Fix printing on Linux (#238) and fix "undefined symbol" error (#230).

Fix OnBeforePluginLoad and change args, see docs.

Add -std=gnu++11 flag to catch OVERRIDE errors.

Minor enhancements to makefiles.

Update build instructions - install python dependencies to make sure
that the right version of Cython is installed (must be exactly 0.19.2).

docs/Build-instructions.md

@@ -39,22 +39,26 @@ binaries from GH releases.
 
 3) Install packages: `sudo apt-get install python-dev cmake g++`
 
-4) Download 64-bit Linux binaries and libraries from
+4) Install python dependencies by executing:
+  `cd cefpython/tools/ && pip install -r requirements.txt`
+  (Cython 0.19.2 required - the version must match exactly)
+
+5) Download 64-bit Linux binaries and libraries from
    [GH releases](https://github.com/cztomczak/cefpython/releases)
    tagged 'v51-upstream'.
 
 
-5) Copy "bin/*" to "cefpython/src/linux/binaries_64bit/"
+6) Copy "bin/*" to "cefpython/src/linux/binaries_64bit/"
 
-6) Copy "lib/*" to "cefpython/src/linux/setup/lib_64bit/" (create dir)
+7) Copy "lib/*" to "cefpython/src/linux/setup/lib_64bit/" (create dir)
 
-7) Build cefpython:
+8) Build cefpython:
 ```
 cd cefpython/src/linux/
 python compile.py 51.0
 ```
 
-8) As of writing only "pygtk_.py" and "kivy_.py" examples are working
+9) As of writing only "pygtk_.py" and "kivy_.py" examples are working
 
 
 ## Requirements

docs/api/RequestHandler.md

@@ -210,13 +210,30 @@ to use [LoadHandler](LoadHandler.md)::OnLoadError() when implementing this on Li
 | Parameter | Type |
 | --- | --- |
 | browser | [Browser](Browser.md) |
-| url | string |
-| policyUrl | string |
+| mime_type | string |
+| plugin_url | string |
+| top_origin_url | string |
 | info | [WebPluginInfo](WebPluginInfo.md) |
 | __Return__ | bool |
 
-Called on the browser process IO thread before a plugin is loaded. Return
-True to block loading of the plugin.
+Description from upstream CEF:
+> Called on multiple browser process threads before a plugin instance is
+> loaded. |mime_type| is the mime type of the plugin that will be loaded.
+> |plugin_url| is the content URL that the plugin will load and may be empty.
+> |top_origin_url| is the URL for the top-level frame that contains the
+> plugin when loading a specific plugin instance or empty when building the
+> initial list of enabled plugins for 'navigator.plugins' JavaScript state.
+> |plugin_info| includes additional information about the plugin that will be
+> loaded. |plugin_policy| is the recommended policy. Modify |plugin_policy|
+> and return true to change the policy. Return false to use the recommended
+> policy. The default plugin policy can be set at runtime using the
+> `--plugin-policy=[allow|detect|block]` command-line flag. Decisions to mark
+> a plugin as disabled by setting |plugin_policy| to PLUGIN_POLICY_DISABLED
+> may be cached when |top_origin_url| is empty. To purge the plugin list
+> cache and potentially trigger new calls to this method call
+> CefRequestContext::PurgePluginListCache.
+
+Return True to block loading of the plugin.
 
 This callback will be executed during browser creation, thus you must call [cefpython](cefpython.md).SetGlobalClientCallback() to use it. The callback name was prefixed with "`_`" to distinguish this special behavior.
 

src/client_handler/Makefile

@@ -6,16 +6,15 @@
 
 # Cython compiler options:
 # -fPIC -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions \
-# 	-Wl,-z,relro
+# -Wl,-z,relro
 
 UNAME_S = $(shell uname -s)
-
 CC = g++
-CCFLAGS = -g -fPIC -Wall -Werror $(CEF_CCFLAGS)
+CCFLAGS = -fPIC -std=gnu++11 -Wall -Werror $(CEF_CCFLAGS)
 
 SRC = client_handler.cpp cookie_visitor.cpp resource_handler.cpp \
-		web_request_client.cpp string_visitor.cpp request_context_handler.cpp \
-		task.cpp x11.cpp
+	web_request_client.cpp string_visitor.cpp request_context_handler.cpp \
+	task.cpp x11.cpp
 
 OBJ = $(SRC:.cpp=.o)
 
@@ -25,26 +24,39 @@ endif
 
 OUT = libclient_handler.a
 
-INC = -I./../ -I/usr/include/python2.7 -I/usr/include/gtk-2.0 \
-	-I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/gtk-2.0/include \
-	-I/usr/lib/i386-linux-gnu/glib-2.0/include -I/usr/include/cairo \
-	-I/usr/include/pango-1.0 -I/usr/include/gdk-pixbuf-2.0 \
-	-I/usr/include/atk-1.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include \
+INC = -I./../ -I/usr/include/python2.7 \
+	-I/usr/include/gtk-2.0 \
+	-I/usr/include/gtk-unix-print-2.0 \
+	-I/usr/include/glib-2.0 \
+	-I/usr/include/cairo \
+	-I/usr/include/pango-1.0 \
+	-I/usr/include/gdk-pixbuf-2.0 \
+	-I/usr/include/atk-1.0 \
 	-I/usr/lib/x86_64-linux-gnu/gtk-2.0/include \
-	-I/usr/lib64/glib-2.0/include -I/usr/lib64/gtk-2.0/include \
-	-I/usr/lib/glib-2.0/include -I/usr/lib/gtk-2.0/include
+	-I/usr/lib/x86_64-linux-gnu/gtk-unix-print-2.0 \
+	-I/usr/lib/x86_64-linux-gnu/glib-2.0/include \
+	-I/usr/lib/i386-linux-gnu/gtk-2.0/include \
+	-I/usr/lib/i386-linux-gnu/gtk-unix-print-2.0 \
+	-I/usr/lib/i386-linux-gnu/glib-2.0/include \
+	-I/usr/lib64/gtk-2.0/include \
+	-I/usr/lib64/gtk-unix-print-2.0 \
+	-I/usr/lib64/glib-2.0/include \
+	-I/usr/lib/gtk-2.0/include \
+	-I/usr/lib/gtk-2.0/gtk-unix-print-2.0 \
+	-I/usr/lib/glib-2.0/include
 
 .cpp.o:
-	@echo [Makefile] Building $@ from $<...
+	@echo [CLIENT HANDLER] Building $@ from $<...
 	$(CC) $(CCFLAGS) $(INC) -c $< -o $@
 
 $(OUT): $(OBJ)
-	@echo [Makefile] Creating library $(OUT) from $(OBJ)...
+	@echo [CLIENT HANDLER] Creating library $(OUT) from $(OBJ)...
 	ar rcs $(OUT) $(OBJ)
 
 util_mac.o: util_mac.mm
-	@echo [Makefile] Building $@ from $<...
+	@echo [CLIENT HANDLER] Building $@ from $<...
 	$(CC) $(CCFLAGS) $(INC) -c $< -o $@
 
 clean:
+	@echo [CLIENT HANDLER] Cleaning...
 	rm *.o *.a

src/client_handler/client_handler.cpp

@@ -327,15 +327,6 @@ void ClientHandler::OnProtocolExecution(CefRefPtr<CefBrowser> browser,
     RequestHandler_OnProtocolExecution(browser, url, allow_os_execution);
 }
 
-bool ClientHandler::OnBeforePluginLoad(CefRefPtr<CefBrowser> browser,
-                              const CefString& url,
-                              const CefString& policy_url,
-                              CefRefPtr<CefWebPluginInfo> info) {
-    REQUIRE_IO_THREAD();
-    return RequestHandler_OnBeforePluginLoad(browser, url, policy_url, info);
-    // Default: return false;
-}
-
 bool ClientHandler::OnCertificateError(
                       CefRefPtr<CefBrowser> browser, // not used
                       cef_errorcode_t cert_error,

src/client_handler/client_handler.h

@@ -194,12 +194,6 @@ class ClientHandler :
   virtual void OnProtocolExecution(CefRefPtr<CefBrowser> browser,
                                    const CefString& url,
                                    bool& allow_os_execution) OVERRIDE;
-
-  virtual bool OnBeforePluginLoad(CefRefPtr<CefBrowser> browser,
-                                  const CefString& url,
-                                  const CefString& policy_url,
-                                  CefRefPtr<CefWebPluginInfo> info) OVERRIDE;
-
   virtual bool OnCertificateError(
       CefRefPtr<CefBrowser> browser, // not used
       cef_errorcode_t cert_error,

src/client_handler/request_context_handler.cpp

@@ -21,3 +21,15 @@ CefRefPtr<CefCookieManager> RequestContextHandler::GetCookieManager() {
     }    
     // Default: return NULL.
 }
+
+bool RequestContextHandler::OnBeforePluginLoad(
+                        const CefString& mime_type,
+                        const CefString& plugin_url,
+                        const CefString& top_origin_url,
+                        CefRefPtr<CefWebPluginInfo> plugin_info,
+                        PluginPolicy* plugin_policy) {
+    // Called on multiple threads
+    return RequestHandler_OnBeforePluginLoad(browser_, mime_type, plugin_url,
+                                             top_origin_url, plugin_info,
+                                             plugin_policy);
+}

src/client_handler/request_context_handler.h

@@ -13,6 +13,10 @@
 class RequestContextHandler :
         public CefRequestContextHandler
 {
+private:
+    CefRefPtr<CefBrowser> browser_;
+    typedef cef_plugin_policy_t PluginPolicy;
+
 public:
     // Browser may be NULL when instantiated from cefpython.CreateBrowserSync.
     // In such case SetBrowser will be called after browser creation.
@@ -26,9 +30,11 @@ class RequestContextHandler :
     }
 
     virtual CefRefPtr<CefCookieManager> GetCookieManager() OVERRIDE;
-
-private:
-    CefRefPtr<CefBrowser> browser_;
+    virtual bool OnBeforePluginLoad(const CefString& mime_type,
+                                  const CefString& plugin_url,
+                                  const CefString& top_origin_url,
+                                  CefRefPtr<CefWebPluginInfo> plugin_info,
+                                  PluginPolicy* plugin_policy) OVERRIDE;
 
 private:
     IMPLEMENT_REFCOUNTING(RequestContextHandler);

src/cython_includes/cef_types.pxd

@@ -328,3 +328,9 @@ cdef extern from "include/internal/cef_types.h":
         PK_LOCAL_APP_DATA,
         PK_USER_DATA,
     ctypedef cef_path_key_t PathKey
+
+    ctypedef enum cef_plugin_policy_t:
+        PLUGIN_POLICY_ALLOW,
+        PLUGIN_POLICY_DETECT_IMPORTANT,
+        PLUGIN_POLICY_BLOCK,
+        PLUGIN_POLICY_DISABLE,

src/linux/binaries_32bit/wxpython.py

@@ -493,15 +493,17 @@ def OnProtocolExecution(self, browser, url, allowExecutionOut):
             print("[wxpython.py] Magnet link allowed!")
             allowExecutionOut[0] = True
 
-    def _OnBeforePluginLoad(self, browser, url, policyUrl, info):
+    def _OnBeforePluginLoad(self, browser, mimeType, pluginUrl, topOriginUrl,
+                            info):
         # This is a global callback set using SetGlobalClientCallback().
         # Plugins are loaded on demand, only when website requires it,
         # the same plugin may be called multiple times.
-        # This callback is called on the IO thread, thus print messages
+        # This callback is called on various threads, thus print messages
         # may not be visible.
         print("[wxpython.py] RequestHandler::_OnBeforePluginLoad()")
-        print("    url = %s" % url)
-        print("    policy url = %s" % policyUrl)
+        print("    mimeType = %s" % mimeType)
+        print("    pluginUrl = %s" % pluginUrl)
+        print("    topOriginUrl = %s" % topOriginUrl)
         print("    info.GetName() = %s" % info.GetName())
         print("    info.GetPath() = %s" % info.GetPath())
         print("    info.GetVersion() = %s" % info.GetVersion())

src/linux/binaries_64bit/wxpython.py

@@ -480,15 +480,17 @@ def OnProtocolExecution(self, browser, url, allowExecutionOut):
             print("[wxpython.py] Magnet link allowed!")
             allowExecutionOut[0] = True
 
-    def _OnBeforePluginLoad(self, browser, url, policyUrl, info):
+    def _OnBeforePluginLoad(self, browser, mimeType, pluginUrl, topOriginUrl,
+                            info):
         # This is a global callback set using SetGlobalClientCallback().
         # Plugins are loaded on demand, only when website requires it,
         # the same plugin may be called multiple times.
-        # This callback is called on the IO thread, thus print messages
+        # This callback is called on various threads, thus print messages
         # may not be visible.
         print("[wxpython.py] RequestHandler::_OnBeforePluginLoad()")
-        print("    url = %s" % url)
-        print("    policy url = %s" % policyUrl)
+        print("    mimeType = %s" % mimeType)
+        print("    pluginUrl = %s" % pluginUrl)
+        print("    topOriginUrl = %s" % topOriginUrl)
         print("    info.GetName() = %s" % info.GetName())
         print("    info.GetPath() = %s" % info.GetPath())
         print("    info.GetVersion() = %s" % info.GetVersion())

src/linux/setup/cefpython.h

@@ -38,7 +38,7 @@ __PYX_EXTERN_C DL_IMPORT(bool) RequestHandler_GetAuthCredentials(CefRefPtr<CefBr
 __PYX_EXTERN_C DL_IMPORT(bool) RequestHandler_OnQuotaRequest(CefRefPtr<CefBrowser>, CefString const &, int64, CefRefPtr<CefRequestCallback>);
 __PYX_EXTERN_C DL_IMPORT(CefRefPtr<CefCookieManager>) RequestHandler_GetCookieManager(CefRefPtr<CefBrowser>, CefString const &);
 __PYX_EXTERN_C DL_IMPORT(void) RequestHandler_OnProtocolExecution(CefRefPtr<CefBrowser>, CefString const &, bool &);
-__PYX_EXTERN_C DL_IMPORT(bool) RequestHandler_OnBeforePluginLoad(CefRefPtr<CefBrowser>, CefString const &, CefString const &, CefRefPtr<CefWebPluginInfo>);
+__PYX_EXTERN_C DL_IMPORT(bool) RequestHandler_OnBeforePluginLoad(CefRefPtr<CefBrowser>, CefString const &, CefString const &, CefString const &, CefRefPtr<CefWebPluginInfo>, cef_plugin_policy_t *);
 __PYX_EXTERN_C DL_IMPORT(bool) RequestHandler_OnCertificateError(int, CefString const &, CefRefPtr<CefRequestCallback>);
 __PYX_EXTERN_C DL_IMPORT(void) RequestHandler_OnRendererProcessTerminated(CefRefPtr<CefBrowser>, cef_termination_status_t);
 __PYX_EXTERN_C DL_IMPORT(void) RequestHandler_OnPluginCrashed(CefRefPtr<CefBrowser>, CefString const &);

src/linux/setup/setup.py

@@ -50,51 +50,62 @@ def CompileTimeConstants():
         r'./../../cython_includes/',
         '/usr/include/gtk-2.0',
         '/usr/include/glib-2.0',
+        '/usr/include/gtk-unix-print-2.0',
         '/usr/include/cairo',
         '/usr/include/pango-1.0',
         '/usr/include/gdk-pixbuf-2.0',
         '/usr/include/atk-1.0',
         # Ubuntu
-        '/usr/lib/x86_64-linux-gnu/glib-2.0/include',
         '/usr/lib/x86_64-linux-gnu/gtk-2.0/include',
+        '/usr/lib/x86_64-linux-gnu/gtk-unix-print-2.0',
+        '/usr/lib/x86_64-linux-gnu/glib-2.0/include',
         '/usr/lib/i386-linux-gnu/gtk-2.0/include',
+        '/usr/lib/i386-linux-gnu/gtk-unix-print-2.0',
         '/usr/lib/i386-linux-gnu/glib-2.0/include',
         # Fedora
-        '/usr/lib64/glib-2.0/include',
         '/usr/lib64/gtk-2.0/include',
-        '/usr/lib/glib-2.0/include',
+        '/usr/lib64/gtk-unix-print-2.0',
+        '/usr/lib64/glib-2.0/include',
         '/usr/lib/gtk-2.0/include',
+        '/usr/lib/gtk-2.0/gtk-unix-print-2.0',
+        '/usr/lib/glib-2.0/include',
     ],
 
     # http_authentication not implemented on Linux.
     library_dirs=[
-        r'./../binaries_%s' % BITS,
         r'./lib_%s' % BITS,
         r'./../../client_handler/',
         r'./../../subprocess/', # libcefpythonapp
         r'./../../cpp_utils/'
     ],
 
+    # Static libraries only. Order is important, if library A depends on B,
+    # then B must be included before A.
     libraries=[
-        # Feed cefpythonapp before cef/cef_dll_wrapper to the linker,
-        # otherwise an "undefined symbol" error may occur when importing
-        # the cefpython .so module (Issue #230).
+        'X11',
+        'gobject-2.0',
+        'glib-2.0',
+        'gtk-x11-2.0',
+        # CEF and CEF Python libraries
+        'cef_dll_wrapper',
         'cefpythonapp',
         'client_handler',
         'cpp_utils',
-        'cef',
-        'cef_dll_wrapper',
-        'gtk-x11-2.0',
     ],
 
-    # Loading libcef.so will only work when running scripts from the same
-    # directory that libcef.so resides in when you put "./" in here.
+    # When you put "./" in here, loading of libcef.so will only work when
+    # running scripts from the same directory that libcef.so resides in.
     # runtime_library_dirs=[
     #    './'
     #],
 
-    extra_compile_args=[],
-    extra_link_args=[],
+    # Fix "ImportError ... undefined symbol ..." caused by CEF's include/base/
+    # headers by adding the -flto flag (Issue #230). Unfortunately -flto
+    # prolongs compilation time significantly.
+    # More on the other flags: https://stackoverflow.com/questions/6687630/
+    extra_compile_args=['-flto', '-fdata-sections', '-ffunction-sections',
+                        '-std=gnu++11'],
+    extra_link_args=['-flto', '-Wl,--gc-sections'],
 
     # Defining macros:
     # define_macros = [("UNICODE","1"), ("_UNICODE","1"), ]

src/mac/binaries_32bit/wxpython.py

@@ -543,15 +543,17 @@ def OnProtocolExecution(self, browser, url, allowExecutionOut):
             print("[wxpython.py] Magnet link allowed!")
             allowExecutionOut[0] = True
 
-    def _OnBeforePluginLoad(self, browser, url, policyUrl, info):
+    def _OnBeforePluginLoad(self, browser, mimeType, pluginUrl, topOriginUrl,
+                            info):
         # This is a global callback set using SetGlobalClientCallback().
         # Plugins are loaded on demand, only when website requires it,
         # the same plugin may be called multiple times.
-        # This callback is called on the IO thread, thus print messages
+        # This callback is called on various threads, thus print messages
         # may not be visible.
         print("[wxpython.py] RequestHandler::_OnBeforePluginLoad()")
-        print("    url = %s" % url)
-        print("    policy url = %s" % policyUrl)
+        print("    mimeType = %s" % mimeType)
+        print("    pluginUrl = %s" % pluginUrl)
+        print("    topOriginUrl = %s" % topOriginUrl)
         print("    info.GetName() = %s" % info.GetName())
         print("    info.GetPath() = %s" % info.GetPath())
         print("    info.GetVersion() = %s" % info.GetVersion())

src/mac/binaries_64bit/wxpython.py

@@ -543,15 +543,17 @@ def OnProtocolExecution(self, browser, url, allowExecutionOut):
             print("[wxpython.py] Magnet link allowed!")
             allowExecutionOut[0] = True
 
-    def _OnBeforePluginLoad(self, browser, url, policyUrl, info):
+    def _OnBeforePluginLoad(self, browser, mimeType, pluginUrl, topOriginUrl,
+                            info):
         # This is a global callback set using SetGlobalClientCallback().
         # Plugins are loaded on demand, only when website requires it,
         # the same plugin may be called multiple times.
-        # This callback is called on the IO thread, thus print messages
+        # This callback is called on various threads, thus print messages
         # may not be visible.
         print("[wxpython.py] RequestHandler::_OnBeforePluginLoad()")
-        print("    url = %s" % url)
-        print("    policy url = %s" % policyUrl)
+        print("    mimeType = %s" % mimeType)
+        print("    pluginUrl = %s" % pluginUrl)
+        print("    topOriginUrl = %s" % topOriginUrl)
         print("    info.GetName() = %s" % info.GetName())
         print("    info.GetPath() = %s" % info.GetPath())
         print("    info.GetVersion() = %s" % info.GetVersion())