Update print handler on Linux (#403) and fix print dialog error (#435)

Author: cztomczak

src/cef_v59..v66_changes.txt

@@ -64,7 +64,7 @@ MISC
 ----
 + Compare src/client_handler/dialog_handler_gtk.cpp (and .h) with upstream
   cefclient files
-- In subprocess/print_handler_gtk.cpp use GetWindow implementation
++ In subprocess/print_handler_gtk.cpp use GetWindow implementation
   from x11.cpp
 
 NEW FEATURES

src/client_handler/x11.cpp

@@ -2,6 +2,9 @@
 // All rights reserved. Licensed under BSD 3-clause license.
 // Project website: https://github.com/cztomczak/cefpython
 
+// NOTE: This file is also used by "subprocess" and "libcefpythonapp"
+//       targets during build.
+
 #include "x11.h"
 #include "include/base/cef_logging.h"
 
@@ -24,6 +27,7 @@ void InstallX11ErrorHandlers() {
     // Copied from upstream cefclient.
     // Install xlib error handlers so that the application won't be terminated
     // on non-fatal errors. Must be done after initializing GTK.
+    LOG(INFO) << "[Browser process] Install X11 error handlers";
     XSetErrorHandler(XErrorHandlerImpl);
     XSetIOErrorHandler(XIOErrorHandlerImpl);
 }
@@ -48,6 +52,7 @@ void SetX11WindowTitle(CefRefPtr<CefBrowser> browser, char* title) {
 }
 
 GtkWindow* CefBrowser_GetGtkWindow(CefRefPtr<CefBrowser> browser) {
+  // TODO: Should return NULL when using the Views framework
   // -- REWRITTEN FOR CEF PYTHON USE CASE --
   // X11 window handle
   ::Window xwindow = browser->GetHost()->GetWindowHandle();
@@ -68,6 +73,10 @@ GtkWindow* CefBrowser_GetGtkWindow(CefRefPtr<CefBrowser> browser) {
     // internally, so GTK wasn't yet initialized and must do it
     // now, so that display is available. Also must install X11
     // error handlers to avoid 'BadWindow' errors.
+    // --
+    // A similar code is in cefpython_app.cpp and it might already
+    // been executed. If making changes here, make changes there
+    // as well.
     LOG(INFO) << "[Browser process] Initialize GTK";
     gtk_init(0, NULL);
     InstallX11ErrorHandlers();

src/subprocess/Makefile

@@ -35,8 +35,8 @@ else ifeq ($(UNAME_S), Darwin)
 endif
 
 ifeq ($(UNAME_S), Linux)
-	CPP_FILES = print_handler_gtk.cpp
-	LIBS = -lcef -lgobject-2.0 -lglib-2.0 -lgtk-x11-2.0
+	CPP_FILES = print_handler_gtk.cpp ../client_handler/x11.cpp
+	LIBS = -lcef -lX11 -lgobject-2.0 -lglib-2.0 -lgtk-x11-2.0 -lgdk-x11-2.0
 else ifeq ($(UNAME_S), Darwin)
 	CPP_FILES =
 	# Include framework before libcef_dll_wrapper

src/subprocess/Makefile-libcefpythonapp

@@ -12,7 +12,7 @@ UNAME_S = $(shell uname -s)
 CCFLAGS = -fPIC -DBROWSER_PROCESS $(CEF_CCFLAGS)
 
 ifeq ($(UNAME_S), Linux)
-	SRC_MORE = print_handler_gtk.cpp \
+	SRC_MORE = print_handler_gtk.cpp ../client_handler/x11.cpp \
 			main_message_loop/main_message_loop_external_pump_linux.cpp
 else ifeq ($(UNAME_S), Darwin)
     SRC_MORE = main_message_loop/main_message_loop_external_pump_mac.mm

src/subprocess/cefpython_app.cpp

@@ -21,6 +21,7 @@
 #include <gtk/gtk.h>
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
+#include "client_handler/x11.h"
 #include "print_handler_gtk.h"
 #endif  // OS_LINUX
 #endif  // BROWSER_PROCESS
@@ -221,10 +222,14 @@ CefRefPtr<CefPrintHandler> CefPythonApp::GetPrintHandler() {
 #if defined(OS_LINUX)
     // For print handler to work GTK must be initialized. This is
     // required for some of the examples.
+    // --
+    // A similar code is in client_handler/x11.cpp. If making changes here,
+    // make changes there as well.
     GdkDisplay* gdk_display = gdk_display_get_default();
     if (!gdk_display) {
         LOG(INFO) << "[Browser process] Initialize GTK";
         gtk_init(0, NULL);
+        InstallX11ErrorHandlers();
     }
 #endif
 #endif

src/subprocess/print_handler_gtk.cpp

@@ -19,6 +19,8 @@
 #include "include/wrapper/cef_helpers.h"
 #include "include/wrapper/cef_closure_task.h"
 
+#include "client_handler/x11.h"
+
 namespace {
 
 // CUPS Duplex attribute and values.
@@ -374,7 +376,7 @@ struct ClientPrintHandlerGtk::PrintHandler {
                      CefRefPtr<CefPrintDialogCallback> callback) {
     dialog_callback_ = callback;
 
-    GtkWindow* parent = GetWindow();
+    GtkWindow* parent = CefBrowser_GetGtkWindow(browser_);
     // TODO(estade): We need a window title here.
     dialog_ = gtk_print_unix_dialog_new(NULL, parent);
     g_signal_connect(dialog_, "delete-event",
@@ -429,18 +431,6 @@ struct ClientPrintHandlerGtk::PrintHandler {
   }
 
  private:
-  // Returns the GtkWindow* for the browser. Will return NULL when using the
-  // Views framework.
-  GtkWindow* GetWindow() {
-    // TODO(cefpython): Test the code that is commented out whether it works
-    /*
-    CefWindowHandle hwnd = browser_->GetWindowHandle();
-    if (hwnd)
-      return GTK_WINDOW(hwnd);
-    */
-    return NULL;
-  }
-
   void OnDialogResponse(GtkDialog* dialog, gint response_id) {
     int num_matched_handlers = g_signal_handlers_disconnect_by_func(
         dialog_, reinterpret_cast<gpointer>(&OnDialogResponseThunk), this);