widget/nsDragServiceProxy.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsDragServiceProxy.h"
   8 #include "mozilla/dom/Document.h"
   9 #include "mozilla/dom/BrowserChild.h"
  10 #include "mozilla/gfx/2D.h"
  11 #include "mozilla/UniquePtr.h"
  12 #include "mozilla/Unused.h"
  13 #include "nsContentUtils.h"
  14
  15 using mozilla::CSSIntRegion;
  16 using mozilla::LayoutDeviceIntRect;
  17 using mozilla::Maybe;
  18 using mozilla::Nothing;
  19 using mozilla::Some;
  20 using mozilla::dom::BrowserChild;
  21 using mozilla::gfx::DataSourceSurface;
  22 using mozilla::gfx::SourceSurface;
  23 using mozilla::gfx::SurfaceFormat;
  24 using mozilla::ipc::Shmem;
  25
  26 nsDragServiceProxy::nsDragServiceProxy() = default;
  27
  28 nsDragServiceProxy::~nsDragServiceProxy() = default;
  29
  30 nsresult nsDragServiceProxy::InvokeDragSessionImpl(
  31     nsIArray* aArrayTransferables, const Maybe<CSSIntRegion>& aRegion,
  32     uint32_t aActionType) {
  33   NS_ENSURE_STATE(mSourceDocument->GetDocShell());
  34   BrowserChild* child = BrowserChild::GetFrom(mSourceDocument->GetDocShell());
  35   NS_ENSURE_STATE(child);
  36   nsTArray<mozilla::dom::IPCDataTransfer> dataTransfers;
  37   nsContentUtils::TransferablesToIPCTransferables(
  38       aArrayTransferables, dataTransfers, false, child->Manager(), nullptr);
  39
  40   nsCOMPtr<nsIPrincipal> principal;
  41   if (mSourceNode) {
  42     principal = mSourceNode->NodePrincipal();
  43   }
  44
  45   nsCOMPtr<nsIContentSecurityPolicy> csp;
  46   if (mSourceDocument) {
  47     csp = mSourceDocument->GetCsp();
  48   }
  49
  50   LayoutDeviceIntRect dragRect;
  51   if (mHasImage || mSelection) {
  52     nsPresContext* pc;
  53     RefPtr<SourceSurface> surface;
  54     DrawDrag(mSourceNode, aRegion, mScreenPosition, &dragRect, &surface, &pc);
  55
  56     if (surface) {
  57       RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
  58       if (dataSurface) {
  59         size_t length;
  60         int32_t stride;
  61         Maybe<Shmem> maybeShm = nsContentUtils::GetSurfaceData(
  62             dataSurface, &length, &stride, child);
  63         if (maybeShm.isNothing()) {
  64           return NS_ERROR_FAILURE;
  65         }
  66
  67         auto surfaceData = maybeShm.value();
  68
  69         // Save the surface data to shared memory.
  70         if (!surfaceData.IsReadable() || !surfaceData.get<char>()) {
  71           NS_WARNING("Failed to create shared memory for drag session.");
  72           return NS_ERROR_FAILURE;
  73         }
  74
  75         mozilla::Unused << child->SendInvokeDragSession(
  76             dataTransfers, aActionType, Some(std::move(surfaceData)), stride,
  77             dataSurface->GetFormat(), dragRect, principal, csp);
  78         StartDragSession();
  79         return NS_OK;
  80       }
  81     }
  82   }
  83
  84   mozilla::Unused << child->SendInvokeDragSession(
  85       dataTransfers, aActionType, Nothing(), 0, static_cast<SurfaceFormat>(0),
  86       dragRect, principal, csp);
  87   StartDragSession();
  88   return NS_OK;
  89 }