ports/cef: Use the CEF translator tool to generate the full set of CEF

bindings.

This replaces hand-implemented CEF bindings with proper Rust wrappers
automatically generated from the C++ headers. This means that, whenever
CEF's C++ headers change, we can easily generate both the appropriate C
API and the appropriate Rust API. It eliminates much of the hand-written
unsafe code within the CEF port, because the CEF translator tool now
knows how to generate Rust smart pointer wrappers for each class that
corrently perform reference counting.

Additionally, this commit adds utility macros (located in `macros.rs`)
that make it easier to correctly expose Rust objects as CEF objects.
They handle the marshaling of objects between Rust and CEF properly.
The net result of this is that you can write mostly-natural-looking Rust
in the CEF port and interact with it with a natural-looking C++ API on
the embedding side.

This setup relies on the branch of CEF located here:

    https://github.com/pcwalton/chromium-embedded-framework

To regenerate, follow the instructions in `ports/cef/README.md`. For
convenience, and because I don't anticipate the API to change much, I
have vendored in all of the appropriate interfaces.

ports/cef/interfaces/cef_jsdialog_handler.rs

@@ -0,0 +1,455 @@
+// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not be edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+
+#![allow(non_snake_case, unused_imports)]
+
+use eutil;
+use interfaces;
+use types;
+use wrappers::CefWrap;
+
+use libc;
+use std::collections::HashMap;
+use std::ptr;
+
+//
+// Callback structure used for asynchronous continuation of JavaScript dialog
+// requests.
+//
+#[repr(C)]
+pub struct _cef_jsdialog_callback_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Continue the JS dialog request. Set |success| to true (1) if the OK button
+  // was pressed. The |user_input| value should be specified for prompt dialogs.
+  //
+  pub cont: Option<extern "C" fn(this: *mut cef_jsdialog_callback_t,
+      success: libc::c_int, user_input: *const types::cef_string_t) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  ref_count: uint,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+} 
+
+pub type cef_jsdialog_callback_t = _cef_jsdialog_callback_t;
+
+
+//
+// Callback structure used for asynchronous continuation of JavaScript dialog
+// requests.
+//
+pub struct CefJSDialogCallback {
+  c_object: *mut cef_jsdialog_callback_t,
+}
+
+impl Clone for CefJSDialogCallback {
+  fn clone(&self) -> CefJSDialogCallback{
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefJSDialogCallback {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefJSDialogCallback {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefJSDialogCallback {
+  pub unsafe fn from_c_object(c_object: *mut cef_jsdialog_callback_t) -> CefJSDialogCallback {
+    CefJSDialogCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_callback_t) -> CefJSDialogCallback {
+    if !c_object.is_null() {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefJSDialogCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_jsdialog_callback_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_callback_t {
+    unsafe {
+      if !self.c_object.is_null() {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null()
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null()
+  }
+
+  //
+  // Continue the JS dialog request. Set |success| to true (1) if the OK button
+  // was pressed. The |user_input| value should be specified for prompt dialogs.
+  //
+  pub fn cont(&self, success: libc::c_int, user_input: &str) -> () {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).cont.unwrap())(
+          self.c_object,
+          CefWrap::to_c(success),
+          CefWrap::to_c(user_input)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_jsdialog_callback_t> for CefJSDialogCallback {
+  fn to_c(rust_object: CefJSDialogCallback) -> *mut cef_jsdialog_callback_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_jsdialog_callback_t) -> CefJSDialogCallback {
+    CefJSDialogCallback::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_jsdialog_callback_t> for Option<CefJSDialogCallback> {
+  fn to_c(rust_object: Option<CefJSDialogCallback>) -> *mut cef_jsdialog_callback_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_jsdialog_callback_t) -> Option<CefJSDialogCallback> {
+    if c_object.is_null() {
+      None
+    } else {
+      Some(CefJSDialogCallback::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
+//
+// Implement this structure to handle events related to JavaScript dialogs. The
+// functions of this structure will be called on the UI thread.
+//
+#[repr(C)]
+pub struct _cef_jsdialog_handler_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Called to run a JavaScript dialog. The |default_prompt_text| value will be
+  // specified for prompt dialogs only. Set |suppress_message| to true (1) and
+  // return false (0) to suppress the message (suppressing messages is
+  // preferable to immediately executing the callback as this is used to detect
+  // presumably malicious behavior like spamming alert messages in
+  // onbeforeunload). Set |suppress_message| to false (0) and return false (0)
+  // to use the default implementation (the default implementation will show one
+  // modal dialog at a time and suppress any additional dialog requests until
+  // the displayed dialog is dismissed). Return true (1) if the application will
+  // use a custom dialog or if the callback has been executed immediately.
+  // Custom dialogs may be either modal or modeless. If a custom dialog is used
+  // the application must execute |callback| once the custom dialog is
+  // dismissed.
+  //
+  pub on_jsdialog: Option<extern "C" fn(this: *mut cef_jsdialog_handler_t,
+      browser: *mut interfaces::cef_browser_t,
+      origin_url: *const types::cef_string_t,
+      accept_lang: *const types::cef_string_t,
+      dialog_type: types::cef_jsdialog_type_t,
+      message_text: *const types::cef_string_t,
+      default_prompt_text: *const types::cef_string_t,
+      callback: *mut interfaces::cef_jsdialog_callback_t,
+      suppress_message: *mut libc::c_int) -> libc::c_int>,
+
+  //
+  // Called to run a dialog asking the user if they want to leave a page. Return
+  // false (0) to use the default dialog implementation. Return true (1) if the
+  // application will use a custom dialog or if the callback has been executed
+  // immediately. Custom dialogs may be either modal or modeless. If a custom
+  // dialog is used the application must execute |callback| once the custom
+  // dialog is dismissed.
+  //
+  pub on_before_unload_dialog: Option<extern "C" fn(
+      this: *mut cef_jsdialog_handler_t,
+      browser: *mut interfaces::cef_browser_t,
+      message_text: *const types::cef_string_t, is_reload: libc::c_int,
+      callback: *mut interfaces::cef_jsdialog_callback_t) -> libc::c_int>,
+
+  //
+  // Called to cancel any pending dialogs and reset any saved dialog state. Will
+  // be called due to events like page navigation irregardless of whether any
+  // dialogs are currently pending.
+  //
+  pub on_reset_dialog_state: Option<extern "C" fn(
+      this: *mut cef_jsdialog_handler_t,
+      browser: *mut interfaces::cef_browser_t) -> ()>,
+
+  //
+  // Called when the default implementation dialog is closed.
+  //
+  pub on_dialog_closed: Option<extern "C" fn(this: *mut cef_jsdialog_handler_t,
+      browser: *mut interfaces::cef_browser_t) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  ref_count: uint,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+} 
+
+pub type cef_jsdialog_handler_t = _cef_jsdialog_handler_t;
+
+
+//
+// Implement this structure to handle events related to JavaScript dialogs. The
+// functions of this structure will be called on the UI thread.
+//
+pub struct CefJSDialogHandler {
+  c_object: *mut cef_jsdialog_handler_t,
+}
+
+impl Clone for CefJSDialogHandler {
+  fn clone(&self) -> CefJSDialogHandler{
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefJSDialogHandler {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefJSDialogHandler {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefJSDialogHandler {
+  pub unsafe fn from_c_object(c_object: *mut cef_jsdialog_handler_t) -> CefJSDialogHandler {
+    CefJSDialogHandler {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_handler_t) -> CefJSDialogHandler {
+    if !c_object.is_null() {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefJSDialogHandler {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_jsdialog_handler_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_handler_t {
+    unsafe {
+      if !self.c_object.is_null() {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null()
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null()
+  }
+
+  //
+  // Called to run a JavaScript dialog. The |default_prompt_text| value will be
+  // specified for prompt dialogs only. Set |suppress_message| to true (1) and
+  // return false (0) to suppress the message (suppressing messages is
+  // preferable to immediately executing the callback as this is used to detect
+  // presumably malicious behavior like spamming alert messages in
+  // onbeforeunload). Set |suppress_message| to false (0) and return false (0)
+  // to use the default implementation (the default implementation will show one
+  // modal dialog at a time and suppress any additional dialog requests until
+  // the displayed dialog is dismissed). Return true (1) if the application will
+  // use a custom dialog or if the callback has been executed immediately.
+  // Custom dialogs may be either modal or modeless. If a custom dialog is used
+  // the application must execute |callback| once the custom dialog is
+  // dismissed.
+  //
+  pub fn on_jsdialog(&self, browser: interfaces::CefBrowser, origin_url: &str,
+      accept_lang: &str, dialog_type: types::cef_jsdialog_type_t,
+      message_text: &str, default_prompt_text: &str,
+      callback: interfaces::CefJSDialogCallback,
+      suppress_message: &mut libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_jsdialog.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(origin_url),
+          CefWrap::to_c(accept_lang),
+          CefWrap::to_c(dialog_type),
+          CefWrap::to_c(message_text),
+          CefWrap::to_c(default_prompt_text),
+          CefWrap::to_c(callback),
+          CefWrap::to_c(suppress_message)))
+    }
+  }
+
+  //
+  // Called to run a dialog asking the user if they want to leave a page. Return
+  // false (0) to use the default dialog implementation. Return true (1) if the
+  // application will use a custom dialog or if the callback has been executed
+  // immediately. Custom dialogs may be either modal or modeless. If a custom
+  // dialog is used the application must execute |callback| once the custom
+  // dialog is dismissed.
+  //
+  pub fn on_before_unload_dialog(&self, browser: interfaces::CefBrowser,
+      message_text: &str, is_reload: libc::c_int,
+      callback: interfaces::CefJSDialogCallback) -> libc::c_int {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_before_unload_dialog.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(message_text),
+          CefWrap::to_c(is_reload),
+          CefWrap::to_c(callback)))
+    }
+  }
+
+  //
+  // Called to cancel any pending dialogs and reset any saved dialog state. Will
+  // be called due to events like page navigation irregardless of whether any
+  // dialogs are currently pending.
+  //
+  pub fn on_reset_dialog_state(&self, browser: interfaces::CefBrowser) -> () {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_reset_dialog_state.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser)))
+    }
+  }
+
+  //
+  // Called when the default implementation dialog is closed.
+  //
+  pub fn on_dialog_closed(&self, browser: interfaces::CefBrowser) -> () {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_dialog_closed.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_jsdialog_handler_t> for CefJSDialogHandler {
+  fn to_c(rust_object: CefJSDialogHandler) -> *mut cef_jsdialog_handler_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_jsdialog_handler_t) -> CefJSDialogHandler {
+    CefJSDialogHandler::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_jsdialog_handler_t> for Option<CefJSDialogHandler> {
+  fn to_c(rust_object: Option<CefJSDialogHandler>) -> *mut cef_jsdialog_handler_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_jsdialog_handler_t) -> Option<CefJSDialogHandler> {
+    if c_object.is_null() {
+      None
+    } else {
+      Some(CefJSDialogHandler::from_c_object_addref(c_object))
+    }
+  }
+}
+