adds transparency

atom/browser/api/atom_api_web_contents.cc

@@ -314,9 +314,12 @@ WebContents::WebContents(v8::Isolate* isolate,
     params.guest_delegate = guest_delegate_.get();
     web_contents = content::WebContents::Create(params);
   } else if (IsOffScreen()) {
+    bool transparent = false;
+    options.Get("transparent", &transparent);
+
     content::WebContents::CreateParams params(session->browser_context());
 
-    auto view = new OffScreenWebContentsView();
+    auto view = new OffScreenWebContentsView(transparent);
     params.view = view;
     params.delegate_view = view;
 

atom/browser/api/atom_api_window.cc

@@ -79,6 +79,10 @@ Window::Window(v8::Isolate* isolate, const mate::Dictionary& options) {
   if (options.Get(options::kBackgroundColor, &value))
     web_preferences.Set(options::kBackgroundColor, value);
 
+  v8::Local<v8::Value> transparent;
+  if (options.Get("transparent", &transparent))
+    web_preferences.Set("transparent", transparent);
+
   // Creates the WebContents used by BrowserWindow.
   auto web_contents = WebContents::Create(isolate, web_preferences);
   web_contents_.Reset(isolate, web_contents.ToV8());

atom/browser/osr_render_widget_host_view.cc

@@ -336,13 +336,15 @@ class AtomBeginFrameTimer : public cc::DelayBasedTimeSourceClient {
 };
 
 OffScreenRenderWidgetHostView::OffScreenRenderWidgetHostView(
-  content::RenderWidgetHost* host, NativeWindow* native_window):
+  const bool transparent, content::RenderWidgetHost* host,
+  NativeWindow* native_window):
     render_widget_host_(content::RenderWidgetHostImpl::From(host)),
     native_window_(native_window),
     software_output_device_(NULL),
     callback_(nullptr),
     frame_rate_(60),
     frame_rate_threshold_ms_(0),
+    transparent_(transparent),
     scale_factor_(kDefaultScaleFactor),
     is_showing_(!render_widget_host_->is_hidden()),
     size_(native_window->GetSize()),
@@ -530,6 +532,17 @@ gfx::Rect OffScreenRenderWidgetHostView::GetViewBounds() const {
   return gfx::Rect(size_);
 }
 
+void OffScreenRenderWidgetHostView::SetBackgroundColor(SkColor color) {
+  if (transparent_)
+    color = SkColorSetARGB(SK_AlphaTRANSPARENT, 0, 0, 0);
+
+  content::RenderWidgetHostViewBase::SetBackgroundColor(color);
+
+  const bool opaque = !transparent_ && GetBackgroundOpaque();
+  if (render_widget_host_)
+    render_widget_host_->SetBackgroundOpaque(opaque);
+}
+
 gfx::Size OffScreenRenderWidgetHostView::GetVisibleViewportSize() const {
   return size_;
 }
@@ -765,6 +778,15 @@ void OffScreenRenderWidgetHostView::DelegatedFrameHostUpdateVSyncParameters(
   render_widget_host_->UpdateVSyncParameters(timebase, interval);
 }
 
+bool OffScreenRenderWidgetHostView::InstallTransparency() {
+  if (transparent_) {
+    SetBackgroundColor(SkColor());
+    compositor_->SetHostHasTransparentBackground(true);
+    return true;
+  }
+  return false;
+}
+
 std::unique_ptr<cc::SoftwareOutputDevice>
   OffScreenRenderWidgetHostView::CreateSoftwareOutputDevice(
     ui::Compositor* compositor) {
@@ -772,7 +794,7 @@ std::unique_ptr<cc::SoftwareOutputDevice>
   DCHECK(!copy_frame_generator_);
   DCHECK(!software_output_device_);
 
-  software_output_device_ = new OffScreenOutputDevice(true,
+  software_output_device_ = new OffScreenOutputDevice(transparent_,
       base::Bind(&OffScreenRenderWidgetHostView::OnPaint,
                  weak_ptr_factory_.GetWeakPtr()));
   return base::WrapUnique(software_output_device_);

atom/browser/osr_render_widget_host_view.h

@@ -63,7 +63,8 @@ class OffScreenRenderWidgetHostView:
   public ui::CompositorDelegate,
   public content::DelegatedFrameHostClient {
  public:
-  OffScreenRenderWidgetHostView(content::RenderWidgetHost*, NativeWindow*);
+  OffScreenRenderWidgetHostView(const bool transparent,
+    content::RenderWidgetHost*, NativeWindow*);
   ~OffScreenRenderWidgetHostView();
 
   // content::RenderWidgetHostView
@@ -85,6 +86,7 @@ class OffScreenRenderWidgetHostView:
   gfx::Rect GetViewBounds(void) const override;
   gfx::Size GetVisibleViewportSize() const override;
   void SetInsets(const gfx::Insets&) override;
+  void SetBackgroundColor(SkColor color) override;
   bool LockMouse(void) override;
   void UnlockMouse(void) override;
   bool GetScreenColorProfile(std::vector<char>*) override;
@@ -165,6 +167,8 @@ class OffScreenRenderWidgetHostView:
     const base::TimeTicks &, const base::TimeDelta &) override;
   void SetBeginFrameSource(cc::BeginFrameSource* source) override;
 
+  bool InstallTransparency();
+
   bool IsAutoResizeEnabled() const;
 
   std::unique_ptr<cc::SoftwareOutputDevice> CreateSoftwareOutputDevice(
@@ -221,6 +225,7 @@ private:
 
   base::Time last_time_;
 
+  const bool transparent_;
   float scale_factor_;
   bool is_showing_;
   gfx::Vector2dF last_scroll_offset_;

atom/browser/osr_render_widget_host_view_mac.mm

@@ -9,7 +9,8 @@
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accelerated_widget_mac/accelerated_widget_mac.h"
 
-ui::AcceleratedWidgetMac* atom::OffScreenRenderWidgetHostView::GetAcceleratedWidgetMac()
+ui::AcceleratedWidgetMac*
+  atom::OffScreenRenderWidgetHostView::GetAcceleratedWidgetMac()
     const {
   if (browser_compositor_)
     return browser_compositor_->accelerated_widget_mac();

atom/browser/osr_web_contents_view.cc

@@ -3,12 +3,12 @@
 // found in the LICENSE file.
 
 #include "atom/browser/osr_web_contents_view.h"
-#include "atom/browser/osr_render_widget_host_view.h"
 
 namespace atom {
 
-OffScreenWebContentsView::OffScreenWebContentsView():
-    web_contents_(nullptr) {
+OffScreenWebContentsView::OffScreenWebContentsView(bool transparent):
+  transparent_(transparent),
+  web_contents_(nullptr) {
 }
 
 OffScreenWebContentsView::~OffScreenWebContentsView() {
@@ -66,7 +66,7 @@ content::RenderWidgetHostViewBase*
   OffScreenWebContentsView::CreateViewForWidget(
     content::RenderWidgetHost* render_widget_host, bool is_guest_view_hack) {
   auto relay = NativeWindowRelay::FromWebContents(web_contents_);
-  view_ = new OffScreenRenderWidgetHostView(render_widget_host,
+  view_ = new OffScreenRenderWidgetHostView(transparent_, render_widget_host,
     relay->window.get());
   return view_;
 }
@@ -75,7 +75,7 @@ content::RenderWidgetHostViewBase*
   OffScreenWebContentsView::CreateViewForPopupWidget(
     content::RenderWidgetHost* render_widget_host) {
   auto relay = NativeWindowRelay::FromWebContents(web_contents_);
-  view_ = new OffScreenRenderWidgetHostView(render_widget_host,
+  view_ = new OffScreenRenderWidgetHostView(transparent_, render_widget_host,
     relay->window.get());
   return view_;
 }
@@ -85,6 +85,8 @@ void OffScreenWebContentsView::SetPageTitle(const base::string16& title) {
 
 void OffScreenWebContentsView::RenderViewCreated(
     content::RenderViewHost* host) {
+  if (view_)
+    view_->InstallTransparency();
 }
 
 void OffScreenWebContentsView::RenderViewSwappedIn(

atom/browser/osr_web_contents_view.h

@@ -9,12 +9,14 @@
 #include "content/browser/web_contents/web_contents_view.h"
 #include "content/public/browser/web_contents.h"
 
+#include "atom/browser/osr_render_widget_host_view.h"
+
 namespace atom {
 
 class OffScreenWebContentsView : public content::WebContentsView,
                                  public content::RenderViewHostDelegateView {
  public:
-  OffScreenWebContentsView();
+  OffScreenWebContentsView(bool transparent);
   ~OffScreenWebContentsView();
 
   void SetWebContents(content::WebContents*);
@@ -60,7 +62,9 @@ class OffScreenWebContentsView : public content::WebContentsView,
   void UpdateDragCursor(blink::WebDragOperation operation) override;
 
  private:
-  content::RenderWidgetHostViewBase* view_;
+  const bool transparent_;
+
+  OffScreenRenderWidgetHostView* view_;
   content::WebContents* web_contents_;
 };