindowMac : public NativeWindow {
@@ -52,11 +54,22 @@ class NativeWindowMac : public NativeWindow {
   virtual bool IsKiosk() OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() OVERRIDE;
 
-  NSWindow*& window() { return window_; }
-
   void NotifyWindowBlur() { NativeWindow::NotifyWindowBlur(); }
 
+  // Returns true if |point| in local Cocoa coordinate system falls within
+  // the draggable region.
+  bool IsWithinDraggableRegion(NSPoint point) const;
+
+  // Called to handle a mouse event.
+  void HandleMouseEvent(NSEvent* event);
+
+  NSWindow*& window() { return window_; }
+  SkRegion* draggable_region() const { return draggable_region_.get(); }
+
  protected:
+  virtual void UpdateDraggableRegions(
+      const std::vector<DraggableRegion>& regions) OVERRIDE;
+
   // Implementations of content::WebContentsDelegate.
   virtual void HandleKeyboardEvent(
       content::WebContents*,
@@ -65,6 +78,9 @@ class NativeWindowMac : public NativeWindow {
  private:
   void InstallView();
   void UninstallView();
+  void InstallDraggableRegionViews();
+  void UpdateDraggableRegionsForCustomDrag(
+      const std::vector<DraggableRegion>& regions);
 
   NSWindow* window_;
 
@@ -72,6 +88,18 @@ class NativeWindowMac : public NativeWindow {
 
   NSInteger attention_request_id_;  // identifier from requestUserAttention
 
+  // For system drag, the whole window is draggable and the non-draggable areas
+  // have to been explicitly excluded.
+  std::vector<gfx::Rect> system_drag_exclude_areas_;
+
+  // For custom drag, the whole window is non-draggable and the draggable region
+  // has to been explicitly provided.
+  scoped_ptr<SkRegion> draggable_region_;  // used in custom drag.
+
+  // Mouse location since the last mouse event, in screen coordinates. This is
+  // used in custom drag to compute the window movement.
+  NSPoint last_mouse_offset_;
+
   DISALLOW_COPY_AND_ASSIGN(NativeWindowMac);
 };
 

browser/native_window_mac.mm

@@ -16,12 +16,25 @@
 #import "browser/atom_event_processing_window.h"
 #include "brightray/browser/inspectable_web_contents.h"
 #include "brightray/browser/inspectable_web_contents_view.h"
+#include "common/draggable_region.h"
 #include "common/options_switches.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #include "content/public/browser/render_view_host.h"
 
+@interface NSWindow (NSPrivateApis)
+- (void)setBottomCornerRounded:(BOOL)rounded;
+@end
+
+@interface NSView (WebContentsView)
+- (void)setMouseDownCanMoveWindow:(BOOL)can_move;
+@end
+
+@interface NSView (PrivateMethods)
+- (CGFloat)roundedCornerRadius;
+@end
+
 @interface AtomNSWindowDelegate : NSObject<NSWindowDelegate> {
  @private
   atom::NativeWindowMac* shell_;
@@ -80,6 +93,83 @@
 
 @end
 
+@interface AtomFramelessNSWindow : AtomNSWindow
+- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view;
+@end
+
+@implementation AtomFramelessNSWindow
+
+- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view {
+  [[NSBezierPath bezierPathWithRect:rect] addClip];
+  [[NSColor clearColor] set];
+  NSRectFill(rect);
+
+  // Set up our clip.
+  CGFloat cornerRadius = 4.0;
+  if ([view respondsToSelector:@selector(roundedCornerRadius)])
+    cornerRadius = [view roundedCornerRadius];
+  [[NSBezierPath bezierPathWithRoundedRect:[view bounds]
+                                   xRadius:cornerRadius
+                                   yRadius:cornerRadius] addClip];
+  [[NSColor whiteColor] set];
+  NSRectFill(rect);
+}
+
++ (NSRect)frameRectForContentRect:(NSRect)contentRect
+                        styleMask:(NSUInteger)mask {
+  return contentRect;
+}
+
++ (NSRect)contentRectForFrameRect:(NSRect)frameRect
+                        styleMask:(NSUInteger)mask {
+  return frameRect;
+}
+
+- (NSRect)frameRectForContentRect:(NSRect)contentRect {
+  return contentRect;
+}
+
+- (NSRect)contentRectForFrameRect:(NSRect)frameRect {
+  return frameRect;
+}
+
+@end
+
+@interface ControlRegionView : NSView {
+ @private
+  atom::NativeWindowMac* shellWindow_;  // Weak; owns self.
+}
+@end
+
+@implementation ControlRegionView
+
+- (id)initWithShellWindow:(atom::NativeWindowMac*)shellWindow {
+  if ((self = [super init]))
+    shellWindow_ = shellWindow;
+  return self;
+}
+
+- (BOOL)mouseDownCanMoveWindow {
+  return NO;
+}
+
+- (NSView*)hitTest:(NSPoint)aPoint {
+  if (!shellWindow_->IsWithinDraggableRegion(aPoint)) {
+    return nil;
+  }
+  return self;
+}
+
+- (void)mouseDown:(NSEvent*)event {
+  shellWindow_->HandleMouseEvent(event);
+}
+
+- (void)mouseDragged:(NSEvent*)event {
+  shellWindow_->HandleMouseEvent(event);
+}
+
+@end
+
 namespace atom {
 
 NativeWindowMac::NativeWindowMac(content::WebContents* web_contents,
@@ -100,7 +190,13 @@ NativeWindowMac::NativeWindowMac(content::WebContents* web_contents,
   NSUInteger style_mask = NSTitledWindowMask | NSClosableWindowMask |
                           NSMiniaturizableWindowMask | NSResizableWindowMask |
                           NSTexturedBackgroundWindowMask;
-  AtomNSWindow* atom_window = [[AtomNSWindow alloc]
+  AtomNSWindow* atom_window = has_frame_ ?
+    [[AtomNSWindow alloc]
+      initWithContentRect:cocoa_bounds
+                styleMask:style_mask
+                  backing:NSBackingStoreBuffered
+                    defer:YES] :
+    [[AtomNSWindow alloc]
       initWithContentRect:cocoa_bounds
                 styleMask:style_mask
                   backing:NSBackingStoreBuffered
@@ -119,6 +215,9 @@ NativeWindowMac::NativeWindowMac(content::WebContents* web_contents,
     [window() setCollectionBehavior:collectionBehavior];
   }
 
+  NSView* view = inspectable_web_contents()->GetView()->GetNativeView();
+  [view setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
+
   InstallView();
 }
 
@@ -324,6 +423,43 @@ gfx::NativeWindow NativeWindowMac::GetNativeWindow() {
   return window();
 }
 
+bool NativeWindowMac::IsWithinDraggableRegion(NSPoint point) const {
+  if (!draggable_region_)
+    return false;
+  NSView* webView = web_contents()->GetView()->GetNativeView();
+  NSInteger webViewHeight = NSHeight([webView bounds]);
+  // |draggable_region_| is stored in local platform-indepdent coordiate system
+  // while |point| is in local Cocoa coordinate system. Do the conversion
+  // to match these two.
+  return draggable_region_->contains(point.x, webViewHeight - point.y);
+}
+
+void NativeWindowMac::HandleMouseEvent(NSEvent* event) {
+  NSPoint current_mouse_location =
+      [window() convertBaseToScreen:[event locationInWindow]];
+
+  if ([event type] == NSLeftMouseDown) {
+    NSPoint frame_origin = [window() frame].origin;
+    last_mouse_offset_ = NSMakePoint(
+        frame_origin.x - current_mouse_location.x,
+        frame_origin.y - current_mouse_location.y);
+  } else if ([event type] == NSLeftMouseDragged) {
+    [window() setFrameOrigin:NSMakePoint(
+        current_mouse_location.x + last_mouse_offset_.x,
+        current_mouse_location.y + last_mouse_offset_.y)];
+  }
+}
+
+void NativeWindowMac::UpdateDraggableRegions(
+    const std::vector<DraggableRegion>& regions) {
+  // Draggable region is not supported for non-frameless window.
+  if (has_frame_)
+    return;
+
+  UpdateDraggableRegionsForCustomDrag(regions);
+  InstallDraggableRegionViews();
+}
+
 void NativeWindowMac::HandleKeyboardEvent(
     content::WebContents*,
     const content::NativeWebKeyboardEvent& event) {
@@ -339,16 +475,87 @@ void NativeWindowMac::HandleKeyboardEvent(
 
 void NativeWindowMac::InstallView() {
   NSView* view = inspectable_web_contents()->GetView()->GetNativeView();
-  [view setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
+  if (has_frame_) {
     [view setFrame:[[window() contentView] bounds]];
     [[window() contentView] addSubview:view];
+  } else {
+    NSView* frameView = [[window() contentView] superview];
+    [view setFrame:[frameView bounds]];
+    [frameView addSubview:view];
+
+    [[window() standardWindowButton:NSWindowZoomButton] setHidden:YES];
+    [[window() standardWindowButton:NSWindowMiniaturizeButton] setHidden:YES];
+    [[window() standardWindowButton:NSWindowCloseButton] setHidden:YES];
+    [[window() standardWindowButton:NSWindowFullScreenButton] setHidden:YES];
+  }
 }
 
 void NativeWindowMac::UninstallView() {
-  NSView* view = GetWebContents()->GetView()->GetNativeView();
+  NSView* view = inspectable_web_contents()->GetView()->GetNativeView();
   [view removeFromSuperview];
 }
 
+void NativeWindowMac::InstallDraggableRegionViews() {
+  DCHECK(!has_frame_);
+
+  // All ControlRegionViews should be added as children of the WebContentsView,
+  // because WebContentsView will be removed and re-added when entering and
+  // leaving fullscreen mode.
+  NSView* webView = GetWebContents()->GetView()->GetNativeView();
+  NSInteger webViewHeight = NSHeight([webView bounds]);
+
+  // Remove all ControlRegionViews that are added last time.
+  // Note that [webView subviews] returns the view's mutable internal array and
+  // it should be copied to avoid mutating the original array while enumerating
+  // it.
+  scoped_nsobject<NSArray> subviews([[webView subviews] copy]);
+  for (NSView* subview in subviews.get())
+    if ([subview isKindOfClass:[ControlRegionView class]])
+      [subview removeFromSuperview];
+
+  // Create and add ControlRegionView for each region that needs to be excluded
+  // from the dragging.
+  for (std::vector<gfx::Rect>::const_iterator iter =
+           system_drag_exclude_areas_.begin();
+       iter != system_drag_exclude_areas_.end();
+       ++iter) {
+    scoped_nsobject<NSView> controlRegion(
+        [[ControlRegionView alloc] initWithShellWindow:this]);
+    [controlRegion setFrame:NSMakeRect(iter->x(),
+                                       webViewHeight - iter->bottom(),
+                                       iter->width(),
+                                       iter->height())];
+    [webView addSubview:controlRegion];
+  }
+}
+
+void NativeWindowMac::UpdateDraggableRegionsForCustomDrag(
+    const std::vector<DraggableRegion>& regions) {
+  // We still need one ControlRegionView to cover the whole window such that
+  // mouse events could be captured.
+  NSView* web_view = GetWebContents()->GetView()->GetNativeView();
+  gfx::Rect window_bounds(
+      0, 0, NSWidth([web_view bounds]), NSHeight([web_view bounds]));
+  system_drag_exclude_areas_.clear();
+  system_drag_exclude_areas_.push_back(window_bounds);
+
+  // Aggregate the draggable areas and non-draggable areas such that hit test
+  // could be performed easily.
+  SkRegion* draggable_region = new SkRegion;
+  for (std::vector<DraggableRegion>::const_iterator iter = regions.begin();
+       iter != regions.end();
+       ++iter) {
+    const DraggableRegion& region = *iter;
+    draggable_region->op(
+        region.bounds.x(),
+        region.bounds.y(),
+        region.bounds.right(),
+        region.bounds.bottom(),
+        region.draggable ? SkRegion::kUnion_Op : SkRegion::kDifference_Op);
+  }
+  draggable_region_.reset(draggable_region);
+}
+
 // static
 NativeWindow* NativeWindow::Create(content::WebContents* web_contents,
                                    base::DictionaryValue* options) {

browser/native_window_win.cc

@@ -6,8 +6,14 @@
 
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
+#include "common/draggable_region.h"
 #include "common/options_switches.h"
 #include "content/public/browser/native_web_keyboard_event.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_view.h"
+#include "ui/gfx/path.h"
 #include "ui/views/controls/webview/webview.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/client_view.h"
@@ -17,6 +23,9 @@ namespace atom {
 
 namespace {
 
+const int kResizeInsideBoundsSize = 5;
+const int kResizeAreaCornerSize = 16;
+
 class NativeWindowClientView : public views::ClientView {
  public:
   NativeWindowClientView(views::Widget* widget,
@@ -60,6 +69,99 @@ class NativeWindowFrameView : public views::NativeFrameView {
   DISALLOW_COPY_AND_ASSIGN(NativeWindowFrameView);
 };
 
+class NativeWindowFramelessView : public views::NonClientFrameView {
+ public:
+  explicit NativeWindowFramelessView(views::Widget* frame,
+                                     NativeWindowWin* shell)
+      : frame_(frame),
+        shell_(shell) {
+  }
+  virtual ~NativeWindowFramelessView() {}
+
+  // views::NonClientFrameView implementations:
+  virtual gfx::Rect NativeWindowFramelessView::GetBoundsForClientView() const
+      OVERRIDE {
+    return bounds();
+  }
+
+  virtual gfx::Rect NativeWindowFramelessView::GetWindowBoundsForClientBounds(
+        const gfx::Rect& client_bounds) const OVERRIDE {
+    gfx::Rect window_bounds = client_bounds;
+    // Enforce minimum size (1, 1) in case that client_bounds is passed with
+    // empty size. This could occur when the frameless window is being
+    // initialized.
+    if (window_bounds.IsEmpty()) {
+      window_bounds.set_width(1);
+      window_bounds.set_height(1);
+    }
+    return window_bounds;
+  }
+
+  virtual int NonClientHitTest(const gfx::Point& point) OVERRIDE {
+    if (frame_->IsFullscreen())
+      return HTCLIENT;
+
+    // Check the frame first, as we allow a small area overlapping the contents
+    // to be used for resize handles.
+    bool can_ever_resize = frame_->widget_delegate() ?
+        frame_->widget_delegate()->CanResize() :
+        false;
+    // Don't allow overlapping resize handles when the window is maximized or
+    // fullscreen, as it can't be resized in those states.
+    int resize_border =
+        frame_->IsMaximized() || frame_->IsFullscreen() ? 0 :
+        kResizeInsideBoundsSize;
+    int frame_component = GetHTComponentForFrame(point,
+                                                 resize_border,
+                                                 resize_border,
+                                                 kResizeAreaCornerSize,
+                                                 kResizeAreaCornerSize,
+                                                 can_ever_resize);
+    if (frame_component != HTNOWHERE)
+      return frame_component;
+
+    // Check for possible draggable region in the client area for the frameless
+    // window.
+    if (shell_->draggable_region() &&
+        shell_->draggable_region()->contains(point.x(), point.y()))
+      return HTCAPTION;
+
+    int client_component = frame_->client_view()->NonClientHitTest(point);
+    if (client_component != HTNOWHERE)
+      return client_component;
+
+    // Caption is a safe default.
+    return HTCAPTION;
+  }
+
+  virtual void GetWindowMask(const gfx::Size& size,
+                             gfx::Path* window_mask) OVERRIDE {}
+  virtual void ResetWindowControls() OVERRIDE {}
+  virtual void UpdateWindowIcon() OVERRIDE {}
+  virtual void UpdateWindowTitle() OVERRIDE {}
+
+  // views::View implementations:
+  virtual gfx::Size NativeWindowFramelessView::GetPreferredSize() OVERRIDE {
+    gfx::Size pref = frame_->client_view()->GetPreferredSize();
+    gfx::Rect bounds(0, 0, pref.width(), pref.height());
+    return frame_->non_client_view()->GetWindowBoundsForClientBounds(
+        bounds).size();
+  }
+
+  virtual gfx::Size GetMinimumSize() OVERRIDE {
+    return shell_->GetMinimumSize();
+  }
+
+  virtual gfx::Size GetMaximumSize() OVERRIDE {
+    return shell_->GetMaximumSize();
+  }
+
+ private:
+  views::Widget* frame_;
+  NativeWindowWin* shell_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeWindowFramelessView);
+};
 
 }  // namespace
 
@@ -71,6 +173,7 @@ NativeWindowWin::NativeWindowWin(content::WebContents* web_contents,
       resizable_(true) {
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
   params.delegate = this;
+  params.remove_standard_frame = !has_frame_;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   window_->set_frame_type(views::Widget::FRAME_TYPE_FORCE_NATIVE);
   window_->Init(params);
@@ -83,6 +186,7 @@ NativeWindowWin::NativeWindowWin(content::WebContents* web_contents,
   window_->CenterWindow(size);
 
   web_view_->SetWebContents(web_contents);
+  OnViewWasResized();
 }
 
 NativeWindowWin::~NativeWindowWin() {
@@ -221,6 +325,30 @@ gfx::NativeWindow NativeWindowWin::GetNativeWindow() {
   return window_->GetNativeView();
 }
 
+void NativeWindowWin::UpdateDraggableRegions(
+    const std::vector<DraggableRegion>& regions) {
+  if (has_frame_)
+    return;
+
+  SkRegion* draggable_region = new SkRegion;
+
+  // By default, the whole window is non-draggable. We need to explicitly
+  // include those draggable regions.
+  for (std::vector<DraggableRegion>::const_iterator iter = regions.begin();
+       iter != regions.end(); ++iter) {
+    const DraggableRegion& region = *iter;
+    draggable_region->op(
+        region.bounds.x(),
+        region.bounds.y(),
+        region.bounds.right(),
+        region.bounds.bottom(),
+        region.draggable ? SkRegion::kUnion_Op : SkRegion::kDifference_Op);
+  }
+
+  draggable_region_.reset(draggable_region);
+  OnViewWasResized();
+}
+
 void NativeWindowWin::HandleKeyboardEvent(
     content::WebContents*,
     const content::NativeWebKeyboardEvent& event) {
@@ -264,7 +392,40 @@ views::ClientView* NativeWindowWin::CreateClientView(views::Widget* widget) {
 
 views::NonClientFrameView* NativeWindowWin::CreateNonClientFrameView(
     views::Widget* widget) {
+  if (has_frame_)
     return new NativeWindowFrameView(widget, this);
+
+  return new NativeWindowFramelessView(widget, this);
+}
+ 
+void NativeWindowWin::OnViewWasResized() {
+  // Set the window shape of the RWHV.
+  gfx::Size sz = web_view_->size();
+  int height = sz.height(), width = sz.width();
+  gfx::Path path;
+  path.addRect(0, 0, width, height);
+  SetWindowRgn(web_contents()->GetView()->GetNativeView(),
+               path.CreateNativeRegion(),
+               1);
+
+  SkRegion* rgn = new SkRegion;
+  if (!window_->IsFullscreen() && !window_->IsMaximized()) {
+    if (draggable_region())
+      rgn->op(*draggable_region(), SkRegion::kUnion_Op);
+
+    if (!has_frame_ && CanResize()) {
+      rgn->op(0, 0, width, kResizeInsideBoundsSize, SkRegion::kUnion_Op);
+      rgn->op(0, 0, kResizeInsideBoundsSize, height, SkRegion::kUnion_Op);
+      rgn->op(width - kResizeInsideBoundsSize, 0, width, height,
+          SkRegion::kUnion_Op);
+      rgn->op(0, height - kResizeInsideBoundsSize, width, height,
+          SkRegion::kUnion_Op);
+    }
+  }
+
+  content::WebContents* web_contents = GetWebContents();
+  if (web_contents->GetRenderViewHost()->GetView())
+    web_contents->GetRenderViewHost()->GetView()->SetClickthroughRegion(rgn);
 }
 
 // static

browser/native_window_win.h

@@ -60,7 +60,12 @@ class NativeWindowWin : public NativeWindow,
   virtual bool IsKiosk() OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() OVERRIDE;
 
+  SkRegion* draggable_region() { return draggable_region_.get(); }
+
  protected:
+  virtual void UpdateDraggableRegions(
+      const std::vector<DraggableRegion>& regions) OVERRIDE;
+
   // Overridden from content::WebContentsDelegate:
   virtual void HandleKeyboardEvent(
       content::WebContents*,
@@ -79,9 +84,13 @@ class NativeWindowWin : public NativeWindow,
       views::Widget* widget) OVERRIDE;
 
  private:
+  void OnViewWasResized();
+
   scoped_ptr<views::Widget> window_;
   views::WebView* web_view_;  // managed by window_.
 
+  scoped_ptr<SkRegion> draggable_region_;
+
   bool resizable_;
   string16 title_;
   gfx::Size minimum_size_;

common/api/api_messages.h

@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/values.h"
+#include "common/draggable_region.h"
 #include "content/public/common/common_param_traits.h"
 #include "ipc/ipc_message_macros.h"
 
@@ -15,6 +16,11 @@
 
 #define IPC_MESSAGE_START ShellMsgStart
 
+IPC_STRUCT_TRAITS_BEGIN(atom::DraggableRegion)
+  IPC_STRUCT_TRAITS_MEMBER(draggable)
+  IPC_STRUCT_TRAITS_MEMBER(bounds)
+IPC_STRUCT_TRAITS_END()
+
 IPC_MESSAGE_ROUTED2(AtomViewHostMsg_Message,
                     std::string /* channel */,
                     ListValue /* arguments */)
@@ -27,3 +33,7 @@ IPC_SYNC_MESSAGE_ROUTED2_1(AtomViewHostMsg_Message_Sync,
 IPC_MESSAGE_ROUTED2(AtomViewMsg_Message,
                     std::string /* channel */,
                     ListValue /* arguments */)
+
+// Sent by the renderer when the draggable regions are updated.
+IPC_MESSAGE_ROUTED1(AtomViewHostMsg_UpdateDraggableRegions,
+                    std::vector<atom::DraggableRegion> /* regions */)

common/draggable_region.cc

@@ -0,0 +1,13 @@
+// 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 "common/draggable_region.h"
+
+namespace atom {
+
+DraggableRegion::DraggableRegion()
+    : draggable(false) {
+}
+
+}  // namespace atom

common/draggable_region.h

@@ -0,0 +1,21 @@
+// 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.
+
+#ifndef ATOM_COMMON_DRAGGABLE_REGION_H_
+#define ATOM_COMMON_DRAGGABLE_REGION_H_
+
+#include "ui/gfx/rect.h"
+
+namespace atom {
+
+struct DraggableRegion {
+  bool draggable;
+  gfx::Rect bounds;
+
+  DraggableRegion();
+};
+
+}  // namespace atom
+
+#endif  // ATOM_COMMON_DRAGGABLE_REGION_H_

docs/browser-window.md

@@ -1,4 +1,4 @@
-## Synopsis
+# browser-window
 
 The `BrowserWindow` class gives you ability to create a browser window, an
 example is:
@@ -15,6 +15,10 @@ win.loadUrl('https://github.com');
 win.show();
 ```
 
+You can also create a window without chrome by using
+[Frameless Window](frameless-window.md) API.
+
+
 **Note:** Be careful not to use `window` as the variable name.
 
 ## Class: BrowserWindow
@@ -38,6 +42,8 @@ win.show();
   * `kiosk` Boolean - The kiosk mode
   * `title` String - Default window title
   * `show` Boolean - Whether window should be shown when created
+  * `frame` Boolean - Specify `false` to create a
+    [Frameless Window](frameless-window.md)
 
 Creates a new `BrowserWindow` with native properties set by the `options`.
 Usually you only need to set the `width` and `height`, other properties will

docs/frameless-window.md

@@ -0,0 +1,64 @@
+# Frameless window
+
+A frameless window is a window that has no chrome.
+
+## Create a frameless window
+
+To create a frameless window, you only need to specify `frame` to `false` in
+[BrowserWindow](browser-window.md)'s `options`:
+
+
+```javascript
+var BrowserWindow = require('browser-window');
+var win = new BrowserWindow({ width: 800, height: 600, frame: false });
+```
+
+## Draggable region
+
+By default, the frameless window is non-draggable. Apps need to specify
+`-webkit-app-region: drag` in CSS to tell atom-shell which regions are draggable
+(like the OS's standard titlebar), and apps can also use
+`-webkit-app-region: no-drag` to exclude the non-draggable area from the
+ draggable region. Note that only rectangular shape is currently supported.
+
+To make the whole window draggable, you can add `-webkit-app-region: drag` as
+`body`'s style:
+
+```html
+<body style="-webkit-app-region: drag">
+</body>
+```
+
+And note that if you have made the whole window draggable, you must also mark
+buttons as non-draggable, otherwise it would be impossible for users to click on
+them:
+
+```css
+button {
+  -webkit-app-region: no-drag;
+}
+```
+
+If you're only using a custom titlebar, you also need to make buttons in
+titlebar non-draggable.
+
+## Text selection
+
+One thing on frameless window is that the dragging behaviour may conflict with
+selecting text, for example, when you drag the titlebar, you may accidentally
+select the text on titlebar. To prevent this, you need to disable text
+selection on dragging area like this:
+
+```css
+.titlebar {
+  -webkit-user-select: none;
+  -webkit-app-region: drag;
+}
+```
+
+##Context menu
+
+On some platforms, the draggable area would be treated as non-client frame, so
+when you right click on it a system menu would be popuped. To make context menu
+behave correctly on all platforms, you should never custom context menu on
+draggable areas.

renderer/atom_render_view_observer.cc

@@ -12,6 +12,8 @@
 #include "ipc/ipc_message_macros.h"
 #include "renderer/api/atom_renderer_bindings.h"
 #include "renderer/atom_renderer_client.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebDraggableRegion.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "v8/include/v8.h"
 
@@ -76,6 +78,19 @@ void AtomRenderViewObserver::FrameWillClose(WebFrame* frame) {
   vec.erase(std::remove(vec.begin(), vec.end(), frame), vec.end());
 }
 
+void AtomRenderViewObserver::DraggableRegionsChanged(WebKit::WebFrame* frame) {
+  WebKit::WebVector<WebKit::WebDraggableRegion> webregions =
+      frame->document().draggableRegions();
+  std::vector<DraggableRegion> regions;
+  for (size_t i = 0; i < webregions.size(); ++i) {
+    DraggableRegion region;
+    region.bounds = webregions[i].bounds;
+    region.draggable = webregions[i].draggable;
+    regions.push_back(region);
+  }
+  Send(new AtomViewHostMsg_UpdateDraggableRegions(routing_id(), regions));
+}
+
 bool AtomRenderViewObserver::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(AtomRenderViewObserver, message)

renderer/atom_render_view_observer.h

@@ -32,6 +32,7 @@ class AtomRenderViewObserver : content::RenderViewObserver {
 
  private:
   // content::RenderViewObserver implementation.
+  virtual void DraggableRegionsChanged(WebKit::WebFrame* frame) OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   void OnBrowserMessage(const std::string& channel,