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

8 files changed, 223 insertions, 3 deletions

diff --git a/chrome/browser/chrome_plugin_host.cc b/chrome/browser/chrome_plugin_host.cc
index 08ad7e7..0d21cdd 100644
--- a/chrome/browser/chrome_plugin_host.cc
+++ b/chrome/browser/chrome_plugin_host.cc
@@ -527,6 +527,20 @@ CPError STDCALL CPB_HandleCommand(
   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) {
+  *identity = *event_id = 0;
+  NOTREACHED() << "Should not be called in browser process.";
+  return CPERR_FAILURE;
+}
+
+CPError STDCALL CPB_SetDropEffect(
+    CPID id, CPBrowsingContext context, struct NPObject* event, int effect) {
+  NOTREACHED() << "Should not be called in browser process.";
+  return CPERR_FAILURE;
+}
+
 //
 // Functions related to network interception
 //
@@ -768,6 +782,8 @@ CPBrowserFuncs* GetCPBrowserFuncsForBrowser() {
     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;
 
     request_funcs.size = sizeof(request_funcs);
     request_funcs.start_request = CPR_StartRequest;
diff --git a/chrome/common/chrome_plugin_api.h b/chrome/common/chrome_plugin_api.h
index 384e9c2..c10985a 100644
--- a/chrome/common/chrome_plugin_api.h
+++ b/chrome/common/chrome_plugin_api.h
@@ -30,7 +30,7 @@ extern "C" {
 // The current version of the API, used by the 'version' field of CPPluginFuncs
 // and CPBrowserFuncs.
 #define CP_MAJOR_VERSION 0
-#define CP_MINOR_VERSION 9
+#define CP_MINOR_VERSION 10
 #define CP_VERSION       ((CP_MAJOR_VERSION << 8) | (CP_MINOR_VERSION))
 
 #define CP_GET_MAJOR_VERSION(version) ((version & 0xff00) >> 8)
@@ -414,6 +414,37 @@ typedef void (STDCALL *CPP_OnFileDialogResultFunc)(void *data,
                                                    const char **files,
                                                    uint32 files_len);
 
+// Asks the browser to verify that NPObject* 'event' is the current drag event
+// the browser is dispatching, and extract drag data from the event if so.  On
+// success, returns the drag 'identity' (an up-counter that the browser chrome
+// increases each time a user drag enters a renderer tab), the drag 'event_id'
+// and the 'drag_type' being a utf8 encoded string with values "Files", "Text"
+// or "URL".  If 'add_data' is true, also return the 'drag_data', again a utf8
+// encoded string with the data for the drag type.  For drag type "Files", the
+// data is a backspace delimited list of file paths.
+//
+// The call fails with a CPError if 'event' is an invalid drag event, and sets
+// the 'identity' and 'event_id' to 0.  Note: on success, non-NULL 'drag_type'
+// and 'drag_data' should be freed with CPB_Free() when done.
+typedef CPError (STDCALL *CPB_GetDragDataFunc)(
+    CPID id, CPBrowsingContext context, struct NPObject* event, bool add_data,
+    int32* identity, int32* event_id, char** drag_type, char** drag_data);
+
+// Asks the browser to verify that NPObject* 'event' is the current drag event
+// the browser is dispatching and show the requested drop 'effect' if so.  The
+// browser displays drop effects during dragenter and dragover events, to give
+// user visible feedback (with a drag cursor, typically) to indicate whether a
+// subsequent drop event will succeed or not.  The implementation supports the
+// so-called "copy" and "none" effects.  When 'effect' is non-zero, the "copy"
+// effect is shown.  Otherwise, the "none" effect is shown, which prevents the
+// subsequent drop event from succeeding.  Returns CPError on failure, meaning
+// the 'event' is an invalid drag event.
+//
+// Note: 'effect' is int to allow for new effects in future.  For example, the
+// HTML5-defined drop effects "move" and "link".
+typedef CPError (STDCALL *CPB_SetDropEffectFunc)(
+    CPID id, CPBrowsingContext context, struct NPObject* event, int effect);
+
 // Function table for issuing requests using via the other side's network stack.
 // For the plugin, this functions deal with issuing requests through the
 // browser.  For the browser, these functions deal with allowing the plugin to
@@ -488,6 +519,8 @@ typedef struct _CPBrowserFuncs {
   CPB_SendSyncMessageFunc send_sync_message;
   CPB_PluginThreadAsyncCallFunc plugin_thread_async_call;
   CPB_OpenFileDialogFunc open_file_dialog;
+  CPB_GetDragDataFunc get_drag_data;
+  CPB_SetDropEffectFunc set_drop_effect;
 } CPBrowserFuncs;
 
 
diff --git a/chrome/common/plugin_messages_internal.h b/chrome/common/plugin_messages_internal.h
index ed2e219..25e7b5a 100644
--- a/chrome/common/plugin_messages_internal.h
+++ b/chrome/common/plugin_messages_internal.h
@@ -261,6 +261,17 @@ IPC_BEGIN_MESSAGES(PluginHost)
                               std::string /* json_arguments */,
                               std::string /* json_retval */)
 
+  IPC_SYNC_MESSAGE_ROUTED2_2(PluginHostMsg_GetDragData,
+                             NPVariant_Param /* event */,
+                             bool /* add_data */,
+                             std::vector<NPVariant_Param> /* result_values */,
+                             bool /* result_success */)
+
+  IPC_SYNC_MESSAGE_ROUTED2_1(PluginHostMsg_SetDropEffect,
+                             NPVariant_Param /* event */,
+                             int /* effect */,
+                             bool /* result_success */)
+
   IPC_MESSAGE_ROUTED1(PluginHostMsg_MissingPluginStatus,
                       int /* status */)
 
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
 
diff --git a/chrome/renderer/webplugin_delegate_proxy.cc b/chrome/renderer/webplugin_delegate_proxy.cc
index 4e05f1d..a9cb138 100644
--- a/chrome/renderer/webplugin_delegate_proxy.cc
+++ b/chrome/renderer/webplugin_delegate_proxy.cc
@@ -23,6 +23,7 @@
 #include "chrome/common/render_messages.h"
 #include "chrome/plugin/npobject_proxy.h"
 #include "chrome/plugin/npobject_stub.h"
+#include "chrome/plugin/npobject_util.h"
 #include "chrome/renderer/render_thread.h"
 #include "chrome/renderer/render_view.h"
 #include "googleurl/src/gurl.h"
@@ -339,6 +340,8 @@ void WebPluginDelegateProxy::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(PluginHostMsg_GetCookies, OnGetCookies)
     IPC_MESSAGE_HANDLER(PluginHostMsg_ShowModalHTMLDialog,
                         OnShowModalHTMLDialog)
+    IPC_MESSAGE_HANDLER(PluginHostMsg_GetDragData, OnGetDragData);
+    IPC_MESSAGE_HANDLER(PluginHostMsg_SetDropEffect, OnSetDropEffect);
     IPC_MESSAGE_HANDLER(PluginHostMsg_MissingPluginStatus,
                         OnMissingPluginStatus)
     IPC_MESSAGE_HANDLER(PluginHostMsg_URLRequest, OnHandleURLRequest)
@@ -726,6 +729,58 @@ void WebPluginDelegateProxy::OnShowModalHTMLDialog(
                                       json_retval);
 }
 
+void WebPluginDelegateProxy::OnGetDragData(const NPVariant_Param& object,
+                                           bool add_data,
+                                           std::vector<NPVariant_Param>* values,
+                                           bool* success) {
+  DCHECK(values && success);
+  *success = false;
+
+  WebView* webview = NULL;
+  if (render_view_)
+    webview = render_view_->webview();
+  if (!webview)
+    return;
+
+  NPVariant results[4];
+  NPObject* event = reinterpret_cast<NPObject*>(object.npobject_pointer);
+  const int32 drag_id = webview->GetDragIdentity();
+  if (!drag_id || !webkit_glue::GetDragData(event, add_data, &results[1]))
+    return;
+
+  INT32_TO_NPVARIANT(drag_id, results[0]);
+  values->push_back(NPVariant_Param());
+  CreateNPVariantParam(results[0], NULL, &values->back(), false, NULL);
+  values->push_back(NPVariant_Param());
+  CreateNPVariantParam(results[1], NULL, &values->back(), false, NULL);
+  values->push_back(NPVariant_Param());
+  CreateNPVariantParam(results[2], NULL, &values->back(), false, NULL);
+  values->push_back(NPVariant_Param());
+  CreateNPVariantParam(results[3], NULL, &values->back(), add_data, NULL);
+
+  *success = true;
+}
+
+void WebPluginDelegateProxy::OnSetDropEffect(const NPVariant_Param& object,
+                                             int effect,
+                                             bool* success) {
+  DCHECK(success);
+  *success = false;
+
+  WebView* webview = NULL;
+  if (render_view_)
+    webview = render_view_->webview();
+  if (!webview)
+    return;
+
+  NPObject* event = reinterpret_cast<NPObject*>(object.npobject_pointer);
+  const int32 drag_id = webview->GetDragIdentity();
+  if (!drag_id || !webkit_glue::IsDragEvent(event))
+    return;
+
+  *success = webview->SetDropEffect(effect != 0);
+}
+
 void WebPluginDelegateProxy::OnMissingPluginStatus(int status) {
   if (render_view_)
     render_view_->OnMissingPluginStatus(this, status);
@@ -825,8 +880,8 @@ void WebPluginDelegateProxy::OnCancelDocumentLoad() {
 }
 
 void WebPluginDelegateProxy::OnInitiateHTTPRangeRequest(
-   const std::string& url, const std::string& range_info,
-   intptr_t existing_stream, bool notify_needed, intptr_t notify_data) {
+    const std::string& url, const std::string& range_info,
+    intptr_t existing_stream, bool notify_needed, intptr_t notify_data) {
   plugin_->InitiateHTTPRangeRequest(url.c_str(), range_info.c_str(),
                                     existing_stream, notify_needed,
                                     notify_data);
diff --git a/chrome/renderer/webplugin_delegate_proxy.h b/chrome/renderer/webplugin_delegate_proxy.h
index 99bd1e1..6baa42a 100644
--- a/chrome/renderer/webplugin_delegate_proxy.h
+++ b/chrome/renderer/webplugin_delegate_proxy.h
@@ -6,6 +6,7 @@
 #define CHROME_RENDERER_WEBPLUGIN_DELEGATE_PROXY_H__
 
 #include <string>
+#include <vector>
 
 #include "base/gfx/rect.h"
 #include "base/gfx/native_widget_types.h"
@@ -19,6 +20,7 @@
 class GURL;
 struct NPObject;
 class NPObjectStub;
+struct NPVariant_Param;
 struct PluginHostMsg_URLRequest_Params;
 class RenderView;
 class SkBitmap;
@@ -125,6 +127,10 @@ class WebPluginDelegateProxy : public WebPluginDelegate,
   void OnShowModalHTMLDialog(const GURL& url, int width, int height,
                              const std::string& json_arguments,
                              std::string* json_retval);
+  void OnGetDragData(const NPVariant_Param& event, bool add_data,
+                     std::vector<NPVariant_Param>* values, bool* success);
+  void OnSetDropEffect(const NPVariant_Param& event, int effect,
+                       bool* success);
   void OnMissingPluginStatus(int status);
   void OnGetCPBrowsingContext(uint32* context);
   void OnCancelDocumentLoad();