CPAPI gears drag drop and renderer IPC....

CPAPI (0.10) functions for gears drag drop; one to extract the
drag type/data given an NPObject *event, one to override the
drop effect (drag cursor).

Gears drag drop API receives a browser event as an NPObject* so
the event is untrusted.  Provide IPC calls to the renderer so
gears can pass the event to renderer/V8 for checking, prior to
drag type/data extraction, or the setting of the drop effect.

V8 event checking is a TODO(noel), http://mondrian/10947778 for
the CPAPI (0.10) change submitted to gears.

BUG=7995

Original patch by Noel Gordon via:
http://codereview.chromium.org/99240
Review URL: http://codereview.chromium.org/115280

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@15986 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 99 insertions, 0 deletions

diff --git a/chrome/plugin/chrome_plugin_host.cc b/chrome/plugin/chrome_plugin_host.cc
index 992afcf..4874e41 100644
--- a/chrome/plugin/chrome_plugin_host.cc
+++ b/chrome/plugin/chrome_plugin_host.cc
@@ -313,6 +313,41 @@ CPError STDCALL CPB_ShowHtmlDialog(
   return CPERR_FAILURE;
 }
 
+CPError STDCALL CPB_GetDragData(
+    CPID id, CPBrowsingContext context, struct NPObject* event, bool add_data,
+    int32 *identity, int32 *event_id, char **drag_type, char **drag_data) {
+  CHECK(ChromePluginLib::IsPluginThread());
+
+  *identity = *event_id = 0;
+  WebPluginProxy* webplugin = WebPluginProxy::FromCPBrowsingContext(context);
+  if (!event || !webplugin)
+    return CPERR_INVALID_PARAMETER;
+
+  std::string type_str, data_str;
+  if (!webplugin->GetDragData(event, add_data,
+                              identity, event_id, &type_str, &data_str)) {
+    return CPERR_FAILURE;
+  }
+
+  if (add_data)
+    *drag_data = CPB_StringDup(CPB_Alloc, data_str);
+  *drag_type = CPB_StringDup(CPB_Alloc, type_str);
+  return CPERR_SUCCESS;
+}
+
+CPError STDCALL CPB_SetDropEffect(
+    CPID id, CPBrowsingContext context, struct NPObject* event, int effect) {
+  CHECK(ChromePluginLib::IsPluginThread());
+
+  WebPluginProxy* webplugin = WebPluginProxy::FromCPBrowsingContext(context);
+  if (!event || !webplugin)
+    return CPERR_INVALID_PARAMETER;
+
+  if (webplugin->SetDropEffect(event, effect))
+    return CPERR_SUCCESS;
+  return CPERR_FAILURE;
+}
+
 CPError STDCALL CPB_GetCommandLineArguments(
     CPID id, CPBrowsingContext context, const char* url, char** arguments) {
   CHECK(ChromePluginLib::IsPluginThread());
@@ -597,6 +632,8 @@ CPBrowserFuncs* GetCPBrowserFuncsForPlugin() {
     browser_funcs.send_sync_message = CPB_SendSyncMessage;
     browser_funcs.plugin_thread_async_call = CPB_PluginThreadAsyncCall;
     browser_funcs.open_file_dialog = CPB_OpenFileDialog;
+    browser_funcs.get_drag_data = CPB_GetDragData;
+    browser_funcs.set_drop_effect = CPB_SetDropEffect;
 
     browser_funcs.request_funcs = &request_funcs;
     browser_funcs.response_funcs = &response_funcs;
diff --git a/chrome/plugin/webplugin_proxy.cc b/chrome/plugin/webplugin_proxy.cc
index 38f3af6..6efff09 100644
--- a/chrome/plugin/webplugin_proxy.cc
+++ b/chrome/plugin/webplugin_proxy.cc
@@ -305,6 +305,58 @@ void WebPluginProxy::HandleURLRequest(const char *method,
   Send(new PluginHostMsg_URLRequest(route_id_, params));
 }
 
+bool WebPluginProxy::GetDragData(struct NPObject* event, bool add_data,
+                                 int32* identity, int32* event_id,
+                                 std::string* type, std::string* data) {
+  DCHECK(event);
+  NPObjectProxy* proxy = NPObjectProxy::GetProxy(event);
+  if (!proxy)  // NPObject* event should have/be a renderer proxy.
+    return false;
+
+  NPVariant_Param event_param;
+  event_param.type = NPVARIANT_PARAM_OBJECT_POINTER;
+  event_param.npobject_pointer = proxy->npobject_ptr();
+  if (!event_param.npobject_pointer)
+    return false;
+
+  std::vector<NPVariant_Param> values;
+  bool success = false;
+  Send(new PluginHostMsg_GetDragData(route_id_, event_param, add_data,
+                                     &values, &success));
+  if (!success)
+    return false;
+
+  DCHECK(values.size() == 4);
+  DCHECK(values[0].type == NPVARIANT_PARAM_INT);
+  *identity = static_cast<int32>(values[0].int_value);
+  DCHECK(values[1].type == NPVARIANT_PARAM_INT);
+  *event_id = static_cast<int32>(values[1].int_value);
+  DCHECK(values[2].type == NPVARIANT_PARAM_STRING);
+  type->swap(values[2].string_value);
+  if (add_data && (values[3].type == NPVARIANT_PARAM_STRING))
+    data->swap(values[3].string_value);
+
+  return true;
+}
+
+bool WebPluginProxy::SetDropEffect(struct NPObject* event, int effect) {
+  DCHECK(event);
+  NPObjectProxy* proxy = NPObjectProxy::GetProxy(event);
+  if (!proxy)  // NPObject* event should have/be a renderer proxy.
+    return false;
+
+  NPVariant_Param event_param;
+  event_param.type = NPVARIANT_PARAM_OBJECT_POINTER;
+  event_param.npobject_pointer = proxy->npobject_ptr();
+  if (!event_param.npobject_pointer)
+    return false;
+
+  bool success = false;
+  Send(new PluginHostMsg_SetDropEffect(route_id_, event_param, effect,
+                                       &success));
+  return success;
+}
+
 void WebPluginProxy::Paint(const gfx::Rect& rect) {
 #if defined(OS_WIN)
   if (!windowless_hdc_)
diff --git a/chrome/plugin/webplugin_proxy.h b/chrome/plugin/webplugin_proxy.h
index 2822fa8..e5594f0 100644
--- a/chrome/plugin/webplugin_proxy.h
+++ b/chrome/plugin/webplugin_proxy.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_PLUGIN_PLUGIN_WEBPLUGIN_PROXY_H__
 #define CHROME_PLUGIN_PLUGIN_WEBPLUGIN_PROXY_H__
 
+#include <string>
+
 #include "base/hash_tables.h"
 #include "base/ref_counted.h"
 #include "base/scoped_handle.h"
@@ -55,6 +57,14 @@ class WebPluginProxy : public WebPlugin {
   void ShowModalHTMLDialog(const GURL& url, int width, int height,
                            const std::string& json_arguments,
                            std::string* json_retval);
+
+  // Called by gears over the CPAPI interface to verify that the given event is
+  // the current (javascript) drag event the browser is dispatching, and return
+  // the drag data, or control the drop effect (drag cursor), if so.
+  bool GetDragData(struct NPObject* event, bool add_data, int32* identity,
+                   int32* event_id, std::string* type, std::string* data);
+  bool SetDropEffect(struct NPObject* event, int effect);
+
   void OnMissingPluginStatus(int status);
   // class-specific methods