webview-sys: vendor the macOS part of the crate

Summary:
Imported from https://github.com/Boscop/web-view/ commit 82d7cbce6228b1a964673cc0f22944ad808eab42.
Non-mac version is dropped (on Windows `edge.exe --app=url` can be a decent
alternative, on Linux it can be challenging to get dependencies ready).

We didn't import it to the repo-wide third-party library because `reindeer`
uses `cargo vendor` and `cargo vendor` cannot skip (hard-to-build) Linux
dependencies even if the crate `webview-sys` is only referred for macOS.
See rust-lang/cargo#7058

Reviewed By: sggutier

Differential Revision: D48531141

fbshipit-source-id: 4a087e83deae3764edcad5725d1a93d28d8ff6a8

Author: quark-zju

eden/scm/lib/third-party/webview-sys/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Serge Zaitsev
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

eden/scm/lib/third-party/webview-sys/build.rs

@@ -0,0 +1,33 @@
+extern crate cc;
+
+use std::env;
+
+fn main() {
+    let target = env::var("TARGET").unwrap();
+
+    let mut build = cc::Build::new();
+
+    build
+        .include("webview.h")
+        .flag_if_supported("-std=c11")
+        .flag_if_supported("-w");
+
+    if env::var("DEBUG").is_err() {
+        build.define("NDEBUG", None);
+    } else {
+        build.define("DEBUG", None);
+    }
+
+    if target.contains("apple") {
+        build
+            .file("webview_cocoa.c")
+            .flag("-x")
+            .flag("objective-c");
+        println!("cargo:rustc-link-lib=framework=Cocoa");
+        println!("cargo:rustc-link-lib=framework=WebKit");
+    } else {
+        panic!("unsupported target (only macos is supported)");
+    }
+
+    build.compile("webview");
+}

eden/scm/lib/third-party/webview-sys/lib.rs

@@ -0,0 +1,46 @@
+//! Raw FFI bindings to [webview].
+//!
+//! To use a custom version of webview, define an environment variable `WEBVIEW_DIR` with the path
+//! to its source directory.
+//!
+//! [webview]: https://github.com/zserge/webview
+
+use std::os::raw::*;
+
+pub enum CWebView {} // opaque type, only used in ffi pointers
+
+type ErasedExternalInvokeFn = extern "C" fn(webview: *mut CWebView, arg: *const c_char);
+type ErasedDispatchFn = extern "C" fn(webview: *mut CWebView, arg: *mut c_void);
+
+extern "C" {
+    pub fn webview_free(this: *mut CWebView);
+    pub fn webview_new(
+        title: *const c_char,
+        url: *const c_char,
+        width: c_int,
+        height: c_int,
+        resizable: c_int,
+        debug: c_int,
+        frameless: c_int,
+        visible: c_int,
+        min_width: c_int,
+        min_height: c_int,
+        hide_instead_of_close: c_int,
+        external_invoke_cb: Option<ErasedExternalInvokeFn>,
+        userdata: *mut c_void,
+    ) -> *mut CWebView;
+    pub fn webview_loop(this: *mut CWebView, blocking: c_int) -> c_int;
+    pub fn webview_exit(this: *mut CWebView);
+    pub fn webview_get_user_data(this: *mut CWebView) -> *mut c_void;
+    pub fn webview_get_window_handle(this: *mut CWebView) -> *mut c_void;
+    pub fn webview_dispatch(this: *mut CWebView, f: Option<ErasedDispatchFn>, arg: *mut c_void);
+    pub fn webview_eval(this: *mut CWebView, js: *const c_char) -> c_int;
+    pub fn webview_set_title(this: *mut CWebView, title: *const c_char);
+    pub fn webview_set_fullscreen(this: *mut CWebView, fullscreen: c_int);
+    pub fn webview_set_maximized(this: *mut CWebView, maximize: c_int);
+    pub fn webview_set_minimized(this: *mut CWebView, minimize: c_int);
+    pub fn webview_set_visible(this: *mut CWebView, visible: c_int);
+    pub fn webview_set_color(this: *mut CWebView, red: u8, green: u8, blue: u8, alpha: u8);
+    pub fn webview_set_zoom_level(this: *mut CWebView, percentage: c_double);
+    pub fn webview_set_html(this: *mut CWebView, html: *const c_char);
+}

eden/scm/lib/third-party/webview-sys/webview.h

@@ -0,0 +1,80 @@
+#ifndef WEBVIEW_H
+#define WEBVIEW_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef WEBVIEW_STATIC
+#define WEBVIEW_API static
+#else
+#define WEBVIEW_API extern
+#endif
+
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+typedef void* webview_t;
+typedef void (*webview_external_invoke_cb_t)(webview_t w, const char *arg);
+typedef void (*webview_dispatch_fn)(webview_t w, void *arg);
+
+WEBVIEW_API void webview_run(webview_t w);
+WEBVIEW_API int webview_loop(webview_t w, int blocking);
+WEBVIEW_API int webview_eval(webview_t w, const char *js);
+WEBVIEW_API void webview_set_title(webview_t w, const char *title);
+WEBVIEW_API void webview_set_fullscreen(webview_t w, int fullscreen);
+WEBVIEW_API void webview_set_maximized(webview_t w, int maximize);
+WEBVIEW_API void webview_set_minimized(webview_t w, int minimize);
+WEBVIEW_API void webview_set_visible(webview_t w, int minimize);
+WEBVIEW_API void webview_set_color(webview_t w, uint8_t r, uint8_t g,
+                                   uint8_t b, uint8_t a);
+WEBVIEW_API void webview_set_zoom_level(webview_t w, const double percentage);
+WEBVIEW_API void webview_set_html(webview_t w, const char *html);
+WEBVIEW_API void webview_dispatch(webview_t w, webview_dispatch_fn fn,
+                                  void *arg);
+WEBVIEW_API void webview_exit(webview_t w);
+WEBVIEW_API void webview_debug(const char *format, ...);
+WEBVIEW_API void webview_print_log(const char *s);
+
+WEBVIEW_API void* webview_get_user_data(webview_t w);
+WEBVIEW_API void* webview_get_window_handle(webview_t w);
+WEBVIEW_API webview_t webview_new(const char* title, const char* url, int width, int height, int resizable, int debug, int frameless, int visible, int min_width, int min_height, int hide_instead_of_close, webview_external_invoke_cb_t external_invoke_cb, void* userdata);
+WEBVIEW_API void webview_free(webview_t w);
+WEBVIEW_API void webview_destroy(webview_t w);
+
+// TODO WEBVIEW_API void webview_navigate(webview_t w, const char* url);
+
+struct webview_dispatch_arg {
+  webview_dispatch_fn fn;
+  webview_t w;
+  void *arg;
+};
+
+// Convert ASCII hex digit to a nibble (four bits, 0 - 15).
+//
+// Use unsigned to avoid signed overflow UB.
+static inline unsigned char hex2nibble(unsigned char c) {
+  if (c >= '0' && c <= '9') {
+    return c - '0';
+  } else if (c >= 'a' && c <= 'f') {
+    return 10 + (c - 'a');
+  } else if (c >= 'A' && c <= 'F') {
+    return 10 + (c - 'A');
+  }
+  return 0;
+}
+
+// Convert ASCII hex string (two characters) to byte.
+//
+// E.g., "0B" => 0x0B, "af" => 0xAF.
+static inline char hex2char(const char* p) {
+  return hex2nibble(p[0]) * 16 + hex2nibble(p[1]);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // WEBVIEW_H