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Add Go binding (#1) * Merge LICENSE files of this repo and core library's repo * Remove myself from LICENSE I haven't made any noteworthy contributions to the Go bindings. * Add Go bindings * Add content to README * Fix Go docs URL and add reference to core library
2023-09-01 06:41:19 +01:00
/*
* MIT License
*
* Copyright (c) 2017 Serge Zaitsev
* Copyright (c) 2022 Steffen André Langnes
*
* 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.
*/
#ifndef WEBVIEW_H
#define WEBVIEW_H
#ifndef WEBVIEW_API
#define WEBVIEW_API extern
#endif
#ifndef WEBVIEW_VERSION_MAJOR
// The current library major version.
#define WEBVIEW_VERSION_MAJOR 0
#endif
#ifndef WEBVIEW_VERSION_MINOR
// The current library minor version.
#define WEBVIEW_VERSION_MINOR 10
#endif
#ifndef WEBVIEW_VERSION_PATCH
// The current library patch version.
#define WEBVIEW_VERSION_PATCH 0
#endif
#ifndef WEBVIEW_VERSION_PRE_RELEASE
// SemVer 2.0.0 pre-release labels prefixed with "-".
#define WEBVIEW_VERSION_PRE_RELEASE ""
#endif
#ifndef WEBVIEW_VERSION_BUILD_METADATA
// SemVer 2.0.0 build metadata prefixed with "+".
#define WEBVIEW_VERSION_BUILD_METADATA ""
#endif
// Utility macro for stringifying a macro argument.
#define WEBVIEW_STRINGIFY(x) #x
// Utility macro for stringifying the result of a macro argument expansion.
#define WEBVIEW_EXPAND_AND_STRINGIFY(x) WEBVIEW_STRINGIFY(x)
// SemVer 2.0.0 version number in MAJOR.MINOR.PATCH format.
#define WEBVIEW_VERSION_NUMBER \
WEBVIEW_EXPAND_AND_STRINGIFY(WEBVIEW_VERSION_MAJOR) \
"." WEBVIEW_EXPAND_AND_STRINGIFY( \
WEBVIEW_VERSION_MINOR) "." WEBVIEW_EXPAND_AND_STRINGIFY(WEBVIEW_VERSION_PATCH)
// Holds the elements of a MAJOR.MINOR.PATCH version number.
typedef struct {
// Major version.
unsigned int major;
// Minor version.
unsigned int minor;
// Patch version.
unsigned int patch;
} webview_version_t;
// Holds the library's version information.
typedef struct {
// The elements of the version number.
webview_version_t version;
// SemVer 2.0.0 version number in MAJOR.MINOR.PATCH format.
char version_number[32];
// SemVer 2.0.0 pre-release labels prefixed with "-" if specified, otherwise
// an empty string.
char pre_release[48];
// SemVer 2.0.0 build metadata prefixed with "+", otherwise an empty string.
char build_metadata[48];
} webview_version_info_t;
#ifdef __cplusplus
extern "C" {
#endif
typedef void *webview_t;
// Creates a new webview instance. If debug is non-zero - developer tools will
// be enabled (if the platform supports them). The window parameter can be a
// pointer to the native window handle. If it's non-null - then child WebView
// is embedded into the given parent window. Otherwise a new window is created.
// Depending on the platform, a GtkWindow, NSWindow or HWND pointer can be
// passed here. Returns null on failure. Creation can fail for various reasons
// such as when required runtime dependencies are missing or when window creation
// fails.
WEBVIEW_API webview_t webview_create(int debug, void *window);
// Destroys a webview and closes the native window.
WEBVIEW_API void webview_destroy(webview_t w);
// Runs the main loop until it's terminated. After this function exits - you
// must destroy the webview.
WEBVIEW_API void webview_run(webview_t w);
// Stops the main loop. It is safe to call this function from another other
// background thread.
WEBVIEW_API void webview_terminate(webview_t w);
// Posts a function to be executed on the main thread. You normally do not need
// to call this function, unless you want to tweak the native window.
WEBVIEW_API void
webview_dispatch(webview_t w, void (*fn)(webview_t w, void *arg), void *arg);
// Returns a native window handle pointer. When using a GTK backend the pointer
// is a GtkWindow pointer, when using a Cocoa backend the pointer is a NSWindow
// pointer, when using a Win32 backend the pointer is a HWND pointer.
WEBVIEW_API void *webview_get_window(webview_t w);
// Updates the title of the native window. Must be called from the UI thread.
WEBVIEW_API void webview_set_title(webview_t w, const char *title);
// Window size hints
#define WEBVIEW_HINT_NONE 0 // Width and height are default size
#define WEBVIEW_HINT_MIN 1 // Width and height are minimum bounds
#define WEBVIEW_HINT_MAX 2 // Width and height are maximum bounds
#define WEBVIEW_HINT_FIXED 3 // Window size can not be changed by a user
// Updates the size of the native window. See WEBVIEW_HINT constants.
WEBVIEW_API void webview_set_size(webview_t w, int width, int height,
int hints);
// Navigates webview to the given URL. URL may be a properly encoded data URI.
// Examples:
// webview_navigate(w, "https://github.com/webview/webview");
// webview_navigate(w, "data:text/html,%3Ch1%3EHello%3C%2Fh1%3E");
// webview_navigate(w, "data:text/html;base64,PGgxPkhlbGxvPC9oMT4=");
WEBVIEW_API void webview_navigate(webview_t w, const char *url);
// Set webview HTML directly.
// Example: webview_set_html(w, "<h1>Hello</h1>");
WEBVIEW_API void webview_set_html(webview_t w, const char *html);
// Injects JavaScript code at the initialization of the new page. Every time
// the webview will open a new page - this initialization code will be
// executed. It is guaranteed that code is executed before window.onload.
WEBVIEW_API void webview_init(webview_t w, const char *js);
// Evaluates arbitrary JavaScript code. Evaluation happens asynchronously, also
// the result of the expression is ignored. Use RPC bindings if you want to
// receive notifications about the results of the evaluation.
WEBVIEW_API void webview_eval(webview_t w, const char *js);
// Binds a native C callback so that it will appear under the given name as a
// global JavaScript function. Internally it uses webview_init(). The callback
// receives a sequential request id, a request string and a user-provided
// argument pointer. The request string is a JSON array of all the arguments
// passed to the JavaScript function.
WEBVIEW_API void webview_bind(webview_t w, const char *name,
void (*fn)(const char *seq, const char *req,
void *arg),
void *arg);
// Removes a native C callback that was previously set by webview_bind.
WEBVIEW_API void webview_unbind(webview_t w, const char *name);
// Allows to return a value from the native binding. A request id pointer must
// be provided to allow the internal RPC engine to match requests and responses.
// If the status is zero - the result is expected to be a valid JSON value.
// If the status is not zero - the result is an error JSON object.
WEBVIEW_API void webview_return(webview_t w, const char *seq, int status,
const char *result);
// Get the library's version information.
// @since 0.10
WEBVIEW_API const webview_version_info_t *webview_version();
#ifdef __cplusplus
}
#ifndef WEBVIEW_HEADER
#if !defined(WEBVIEW_GTK) && !defined(WEBVIEW_COCOA) && !defined(WEBVIEW_EDGE)
#if defined(__APPLE__)
#define WEBVIEW_COCOA
#elif defined(__unix__)
#define WEBVIEW_GTK
#elif defined(_WIN32)
#define WEBVIEW_EDGE
#else
#error "please, specify webview backend"
#endif
#endif
#ifndef WEBVIEW_DEPRECATED
#if __cplusplus >= 201402L
#define WEBVIEW_DEPRECATED(reason) [[deprecated(reason)]]
#elif defined(_MSC_VER)
#define WEBVIEW_DEPRECATED(reason) __declspec(deprecated(reason))
#else
#define WEBVIEW_DEPRECATED(reason) __attribute__((deprecated(reason)))
#endif
#endif
#ifndef WEBVIEW_DEPRECATED_PRIVATE
#define WEBVIEW_DEPRECATED_PRIVATE \
WEBVIEW_DEPRECATED("Private API should not be used")
#endif
#include <array>
#include <atomic>
#include <cstdint>
#include <functional>
#include <future>
#include <map>
#include <string>
#include <utility>
#include <vector>
#include <cstring>
namespace webview {
using dispatch_fn_t = std::function<void()>;
namespace detail {
// The library's version information.
constexpr const webview_version_info_t library_version_info{
{WEBVIEW_VERSION_MAJOR, WEBVIEW_VERSION_MINOR, WEBVIEW_VERSION_PATCH},
WEBVIEW_VERSION_NUMBER,
WEBVIEW_VERSION_PRE_RELEASE,
WEBVIEW_VERSION_BUILD_METADATA};
inline int json_parse_c(const char *s, size_t sz, const char *key, size_t keysz,
const char **value, size_t *valuesz) {
enum {
JSON_STATE_VALUE,
JSON_STATE_LITERAL,
JSON_STATE_STRING,
JSON_STATE_ESCAPE,
JSON_STATE_UTF8
} state = JSON_STATE_VALUE;
const char *k = nullptr;
int index = 1;
int depth = 0;
int utf8_bytes = 0;
*value = nullptr;
*valuesz = 0;
if (key == nullptr) {
index = static_cast<decltype(index)>(keysz);
if (index < 0) {
return -1;
}
keysz = 0;
}
for (; sz > 0; s++, sz--) {
enum {
JSON_ACTION_NONE,
JSON_ACTION_START,
JSON_ACTION_END,
JSON_ACTION_START_STRUCT,
JSON_ACTION_END_STRUCT
} action = JSON_ACTION_NONE;
auto c = static_cast<unsigned char>(*s);
switch (state) {
case JSON_STATE_VALUE:
if (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == ',' ||
c == ':') {
continue;
} else if (c == '"') {
action = JSON_ACTION_START;
state = JSON_STATE_STRING;
} else if (c == '{' || c == '[') {
action = JSON_ACTION_START_STRUCT;
} else if (c == '}' || c == ']') {
action = JSON_ACTION_END_STRUCT;
} else if (c == 't' || c == 'f' || c == 'n' || c == '-' ||
(c >= '0' && c <= '9')) {
action = JSON_ACTION_START;
state = JSON_STATE_LITERAL;
} else {
return -1;
}
break;
case JSON_STATE_LITERAL:
if (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == ',' ||
c == ']' || c == '}' || c == ':') {
state = JSON_STATE_VALUE;
s--;
sz++;
action = JSON_ACTION_END;
} else if (c < 32 || c > 126) {
return -1;
} // fallthrough
case JSON_STATE_STRING:
if (c < 32 || (c > 126 && c < 192)) {
return -1;
} else if (c == '"') {
action = JSON_ACTION_END;
state = JSON_STATE_VALUE;
} else if (c == '\\') {
state = JSON_STATE_ESCAPE;
} else if (c >= 192 && c < 224) {
utf8_bytes = 1;
state = JSON_STATE_UTF8;
} else if (c >= 224 && c < 240) {
utf8_bytes = 2;
state = JSON_STATE_UTF8;
} else if (c >= 240 && c < 247) {
utf8_bytes = 3;
state = JSON_STATE_UTF8;
} else if (c >= 128 && c < 192) {
return -1;
}
break;
case JSON_STATE_ESCAPE:
if (c == '"' || c == '\\' || c == '/' || c == 'b' || c == 'f' ||
c == 'n' || c == 'r' || c == 't' || c == 'u') {
state = JSON_STATE_STRING;
} else {
return -1;
}
break;
case JSON_STATE_UTF8:
if (c < 128 || c > 191) {
return -1;
}
utf8_bytes--;
if (utf8_bytes == 0) {
state = JSON_STATE_STRING;
}
break;
default:
return -1;
}
if (action == JSON_ACTION_END_STRUCT) {
depth--;
}
if (depth == 1) {
if (action == JSON_ACTION_START || action == JSON_ACTION_START_STRUCT) {
if (index == 0) {
*value = s;
} else if (keysz > 0 && index == 1) {
k = s;
} else {
index--;
}
} else if (action == JSON_ACTION_END ||
action == JSON_ACTION_END_STRUCT) {
if (*value != nullptr && index == 0) {
*valuesz = (size_t)(s + 1 - *value);
return 0;
} else if (keysz > 0 && k != nullptr) {
if (keysz == (size_t)(s - k - 1) && memcmp(key, k + 1, keysz) == 0) {
index = 0;
} else {
index = 2;
}
k = nullptr;
}
}
}
if (action == JSON_ACTION_START_STRUCT) {
depth++;
}
}
return -1;
}
inline std::string json_escape(const std::string &s) {
// TODO: implement
return '"' + s + '"';
}
inline int json_unescape(const char *s, size_t n, char *out) {
int r = 0;
if (*s++ != '"') {
return -1;
}
while (n > 2) {
char c = *s;
if (c == '\\') {
s++;
n--;
switch (*s) {
case 'b':
c = '\b';
break;
case 'f':
c = '\f';
break;
case 'n':
c = '\n';
break;
case 'r':
c = '\r';
break;
case 't':
c = '\t';
break;
case '\\':
c = '\\';
break;
case '/':
c = '/';
break;
case '\"':
c = '\"';
break;
default: // TODO: support unicode decoding
return -1;
}
}
if (out != nullptr) {
*out++ = c;
}
s++;
n--;
r++;
}
if (*s != '"') {
return -1;
}
if (out != nullptr) {
*out = '\0';
}
return r;
}
inline std::string json_parse(const std::string &s, const std::string &key,
const int index) {
const char *value;
size_t value_sz;
if (key.empty()) {
json_parse_c(s.c_str(), s.length(), nullptr, index, &value, &value_sz);
} else {
json_parse_c(s.c_str(), s.length(), key.c_str(), key.length(), &value,
&value_sz);
}
if (value != nullptr) {
if (value[0] != '"') {
return {value, value_sz};
}
int n = json_unescape(value, value_sz, nullptr);
if (n > 0) {
char *decoded = new char[n + 1];
json_unescape(value, value_sz, decoded);
std::string result(decoded, n);
delete[] decoded;
return result;
}
}
return "";
}
} // namespace detail
WEBVIEW_DEPRECATED_PRIVATE
inline int json_parse_c(const char *s, size_t sz, const char *key, size_t keysz,
const char **value, size_t *valuesz) {
return detail::json_parse_c(s, sz, key, keysz, value, valuesz);
}
WEBVIEW_DEPRECATED_PRIVATE
inline std::string json_escape(const std::string &s) {
return detail::json_escape(s);
}
WEBVIEW_DEPRECATED_PRIVATE
inline int json_unescape(const char *s, size_t n, char *out) {
return detail::json_unescape(s, n, out);
}
WEBVIEW_DEPRECATED_PRIVATE
inline std::string json_parse(const std::string &s, const std::string &key,
const int index) {
return detail::json_parse(s, key, index);
}
} // namespace webview
#if defined(WEBVIEW_GTK)
//
// ====================================================================
//
// This implementation uses webkit2gtk backend. It requires gtk+3.0 and
// webkit2gtk-4.0 libraries. Proper compiler flags can be retrieved via:
//
// pkg-config --cflags --libs gtk+-3.0 webkit2gtk-4.0
//
// ====================================================================
//
#include <JavaScriptCore/JavaScript.h>
#include <gtk/gtk.h>
#include <webkit2/webkit2.h>
namespace webview {
namespace detail {
class gtk_webkit_engine {
public:
gtk_webkit_engine(bool debug, void *window)
: m_window(static_cast<GtkWidget *>(window)) {
if (gtk_init_check(nullptr, nullptr) == FALSE) {
return;
}
m_window = static_cast<GtkWidget *>(window);
if (m_window == nullptr) {
m_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
}
g_signal_connect(G_OBJECT(m_window), "destroy",
G_CALLBACK(+[](GtkWidget *, gpointer arg) {
static_cast<gtk_webkit_engine *>(arg)->terminate();
}),
this);
// Initialize webview widget
m_webview = webkit_web_view_new();
WebKitUserContentManager *manager =
webkit_web_view_get_user_content_manager(WEBKIT_WEB_VIEW(m_webview));
g_signal_connect(manager, "script-message-received::external",
G_CALLBACK(+[](WebKitUserContentManager *,
WebKitJavascriptResult *r, gpointer arg) {
auto *w = static_cast<gtk_webkit_engine *>(arg);
char *s = get_string_from_js_result(r);
w->on_message(s);
g_free(s);
}),
this);
webkit_user_content_manager_register_script_message_handler(manager,
"external");
init("window.external={invoke:function(s){window.webkit.messageHandlers."
"external.postMessage(s);}}");
gtk_container_add(GTK_CONTAINER(m_window), GTK_WIDGET(m_webview));
gtk_widget_grab_focus(GTK_WIDGET(m_webview));
WebKitSettings *settings =
webkit_web_view_get_settings(WEBKIT_WEB_VIEW(m_webview));
webkit_settings_set_javascript_can_access_clipboard(settings, true);
if (debug) {
webkit_settings_set_enable_write_console_messages_to_stdout(settings,
true);
webkit_settings_set_enable_developer_extras(settings, true);
}
gtk_widget_show_all(m_window);
}
virtual ~gtk_webkit_engine() = default;
void *window() { return (void *)m_window; }
void run() { gtk_main(); }
void terminate() { gtk_main_quit(); }
void dispatch(std::function<void()> f) {
g_idle_add_full(G_PRIORITY_HIGH_IDLE, (GSourceFunc)([](void *f) -> int {
(*static_cast<dispatch_fn_t *>(f))();
return G_SOURCE_REMOVE;
}),
new std::function<void()>(f),
[](void *f) { delete static_cast<dispatch_fn_t *>(f); });
}
void set_title(const std::string &title) {
gtk_window_set_title(GTK_WINDOW(m_window), title.c_str());
}
void set_size(int width, int height, int hints) {
gtk_window_set_resizable(GTK_WINDOW(m_window), hints != WEBVIEW_HINT_FIXED);
if (hints == WEBVIEW_HINT_NONE) {
gtk_window_resize(GTK_WINDOW(m_window), width, height);
} else if (hints == WEBVIEW_HINT_FIXED) {
gtk_widget_set_size_request(m_window, width, height);
} else {
GdkGeometry g;
g.min_width = g.max_width = width;
g.min_height = g.max_height = height;
GdkWindowHints h =
(hints == WEBVIEW_HINT_MIN ? GDK_HINT_MIN_SIZE : GDK_HINT_MAX_SIZE);
// This defines either MIN_SIZE, or MAX_SIZE, but not both:
gtk_window_set_geometry_hints(GTK_WINDOW(m_window), nullptr, &g, h);
}
}
void navigate(const std::string &url) {
webkit_web_view_load_uri(WEBKIT_WEB_VIEW(m_webview), url.c_str());
}
void set_html(const std::string &html) {
webkit_web_view_load_html(WEBKIT_WEB_VIEW(m_webview), html.c_str(),
nullptr);
}
void init(const std::string &js) {
WebKitUserContentManager *manager =
webkit_web_view_get_user_content_manager(WEBKIT_WEB_VIEW(m_webview));
webkit_user_content_manager_add_script(
manager,
webkit_user_script_new(js.c_str(), WEBKIT_USER_CONTENT_INJECT_TOP_FRAME,
WEBKIT_USER_SCRIPT_INJECT_AT_DOCUMENT_START,
nullptr, nullptr));
}
void eval(const std::string &js) {
webkit_web_view_run_javascript(WEBKIT_WEB_VIEW(m_webview), js.c_str(),
nullptr, nullptr, nullptr);
}
private:
virtual void on_message(const std::string &msg) = 0;
static char *get_string_from_js_result(WebKitJavascriptResult *r) {
char *s;
#if WEBKIT_MAJOR_VERSION >= 2 && WEBKIT_MINOR_VERSION >= 22
JSCValue *value = webkit_javascript_result_get_js_value(r);
s = jsc_value_to_string(value);
#else
JSGlobalContextRef ctx = webkit_javascript_result_get_global_context(r);
JSValueRef value = webkit_javascript_result_get_value(r);
JSStringRef js = JSValueToStringCopy(ctx, value, nullptr);
size_t n = JSStringGetMaximumUTF8CStringSize(js);
s = g_new(char, n);
JSStringGetUTF8CString(js, s, n);
JSStringRelease(js);
#endif
return s;
}
GtkWidget *m_window;
GtkWidget *m_webview;
};
} // namespace detail
using browser_engine = detail::gtk_webkit_engine;
} // namespace webview
#elif defined(WEBVIEW_COCOA)
//
// ====================================================================
//
// This implementation uses Cocoa WKWebView backend on macOS. It is
// written using ObjC runtime and uses WKWebView class as a browser runtime.
// You should pass "-framework Webkit" flag to the compiler.
//
// ====================================================================
//
#include <CoreGraphics/CoreGraphics.h>
#include <objc/NSObjCRuntime.h>
#include <objc/objc-runtime.h>
namespace webview {
namespace detail {
namespace objc {
// A convenient template function for unconditionally casting the specified
// C-like function into a function that can be called with the given return
// type and arguments. Caller takes full responsibility for ensuring that
// the function call is valid. It is assumed that the function will not
// throw exceptions.
template <typename Result, typename Callable, typename... Args>
Result invoke(Callable callable, Args... args) noexcept {
return reinterpret_cast<Result (*)(Args...)>(callable)(args...);
}
// Calls objc_msgSend.
template <typename Result, typename... Args>
Result msg_send(Args... args) noexcept {
return invoke<Result>(objc_msgSend, args...);
}
// Wrapper around NSAutoreleasePool that drains the pool on destruction.
class autoreleasepool {
public:
autoreleasepool()
: m_pool(msg_send<id>(objc_getClass("NSAutoreleasePool"),
sel_registerName("new"))) {}
~autoreleasepool() {
if (m_pool) {
msg_send<void>(m_pool, sel_registerName("drain"));
}
}
autoreleasepool(const autoreleasepool &) = delete;
autoreleasepool &operator=(const autoreleasepool &) = delete;
autoreleasepool(autoreleasepool &&) = delete;
autoreleasepool &operator=(autoreleasepool &&) = delete;
private:
id m_pool{};
};
} // namespace objc
enum NSBackingStoreType : NSUInteger { NSBackingStoreBuffered = 2 };
enum NSWindowStyleMask : NSUInteger {
NSWindowStyleMaskTitled = 1,
NSWindowStyleMaskClosable = 2,
NSWindowStyleMaskMiniaturizable = 4,
NSWindowStyleMaskResizable = 8
};
enum NSApplicationActivationPolicy : NSInteger {
NSApplicationActivationPolicyRegular = 0
};
enum WKUserScriptInjectionTime : NSInteger {
WKUserScriptInjectionTimeAtDocumentStart = 0
};
enum NSModalResponse : NSInteger { NSModalResponseOK = 1 };
// Convenient conversion of string literals.
inline id operator"" _cls(const char *s, std::size_t) {
return (id)objc_getClass(s);
}
inline SEL operator"" _sel(const char *s, std::size_t) {
return sel_registerName(s);
}
inline id operator"" _str(const char *s, std::size_t) {
return objc::msg_send<id>("NSString"_cls, "stringWithUTF8String:"_sel, s);
}
class cocoa_wkwebview_engine {
public:
cocoa_wkwebview_engine(bool debug, void *window)
: m_debug{debug}, m_parent_window{window} {
auto app = get_shared_application();
auto delegate = create_app_delegate();
objc_setAssociatedObject(delegate, "webview", (id)this,
OBJC_ASSOCIATION_ASSIGN);
objc::msg_send<void>(app, "setDelegate:"_sel, delegate);
// See comments related to application lifecycle in create_app_delegate().
if (window) {
on_application_did_finish_launching(delegate, app);
} else {
// Start the main run loop so that the app delegate gets the
// NSApplicationDidFinishLaunchingNotification notification after the run
// loop has started in order to perform further initialization.
// We need to return from this constructor so this run loop is only
// temporary.
objc::msg_send<void>(app, "run"_sel);
}
}
virtual ~cocoa_wkwebview_engine() = default;
void *window() { return (void *)m_window; }
void terminate() { stop_run_loop(); }
void run() {
auto app = get_shared_application();
objc::msg_send<void>(app, "run"_sel);
}
void dispatch(std::function<void()> f) {
dispatch_async_f(dispatch_get_main_queue(), new dispatch_fn_t(f),
(dispatch_function_t)([](void *arg) {
auto f = static_cast<dispatch_fn_t *>(arg);
(*f)();
delete f;
}));
}
void set_title(const std::string &title) {
objc::msg_send<void>(m_window, "setTitle:"_sel,
objc::msg_send<id>("NSString"_cls,
"stringWithUTF8String:"_sel,
title.c_str()));
}
void set_size(int width, int height, int hints) {
auto style = static_cast<NSWindowStyleMask>(
NSWindowStyleMaskTitled | NSWindowStyleMaskClosable |
NSWindowStyleMaskMiniaturizable);
if (hints != WEBVIEW_HINT_FIXED) {
style =
static_cast<NSWindowStyleMask>(style | NSWindowStyleMaskResizable);
}
objc::msg_send<void>(m_window, "setStyleMask:"_sel, style);
if (hints == WEBVIEW_HINT_MIN) {
objc::msg_send<void>(m_window, "setContentMinSize:"_sel,
CGSizeMake(width, height));
} else if (hints == WEBVIEW_HINT_MAX) {
objc::msg_send<void>(m_window, "setContentMaxSize:"_sel,
CGSizeMake(width, height));
} else {
objc::msg_send<void>(m_window, "setFrame:display:animate:"_sel,
CGRectMake(0, 0, width, height), YES, NO);
}
objc::msg_send<void>(m_window, "center"_sel);
}
void navigate(const std::string &url) {
objc::autoreleasepool pool;
auto nsurl = objc::msg_send<id>(
"NSURL"_cls, "URLWithString:"_sel,
objc::msg_send<id>("NSString"_cls, "stringWithUTF8String:"_sel,
url.c_str()));
objc::msg_send<void>(
m_webview, "loadRequest:"_sel,
objc::msg_send<id>("NSURLRequest"_cls, "requestWithURL:"_sel, nsurl));
}
void set_html(const std::string &html) {
objc::autoreleasepool pool;
objc::msg_send<void>(m_webview, "loadHTMLString:baseURL:"_sel,
objc::msg_send<id>("NSString"_cls,
"stringWithUTF8String:"_sel,
html.c_str()),
nullptr);
}
void init(const std::string &js) {
// Equivalent Obj-C:
// [m_manager addUserScript:[[WKUserScript alloc] initWithSource:[NSString stringWithUTF8String:js.c_str()] injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:YES]]
objc::msg_send<void>(
m_manager, "addUserScript:"_sel,
objc::msg_send<id>(objc::msg_send<id>("WKUserScript"_cls, "alloc"_sel),
"initWithSource:injectionTime:forMainFrameOnly:"_sel,
objc::msg_send<id>("NSString"_cls,
"stringWithUTF8String:"_sel,
js.c_str()),
WKUserScriptInjectionTimeAtDocumentStart, YES));
}
void eval(const std::string &js) {
objc::msg_send<void>(m_webview, "evaluateJavaScript:completionHandler:"_sel,
objc::msg_send<id>("NSString"_cls,
"stringWithUTF8String:"_sel,
js.c_str()),
nullptr);
}
private:
virtual void on_message(const std::string &msg) = 0;
id create_app_delegate() {
// Note: Avoid registering the class name "AppDelegate" as it is the
// default name in projects created with Xcode, and using the same name
// causes objc_registerClassPair to crash.
auto cls = objc_allocateClassPair((Class) "NSResponder"_cls,
"WebviewAppDelegate", 0);
class_addProtocol(cls, objc_getProtocol("NSTouchBarProvider"));
class_addMethod(cls, "applicationShouldTerminateAfterLastWindowClosed:"_sel,
(IMP)(+[](id, SEL, id) -> BOOL { return YES; }), "c@:@");
class_addMethod(cls, "applicationShouldTerminate:"_sel,
(IMP)(+[](id self, SEL, id sender) -> int {
auto w = get_associated_webview(self);
return w->on_application_should_terminate(self, sender);
}),
"i@:@");
// If the library was not initialized with an existing window then the user
// is likely managing the application lifecycle and we would not get the
// "applicationDidFinishLaunching:" message and therefore do not need to
// add this method.
if (!m_parent_window) {
class_addMethod(cls, "applicationDidFinishLaunching:"_sel,
(IMP)(+[](id self, SEL, id notification) {
auto app =
objc::msg_send<id>(notification, "object"_sel);
auto w = get_associated_webview(self);
w->on_application_did_finish_launching(self, app);
}),
"v@:@");
}
objc_registerClassPair(cls);
return objc::msg_send<id>((id)cls, "new"_sel);
}
id create_script_message_handler() {
auto cls = objc_allocateClassPair((Class) "NSResponder"_cls,
"WebkitScriptMessageHandler", 0);
class_addProtocol(cls, objc_getProtocol("WKScriptMessageHandler"));
class_addMethod(
cls, "userContentController:didReceiveScriptMessage:"_sel,
(IMP)(+[](id self, SEL, id, id msg) {
auto w = get_associated_webview(self);
w->on_message(objc::msg_send<const char *>(
objc::msg_send<id>(msg, "body"_sel), "UTF8String"_sel));
}),
"v@:@@");
objc_registerClassPair(cls);
auto instance = objc::msg_send<id>((id)cls, "new"_sel);
objc_setAssociatedObject(instance, "webview", (id)this,
OBJC_ASSOCIATION_ASSIGN);
return instance;
}
static id create_webkit_ui_delegate() {
auto cls =
objc_allocateClassPair((Class) "NSObject"_cls, "WebkitUIDelegate", 0);
class_addProtocol(cls, objc_getProtocol("WKUIDelegate"));
class_addMethod(
cls,
"webView:runOpenPanelWithParameters:initiatedByFrame:completionHandler:"_sel,
(IMP)(+[](id, SEL, id, id parameters, id, id completion_handler) {
auto allows_multiple_selection =
objc::msg_send<BOOL>(parameters, "allowsMultipleSelection"_sel);
auto allows_directories =
objc::msg_send<BOOL>(parameters, "allowsDirectories"_sel);
// Show a panel for selecting files.
auto panel = objc::msg_send<id>("NSOpenPanel"_cls, "openPanel"_sel);
objc::msg_send<void>(panel, "setCanChooseFiles:"_sel, YES);
objc::msg_send<void>(panel, "setCanChooseDirectories:"_sel,
allows_directories);
objc::msg_send<void>(panel, "setAllowsMultipleSelection:"_sel,
allows_multiple_selection);
auto modal_response =
objc::msg_send<NSModalResponse>(panel, "runModal"_sel);
// Get the URLs for the selected files. If the modal was canceled
// then we pass null to the completion handler to signify
// cancellation.
id urls = modal_response == NSModalResponseOK
? objc::msg_send<id>(panel, "URLs"_sel)
: nullptr;
// Invoke the completion handler block.
auto sig = objc::msg_send<id>("NSMethodSignature"_cls,
"signatureWithObjCTypes:"_sel, "v@?@");
auto invocation = objc::msg_send<id>(
"NSInvocation"_cls, "invocationWithMethodSignature:"_sel, sig);
objc::msg_send<void>(invocation, "setTarget:"_sel,
completion_handler);
objc::msg_send<void>(invocation, "setArgument:atIndex:"_sel, &urls,
1);
objc::msg_send<void>(invocation, "invoke"_sel);
}),
"v@:@@@@");
objc_registerClassPair(cls);
return objc::msg_send<id>((id)cls, "new"_sel);
}
static id get_shared_application() {
return objc::msg_send<id>("NSApplication"_cls, "sharedApplication"_sel);
}
static cocoa_wkwebview_engine *get_associated_webview(id object) {
auto w =
(cocoa_wkwebview_engine *)objc_getAssociatedObject(object, "webview");
assert(w);
return w;
}
static id get_main_bundle() noexcept {
return objc::msg_send<id>("NSBundle"_cls, "mainBundle"_sel);
}
static bool is_app_bundled() noexcept {
auto bundle = get_main_bundle();
if (!bundle) {
return false;
}
auto bundle_path = objc::msg_send<id>(bundle, "bundlePath"_sel);
auto bundled =
objc::msg_send<BOOL>(bundle_path, "hasSuffix:"_sel, ".app"_str);
return !!bundled;
}
void on_application_did_finish_launching(id /*delegate*/, id app) {
// See comments related to application lifecycle in create_app_delegate().
if (!m_parent_window) {
// Stop the main run loop so that we can return
// from the constructor.
stop_run_loop();
}
// Activate the app if it is not bundled.
// Bundled apps launched from Finder are activated automatically but
// otherwise not. Activating the app even when it has been launched from
// Finder does not seem to be harmful but calling this function is rarely
// needed as proper activation is normally taken care of for us.
// Bundled apps have a default activation policy of
// NSApplicationActivationPolicyRegular while non-bundled apps have a
// default activation policy of NSApplicationActivationPolicyProhibited.
if (!is_app_bundled()) {
// "setActivationPolicy:" must be invoked before
// "activateIgnoringOtherApps:" for activation to work.
objc::msg_send<void>(app, "setActivationPolicy:"_sel,
NSApplicationActivationPolicyRegular);
// Activate the app regardless of other active apps.
// This can be obtrusive so we only do it when necessary.
objc::msg_send<void>(app, "activateIgnoringOtherApps:"_sel, YES);
}
// Main window
if (!m_parent_window) {
m_window = objc::msg_send<id>("NSWindow"_cls, "alloc"_sel);
auto style = NSWindowStyleMaskTitled;
m_window = objc::msg_send<id>(
m_window, "initWithContentRect:styleMask:backing:defer:"_sel,
CGRectMake(0, 0, 0, 0), style, NSBackingStoreBuffered, NO);
} else {
m_window = (id)m_parent_window;
}
// Webview
auto config = objc::msg_send<id>("WKWebViewConfiguration"_cls, "new"_sel);
m_manager = objc::msg_send<id>(config, "userContentController"_sel);
m_webview = objc::msg_send<id>("WKWebView"_cls, "alloc"_sel);
if (m_debug) {
// Equivalent Obj-C:
// [[config preferences] setValue:@YES forKey:@"developerExtrasEnabled"];
objc::msg_send<id>(
objc::msg_send<id>(config, "preferences"_sel), "setValue:forKey:"_sel,
objc::msg_send<id>("NSNumber"_cls, "numberWithBool:"_sel, YES),
"developerExtrasEnabled"_str);
}
// Equivalent Obj-C:
// [[config preferences] setValue:@YES forKey:@"fullScreenEnabled"];
objc::msg_send<id>(
objc::msg_send<id>(config, "preferences"_sel), "setValue:forKey:"_sel,
objc::msg_send<id>("NSNumber"_cls, "numberWithBool:"_sel, YES),
"fullScreenEnabled"_str);
// Equivalent Obj-C:
// [[config preferences] setValue:@YES forKey:@"javaScriptCanAccessClipboard"];
objc::msg_send<id>(
objc::msg_send<id>(config, "preferences"_sel), "setValue:forKey:"_sel,
objc::msg_send<id>("NSNumber"_cls, "numberWithBool:"_sel, YES),
"javaScriptCanAccessClipboard"_str);
// Equivalent Obj-C:
// [[config preferences] setValue:@YES forKey:@"DOMPasteAllowed"];
objc::msg_send<id>(
objc::msg_send<id>(config, "preferences"_sel), "setValue:forKey:"_sel,
objc::msg_send<id>("NSNumber"_cls, "numberWithBool:"_sel, YES),
"DOMPasteAllowed"_str);
auto ui_delegate = create_webkit_ui_delegate();
objc::msg_send<void>(m_webview, "initWithFrame:configuration:"_sel,
CGRectMake(0, 0, 0, 0), config);
objc::msg_send<void>(m_webview, "setUIDelegate:"_sel, ui_delegate);
if (m_debug) {
// Explicitly make WKWebView inspectable via Safari on OS versions that
// disable the feature by default (macOS 13.3 and later) and support
// enabling it. According to Apple, the behavior on older OS versions is
// for content to always be inspectable in "debug builds".
// Testing shows that this is true for macOS 12.6 but somehow not 10.15.
// https://webkit.org/blog/13936/enabling-the-inspection-of-web-content-in-apps/
#if defined(__has_builtin)
#if __has_builtin(__builtin_available)
if (__builtin_available(macOS 13.3, iOS 16.4, tvOS 16.4, *)) {
objc::msg_send<void>(
m_webview, "setInspectable:"_sel,
objc::msg_send<id>("NSNumber"_cls, "numberWithBool:"_sel, YES));
}
#else
#error __builtin_available not supported by compiler
#endif
#else
#error __has_builtin not supported by compiler
#endif
}
auto script_message_handler = create_script_message_handler();
objc::msg_send<void>(m_manager, "addScriptMessageHandler:name:"_sel,
script_message_handler, "external"_str);
init(R""(
window.external = {
invoke: function(s) {
window.webkit.messageHandlers.external.postMessage(s);
},
};
)"");
objc::msg_send<void>(m_window, "setContentView:"_sel, m_webview);
objc::msg_send<void>(m_window, "makeKeyAndOrderFront:"_sel, nullptr);
}
int on_application_should_terminate(id /*delegate*/, id app) {
dispatch([app, this] {
// Don't terminate the application.
objc::msg_send<void>(app, "replyToApplicationShouldTerminate:"_sel, NO);
// Instead stop the run loop.
stop_run_loop();
});
return 2 /*NSTerminateLater*/;
}
void stop_run_loop() {
auto app = get_shared_application();
// Request the run loop to stop. This doesn't immediately stop the loop.
objc::msg_send<void>(app, "stop:"_sel, nullptr);
// The run loop will stop after processing an NSEvent.
// Event type: NSEventTypeApplicationDefined (macOS 10.12+),
// NSApplicationDefined (macOS 10.0–10.12)
int type = 15;
auto event = objc::msg_send<id>(
"NSEvent"_cls,
"otherEventWithType:location:modifierFlags:timestamp:windowNumber:context:subtype:data1:data2:"_sel,
type, CGPointMake(0, 0), 0, 0, 0, nullptr, 0, 0, 0);
objc::msg_send<void>(app, "postEvent:atStart:"_sel, event, YES);
}
bool m_debug;
void *m_parent_window;
id m_window;
id m_webview;
id m_manager;
};
} // namespace detail
using browser_engine = detail::cocoa_wkwebview_engine;
} // namespace webview
#elif defined(WEBVIEW_EDGE)
//
// ====================================================================
//
// This implementation uses Win32 API to create a native window. It
// uses Edge/Chromium webview2 backend as a browser engine.
//
// ====================================================================
//
#define WIN32_LEAN_AND_MEAN
#include <shlobj.h>
#include <shlwapi.h>
#include <stdlib.h>
#include <windows.h>
#include "WebView2.h"
#ifdef _MSC_VER
#pragma comment(lib, "advapi32.lib")
#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "shell32.lib")
#pragma comment(lib, "shlwapi.lib")
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "version.lib")
#endif
namespace webview {
namespace detail {
using msg_cb_t = std::function<void(const std::string)>;
// Converts a narrow (UTF-8-encoded) string into a wide (UTF-16-encoded) string.
inline std::wstring widen_string(const std::string &input) {
if (input.empty()) {
return std::wstring();
}
UINT cp = CP_UTF8;
DWORD flags = MB_ERR_INVALID_CHARS;
auto input_c = input.c_str();
auto input_length = static_cast<int>(input.size());
auto required_length =
MultiByteToWideChar(cp, flags, input_c, input_length, nullptr, 0);
if (required_length > 0) {
std::wstring output(static_cast<std::size_t>(required_length), L'\0');
if (MultiByteToWideChar(cp, flags, input_c, input_length, &output[0],
required_length) > 0) {
return output;
}
}
// Failed to convert string from UTF-8 to UTF-16
return std::wstring();
}
// Converts a wide (UTF-16-encoded) string into a narrow (UTF-8-encoded) string.
inline std::string narrow_string(const std::wstring &input) {
struct wc_flags {
enum TYPE : unsigned int {
// WC_ERR_INVALID_CHARS
err_invalid_chars = 0x00000080U
};
};
if (input.empty()) {
return std::string();
}
UINT cp = CP_UTF8;
DWORD flags = wc_flags::err_invalid_chars;
auto input_c = input.c_str();
auto input_length = static_cast<int>(input.size());
auto required_length = WideCharToMultiByte(cp, flags, input_c, input_length,
nullptr, 0, nullptr, nullptr);
if (required_length > 0) {
std::string output(static_cast<std::size_t>(required_length), '\0');
if (WideCharToMultiByte(cp, flags, input_c, input_length, &output[0],
required_length, nullptr, nullptr) > 0) {
return output;
}
}
// Failed to convert string from UTF-16 to UTF-8
return std::string();
}
// Parses a version string with 1-4 integral components, e.g. "1.2.3.4".
// Missing or invalid components default to 0, and excess components are ignored.
template <typename T>
std::array<unsigned int, 4>
parse_version(const std::basic_string<T> &version) noexcept {
auto parse_component = [](auto sb, auto se) -> unsigned int {
try {
auto n = std::stol(std::basic_string<T>(sb, se));
return n < 0 ? 0 : n;
} catch (std::exception &) {
return 0;
}
};
auto end = version.end();
auto sb = version.begin(); // subrange begin
auto se = sb; // subrange end
unsigned int ci = 0; // component index
std::array<unsigned int, 4> components{};
while (sb != end && se != end && ci < components.size()) {
if (*se == static_cast<T>('.')) {
components[ci++] = parse_component(sb, se);
sb = ++se;
continue;
}
++se;
}
if (sb < se && ci < components.size()) {
components[ci] = parse_component(sb, se);
}
return components;
}
template <typename T, std::size_t Length>
auto parse_version(const T (&version)[Length]) noexcept {
return parse_version(std::basic_string<T>(version, Length));
}
std::wstring get_file_version_string(const std::wstring &file_path) noexcept {
DWORD dummy_handle; // Unused
DWORD info_buffer_length =
GetFileVersionInfoSizeW(file_path.c_str(), &dummy_handle);
if (info_buffer_length == 0) {
return std::wstring();
}
std::vector<char> info_buffer;
info_buffer.reserve(info_buffer_length);
if (!GetFileVersionInfoW(file_path.c_str(), 0, info_buffer_length,
info_buffer.data())) {
return std::wstring();
}
auto sub_block = L"\\StringFileInfo\\040904B0\\ProductVersion";
LPWSTR version = nullptr;
unsigned int version_length = 0;
if (!VerQueryValueW(info_buffer.data(), sub_block,
reinterpret_cast<LPVOID *>(&version), &version_length)) {
return std::wstring();
}
if (!version || version_length == 0) {
return std::wstring();
}
return std::wstring(version, version_length);
}
// A wrapper around COM library initialization. Calls CoInitializeEx in the
// constructor and CoUninitialize in the destructor.
class com_init_wrapper {
public:
com_init_wrapper(DWORD dwCoInit) {
// We can safely continue as long as COM was either successfully
// initialized or already initialized.
// RPC_E_CHANGED_MODE means that CoInitializeEx was already called with
// a different concurrency model.
switch (CoInitializeEx(nullptr, dwCoInit)) {
case S_OK:
case S_FALSE:
m_initialized = true;
break;
}
}
~com_init_wrapper() {
if (m_initialized) {
CoUninitialize();
m_initialized = false;
}
}
com_init_wrapper(const com_init_wrapper &other) = delete;
com_init_wrapper &operator=(const com_init_wrapper &other) = delete;
com_init_wrapper(com_init_wrapper &&other) = delete;
com_init_wrapper &operator=(com_init_wrapper &&other) = delete;
bool is_initialized() const { return m_initialized; }
private:
bool m_initialized = false;
};
// Holds a symbol name and associated type for code clarity.
template <typename T> class library_symbol {
public:
using type = T;
constexpr explicit library_symbol(const char *name) : m_name(name) {}
constexpr const char *get_name() const { return m_name; }
private:
const char *m_name;
};
// Loads a native shared library and allows one to get addresses for those
// symbols.
class native_library {
public:
explicit native_library(const wchar_t *name) : m_handle(LoadLibraryW(name)) {}
~native_library() {
if (m_handle) {
FreeLibrary(m_handle);
m_handle = nullptr;
}
}
native_library(const native_library &other) = delete;
native_library &operator=(const native_library &other) = delete;
native_library(native_library &&other) = default;
native_library &operator=(native_library &&other) = default;
// Returns true if the library is currently loaded; otherwise false.
operator bool() const { return is_loaded(); }
// Get the address for the specified symbol or nullptr if not found.
template <typename Symbol>
typename Symbol::type get(const Symbol &symbol) const {
if (is_loaded()) {
return reinterpret_cast<typename Symbol::type>(
GetProcAddress(m_handle, symbol.get_name()));
}
return nullptr;
}
// Returns true if the library is currently loaded; otherwise false.
bool is_loaded() const { return !!m_handle; }
void detach() { m_handle = nullptr; }
private:
HMODULE m_handle = nullptr;
};
namespace ntdll_symbols {
using RtlGetVersion_t =
unsigned int /*NTSTATUS*/ (WINAPI *)(RTL_OSVERSIONINFOW *);
constexpr auto RtlGetVersion = library_symbol<RtlGetVersion_t>("RtlGetVersion");
}; // namespace ntdll_symbols
namespace user32_symbols {
using DPI_AWARENESS_CONTEXT = HANDLE;
using SetProcessDpiAwarenessContext_t = BOOL(WINAPI *)(DPI_AWARENESS_CONTEXT);
using SetProcessDPIAware_t = BOOL(WINAPI *)();
using GetDpiForWindow_t = UINT(WINAPI *)(HWND);
using EnableNonClientDpiScaling_t = BOOL(WINAPI *)(HWND);
using AdjustWindowRectExForDpi_t = BOOL(WINAPI *)(LPRECT, DWORD, BOOL, DWORD,
UINT);
using GetWindowDpiAwarenessContext_t = DPI_AWARENESS_CONTEXT(WINAPI *)(HWND);
using AreDpiAwarenessContextsEqual_t = BOOL(WINAPI *)(DPI_AWARENESS_CONTEXT,
DPI_AWARENESS_CONTEXT);
// Use intptr_t as the underlying type because we need to
// reinterpret_cast<DPI_AWARENESS_CONTEXT> which is a pointer.
// Available since Windows 10, version 1607
enum class dpi_awareness : intptr_t {
per_monitor_v2_aware = -4, // Available since Windows 10, version 1703
per_monitor_aware = -3
};
constexpr auto SetProcessDpiAwarenessContext =
library_symbol<SetProcessDpiAwarenessContext_t>(
"SetProcessDpiAwarenessContext");
constexpr auto SetProcessDPIAware =
library_symbol<SetProcessDPIAware_t>("SetProcessDPIAware");
constexpr auto GetDpiForWindow =
library_symbol<GetDpiForWindow_t>("GetDpiForWindow");
constexpr auto EnableNonClientDpiScaling =
library_symbol<EnableNonClientDpiScaling_t>("EnableNonClientDpiScaling");
constexpr auto AdjustWindowRectExForDpi =
library_symbol<AdjustWindowRectExForDpi_t>("AdjustWindowRectExForDpi");
constexpr auto GetWindowDpiAwarenessContext =
library_symbol<GetWindowDpiAwarenessContext_t>(
"GetWindowDpiAwarenessContext");
constexpr auto AreDpiAwarenessContextsEqual =
library_symbol<AreDpiAwarenessContextsEqual_t>(
"AreDpiAwarenessContextsEqual");
}; // namespace user32_symbols
namespace dwmapi_symbols {
typedef enum {
// This undocumented value is used instead of DWMWA_USE_IMMERSIVE_DARK_MODE
// on Windows 10 older than build 19041 (2004/20H1).
DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_V10_0_19041 = 19,
// Documented as being supported since Windows 11 build 22000 (21H2) but it
// works since Windows 10 build 19041 (2004/20H1).
DWMWA_USE_IMMERSIVE_DARK_MODE = 20
} DWMWINDOWATTRIBUTE;
using DwmSetWindowAttribute_t = HRESULT(WINAPI *)(HWND, DWORD, LPCVOID, DWORD);
constexpr auto DwmSetWindowAttribute =
library_symbol<DwmSetWindowAttribute_t>("DwmSetWindowAttribute");
}; // namespace dwmapi_symbols
namespace shcore_symbols {
typedef enum { PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS;
using SetProcessDpiAwareness_t = HRESULT(WINAPI *)(PROCESS_DPI_AWARENESS);
constexpr auto SetProcessDpiAwareness =
library_symbol<SetProcessDpiAwareness_t>("SetProcessDpiAwareness");
}; // namespace shcore_symbols
class reg_key {
public:
explicit reg_key(HKEY root_key, const wchar_t *sub_key, DWORD options,
REGSAM sam_desired) {
HKEY handle;
auto status =
RegOpenKeyExW(root_key, sub_key, options, sam_desired, &handle);
if (status == ERROR_SUCCESS) {
m_handle = handle;
}
}
explicit reg_key(HKEY root_key, const std::wstring &sub_key, DWORD options,
REGSAM sam_desired)
: reg_key(root_key, sub_key.c_str(), options, sam_desired) {}
virtual ~reg_key() {
if (m_handle) {
RegCloseKey(m_handle);
m_handle = nullptr;
}
}
reg_key(const reg_key &other) = delete;
reg_key &operator=(const reg_key &other) = delete;
reg_key(reg_key &&other) = delete;
reg_key &operator=(reg_key &&other) = delete;
bool is_open() const { return !!m_handle; }
bool get_handle() const { return m_handle; }
template <typename Container>
void query_bytes(const wchar_t *name, Container &result) const {
DWORD buf_length = 0;
// Get the size of the data in bytes.
auto status = RegQueryValueExW(m_handle, name, nullptr, nullptr, nullptr,
&buf_length);
if (status != ERROR_SUCCESS && status != ERROR_MORE_DATA) {
result.resize(0);
return;
}
// Read the data.
result.resize(buf_length / sizeof(typename Container::value_type));
auto *buf = reinterpret_cast<LPBYTE>(&result[0]);
status =
RegQueryValueExW(m_handle, name, nullptr, nullptr, buf, &buf_length);
if (status != ERROR_SUCCESS) {
result.resize(0);
return;
}
}
std::wstring query_string(const wchar_t *name) const {
std::wstring result;
query_bytes(name, result);
// Remove trailing null-characters.
for (std::size_t length = result.size(); length > 0; --length) {
if (result[length - 1] != 0) {
result.resize(length);
break;
}
}
return result;
}
unsigned int query_uint(const wchar_t *name,
unsigned int default_value) const {
std::vector<char> data;
query_bytes(name, data);
if (data.size() < sizeof(DWORD)) {
return default_value;
}
return static_cast<unsigned int>(*reinterpret_cast<DWORD *>(data.data()));
}
private:
HKEY m_handle = nullptr;
};
// Compare the specified version against the OS version.
// Returns less than 0 if the OS version is less.
// Returns 0 if the versions are equal.
// Returns greater than 0 if the specified version is greater.
inline int compare_os_version(unsigned int major, unsigned int minor,
unsigned int build) {
// Use RtlGetVersion both to bypass potential issues related to
// VerifyVersionInfo and manifests, and because both GetVersion and
// GetVersionEx are deprecated.
auto ntdll = native_library(L"ntdll.dll");
if (auto fn = ntdll.get(ntdll_symbols::RtlGetVersion)) {
RTL_OSVERSIONINFOW vi{};
vi.dwOSVersionInfoSize = sizeof(vi);
if (fn(&vi) != 0) {
return false;
}
if (vi.dwMajorVersion == major) {
if (vi.dwMinorVersion == minor) {
return static_cast<int>(vi.dwBuildNumber) - static_cast<int>(build);
}
return static_cast<int>(vi.dwMinorVersion) - static_cast<int>(minor);
}
return static_cast<int>(vi.dwMajorVersion) - static_cast<int>(major);
}
return false;
}
inline bool is_per_monitor_v2_awareness_available() {
// Windows 10, version 1703
return compare_os_version(10, 0, 15063) >= 0;
}
inline bool enable_dpi_awareness() {
auto user32 = native_library(L"user32.dll");
if (auto fn = user32.get(user32_symbols::SetProcessDpiAwarenessContext)) {
auto dpi_awareness =
reinterpret_cast<user32_symbols::DPI_AWARENESS_CONTEXT>(
is_per_monitor_v2_awareness_available()
? user32_symbols::dpi_awareness::per_monitor_v2_aware
: user32_symbols::dpi_awareness::per_monitor_aware);
if (fn(dpi_awareness)) {
return true;
}
return GetLastError() == ERROR_ACCESS_DENIED;
}
if (auto shcore = native_library(L"shcore.dll")) {
if (auto fn = shcore.get(shcore_symbols::SetProcessDpiAwareness)) {
auto result = fn(shcore_symbols::PROCESS_PER_MONITOR_DPI_AWARE);
return result == S_OK || result == E_ACCESSDENIED;
}
}
if (auto fn = user32.get(user32_symbols::SetProcessDPIAware)) {
return !!fn();
}
return true;
}
inline bool enable_non_client_dpi_scaling_if_needed(HWND window) {
auto user32 = native_library(L"user32.dll");
auto get_ctx_fn = user32.get(user32_symbols::GetWindowDpiAwarenessContext);
if (!get_ctx_fn) {
return true;
}
auto awareness = get_ctx_fn(window);
if (!awareness) {
return false;
}
auto ctx_equal_fn = user32.get(user32_symbols::AreDpiAwarenessContextsEqual);
if (!ctx_equal_fn) {
return true;
}
// EnableNonClientDpiScaling is only needed with per monitor v1 awareness.
auto per_monitor = reinterpret_cast<user32_symbols::DPI_AWARENESS_CONTEXT>(
user32_symbols::dpi_awareness::per_monitor_aware);
if (!ctx_equal_fn(awareness, per_monitor)) {
return true;
}
auto enable_fn = user32.get(user32_symbols::EnableNonClientDpiScaling);
if (!enable_fn) {
return true;
}
return !!enable_fn(window);
}
constexpr int get_default_window_dpi() {
constexpr const int default_dpi = 96; // USER_DEFAULT_SCREEN_DPI
return default_dpi;
}
inline int get_window_dpi(HWND window) {
auto user32 = native_library(L"user32.dll");
if (auto fn = user32.get(user32_symbols::GetDpiForWindow)) {
auto dpi = static_cast<int>(fn(window));
return dpi;
}
return get_default_window_dpi();
}
constexpr int scale_value_for_dpi(int value, int from_dpi, int to_dpi) {
return (value * to_dpi) / from_dpi;
}
constexpr SIZE scale_size(int width, int height, int from_dpi, int to_dpi) {
auto scaled_width = scale_value_for_dpi(width, from_dpi, to_dpi);
auto scaled_height = scale_value_for_dpi(height, from_dpi, to_dpi);
return {scaled_width, scaled_height};
}
inline SIZE make_window_frame_size(HWND window, int width, int height,
int dpi) {
auto style = GetWindowLong(window, GWL_STYLE);
RECT r{0, 0, width, height};
auto user32 = native_library(L"user32.dll");
if (auto fn = user32.get(user32_symbols::AdjustWindowRectExForDpi)) {
fn(&r, style, FALSE, 0, static_cast<UINT>(dpi));
} else {
AdjustWindowRect(&r, style, 0);
}
auto frame_width = r.right - r.left;
auto frame_height = r.bottom - r.top;
return {frame_width, frame_height};
}
inline bool is_dark_theme_enabled() {
constexpr auto *sub_key =
L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
reg_key key(HKEY_CURRENT_USER, sub_key, 0, KEY_READ);
if (!key.is_open()) {
// Default is light theme
return false;
}
return key.query_uint(L"AppsUseLightTheme", 1) == 0;
}
inline void apply_window_theme(HWND window) {
auto dark_theme_enabled = is_dark_theme_enabled();
// Use "immersive dark mode" on systems that support it.
// Changes the color of the window's title bar (light or dark).
BOOL use_dark_mode{dark_theme_enabled ? TRUE : FALSE};
static native_library dwmapi{L"dwmapi.dll"};
if (auto fn = dwmapi.get(dwmapi_symbols::DwmSetWindowAttribute)) {
// Try the modern, documented attribute before the older, undocumented one.
if (fn(window, dwmapi_symbols::DWMWA_USE_IMMERSIVE_DARK_MODE,
&use_dark_mode, sizeof(use_dark_mode)) != S_OK) {
fn(window,
dwmapi_symbols::DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_V10_0_19041,
&use_dark_mode, sizeof(use_dark_mode));
}
}
}
// Enable built-in WebView2Loader implementation by default.
#ifndef WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL
#define WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL 1
#endif
// Link WebView2Loader.dll explicitly by default only if the built-in
// implementation is enabled.
#ifndef WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK
#define WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL
#endif
// Explicit linking of WebView2Loader.dll should be used along with
// the built-in implementation.
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1 && \
WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK != 1
#undef WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK
#error Please set WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK=1.
#endif
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1
// Gets the last component of a Windows native file path.
// For example, if the path is "C:\a\b" then the result is "b".
template <typename T>
std::basic_string<T>
get_last_native_path_component(const std::basic_string<T> &path) {
auto pos = path.find_last_of(static_cast<T>('\\'));
if (pos != std::basic_string<T>::npos) {
return path.substr(pos + 1);
}
return std::basic_string<T>();
}
#endif /* WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL */
template <typename T> struct cast_info_t {
using type = T;
IID iid;
};
namespace mswebview2 {
static constexpr IID
IID_ICoreWebView2CreateCoreWebView2ControllerCompletedHandler{
0x6C4819F3, 0xC9B7, 0x4260, 0x81, 0x27, 0xC9,
0xF5, 0xBD, 0xE7, 0xF6, 0x8C};
static constexpr IID
IID_ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler{
0x4E8A3389, 0xC9D8, 0x4BD2, 0xB6, 0xB5, 0x12,
0x4F, 0xEE, 0x6C, 0xC1, 0x4D};
static constexpr IID IID_ICoreWebView2PermissionRequestedEventHandler{
0x15E1C6A3, 0xC72A, 0x4DF3, 0x91, 0xD7, 0xD0, 0x97, 0xFB, 0xEC, 0x6B, 0xFD};
static constexpr IID IID_ICoreWebView2WebMessageReceivedEventHandler{
0x57213F19, 0x00E6, 0x49FA, 0x8E, 0x07, 0x89, 0x8E, 0xA0, 0x1E, 0xCB, 0xD2};
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1
enum class webview2_runtime_type { installed = 0, embedded = 1 };
namespace webview2_symbols {
using CreateWebViewEnvironmentWithOptionsInternal_t =
HRESULT(STDMETHODCALLTYPE *)(
bool, webview2_runtime_type, PCWSTR, IUnknown *,
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler *);
using DllCanUnloadNow_t = HRESULT(STDMETHODCALLTYPE *)();
static constexpr auto CreateWebViewEnvironmentWithOptionsInternal =
library_symbol<CreateWebViewEnvironmentWithOptionsInternal_t>(
"CreateWebViewEnvironmentWithOptionsInternal");
static constexpr auto DllCanUnloadNow =
library_symbol<DllCanUnloadNow_t>("DllCanUnloadNow");
} // namespace webview2_symbols
#endif /* WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL */
#if WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK == 1
namespace webview2_symbols {
using CreateCoreWebView2EnvironmentWithOptions_t = HRESULT(STDMETHODCALLTYPE *)(
PCWSTR, PCWSTR, ICoreWebView2EnvironmentOptions *,
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler *);
using GetAvailableCoreWebView2BrowserVersionString_t =
HRESULT(STDMETHODCALLTYPE *)(PCWSTR, LPWSTR *);
static constexpr auto CreateCoreWebView2EnvironmentWithOptions =
library_symbol<CreateCoreWebView2EnvironmentWithOptions_t>(
"CreateCoreWebView2EnvironmentWithOptions");
static constexpr auto GetAvailableCoreWebView2BrowserVersionString =
library_symbol<GetAvailableCoreWebView2BrowserVersionString_t>(
"GetAvailableCoreWebView2BrowserVersionString");
} // namespace webview2_symbols
#endif /* WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK */
class loader {
public:
HRESULT create_environment_with_options(
PCWSTR browser_dir, PCWSTR user_data_dir,
ICoreWebView2EnvironmentOptions *env_options,
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler
*created_handler) const {
#if WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK == 1
if (m_lib.is_loaded()) {
if (auto fn = m_lib.get(
webview2_symbols::CreateCoreWebView2EnvironmentWithOptions)) {
return fn(browser_dir, user_data_dir, env_options, created_handler);
}
}
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1
return create_environment_with_options_impl(browser_dir, user_data_dir,
env_options, created_handler);
#else
return S_FALSE;
#endif
#else
return ::CreateCoreWebView2EnvironmentWithOptions(
browser_dir, user_data_dir, env_options, created_handler);
#endif /* WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK */
}
HRESULT
get_available_browser_version_string(PCWSTR browser_dir,
LPWSTR *version) const {
#if WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK == 1
if (m_lib.is_loaded()) {
if (auto fn = m_lib.get(
webview2_symbols::GetAvailableCoreWebView2BrowserVersionString)) {
return fn(browser_dir, version);
}
}
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1
return get_available_browser_version_string_impl(browser_dir, version);
#else
return S_FALSE;
#endif
#else
return ::GetAvailableCoreWebView2BrowserVersionString(browser_dir, version);
#endif /* WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK */
}
private:
#if WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL == 1
struct client_info_t {
bool found = false;
std::wstring dll_path;
std::wstring version;
webview2_runtime_type runtime_type;
};
HRESULT create_environment_with_options_impl(
PCWSTR browser_dir, PCWSTR user_data_dir,
ICoreWebView2EnvironmentOptions *env_options,
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler
*created_handler) const {
auto found_client = find_available_client(browser_dir);
if (!found_client.found) {
return -1;
}
auto client_dll = native_library(found_client.dll_path.c_str());
if (auto fn = client_dll.get(
webview2_symbols::CreateWebViewEnvironmentWithOptionsInternal)) {
return fn(true, found_client.runtime_type, user_data_dir, env_options,
created_handler);
}
if (auto fn = client_dll.get(webview2_symbols::DllCanUnloadNow)) {
if (!fn()) {
client_dll.detach();
}
}
return ERROR_SUCCESS;
}
HRESULT
get_available_browser_version_string_impl(PCWSTR browser_dir,
LPWSTR *version) const {
if (!version) {
return -1;
}
auto found_client = find_available_client(browser_dir);
if (!found_client.found) {
return -1;
}
auto info_length_bytes =
found_client.version.size() * sizeof(found_client.version[0]);
auto info = static_cast<LPWSTR>(CoTaskMemAlloc(info_length_bytes));
if (!info) {
return -1;
}
CopyMemory(info, found_client.version.c_str(), info_length_bytes);
*version = info;
return 0;
}
client_info_t find_available_client(PCWSTR browser_dir) const {
if (browser_dir) {
return find_embedded_client(api_version, browser_dir);
}
auto found_client =
find_installed_client(api_version, true, default_release_channel_guid);
if (!found_client.found) {
found_client = find_installed_client(api_version, false,
default_release_channel_guid);
}
return found_client;
}
std::wstring make_client_dll_path(const std::wstring &dir) const {
auto dll_path = dir;
if (!dll_path.empty()) {
auto last_char = dir[dir.size() - 1];
if (last_char != L'\\' && last_char != L'/') {
dll_path += L'\\';
}
}
dll_path += L"EBWebView\\";
#if defined(_M_X64) || defined(__x86_64__)
dll_path += L"x64";
#elif defined(_M_IX86) || defined(__i386__)
dll_path += L"x86";
#elif defined(_M_ARM64) || defined(__aarch64__)
dll_path += L"arm64";
#else
#error WebView2 integration for this platform is not yet supported.
#endif
dll_path += L"\\EmbeddedBrowserWebView.dll";
return dll_path;
}
client_info_t
find_installed_client(unsigned int min_api_version, bool system,
const std::wstring &release_channel) const {
std::wstring sub_key = client_state_reg_sub_key;
sub_key += release_channel;
auto root_key = system ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
reg_key key(root_key, sub_key, 0, KEY_READ | KEY_WOW64_32KEY);
if (!key.is_open()) {
return {};
}
auto ebwebview_value = key.query_string(L"EBWebView");
auto client_version_string =
get_last_native_path_component(ebwebview_value);
auto client_version = parse_version(client_version_string);
if (client_version[2] < min_api_version) {
// Our API version is greater than the runtime API version.
return {};
}
auto client_dll_path = make_client_dll_path(ebwebview_value);
return {true, client_dll_path, client_version_string,
webview2_runtime_type::installed};
}
client_info_t find_embedded_client(unsigned int min_api_version,
const std::wstring &dir) const {
auto client_dll_path = make_client_dll_path(dir);
auto client_version_string = get_file_version_string(client_dll_path);
auto client_version = parse_version(client_version_string);
if (client_version[2] < min_api_version) {
// Our API version is greater than the runtime API version.
return {};
}
return {true, client_dll_path, client_version_string,
webview2_runtime_type::embedded};
}
// The minimum WebView2 API version we need regardless of the SDK release
// actually used. The number comes from the SDK release version,
// e.g. 1.0.1150.38. To be safe the SDK should have a number that is greater
// than or equal to this number. The Edge browser webview client must
// have a number greater than or equal to this number.
static constexpr unsigned int api_version = 1150;
static constexpr auto client_state_reg_sub_key =
L"SOFTWARE\\Microsoft\\EdgeUpdate\\ClientState\\";
// GUID for the stable release channel.
static constexpr auto stable_release_guid =
L"{F3017226-FE2A-4295-8BDF-00C3A9A7E4C5}";
static constexpr auto default_release_channel_guid = stable_release_guid;
#endif /* WEBVIEW_MSWEBVIEW2_BUILTIN_IMPL */
#if WEBVIEW_MSWEBVIEW2_EXPLICIT_LINK == 1
native_library m_lib{L"WebView2Loader.dll"};
#endif
};
namespace cast_info {
static constexpr auto controller_completed =
cast_info_t<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>{
IID_ICoreWebView2CreateCoreWebView2ControllerCompletedHandler};
static constexpr auto environment_completed =
cast_info_t<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>{
IID_ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler};
static constexpr auto message_received =
cast_info_t<ICoreWebView2WebMessageReceivedEventHandler>{
IID_ICoreWebView2WebMessageReceivedEventHandler};
static constexpr auto permission_requested =
cast_info_t<ICoreWebView2PermissionRequestedEventHandler>{
IID_ICoreWebView2PermissionRequestedEventHandler};
} // namespace cast_info
} // namespace mswebview2
class webview2_com_handler
: public ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler,
public ICoreWebView2CreateCoreWebView2ControllerCompletedHandler,
public ICoreWebView2WebMessageReceivedEventHandler,
public ICoreWebView2PermissionRequestedEventHandler {
using webview2_com_handler_cb_t =
std::function<void(ICoreWebView2Controller *, ICoreWebView2 *webview)>;
public:
webview2_com_handler(HWND hwnd, msg_cb_t msgCb, webview2_com_handler_cb_t cb)
: m_window(hwnd), m_msgCb(msgCb), m_cb(cb) {}
virtual ~webview2_com_handler() = default;
webview2_com_handler(const webview2_com_handler &other) = delete;
webview2_com_handler &operator=(const webview2_com_handler &other) = delete;
webview2_com_handler(webview2_com_handler &&other) = delete;
webview2_com_handler &operator=(webview2_com_handler &&other) = delete;
ULONG STDMETHODCALLTYPE AddRef() { return ++m_ref_count; }
ULONG STDMETHODCALLTYPE Release() {
if (m_ref_count > 1) {
return --m_ref_count;
}
delete this;
return 0;
}
HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, LPVOID *ppv) {
using namespace mswebview2::cast_info;
if (!ppv) {
return E_POINTER;
}
// All of the COM interfaces we implement should be added here regardless
// of whether they are required.
// This is just to be on the safe side in case the WebView2 Runtime ever
// requests a pointer to an interface we implement.
// The WebView2 Runtime must at the very least be able to get a pointer to
// ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler when we use
// our custom WebView2 loader implementation, and observations have shown
// that it is the only interface requested in this case. None have been
// observed to be requested when using the official WebView2 loader.
if (cast_if_equal_iid(riid, controller_completed, ppv) ||
cast_if_equal_iid(riid, environment_completed, ppv) ||
cast_if_equal_iid(riid, message_received, ppv) ||
cast_if_equal_iid(riid, permission_requested, ppv)) {
return S_OK;
}
return E_NOINTERFACE;
}
HRESULT STDMETHODCALLTYPE Invoke(HRESULT res, ICoreWebView2Environment *env) {
if (SUCCEEDED(res)) {
res = env->CreateCoreWebView2Controller(m_window, this);
if (SUCCEEDED(res)) {
return S_OK;
}
}
try_create_environment();
return S_OK;
}
HRESULT STDMETHODCALLTYPE Invoke(HRESULT res,
ICoreWebView2Controller *controller) {
if (FAILED(res)) {
// See try_create_environment() regarding
// HRESULT_FROM_WIN32(ERROR_INVALID_STATE).
// The result is E_ABORT if the parent window has been destroyed already.
switch (res) {
case HRESULT_FROM_WIN32(ERROR_INVALID_STATE):
case E_ABORT:
return S_OK;
}
try_create_environment();
return S_OK;
}
ICoreWebView2 *webview;
::EventRegistrationToken token;
controller->get_CoreWebView2(&webview);
webview->add_WebMessageReceived(this, &token);
webview->add_PermissionRequested(this, &token);
m_cb(controller, webview);
return S_OK;
}
HRESULT STDMETHODCALLTYPE Invoke(
ICoreWebView2 *sender, ICoreWebView2WebMessageReceivedEventArgs *args) {
LPWSTR message;
args->TryGetWebMessageAsString(&message);
m_msgCb(narrow_string(message));
sender->PostWebMessageAsString(message);
CoTaskMemFree(message);
return S_OK;
}
HRESULT STDMETHODCALLTYPE
Invoke(ICoreWebView2 * /*sender*/,
ICoreWebView2PermissionRequestedEventArgs *args) {
COREWEBVIEW2_PERMISSION_KIND kind;
args->get_PermissionKind(&kind);
if (kind == COREWEBVIEW2_PERMISSION_KIND_CLIPBOARD_READ) {
args->put_State(COREWEBVIEW2_PERMISSION_STATE_ALLOW);
}
return S_OK;
}
// Checks whether the specified IID equals the IID of the specified type and
// if so casts the "this" pointer to T and returns it. Returns nullptr on
// mismatching IIDs.
// If ppv is specified then the pointer will also be assigned to *ppv.
template <typename T>
T *cast_if_equal_iid(REFIID riid, const cast_info_t<T> &info,
LPVOID *ppv = nullptr) noexcept {
T *ptr = nullptr;
if (IsEqualIID(riid, info.iid)) {
ptr = static_cast<T *>(this);
ptr->AddRef();
}
if (ppv) {
*ppv = ptr;
}
return ptr;
}
// Set the function that will perform the initiating logic for creating
// the WebView2 environment.
void set_attempt_handler(std::function<HRESULT()> attempt_handler) noexcept {
m_attempt_handler = attempt_handler;
}
// Retry creating a WebView2 environment.
// The initiating logic for creating the environment is defined by the
// caller of set_attempt_handler().
void try_create_environment() noexcept {
// WebView creation fails with HRESULT_FROM_WIN32(ERROR_INVALID_STATE) if
// a running instance using the same user data folder exists, and the
// Environment objects have different EnvironmentOptions.
// Source: https://docs.microsoft.com/en-us/microsoft-edge/webview2/reference/win32/icorewebview2environment?view=webview2-1.0.1150.38
if (m_attempts < m_max_attempts) {
++m_attempts;
auto res = m_attempt_handler();
if (SUCCEEDED(res)) {
return;
}
// Not entirely sure if this error code only applies to
// CreateCoreWebView2Controller so we check here as well.
if (res == HRESULT_FROM_WIN32(ERROR_INVALID_STATE)) {
return;
}
try_create_environment();
return;
}
// Give up.
m_cb(nullptr, nullptr);
}
private:
HWND m_window;
msg_cb_t m_msgCb;
webview2_com_handler_cb_t m_cb;
std::atomic<ULONG> m_ref_count{1};
std::function<HRESULT()> m_attempt_handler;
unsigned int m_max_attempts = 5;
unsigned int m_attempts = 0;
};
class win32_edge_engine {
public:
win32_edge_engine(bool debug, void *window) {
if (!is_webview2_available()) {
return;
}
if (!m_com_init.is_initialized()) {
return;
}
enable_dpi_awareness();
if (window == nullptr) {
HINSTANCE hInstance = GetModuleHandle(nullptr);
HICON icon = (HICON)LoadImage(
hInstance, IDI_APPLICATION, IMAGE_ICON, GetSystemMetrics(SM_CXICON),
GetSystemMetrics(SM_CYICON), LR_DEFAULTCOLOR);
WNDCLASSEXW wc;
ZeroMemory(&wc, sizeof(WNDCLASSEX));
wc.cbSize = sizeof(WNDCLASSEX);
wc.hInstance = hInstance;
wc.lpszClassName = L"webview";
wc.hIcon = icon;
wc.lpfnWndProc = (WNDPROC)(+[](HWND hwnd, UINT msg, WPARAM wp,
LPARAM lp) -> LRESULT {
win32_edge_engine *w{};
if (msg == WM_NCCREATE) {
auto *lpcs{reinterpret_cast<LPCREATESTRUCT>(lp)};
w = static_cast<win32_edge_engine *>(lpcs->lpCreateParams);
w->m_window = hwnd;
SetWindowLongPtrW(hwnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(w));
enable_non_client_dpi_scaling_if_needed(hwnd);
apply_window_theme(hwnd);
} else {
w = reinterpret_cast<win32_edge_engine *>(
GetWindowLongPtrW(hwnd, GWLP_USERDATA));
}
if (!w) {
return DefWindowProcW(hwnd, msg, wp, lp);
}
switch (msg) {
case WM_SIZE:
w->resize_widget();
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
w->terminate();
break;
case WM_GETMINMAXINFO: {
auto lpmmi = (LPMINMAXINFO)lp;
if (w == nullptr) {
return 0;
}
if (w->m_maxsz.x > 0 && w->m_maxsz.y > 0) {
lpmmi->ptMaxSize = w->m_maxsz;
lpmmi->ptMaxTrackSize = w->m_maxsz;
}
if (w->m_minsz.x > 0 && w->m_minsz.y > 0) {
lpmmi->ptMinTrackSize = w->m_minsz;
}
} break;
case 0x02E4 /*WM_GETDPISCALEDSIZE*/: {
auto dpi = static_cast<int>(wp);
auto *size{reinterpret_cast<SIZE *>(lp)};
*size = w->get_scaled_size(w->m_dpi, dpi);
return TRUE;
}
case 0x02E0 /*WM_DPICHANGED*/: {
// Windows 10: The size we get here is exactly what we supplied to WM_GETDPISCALEDSIZE.
// Windows 11: The size we get here is NOT what we supplied to WM_GETDPISCALEDSIZE.
// Due to this difference, don't use the suggested bounds.
auto dpi = static_cast<int>(HIWORD(wp));
w->on_dpi_changed(dpi);
break;
}
case WM_SETTINGCHANGE: {
auto *area = reinterpret_cast<const wchar_t *>(lp);
if (area) {
w->on_system_setting_change(area);
}
break;
}
default:
return DefWindowProcW(hwnd, msg, wp, lp);
}
return 0;
});
RegisterClassExW(&wc);
CreateWindowW(L"webview", L"", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,
CW_USEDEFAULT, 0, 0, nullptr, nullptr, hInstance, this);
if (m_window == nullptr) {
return;
}
m_dpi = get_window_dpi(m_window);
constexpr const int initial_width = 640;
constexpr const int initial_height = 480;
set_size(initial_width, initial_height, WEBVIEW_HINT_NONE);
} else {
m_window = *(static_cast<HWND *>(window));
m_dpi = get_window_dpi(m_window);
}
ShowWindow(m_window, SW_SHOW);
UpdateWindow(m_window);
SetFocus(m_window);
auto cb =
std::bind(&win32_edge_engine::on_message, this, std::placeholders::_1);
embed(m_window, debug, cb);
resize_widget();
m_controller->MoveFocus(COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC);
}
virtual ~win32_edge_engine() {
if (m_com_handler) {
m_com_handler->Release();
m_com_handler = nullptr;
}
if (m_webview) {
m_webview->Release();
m_webview = nullptr;
}
if (m_controller) {
m_controller->Release();
m_controller = nullptr;
}
}
win32_edge_engine(const win32_edge_engine &other) = delete;
win32_edge_engine &operator=(const win32_edge_engine &other) = delete;
win32_edge_engine(win32_edge_engine &&other) = delete;
win32_edge_engine &operator=(win32_edge_engine &&other) = delete;
void run() {
MSG msg;
BOOL res;
while ((res = GetMessage(&msg, nullptr, 0, 0)) != -1) {
if (msg.hwnd) {
TranslateMessage(&msg);
DispatchMessage(&msg);
continue;
}
if (msg.message == WM_APP) {
auto f = (dispatch_fn_t *)(msg.lParam);
(*f)();
delete f;
} else if (msg.message == WM_QUIT) {
return;
}
}
}
void *window() { return (void *)m_window; }
void terminate() { PostQuitMessage(0); }
void dispatch(dispatch_fn_t f) {
PostThreadMessage(m_main_thread, WM_APP, 0, (LPARAM) new dispatch_fn_t(f));
}
void set_title(const std::string &title) {
SetWindowTextW(m_window, widen_string(title).c_str());
}
void set_size(int width, int height, int hints) {
auto style = GetWindowLong(m_window, GWL_STYLE);
if (hints == WEBVIEW_HINT_FIXED) {
style &= ~(WS_THICKFRAME | WS_MAXIMIZEBOX);
} else {
style |= (WS_THICKFRAME | WS_MAXIMIZEBOX);
}
SetWindowLong(m_window, GWL_STYLE, style);
if (hints == WEBVIEW_HINT_MAX) {
m_maxsz.x = width;
m_maxsz.y = height;
} else if (hints == WEBVIEW_HINT_MIN) {
m_minsz.x = width;
m_minsz.y = height;
} else {
auto dpi = get_window_dpi(m_window);
m_dpi = dpi;
auto scaled_size =
scale_size(width, height, get_default_window_dpi(), dpi);
auto frame_size =
make_window_frame_size(m_window, scaled_size.cx, scaled_size.cy, dpi);
SetWindowPos(m_window, nullptr, 0, 0, frame_size.cx, frame_size.cy,
SWP_NOZORDER | SWP_NOACTIVATE | SWP_NOMOVE |
SWP_FRAMECHANGED);
}
}
void navigate(const std::string &url) {
auto wurl = widen_string(url);
m_webview->Navigate(wurl.c_str());
}
void init(const std::string &js) {
auto wjs = widen_string(js);
m_webview->AddScriptToExecuteOnDocumentCreated(wjs.c_str(), nullptr);
}
void eval(const std::string &js) {
auto wjs = widen_string(js);
m_webview->ExecuteScript(wjs.c_str(), nullptr);
}
void set_html(const std::string &html) {
m_webview->NavigateToString(widen_string(html).c_str());
}
private:
bool embed(HWND wnd, bool debug, msg_cb_t cb) {
std::atomic_flag flag = ATOMIC_FLAG_INIT;
flag.test_and_set();
wchar_t currentExePath[MAX_PATH];
GetModuleFileNameW(nullptr, currentExePath, MAX_PATH);
wchar_t *currentExeName = PathFindFileNameW(currentExePath);
wchar_t dataPath[MAX_PATH];
if (!SUCCEEDED(
SHGetFolderPathW(nullptr, CSIDL_APPDATA, nullptr, 0, dataPath))) {
return false;
}
wchar_t userDataFolder[MAX_PATH];
PathCombineW(userDataFolder, dataPath, currentExeName);
m_com_handler = new webview2_com_handler(
wnd, cb,
[&](ICoreWebView2Controller *controller, ICoreWebView2 *webview) {
if (!controller || !webview) {
flag.clear();
return;
}
controller->AddRef();
webview->AddRef();
m_controller = controller;
m_webview = webview;
flag.clear();
});
m_com_handler->set_attempt_handler([&] {
return m_webview2_loader.create_environment_with_options(
nullptr, userDataFolder, nullptr, m_com_handler);
});
m_com_handler->try_create_environment();
MSG msg = {};
while (flag.test_and_set() && GetMessage(&msg, nullptr, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
if (!m_controller || !m_webview) {
return false;
}
ICoreWebView2Settings *settings = nullptr;
auto res = m_webview->get_Settings(&settings);
if (res != S_OK) {
return false;
}
res = settings->put_AreDevToolsEnabled(debug ? TRUE : FALSE);
if (res != S_OK) {
return false;
}
init("window.external={invoke:s=>window.chrome.webview.postMessage(s)}");
return true;
}
void resize_widget() {
if (m_controller == nullptr) {
return;
}
RECT bounds;
GetClientRect(m_window, &bounds);
m_controller->put_Bounds(bounds);
}
bool is_webview2_available() const noexcept {
LPWSTR version_info = nullptr;
auto res = m_webview2_loader.get_available_browser_version_string(
nullptr, &version_info);
// The result will be equal to HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND)
// if the WebView2 runtime is not installed.
auto ok = SUCCEEDED(res) && version_info;
if (version_info) {
CoTaskMemFree(version_info);
}
return ok;
}
void on_dpi_changed(int dpi) {
auto scaled_size = get_scaled_size(m_dpi, dpi);
auto frame_size =
make_window_frame_size(m_window, scaled_size.cx, scaled_size.cy, dpi);
SetWindowPos(m_window, nullptr, 0, 0, frame_size.cx, frame_size.cy,
SWP_NOZORDER | SWP_NOACTIVATE | SWP_NOMOVE | SWP_FRAMECHANGED);
m_dpi = dpi;
}
SIZE get_size() const {
RECT bounds;
GetClientRect(m_window, &bounds);
auto width = bounds.right - bounds.left;
auto height = bounds.bottom - bounds.top;
return {width, height};
}
SIZE get_scaled_size(int from_dpi, int to_dpi) const {
auto size = get_size();
return scale_size(size.cx, size.cy, from_dpi, to_dpi);
}
void on_system_setting_change(const wchar_t *area) {
// Detect light/dark mode change in system.
if (lstrcmpW(area, L"ImmersiveColorSet") == 0) {
apply_window_theme(m_window);
}
}
virtual void on_message(const std::string &msg) = 0;
// The app is expected to call CoInitializeEx before
// CreateCoreWebView2EnvironmentWithOptions.
// Source: https://docs.microsoft.com/en-us/microsoft-edge/webview2/reference/win32/webview2-idl#createcorewebview2environmentwithoptions
com_init_wrapper m_com_init{COINIT_APARTMENTTHREADED};
HWND m_window = nullptr;
POINT m_minsz = POINT{0, 0};
POINT m_maxsz = POINT{0, 0};
DWORD m_main_thread = GetCurrentThreadId();
ICoreWebView2 *m_webview = nullptr;
ICoreWebView2Controller *m_controller = nullptr;
webview2_com_handler *m_com_handler = nullptr;
mswebview2::loader m_webview2_loader;
int m_dpi{};
};
} // namespace detail
using browser_engine = detail::win32_edge_engine;
} // namespace webview
#endif /* WEBVIEW_GTK, WEBVIEW_COCOA, WEBVIEW_EDGE */
namespace webview {
class webview : public browser_engine {
public:
webview(bool debug = false, void *wnd = nullptr)
: browser_engine(debug, wnd) {}
void navigate(const std::string &url) {
if (url.empty()) {
browser_engine::navigate("about:blank");
return;
}
browser_engine::navigate(url);
}
using binding_t = std::function<void(std::string, std::string, void *)>;
class binding_ctx_t {
public:
binding_ctx_t(binding_t callback, void *arg)
: callback(callback), arg(arg) {}
// This function is called upon execution of the bound JS function
binding_t callback;
// This user-supplied argument is passed to the callback
void *arg;
};
using sync_binding_t = std::function<std::string(std::string)>;
// Synchronous bind
void bind(const std::string &name, sync_binding_t fn) {
auto wrapper = [this, fn](const std::string &seq, const std::string &req,
void * /*arg*/) { resolve(seq, 0, fn(req)); };
bind(name, wrapper, nullptr);
}
// Asynchronous bind
void bind(const std::string &name, binding_t fn, void *arg) {
if (bindings.count(name) > 0) {
return;
}
bindings.emplace(name, binding_ctx_t(fn, arg));
auto js = "(function() { var name = '" + name + "';" + R""(
var RPC = window._rpc = (window._rpc || {nextSeq: 1});
window[name] = function() {
var seq = RPC.nextSeq++;
var promise = new Promise(function(resolve, reject) {
RPC[seq] = {
resolve: resolve,
reject: reject,
};
});
window.external.invoke(JSON.stringify({
id: seq,
method: name,
params: Array.prototype.slice.call(arguments),
}));
return promise;
}
})())"";
init(js);
eval(js);
}
void unbind(const std::string &name) {
auto found = bindings.find(name);
if (found != bindings.end()) {
auto js = "delete window['" + name + "'];";
init(js);
eval(js);
bindings.erase(found);
}
}
void resolve(const std::string &seq, int status, const std::string &result) {
dispatch([seq, status, result, this]() {
if (status == 0) {
eval("window._rpc[" + seq + "].resolve(" + result +
"); delete window._rpc[" + seq + "]");
} else {
eval("window._rpc[" + seq + "].reject(" + result +
"); delete window._rpc[" + seq + "]");
}
});
}
private:
void on_message(const std::string &msg) {
auto seq = detail::json_parse(msg, "id", 0);
auto name = detail::json_parse(msg, "method", 0);
auto args = detail::json_parse(msg, "params", 0);
auto found = bindings.find(name);
if (found == bindings.end()) {
return;
}
const auto &context = found->second;
context.callback(seq, args, context.arg);
}
std::map<std::string, binding_ctx_t> bindings;
};
} // namespace webview
WEBVIEW_API webview_t webview_create(int debug, void *wnd) {
auto w = new webview::webview(debug, wnd);
if (!w->window()) {
delete w;
return nullptr;
}
return w;
}
WEBVIEW_API void webview_destroy(webview_t w) {
delete static_cast<webview::webview *>(w);
}
WEBVIEW_API void webview_run(webview_t w) {
static_cast<webview::webview *>(w)->run();
}
WEBVIEW_API void webview_terminate(webview_t w) {
static_cast<webview::webview *>(w)->terminate();
}
WEBVIEW_API void webview_dispatch(webview_t w, void (*fn)(webview_t, void *),
void *arg) {
static_cast<webview::webview *>(w)->dispatch([=]() { fn(w, arg); });
}
WEBVIEW_API void *webview_get_window(webview_t w) {
return static_cast<webview::webview *>(w)->window();
}
WEBVIEW_API void webview_set_title(webview_t w, const char *title) {
static_cast<webview::webview *>(w)->set_title(title);
}
WEBVIEW_API void webview_set_size(webview_t w, int width, int height,
int hints) {
static_cast<webview::webview *>(w)->set_size(width, height, hints);
}
WEBVIEW_API void webview_navigate(webview_t w, const char *url) {
static_cast<webview::webview *>(w)->navigate(url);
}
WEBVIEW_API void webview_set_html(webview_t w, const char *html) {
static_cast<webview::webview *>(w)->set_html(html);
}
WEBVIEW_API void webview_init(webview_t w, const char *js) {
static_cast<webview::webview *>(w)->init(js);
}
WEBVIEW_API void webview_eval(webview_t w, const char *js) {
static_cast<webview::webview *>(w)->eval(js);
}
WEBVIEW_API void webview_bind(webview_t w, const char *name,
void (*fn)(const char *seq, const char *req,
void *arg),
void *arg) {
static_cast<webview::webview *>(w)->bind(
name,
[=](const std::string &seq, const std::string &req, void *arg) {
fn(seq.c_str(), req.c_str(), arg);
},
arg);
}
WEBVIEW_API void webview_unbind(webview_t w, const char *name) {
static_cast<webview::webview *>(w)->unbind(name);
}
WEBVIEW_API void webview_return(webview_t w, const char *seq, int status,
const char *result) {
static_cast<webview::webview *>(w)->resolve(seq, status, result);
}
WEBVIEW_API const webview_version_info_t *webview_version() {
return &webview::detail::library_version_info;
}
#endif /* WEBVIEW_HEADER */
#endif /* __cplusplus */
#endif /* WEBVIEW_H */