Add CefPrintHandler::OnPrintStart callback (issue #1736)

include/capi/cef_print_handler_capi.h

@@ -95,6 +95,15 @@ typedef struct _cef_print_handler_t {
   ///
   cef_base_t base;
 
+  ///
+  // Called when printing has started for the specified |browser|. This function
+  // will be called before the other OnPrint*() functions and irrespective of
+  // how printing was initiated (e.g. cef_browser_host_t::print(), JavaScript
+  // window.print() or PDF extension print button).
+  ///
+  void (CEF_CALLBACK *on_print_start)(struct _cef_print_handler_t* self,
+      struct _cef_browser_t* browser);
+
   ///
   // Synchronize |settings| with client state. If |get_defaults| is true (1)
   // then populate |settings| with the default print settings. Do not keep a

include/cef_print_handler.h

@@ -82,6 +82,15 @@ class CefPrintJobCallback : public virtual CefBase {
 /*--cef(source=client)--*/
 class CefPrintHandler : public virtual CefBase {
  public:
+  ///
+  // Called when printing has started for the specified |browser|. This method
+  // will be called before the other OnPrint*() methods and irrespective of how
+  // printing was initiated (e.g. CefBrowserHost::Print(), JavaScript
+  // window.print() or PDF extension print button).
+  ///
+  /*--cef()--*/
+  virtual void OnPrintStart(CefRefPtr<CefBrowser> browser) =0;
+
   ///
   // Synchronize |settings| with client state. If |get_defaults| is true then
   // populate |settings| with the default print settings. Do not keep a

libcef/browser/content_browser_client.cc

@@ -985,15 +985,7 @@ void CefContentBrowserClient::OverrideWebkitPrefs(
       base::CommandLine::ForCurrentProcess();
 
   CefRefPtr<CefBrowserHostImpl> browser =
-      CefBrowserHostImpl::GetBrowserForHost(rvh);
+      extensions::GetOwnerBrowserForHost(rvh);
-  if (!browser.get() && extensions::ExtensionsEnabled()) {
-    // Retrieve the owner browser, if any.
-    content::WebContents* owner = extensions::GetOwnerForGuestContents(
-        content::WebContents::FromRenderViewHost(rvh));
-    if (owner)
-      browser = CefBrowserHostImpl::GetBrowserForContents(owner);
-  }
-
   if (browser.get()) {
     // Populate WebPreferences based on CefBrowserSettings.
     BrowserToWebSettings(browser->settings(), *prefs);

libcef/browser/extensions/browser_extensions_util.cc

@@ -4,6 +4,8 @@
 
 #include "libcef/browser/extensions/browser_extensions_util.h"
 
+#include "libcef/common/extensions/extensions_util.h"
+
 #include "content/browser/browser_plugin/browser_plugin_embedder.h"
 #include "content/browser/browser_plugin/browser_plugin_guest.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ -55,4 +57,27 @@ content::WebContents* GetOwnerForGuestContents(content::WebContents* guest) {
   return NULL;
 }
 
+CefRefPtr<CefBrowserHostImpl> GetOwnerBrowserForView(int render_process_id,
+                                                     int render_routing_id) {
+  content::RenderViewHost* host =
+      content::RenderViewHost::FromID(render_process_id, render_routing_id);
+  if (host)
+    return GetOwnerBrowserForHost(host);
+  return NULL;
+}
+
+CefRefPtr<CefBrowserHostImpl> GetOwnerBrowserForHost(
+    content::RenderViewHost* host) {
+  CefRefPtr<CefBrowserHostImpl> browser =
+      CefBrowserHostImpl::GetBrowserForHost(host);
+  if (!browser.get() && ExtensionsEnabled()) {
+    // Retrieve the owner browser, if any.
+    content::WebContents* owner = GetOwnerForGuestContents(
+        content::WebContents::FromRenderViewHost(host));
+    if (owner)
+      browser = CefBrowserHostImpl::GetBrowserForContents(owner);
+  }
+  return browser;
+}
+
 }  // namespace extensions

libcef/browser/extensions/browser_extensions_util.h

@@ -7,7 +7,10 @@
 
 #include <vector>
 
+#include "libcef/browser/browser_host_impl.h"
+
 namespace content {
+class RenderViewHost;
 class WebContents;
 }
 
@@ -24,6 +27,15 @@ void GetAllGuestsForOwnerContents(content::WebContents* owner,
 // Returns the WebContents that owns the specified |guest|, if any.
 content::WebContents* GetOwnerForGuestContents(content::WebContents* guest);
 
+// Returns the CefBrowserHostImpl that owns the host identified by the specified
+// view routing IDs, if any.
+CefRefPtr<CefBrowserHostImpl> GetOwnerBrowserForView(int render_process_id,
+                                                     int render_routing_id);
+
+// Returns the CefBrowserHostImpl that owns the specified |host|, if any.
+CefRefPtr<CefBrowserHostImpl> GetOwnerBrowserForHost(
+    content::RenderViewHost* host);
+
 }  // namespace extensions
 
 #endif  // CEF_LIBCEF_BROWSER_EXTENSIONS_BROWSER_EXTENSIONS_UTIL_H_

libcef/browser/printing/print_dialog_linux.cc

@@ -8,6 +8,8 @@
 #include <string>
 #include <vector>
 
+#include "libcef/browser/browser_host_impl.h"
+#include "libcef/browser/extensions/browser_extensions_util.h"
 #include "libcef/browser/print_settings_impl.h"
 #include "libcef/browser/thread_util.h"
 #include "libcef/common/content_client.h"
@@ -134,6 +136,35 @@ gfx::Size CefPrintDialogLinux::GetPdfPaperSize(
   return size;
 }
 
+// static
+void CefPrintDialogLinux::OnPrintStart(int render_process_id,
+                                       int render_routing_id) {
+  if (!CEF_CURRENTLY_ON(CEF_UIT)) {
+    CEF_POST_TASK(CEF_UIT,
+        base::Bind(&CefPrintDialogLinux::OnPrintStart,
+                   render_process_id, render_routing_id));
+    return;
+  }
+
+  CefRefPtr<CefApp> app = CefContentClient::Get()->application();
+  if (!app.get())
+    return;
+
+  CefRefPtr<CefBrowserProcessHandler> browser_handler =
+      app->GetBrowserProcessHandler();
+  if (!browser_handler.get())
+    return;
+
+  CefRefPtr<CefPrintHandler> handler = browser_handler->GetPrintHandler();
+  if (!handler.get())
+    return;
+
+  CefRefPtr<CefBrowserHostImpl> browser =
+      extensions::GetOwnerBrowserForView(render_process_id, render_routing_id);
+  if (browser.get())
+    handler->OnPrintStart(browser.get());
+}
+
 CefPrintDialogLinux::CefPrintDialogLinux(PrintingContextLinux* context)
     : context_(context) {
 }

libcef/browser/printing/print_dialog_linux.h

@@ -37,6 +37,10 @@ class CefPrintDialogLinux
   static gfx::Size GetPdfPaperSize(
     printing::PrintingContextLinux* context);
 
+  // Notify the client when printing has started.
+  static void OnPrintStart(int render_process_id,
+                           int render_routing_id);
+
   // printing::CefPrintDialogLinuxInterface implementation.
   void UseDefaultSettings() override;
   bool UpdateSettings(printing::PrintSettings* settings) override;

libcef/browser/printing/printing_message_filter.cc

@@ -17,6 +17,10 @@
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/child_process_host.h"
 
+#if defined(OS_LINUX)
+#include "libcef/browser/printing/print_dialog_linux.h"
+#endif
+
 using content::BrowserThread;
 
 namespace printing {
@@ -72,6 +76,12 @@ void PrintingMessageFilter::OnIsPrintingEnabled(bool* is_enabled) {
 
 void PrintingMessageFilter::OnGetDefaultPrintSettings(IPC::Message* reply_msg) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+#if defined(OS_LINUX)
+  // Send notification to the client.
+  CefPrintDialogLinux::OnPrintStart(render_process_id_,
+                                    reply_msg->routing_id());
+#endif
+
   scoped_refptr<PrinterQuery> printer_query;
   printer_query = queue_->PopPrinterQuery(0);
   if (!printer_query.get()) {

libcef_dll/cpptoc/print_handler_cpptoc.cc

@@ -11,6 +11,7 @@
 //
 
 #include "libcef_dll/cpptoc/print_handler_cpptoc.h"
+#include "libcef_dll/ctocpp/browser_ctocpp.h"
 #include "libcef_dll/ctocpp/print_dialog_callback_ctocpp.h"
 #include "libcef_dll/ctocpp/print_job_callback_ctocpp.h"
 #include "libcef_dll/ctocpp/print_settings_ctocpp.h"
@@ -20,6 +21,23 @@ namespace {
 
 // MEMBER FUNCTIONS - Body may be edited by hand.
 
+void CEF_CALLBACK print_handler_on_print_start(
+    struct _cef_print_handler_t* self, cef_browser_t* browser) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+
+  // Execute
+  CefPrintHandlerCppToC::Get(self)->OnPrintStart(
+      CefBrowserCToCpp::Wrap(browser));
+}
+
 void CEF_CALLBACK print_handler_on_print_settings(
     struct _cef_print_handler_t* self, struct _cef_print_settings_t* settings,
     int get_defaults) {
@@ -126,6 +144,7 @@ cef_size_t CEF_CALLBACK print_handler_get_pdf_paper_size(
 // CONSTRUCTOR - Do not edit by hand.
 
 CefPrintHandlerCppToC::CefPrintHandlerCppToC() {
+  GetStruct()->on_print_start = print_handler_on_print_start;
   GetStruct()->on_print_settings = print_handler_on_print_settings;
   GetStruct()->on_print_dialog = print_handler_on_print_dialog;
   GetStruct()->on_print_job = print_handler_on_print_job;

libcef_dll/ctocpp/print_handler_ctocpp.cc

@@ -10,6 +10,7 @@
 // for more information.
 //
 
+#include "libcef_dll/cpptoc/browser_cpptoc.h"
 #include "libcef_dll/cpptoc/print_dialog_callback_cpptoc.h"
 #include "libcef_dll/cpptoc/print_job_callback_cpptoc.h"
 #include "libcef_dll/cpptoc/print_settings_cpptoc.h"
@@ -18,6 +19,23 @@
 
 // VIRTUAL METHODS - Body may be edited by hand.
 
+void CefPrintHandlerCToCpp::OnPrintStart(CefRefPtr<CefBrowser> browser) {
+  cef_print_handler_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_print_start))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+
+  // Execute
+  _struct->on_print_start(_struct,
+      CefBrowserCppToC::Wrap(browser));
+}
+
 void CefPrintHandlerCToCpp::OnPrintSettings(
     CefRefPtr<CefPrintSettings> settings, bool get_defaults) {
   cef_print_handler_t* _struct = GetStruct();

libcef_dll/ctocpp/print_handler_ctocpp.h

@@ -31,6 +31,7 @@ class CefPrintHandlerCToCpp
   CefPrintHandlerCToCpp();
 
   // CefPrintHandler methods.
+  void OnPrintStart(CefRefPtr<CefBrowser> browser) override;
   void OnPrintSettings(CefRefPtr<CefPrintSettings> settings,
       bool get_defaults) override;
   bool OnPrintDialog(bool has_selection,

tests/cefclient/browser/print_handler_gtk.cc

@@ -282,6 +282,9 @@ ClientPrintHandlerGtk::ClientPrintHandlerGtk()
       printer_(NULL) {
 }
 
+void ClientPrintHandlerGtk::OnPrintStart(CefRefPtr<CefBrowser> browser) {
+}
+
 void ClientPrintHandlerGtk::OnPrintSettings(
     CefRefPtr<CefPrintSettings> settings,
     bool get_defaults) {

tests/cefclient/browser/print_handler_gtk.h

@@ -19,6 +19,7 @@ class ClientPrintHandlerGtk : public CefPrintHandler {
   ClientPrintHandlerGtk();
 
   // CefPrintHandler methods.
+  void OnPrintStart(CefRefPtr<CefBrowser> browser) OVERRIDE;
   void OnPrintSettings(CefRefPtr<CefPrintSettings> settings,
                        bool get_defaults) OVERRIDE;
   bool OnPrintDialog(