Print Preview: Properly handle window.print().

chrome/browser/printing/print_view_manager.cc

Index: chrome/browser/printing/print_view_manager.cc
diff --git a/chrome/browser/printing/print_view_manager.cc b/chrome/browser/printing/print_view_manager.cc
index 77dda243a46ab497e19bf7569fad4cbcfca4ebb8..e5187ea8c9ec3502eac4776a715b70e5f5cd61a9 100644
--- a/chrome/browser/printing/print_view_manager.cc
+++ b/chrome/browser/printing/print_view_manager.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/printing/print_view_manager.h"
 
 #include "base/bind.h"
+#include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ -50,6 +51,13 @@ void ReleasePrinterQuery(int cookie) {
   }
 }
 
+// Keeps track of pending scripted print preview closures.
+// No locking, only access on the UI thread.
+typedef std::map<RenderProcessHost*, base::Closure>
+    ScriptedPrintPreviewClosureMap;
+static base::LazyInstance<ScriptedPrintPreviewClosureMap>
+    g_scripted_print_preview_closure_map(base::LINKER_INITIALIZED);
+
 }  // namespace
 
 namespace printing {
@@ -61,13 +69,16 @@ PrintViewManager::PrintViewManager(TabContentsWrapper* tab)
       printing_succeeded_(false),
       inside_inner_message_loop_(false),
       observer_(NULL),
-      cookie_(0) {
+      cookie_(0),
+      print_preview_state_(NOT_PREVIEWING),
+      scripted_print_preview_rph_(NULL) {
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   expecting_first_page_ = true;
 #endif
 }
 
 PrintViewManager::~PrintViewManager() {
+  DCHECK_EQ(NOT_PREVIEWING, print_preview_state_);

[vandebo (ex-Chrome), 2011/11/10 23:59:59]

What if you close a tab/window while previewing?

[Lei Zhang, 2011/11/11 11:45:11]

RemoveInitiatorTab() will call PrintPreviewDone() first.

   ReleasePrinterQuery(cookie_);
   DisconnectFromCurrentPrintJob();
 }
@@ -103,9 +114,34 @@ bool PrintViewManager::AdvancedPrintNow() {
 }
 
 bool PrintViewManager::PrintPreviewNow() {
+  if (print_preview_state_ != NOT_PREVIEWING) {
+    NOTREACHED();
+    return false;
+  }
+  print_preview_state_ = USER_INITIATED_PREVIEW;
   return PrintNowInternal(new PrintMsg_InitiatePrintPreview(routing_id()));
 }
 
+void PrintViewManager::PrintPreviewDone() {
+  BrowserThread::CurrentlyOn(BrowserThread::UI);
+
+  // Check for spurious call.

[vandebo (ex-Chrome), 2011/11/10 23:59:59]

This makes me sad.  If you can explain why there might be a spurious call that
we should ignore, explaining that here would make me less sad.

[Lei Zhang, 2011/11/11 11:45:11]

This is a defensive move. I'll check whether it's needed or not.

[Lei Zhang, 2011/11/11 22:34:26]

Got rid of this and turned it into a DCHECK.

+  if (print_preview_state_ == NOT_PREVIEWING)
+    return;
+
+  if (print_preview_state_ == SCRIPTED_PREVIEW) {
+    ScriptedPrintPreviewClosureMap& map =
+        g_scripted_print_preview_closure_map.Get();
+    ScriptedPrintPreviewClosureMap::iterator it =
+        map.find(scripted_print_preview_rph_);
+    CHECK(it != map.end());
+    it->second.Run();
+    map.erase(scripted_print_preview_rph_);
+    scripted_print_preview_rph_ = NULL;
+  }
+  print_preview_state_ = NOT_PREVIEWING;
+}
+
 void PrintViewManager::PreviewPrintingRequestCancelled() {
   if (!tab_contents())
     return;
@@ -227,6 +263,35 @@ void PrintViewManager::OnPrintingFailed(int cookie) {
       content::NotificationService::NoDetails());
 }
 
+void PrintViewManager::OnScriptedPrintPreview(IPC::Message* reply_msg) {
+  BrowserThread::CurrentlyOn(BrowserThread::UI);
+  if (print_preview_state_ != NOT_PREVIEWING) {
+    // If a user initiated print dialog is already open, ignore the scripted
+    // print message.
+    DCHECK_EQ(USER_INITIATED_PREVIEW, print_preview_state_);
+    Send(reply_msg);
+    return;
+  }
+
+  print_preview_state_ = SCRIPTED_PREVIEW;
+  scripted_print_preview_rph_ = tab_contents()->render_view_host()->process();
+  base::Closure callback =
+      base::Bind(&PrintViewManager::OnScriptedPrintPreviewReply,
+                 base::Unretained(this),
+                 reply_msg);
+  ScriptedPrintPreviewClosureMap& map =
+      g_scripted_print_preview_closure_map.Get();
+  CHECK_EQ(0U, map.count(scripted_print_preview_rph_));
+  map[scripted_print_preview_rph_] = callback;
+
+  PrintNowInternal(new PrintMsg_InitiatePrintPreview(routing_id()));

[vandebo (ex-Chrome), 2011/11/10 23:59:59]

This will trigger GetPrintFrame(), but the caller already set the print frame.

[Lei Zhang, 2011/11/11 11:45:11]

I'm surprised this didn't blow up, fixed.

+}
+
+void PrintViewManager::OnScriptedPrintPreviewReply(IPC::Message* reply_msg) {
+  BrowserThread::CurrentlyOn(BrowserThread::UI);
+  Send(reply_msg);
+}
+
 bool PrintViewManager::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintViewManager, message)
@@ -237,6 +302,8 @@ bool PrintViewManager::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidShowPrintDialog, OnDidShowPrintDialog)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidPrintPage, OnDidPrintPage)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintingFailed, OnPrintingFailed)
+    IPC_MESSAGE_HANDLER_DELAY_REPLY(PrintHostMsg_ScriptedPrintPreview,
+                                    OnScriptedPrintPreview)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;