src/content/browser/web_contents/web_drag_source_win.cc

   1 // Copyright (c) 2012 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 "content/browser/web_contents/web_drag_source_win.h"
   6
   7 #include "base/bind.h"
   8 #include "content/browser/renderer_host/render_view_host_impl.h"
   9 #include "content/browser/web_contents/web_contents_impl.h"
  10 #include "content/browser/web_contents/web_drag_utils_win.h"
  11 #include "content/public/browser/browser_thread.h"
  12 #include "content/public/browser/notification_source.h"
  13 #include "content/public/browser/notification_types.h"
  14 #include "ui/base/dragdrop/os_exchange_data.h"
  15
  16 using WebKit::WebDragOperationNone;
  17
  18 namespace content {
  19 namespace {
  20
  21 static void GetCursorPositions(gfx::NativeWindow wnd, gfx::Point* client,
  22                                gfx::Point* screen) {
  23   POINT cursor_pos;
  24   GetCursorPos(&cursor_pos);
  25   screen->SetPoint(cursor_pos.x, cursor_pos.y);
  26   ScreenToClient(wnd, &cursor_pos);
  27   client->SetPoint(cursor_pos.x, cursor_pos.y);
  28 }
  29
  30 }  // namespace
  31
  32 ///////////////////////////////////////////////////////////////////////////////
  33 // WebDragSource, public:
  34
  35 WebDragSource::WebDragSource(gfx::NativeWindow source_wnd,
  36                              WebContents* web_contents)
  37     : ui::DragSourceWin(),
  38       source_wnd_(source_wnd),
  39       web_contents_(static_cast<WebContentsImpl*>(web_contents)),
  40       effect_(DROPEFFECT_NONE),
  41       data_(NULL) {
  42   registrar_.Add(this, NOTIFICATION_RENDER_VIEW_HOST_CHANGED,
  43                  Source<WebContents>(web_contents));
  44   registrar_.Add(this, NOTIFICATION_WEB_CONTENTS_DISCONNECTED,
  45                  Source<WebContents>(web_contents));
  46 }
  47
  48 WebDragSource::~WebDragSource() {
  49 }
  50
  51 void WebDragSource::OnDragSourceCancel() {
  52   // Delegate to the UI thread if we do drag-and-drop in the background thread.
  53   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
  54     BrowserThread::PostTask(
  55         BrowserThread::UI, FROM_HERE,
  56         base::Bind(&WebDragSource::OnDragSourceCancel, this));
  57     return;
  58   }
  59
  60   if (!web_contents_)
  61     return;
  62
  63   gfx::Point client;
  64   gfx::Point screen;
  65   GetCursorPositions(source_wnd_, &client, &screen);
  66   web_contents_->DragSourceEndedAt(client.x(), client.y(),
  67                                    screen.x(), screen.y(),
  68                                    WebDragOperationNone);
  69 }
  70
  71 void WebDragSource::OnDragSourceDrop() {
  72   DCHECK(data_);
  73   data_->SetInDragLoop(false);
  74   // On Windows, we check for drag end in IDropSource::QueryContinueDrag which
  75   // happens before IDropTarget::Drop is called. HTML5 requires the "dragend"
  76   // event to happen after the "drop" event. Since  Windows calls these two
  77   // directly after each other we can just post a task to handle the
  78   // OnDragSourceDrop after the current task.
  79   BrowserThread::PostTask(
  80       BrowserThread::UI, FROM_HERE,
  81       base::Bind(&WebDragSource::DelayedOnDragSourceDrop, this));
  82 }
  83
  84 void WebDragSource::DelayedOnDragSourceDrop() {
  85   if (!web_contents_)
  86     return;
  87
  88   gfx::Point client;
  89   gfx::Point screen;
  90   GetCursorPositions(source_wnd_, &client, &screen);
  91   web_contents_->DragSourceEndedAt(client.x(), client.y(), screen.x(),
  92                                    screen.y(), WinDragOpToWebDragOp(effect_));
  93 }
  94
  95 void WebDragSource::OnDragSourceMove() {
  96   // Delegate to the UI thread if we do drag-and-drop in the background thread.
  97   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
  98     BrowserThread::PostTask(
  99         BrowserThread::UI, FROM_HERE,
 100         base::Bind(&WebDragSource::OnDragSourceMove, this));
 101     return;
 102   }
 103
 104   if (!web_contents_)
 105     return;
 106
 107   gfx::Point client;
 108   gfx::Point screen;
 109   GetCursorPositions(source_wnd_, &client, &screen);
 110   web_contents_->DragSourceMovedTo(client.x(), client.y(),
 111                                    screen.x(), screen.y());
 112 }
 113
 114 void WebDragSource::Observe(int type,
 115                             const NotificationSource& source,
 116                             const NotificationDetails& details) {
 117   if (type == NOTIFICATION_RENDER_VIEW_HOST_CHANGED) {
 118     // When the WebContents get swapped, our render view host goes away.
 119     // That's OK, we can continue the drag, we just can't send messages back to
 120     // our drag source.
 121     web_contents_ = NULL;
 122   } else if (type == NOTIFICATION_WEB_CONTENTS_DISCONNECTED) {
 123     // This could be possible when we close the tab and the source is still
 124     // being used in DoDragDrop at the time that the virtual file is being
 125     // downloaded.
 126     web_contents_ = NULL;
 127   }
 128 }
 129
 130 }  // namespace content