1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
// Copyright 2020-2023 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

//! [`WebView`] struct and associated types.

mod web_context;

pub use web_context::WebContext;

#[cfg(target_os = "android")]
pub(crate) mod android;
#[cfg(target_os = "android")]
pub mod prelude {
  pub use super::android::{binding::*, setup};
}
#[cfg(target_os = "android")]
pub use android::JniHandle;
#[cfg(target_os = "android")]
use android::*;
#[cfg(any(
  target_os = "linux",
  target_os = "dragonfly",
  target_os = "freebsd",
  target_os = "netbsd",
  target_os = "openbsd"
))]
pub(crate) mod webkitgtk;
#[cfg(any(
  target_os = "linux",
  target_os = "dragonfly",
  target_os = "freebsd",
  target_os = "netbsd",
  target_os = "openbsd"
))]
use webkitgtk::*;
#[cfg(any(target_os = "macos", target_os = "ios"))]
pub(crate) mod wkwebview;
#[cfg(any(target_os = "macos", target_os = "ios"))]
use wkwebview::*;
#[cfg(target_os = "windows")]
pub(crate) mod webview2;
#[cfg(target_os = "windows")]
use self::webview2::*;
use crate::Result;
#[cfg(target_os = "windows")]
use webview2_com::Microsoft::Web::WebView2::Win32::ICoreWebView2Controller;
#[cfg(target_os = "windows")]
use windows::{Win32::Foundation::HWND, Win32::UI::WindowsAndMessaging::DestroyWindow};

use std::{borrow::Cow, path::PathBuf, rc::Rc};

pub use url::Url;

#[cfg(target_os = "windows")]
use crate::application::platform::windows::WindowExtWindows;
use crate::application::{dpi::PhysicalSize, window::Window};

use http::{Request, Response};

pub struct WebViewAttributes {
  /// Whether the WebView should have a custom user-agent.
  pub user_agent: Option<String>,
  /// Whether the WebView window should be visible.
  pub visible: bool,
  /// Whether the WebView should be transparent.
  ///
  /// ## Platform-specific:
  ///
  /// **Windows 7**: Not supported.
  pub transparent: bool,
  /// Specify the webview background color. This will be ignored if `transparent` is set to `true`.
  ///
  /// The color uses the RGBA format.
  ///
  /// ## Platform-specific:
  ///
  /// - **macOS / iOS**: Not implemented.
  /// - **Windows**:
  ///   - On Windows 7, transparency is not supported and the alpha value will be ignored.
  ///   - On Windows higher than 7: translucent colors are not supported so any alpha value other than `0` will be replaced by `255`
  pub background_color: Option<RGBA>,
  /// Whether load the provided URL to [`WebView`].
  pub url: Option<Url>,
  /// Headers used when loading the requested `url`.
  pub headers: Option<http::HeaderMap>,
  /// Whether page zooming by hotkeys is enabled
  ///
  /// ## Platform-specific
  ///
  /// **macOS / Linux / Android / iOS**: Unsupported
  pub zoom_hotkeys_enabled: bool,
  /// Whether load the provided html string to [`WebView`].
  /// This will be ignored if the `url` is provided.
  ///
  /// # Warning
  /// The loaded from html string will have different Origin on different platforms. And
  /// servers which enforce CORS will need to add exact same Origin header in `Access-Control-Allow-Origin`
  /// if you wish to send requests with native `fetch` and `XmlHttpRequest` APIs. Here are the
  /// different Origin headers across platforms:
  ///
  /// - macOS: `http://localhost`
  /// - Linux: `http://localhost`
  /// - Windows: `null`
  /// - Android: Not supported
  /// - iOS: Not supported
  pub html: Option<String>,
  /// Initialize javascript code when loading new pages. When webview load a new page, this
  /// initialization code will be executed. It is guaranteed that code is executed before
  /// `window.onload`.
  ///
  /// ## Platform-specific
  ///
  /// - **Android:** The Android WebView does not provide an API for initialization scripts,
  /// so we prepend them to each HTML head. They are only implemented on custom protocol URLs.
  pub initialization_scripts: Vec<String>,
  /// Register custom file loading protocols with pairs of scheme uri string and a handling
  /// closure.
  ///
  /// The closure takes a [Request] and returns a [Response].
  ///
  /// # Warning
  /// Pages loaded from custom protocol will have different Origin on different platforms. And
  /// servers which enforce CORS will need to add exact same Origin header in `Access-Control-Allow-Origin`
  /// if you wish to send requests with native `fetch` and `XmlHttpRequest` APIs. Here are the
  /// different Origin headers across platforms:
  ///
  /// - macOS: `<scheme_name>://<path>` (so it will be `wry://examples` in `custom_protocol` example)
  /// - Linux: Though it's same as macOS, there's a [bug] that Origin header in the request will be
  /// empty. So the only way to pass the server is setting `Access-Control-Allow-Origin: *`.
  /// - Windows: `https://<scheme_name>.<path>` (so it will be `https://wry.examples` in `custom_protocol` example)
  /// - Android: Custom protocol on Android is fixed to `https://tauri.wry/` due to its design and
  /// our approach to use it. On Android, We only handle the scheme name and ignore the closure. So
  /// when you load the url like `wry://assets/index.html`, it will become
  /// `https://tauri.wry/assets/index.html`. Android has `assets` and `resource` path finder to
  /// locate your files in those directories. For more information, see [Loading in-app content](https://developer.android.com/guide/webapps/load-local-content) page.
  /// - iOS: Same as macOS. To get the path of your assets, you can call [`CFBundle::resources_path`](https://docs.rs/core-foundation/latest/core_foundation/bundle/struct.CFBundle.html#method.resources_path). So url like `wry://assets/index.html` could get the html file in assets directory.
  ///
  /// [bug]: https://bugs.webkit.org/show_bug.cgi?id=229034
  pub custom_protocols: Vec<(
    String,
    Box<dyn Fn(&Request<Vec<u8>>) -> Result<Response<Cow<'static, [u8]>>>>,
  )>,
  /// Set the IPC handler to receive the message from Javascript on webview to host Rust code.
  /// The message sent from webview should call `window.ipc.postMessage("insert_message_here");`.
  ///
  /// Both functions return promises but `notify()` resolves immediately.
  pub ipc_handler: Option<Box<dyn Fn(&Window, String)>>,
  /// Set a handler closure to process incoming [`FileDropEvent`] of the webview.
  ///
  /// # Blocking OS Default Behavior
  /// Return `true` in the callback to block the OS' default behavior of handling a file drop.
  ///
  /// Note, that if you do block this behavior, it won't be possible to drop files on `<input type="file">` forms.
  /// Also note, that it's not possible to manually set the value of a `<input type="file">` via JavaScript for security reasons.
  #[cfg(feature = "file-drop")]
  pub file_drop_handler: Option<Box<dyn Fn(&Window, FileDropEvent) -> bool>>,
  #[cfg(not(feature = "file-drop"))]
  file_drop_handler: Option<Box<dyn Fn(&Window, FileDropEvent) -> bool>>,

  /// Set a navigation handler to decide if incoming url is allowed to navigate.
  ///
  /// The closure take a `String` parameter as url and return `bool` to determine the url. True is
  /// allow to navigate and false is not.
  pub navigation_handler: Option<Box<dyn Fn(String) -> bool>>,

  /// Set a download started handler to manage incoming downloads.
  ///
  /// The closure takes two parameters - the first is a `String` representing the url being downloaded from and and the
  /// second is a mutable `PathBuf` reference that (possibly) represents where the file will be downloaded to. The latter
  /// parameter can be used to set the download location by assigning a new path to it - the assigned path _must_ be
  /// absolute. The closure returns a `bool` to allow or deny the download.
  pub download_started_handler: Option<Box<dyn FnMut(String, &mut PathBuf) -> bool>>,

  /// Sets a download completion handler to manage downloads that have finished.
  ///
  /// The closure is fired when the download completes, whether it was successful or not.
  /// The closure takes a `String` representing the URL of the original download request, an `Option<PathBuf>`
  /// potentially representing the filesystem path the file was downloaded to, and a `bool` indicating if the download
  /// succeeded. A value of `None` being passed instead of a `PathBuf` does not necessarily indicate that the download
  /// did not succeed, and may instead indicate some other failure - always check the third parameter if you need to
  /// know if the download succeeded.
  ///
  /// ## Platform-specific:
  ///
  /// - **macOS**: The second parameter indicating the path the file was saved to is always empty, due to API
  /// limitations.
  pub download_completed_handler: Option<Rc<dyn Fn(String, Option<PathBuf>, bool) + 'static>>,

  /// Set a new window handler to decide if incoming url is allowed to open in a new window.
  ///
  /// The closure take a `String` parameter as url and return `bool` to determine the url. True is
  /// allow to navigate and false is not.
  pub new_window_req_handler: Option<Box<dyn Fn(String) -> bool>>,

  /// Enables clipboard access for the page rendered on **Linux** and **Windows**.
  ///
  /// macOS doesn't provide such method and is always enabled by default. But you still need to add menu
  /// item accelerators to use shortcuts.
  pub clipboard: bool,

  /// Enable web inspector which is usually called dev tool.
  ///
  /// Note this only enables dev tool to the webview. To open it, you can call
  /// [`WebView::open_devtools`], or right click the page and open it from the context menu.
  ///
  /// ## Platform-specific
  ///
  /// - macOS: This will call private functions on **macOS**. It's still enabled if set in **debug** build on mac,
  /// but requires `devtools` feature flag to actually enable it in **release** build.
  /// - Android: Open `chrome://inspect/#devices` in Chrome to get the devtools window. Wry's `WebView` devtools API isn't supported on Android.
  /// - iOS: Open Safari > Develop > [Your Device Name] > [Your WebView] to get the devtools window.
  pub devtools: bool,
  /// Whether clicking an inactive window also clicks through to the webview. Default is `false`.
  ///
  /// ## Platform-specific
  ///
  /// This configuration only impacts macOS.
  pub accept_first_mouse: bool,

  /// Indicates whether horizontal swipe gestures trigger backward and forward page navigation.
  ///
  /// ## Platform-specific
  ///
  /// This configuration only impacts macOS.
  /// [Documentation](https://developer.apple.com/documentation/webkit/wkwebview/1414995-allowsbackforwardnavigationgestu).
  pub back_forward_navigation_gestures: bool,

  /// Set a handler closure to process the change of the webview's document title.
  pub document_title_changed_handler: Option<Box<dyn Fn(&Window, String)>>,
}

impl Default for WebViewAttributes {
  fn default() -> Self {
    Self {
      user_agent: None,
      visible: true,
      transparent: false,
      background_color: None,
      url: None,
      headers: None,
      html: None,
      initialization_scripts: vec![],
      custom_protocols: vec![],
      ipc_handler: None,
      file_drop_handler: None,
      navigation_handler: None,
      download_started_handler: None,
      download_completed_handler: None,
      new_window_req_handler: None,
      clipboard: false,
      #[cfg(debug_assertions)]
      devtools: true,
      #[cfg(not(debug_assertions))]
      devtools: false,
      zoom_hotkeys_enabled: false,
      accept_first_mouse: false,
      back_forward_navigation_gestures: false,
      document_title_changed_handler: None,
    }
  }
}

#[cfg(windows)]
#[derive(Clone)]
pub(crate) struct PlatformSpecificWebViewAttributes {
  additional_browser_args: Option<String>,
  browser_accelerator_keys: bool,
  theme: Option<Theme>,
  https_scheme: bool,
  focused: bool,
}
#[cfg(windows)]
impl Default for PlatformSpecificWebViewAttributes {
  fn default() -> Self {
    Self {
      additional_browser_args: None,
      browser_accelerator_keys: true, // This is WebView2's default behavior
      theme: None,
      https_scheme: true,
      focused: true,
    }
  }
}
#[cfg(any(
  target_os = "linux",
  target_os = "dragonfly",
  target_os = "freebsd",
  target_os = "netbsd",
  target_os = "openbsd",
))]
#[derive(Clone)]
pub(crate) struct PlatformSpecificWebViewAttributes {
  focused: bool,
}
#[cfg(any(
  target_os = "linux",
  target_os = "dragonfly",
  target_os = "freebsd",
  target_os = "netbsd",
  target_os = "openbsd",
))]
impl Default for PlatformSpecificWebViewAttributes {
  fn default() -> Self {
    Self { focused: true }
  }
}
#[cfg(any(target_os = "macos", target_os = "android", target_os = "ios",))]
#[derive(Default)]
pub(crate) struct PlatformSpecificWebViewAttributes;

/// Type alias for a color in the RGBA format.
///
/// Each value can be 0..255 inclusive.
pub type RGBA = (u8, u8, u8, u8);

/// Builder type of [`WebView`].
///
/// [`WebViewBuilder`] / [`WebView`] are the basic building blocks to construct WebView contents and
/// scripts for those who prefer to control fine grained window creation and event handling.
/// [`WebViewBuilder`] provides ability to setup initialization before web engine starts.
pub struct WebViewBuilder<'a> {
  pub webview: WebViewAttributes,
  platform_specific: PlatformSpecificWebViewAttributes,
  web_context: Option<&'a mut WebContext>,
  window: Window,
}

impl<'a> WebViewBuilder<'a> {
  /// Create [`WebViewBuilder`] from provided [`Window`].
  pub fn new(window: Window) -> Result<Self> {
    let webview = WebViewAttributes::default();
    let web_context = None;
    let platform_specific = PlatformSpecificWebViewAttributes::default();

    Ok(Self {
      webview,
      web_context,
      window,
      platform_specific,
    })
  }

  /// Indicates whether horizontal swipe gestures trigger backward and forward page navigation.
  ///
  /// ## Platform-specific
  ///
  /// This configuration only impacts macOS.
  /// [Documentation](https://developer.apple.com/documentation/webkit/wkwebview/1414995-allowsbackforwardnavigationgestu).
  pub fn with_back_forward_navigation_gestures(mut self, gesture: bool) -> Self {
    self.webview.back_forward_navigation_gestures = gesture;
    self
  }

  /// Sets whether the WebView should be transparent.
  ///
  /// ## Platform-specific:
  ///
  /// **Windows 7**: Not supported.
  pub fn with_transparent(mut self, transparent: bool) -> Self {
    self.webview.transparent = transparent;
    self
  }

  /// Specify the webview background color. This will be ignored if `transparent` is set to `true`.
  ///
  /// The color uses the RGBA format.
  ///
  /// ## Platfrom-specific:
  ///
  /// - **macOS / iOS**: Not implemented.
  /// - **Windows**:
  ///   - on Windows 7, transparency is not supported and the alpha value will be ignored.
  ///   - on Windows higher than 7: translucent colors are not supported so any alpha value other than `0` will be replaced by `255`
  pub fn with_background_color(mut self, background_color: RGBA) -> Self {
    self.webview.background_color = Some(background_color);
    self
  }

  /// Sets whether the WebView should be transparent.
  pub fn with_visible(mut self, visible: bool) -> Self {
    self.webview.visible = visible;
    self
  }

  /// Initialize javascript code when loading new pages. When webview load a new page, this
  /// initialization code will be executed. It is guaranteed that code is executed before
  /// `window.onload`.
  ///
  /// ## Platform-specific
  ///
  /// - **Android:** The Android WebView does not provide an API for initialization scripts,
  /// so we prepend them to each HTML head. They are only implemented on custom protocol URLs.
  pub fn with_initialization_script(mut self, js: &str) -> Self {
    if !js.is_empty() {
      self.webview.initialization_scripts.push(js.to_string());
    }
    self
  }

  /// Register custom file loading protocols with pairs of scheme uri string and a handling
  /// closure.
  ///
  /// The closure takes a [Request] and returns a [Response]
  ///
  /// # Warning
  /// Pages loaded from custom protocol will have different Origin on different platforms. And
  /// servers which enforce CORS will need to add exact same Origin header in `Access-Control-Allow-Origin`
  /// if you wish to send requests with native `fetch` and `XmlHttpRequest` APIs. Here are the
  /// different Origin headers across platforms:
  ///
  /// - macOS: `<scheme_name>://<path>` (so it will be `wry://examples` in `custom_protocol` example)
  /// - Linux: Though it's same as macOS, there's a [bug] that Origin header in the request will be
  /// empty. So the only way to pass the server is setting `Access-Control-Allow-Origin: *`.
  /// - Windows: `https://<scheme_name>.<path>` (so it will be `https://wry.examples` in `custom_protocol` example)
  /// - Android: Custom protocol on Android is fixed to `https://tauri.wry/` due to its design and
  /// our approach to use it. On Android, We only handle the scheme name and ignore the closure. So
  /// when you load the url like `wry://assets/index.html`, it will become
  /// `https://tauri.wry/assets/index.html`. Android has `assets` and `resource` path finder to
  /// locate your files in those directories. For more information, see [Loading in-app content](https://developer.android.com/guide/webapps/load-local-content) page.
  /// - iOS: Same as macOS. To get the path of your assets, you can call [`CFBundle::resources_path`](https://docs.rs/core-foundation/latest/core_foundation/bundle/struct.CFBundle.html#method.resources_path). So url like `wry://assets/index.html` could get the html file in assets directory.
  ///
  /// [bug]: https://bugs.webkit.org/show_bug.cgi?id=229034
  #[cfg(feature = "protocol")]
  pub fn with_custom_protocol<F>(mut self, name: String, handler: F) -> Self
  where
    F: Fn(&Request<Vec<u8>>) -> Result<Response<Cow<'static, [u8]>>> + 'static,
  {
    self
      .webview
      .custom_protocols
      .push((name, Box::new(handler)));
    self
  }

  /// Set the IPC handler to receive the message from Javascript on webview to host Rust code.
  /// The message sent from webview should call `window.ipc.postMessage("insert_message_here");`.
  pub fn with_ipc_handler<F>(mut self, handler: F) -> Self
  where
    F: Fn(&Window, String) + 'static,
  {
    self.webview.ipc_handler = Some(Box::new(handler));
    self
  }

  /// Set a handler closure to process incoming [`FileDropEvent`] of the webview.
  ///
  /// # Blocking OS Default Behavior
  /// Return `true` in the callback to block the OS' default behavior of handling a file drop.
  ///
  /// Note, that if you do block this behavior, it won't be possible to drop files on `<input type="file">` forms.
  /// Also note, that it's not possible to manually set the value of a `<input type="file">` via JavaScript for security reasons.
  #[cfg(feature = "file-drop")]
  pub fn with_file_drop_handler<F>(mut self, handler: F) -> Self
  where
    F: Fn(&Window, FileDropEvent) -> bool + 'static,
  {
    self.webview.file_drop_handler = Some(Box::new(handler));
    self
  }

  /// Load the provided URL with given headers when the builder calling [`WebViewBuilder::build`] to create the
  /// [`WebView`]. The provided URL must be valid.
  pub fn with_url_and_headers(mut self, url: &str, headers: http::HeaderMap) -> Result<Self> {
    self.webview.url = Some(url.parse()?);
    self.webview.headers = Some(headers);
    Ok(self)
  }

  /// Load the provided URL when the builder calling [`WebViewBuilder::build`] to create the
  /// [`WebView`]. The provided URL must be valid.
  pub fn with_url(mut self, url: &str) -> Result<Self> {
    self.webview.url = Some(Url::parse(url)?);
    self.webview.headers = None;
    Ok(self)
  }

  /// Load the provided HTML string when the builder calling [`WebViewBuilder::build`] to create the
  /// [`WebView`]. This will be ignored if `url` is provided.
  ///
  /// # Warning
  /// The Page loaded from html string will have different Origin on different platforms. And
  /// servers which enforce CORS will need to add exact same Origin header in `Access-Control-Allow-Origin`
  /// if you wish to send requests with native `fetch` and `XmlHttpRequest` APIs. Here are the
  /// different Origin headers across platforms:
  ///
  /// - macOS: `http://localhost`
  /// - Linux: `http://localhost`
  /// - Windows: `null`
  /// - Android: Not supported
  /// - iOS: Not supported
  ///
  /// ## PLatform-specific:
  ///
  /// - **Windows:** the string can not be larger than 2 MB (2 * 1024 * 1024 bytes) in total size
  pub fn with_html(mut self, html: impl Into<String>) -> Result<Self> {
    self.webview.html = Some(html.into());
    Ok(self)
  }

  /// Set the web context that can share with multiple [`WebView`]s.
  pub fn with_web_context(mut self, web_context: &'a mut WebContext) -> Self {
    self.web_context = Some(web_context);
    self
  }

  /// Set a custom [user-agent](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent) for the WebView.
  pub fn with_user_agent(mut self, user_agent: &str) -> Self {
    self.webview.user_agent = Some(user_agent.to_string());
    self
  }

  /// Enable or disable web inspector which is usually called dev tool.
  ///
  /// Note this only enables dev tool to the webview. To open it, you can call
  /// [`WebView::open_devtools`], or right click the page and open it from the context menu.
  ///
  /// ## Platform-specific
  ///
  /// - macOS: This will call private functions on **macOS**. It's still enabled if set in **debug** build on mac,
  /// but requires `devtools` feature flag to actually enable it in **release** build.
  /// - Android: Open `chrome://inspect/#devices` in Chrome to get the devtools window. Wry's `WebView` devtools API isn't supported on Android.
  /// - iOS: Open Safari > Develop > [Your Device Name] > [Your WebView] to get the devtools window.
  pub fn with_devtools(mut self, devtools: bool) -> Self {
    self.webview.devtools = devtools;
    self
  }

  /// Whether page zooming by hotkeys or gestures is enabled
  ///
  /// ## Platform-specific
  ///
  /// **macOS / Linux / Android / iOS**: Unsupported
  pub fn with_hotkeys_zoom(mut self, zoom: bool) -> Self {
    self.webview.zoom_hotkeys_enabled = zoom;
    self
  }

  /// Set a navigation handler to decide if incoming url is allowed to navigate.
  ///
  /// The closure takes a `String` parameter as url and return `bool` to determine the url. True is
  /// allowed to navigate and false is not.
  pub fn with_navigation_handler(mut self, callback: impl Fn(String) -> bool + 'static) -> Self {
    self.webview.navigation_handler = Some(Box::new(callback));
    self
  }

  /// Set a download started handler to manage incoming downloads.
  ///
  /// The closure takes two parameters - the first is a `String` representing the url being downloaded from and and the
  /// second is a mutable `PathBuf` reference that (possibly) represents where the file will be downloaded to. The latter
  /// parameter can be used to set the download location by assigning a new path to it - the assigned path _must_ be
  /// absolute. The closure returns a `bool` to allow or deny the download.
  pub fn with_download_started_handler(
    mut self,
    started_handler: impl FnMut(String, &mut PathBuf) -> bool + 'static,
  ) -> Self {
    self.webview.download_started_handler = Some(Box::new(started_handler));
    self
  }

  /// Sets a download completion handler to manage downloads that have finished.
  ///
  /// The closure is fired when the download completes, whether it was successful or not.
  /// The closure takes a `String` representing the URL of the original download request, an `Option<PathBuf>`
  /// potentially representing the filesystem path the file was downloaded to, and a `bool` indicating if the download
  /// succeeded. A value of `None` being passed instead of a `PathBuf` does not necessarily indicate that the download
  /// did not succeed, and may instead indicate some other failure - always check the third parameter if you need to
  /// know if the download succeeded.
  ///
  /// ## Platform-specific:
  ///
  /// - **macOS**: The second parameter indicating the path the file was saved to is always empty, due to API
  /// limitations.
  pub fn with_download_completed_handler(
    mut self,
    download_completed_handler: impl Fn(String, Option<PathBuf>, bool) + 'static,
  ) -> Self {
    self.webview.download_completed_handler = Some(Rc::new(download_completed_handler));
    self
  }

  /// Enables clipboard access for the page rendered on **Linux** and **Windows**.
  ///
  /// macOS doesn't provide such method and is always enabled by default. But you still need to add menu
  /// item accelerators to use shortcuts.
  pub fn with_clipboard(mut self, clipboard: bool) -> Self {
    self.webview.clipboard = clipboard;
    self
  }

  /// Set a new window request handler to decide if incoming url is allowed to be opened.
  ///
  /// The closure takes a `String` parameter as url and return `bool` to determine if the url can be
  /// opened in a new window. Returning true will open the url in a new window, whilst returning false
  /// will neither open a new window nor allow any navigation.
  pub fn with_new_window_req_handler(
    mut self,
    callback: impl Fn(String) -> bool + 'static,
  ) -> Self {
    self.webview.new_window_req_handler = Some(Box::new(callback));
    self
  }

  /// Sets whether clicking an inactive window also clicks through to the webview. Default is `false`.
  ///
  /// ## Platform-specific
  ///
  /// This configuration only impacts macOS.
  pub fn with_accept_first_mouse(mut self, accept_first_mouse: bool) -> Self {
    self.webview.accept_first_mouse = accept_first_mouse;
    self
  }

  /// Set a handler closure to process the change of the webview's document title.
  pub fn with_document_title_changed_handler(
    mut self,
    callback: impl Fn(&Window, String) + 'static,
  ) -> Self {
    self.webview.document_title_changed_handler = Some(Box::new(callback));
    self
  }

  /// Set whether the webview should be focused when created.
  ///
  /// ## Platform-specific:
  ///
  /// - **macOS / Android / iOS:** Unsupported.
  pub fn with_focused(mut self, _focused: bool) -> Self {
    #[cfg(any(
      windows,
      target_os = "linux",
      target_os = "dragonfly",
      target_os = "freebsd",
      target_os = "netbsd",
      target_os = "openbsd",
    ))]
    {
      self.platform_specific.focused = _focused;
    }
    self
  }

  /// Consume the builder and create the [`WebView`].
  ///
  /// Platform-specific behavior:
  ///
  /// - **Unix:** This method must be called in a gtk thread. Usually this means it should be
  /// called in the same thread with the [`EventLoop`] you create.
  ///
  /// [`EventLoop`]: crate::application::event_loop::EventLoop
  pub fn build(self) -> Result<WebView> {
    let window = Rc::new(self.window);
    let webview = InnerWebView::new(
      window.clone(),
      self.webview,
      self.platform_specific,
      self.web_context,
    )?;
    Ok(WebView { window, webview })
  }
}

#[cfg(windows)]
pub trait WebViewBuilderExtWindows {
  /// Pass additional args to Webview2 upon creating the webview.
  ///
  /// ## Warning
  ///
  /// By default wry passes `--disable-features=msWebOOUI,msPdfOOUI,msSmartScreenProtection`
  /// so if you use this method, you also need to disable these components by yourself if you want.
  fn with_additional_browser_args<S: Into<String>>(self, additional_args: S) -> Self;

  /// Determines whether browser-specific accelerator keys are enabled. When this setting is set to
  /// `false`, it disables all accelerator keys that access features specific to a web browser.
  /// The default value is `true`. See the following link to know more details.
  ///
  /// https://learn.microsoft.com/en-us/microsoft-edge/webview2/reference/winrt/microsoft_web_webview2_core/corewebview2settings#arebrowseracceleratorkeysenabled
  fn with_browser_accelerator_keys(self, enabled: bool) -> Self;

  /// Specifies the theme of webview2. This affects things like `prefers-color-scheme`.
  ///
  /// Defaults to [`Theme::Auto`] which will follow the OS defaults.
  fn with_theme(self, theme: Theme) -> Self;

  /// Determines whether the custom protocols should use `http://<scheme>.localhost` instead of the default `https://<scheme>.localhost`.
  ///
  /// Using a `http` scheme will allow mixed content when trying to fetch `http` endpoints
  /// and is therefore less secure but will match the behavior of the `<scheme>://localhost` protocols used on macOS and Linux.
  ///
  /// The default value is `true`.
  fn with_https_scheme(self, enabled: bool) -> Self;
}

#[cfg(windows)]
impl WebViewBuilderExtWindows for WebViewBuilder<'_> {
  fn with_additional_browser_args<S: Into<String>>(mut self, additional_args: S) -> Self {
    self.platform_specific.additional_browser_args = Some(additional_args.into());
    self
  }

  fn with_browser_accelerator_keys(mut self, enabled: bool) -> Self {
    self.platform_specific.browser_accelerator_keys = enabled;
    self
  }

  fn with_theme(mut self, theme: Theme) -> Self {
    self.platform_specific.theme = Some(theme);
    self
  }

  fn with_https_scheme(mut self, enabled: bool) -> Self {
    self.platform_specific.https_scheme = enabled;
    self
  }
}

/// The fundamental type to present a [`WebView`].
///
/// [`WebViewBuilder`] / [`WebView`] are the basic building blocks to construct WebView contents and
/// scripts for those who prefer to control fine grained window creation and event handling.
/// [`WebView`] presents the actual WebView window and let you still able to perform actions
/// during event handling to it. [`WebView`] also contains the associate [`Window`] with it.
pub struct WebView {
  window: Rc<Window>,
  webview: InnerWebView,
}

// Signal the Window to drop on Linux and Windows. On mac, we need to handle several unsafe code
// blocks and raw pointer properly.
#[cfg(any(
  target_os = "linux",
  target_os = "dragonfly",
  target_os = "freebsd",
  target_os = "netbsd",
  target_os = "openbsd"
))]
impl Drop for WebView {
  fn drop(&mut self) {
    unsafe {
      use crate::application::platform::unix::WindowExtUnix;
      use gtk::prelude::WidgetExtManual;
      self.window().gtk_window().destroy();
    }
  }
}

#[cfg(target_os = "windows")]
impl Drop for WebView {
  fn drop(&mut self) {
    unsafe {
      DestroyWindow(HWND(self.window.hwnd() as _));
    }
  }
}

impl WebView {
  /// Create a [`WebView`] from provided [`Window`]. Note that calling this directly loses
  /// abilities to initialize scripts, add ipc handler, and many more before starting WebView. To
  /// benefit from above features, create a [`WebViewBuilder`] instead.
  ///
  /// Platform-specific behavior:
  ///
  /// - **Unix:** This method must be called in a gtk thread. Usually this means it should be
  /// called in the same thread with the [`EventLoop`] you create.
  ///
  /// [`EventLoop`]: crate::application::event_loop::EventLoop
  pub fn new(window: Window) -> Result<Self> {
    WebViewBuilder::new(window)?.build()
  }

  /// Get the [`Window`] associate with the [`WebView`]. This can let you perform window related
  /// actions.
  pub fn window(&self) -> &Window {
    &self.window
  }

  /// Get the current url of the webview
  pub fn url(&self) -> Url {
    self.webview.url()
  }

  /// Evaluate and run javascript code. Must be called on the same thread who created the
  /// [`WebView`]. Use [`EventLoopProxy`] and a custom event to send scripts from other threads.
  ///
  /// [`EventLoopProxy`]: crate::application::event_loop::EventLoopProxy
  pub fn evaluate_script(&self, js: &str) -> Result<()> {
    self.webview.eval(js)
  }

  /// Launch print modal for the webview content.
  pub fn print(&self) -> Result<()> {
    self.webview.print();
    Ok(())
  }

  /// Open the web inspector which is usually called dev tool.
  ///
  /// ## Platform-specific
  ///
  /// - **Android / iOS:** Not supported.
  #[cfg(any(debug_assertions, feature = "devtools"))]
  pub fn open_devtools(&self) {
    self.webview.open_devtools();
  }

  /// Close the web inspector which is usually called dev tool.
  ///
  /// ## Platform-specific
  ///
  /// - **Windows / Android / iOS:** Not supported.
  #[cfg(any(debug_assertions, feature = "devtools"))]
  pub fn close_devtools(&self) {
    self.webview.close_devtools();
  }

  /// Gets the devtool window's current visibility state.
  ///
  /// ## Platform-specific
  ///
  /// - **Windows / Android / iOS:** Not supported.
  #[cfg(any(debug_assertions, feature = "devtools"))]
  pub fn is_devtools_open(&self) -> bool {
    self.webview.is_devtools_open()
  }

  pub fn inner_size(&self) -> PhysicalSize<u32> {
    #[cfg(target_os = "macos")]
    {
      let scale_factor = self.window.scale_factor();
      self.webview.inner_size(scale_factor)
    }
    #[cfg(not(target_os = "macos"))]
    self.window.inner_size()
  }

  /// Set the webview zoom level
  ///
  /// ## Platform-specific:
  ///
  /// - **Android**: Not supported.
  /// - **macOS**: available on macOS 11+ only.
  /// - **iOS**: available on iOS 14+ only.
  pub fn zoom(&self, scale_factor: f64) {
    self.webview.zoom(scale_factor);
  }

  /// Specify the webview background color.
  ///
  /// The color uses the RGBA format.
  ///
  /// ## Platfrom-specific:
  ///
  /// - **macOS / iOS**: Not implemented.
  /// - **Windows**:
  ///   - On Windows 7, transparency is not supported and the alpha value will be ignored.
  ///   - On Windows higher than 7: translucent colors are not supported so any alpha value other than `0` will be replaced by `255`
  pub fn set_background_color(&self, background_color: RGBA) -> Result<()> {
    self.webview.set_background_color(background_color)
  }

  pub fn load_url(&self, url: &str) {
    self.webview.load_url(url)
  }

  pub fn load_url_with_headers(&self, url: &str, headers: http::HeaderMap) {
    self.webview.load_url_with_headers(url, headers)
  }
}

/// An event enumeration sent to [`FileDropHandler`].
#[non_exhaustive]
#[derive(Debug, Serialize, Clone)]
pub enum FileDropEvent {
  /// The file(s) have been dragged onto the window, but have not been dropped yet.
  Hovered(Vec<PathBuf>),
  /// The file(s) have been dropped onto the window.
  Dropped(Vec<PathBuf>),
  /// The file drop was aborted.
  Cancelled,
}

/// Get Webview/Webkit version on current platform.
pub fn webview_version() -> Result<String> {
  platform_webview_version()
}

/// Additional methods on `WebView` that are specific to Windows.
#[cfg(target_os = "windows")]
pub trait WebviewExtWindows {
  /// Returns WebView2 Controller
  fn controller(&self) -> ICoreWebView2Controller;

  // Changes the webview2 theme.
  fn set_theme(&self, theme: Theme);
}

#[cfg(target_os = "windows")]
impl WebviewExtWindows for WebView {
  fn controller(&self) -> ICoreWebView2Controller {
    self.webview.controller.clone()
  }

  fn set_theme(&self, theme: Theme) {
    self.webview.set_theme(theme)
  }
}

/// Additional methods on `WebView` that are specific to Linux.
#[cfg(target_os = "linux")]
pub trait WebviewExtUnix {
  /// Returns Webkit2gtk Webview handle
  fn webview(&self) -> Rc<webkit2gtk::WebView>;
}

#[cfg(target_os = "linux")]
impl WebviewExtUnix for WebView {
  fn webview(&self) -> Rc<webkit2gtk::WebView> {
    self.webview.webview.clone()
  }
}

/// Additional methods on `WebView` that are specific to macOS.
#[cfg(target_os = "macos")]
pub trait WebviewExtMacOS {
  /// Returns WKWebView handle
  fn webview(&self) -> cocoa::base::id;
  /// Returns WKWebView manager [(userContentController)](https://developer.apple.com/documentation/webkit/wkscriptmessagehandler/1396222-usercontentcontroller) handle
  fn manager(&self) -> cocoa::base::id;
  /// Returns NSWindow associated with the WKWebView webview
  fn ns_window(&self) -> cocoa::base::id;
}

#[cfg(target_os = "macos")]
impl WebviewExtMacOS for WebView {
  fn webview(&self) -> cocoa::base::id {
    self.webview.webview
  }

  fn manager(&self) -> cocoa::base::id {
    self.webview.manager
  }

  fn ns_window(&self) -> cocoa::base::id {
    self.webview.ns_window
  }
}

#[cfg(target_os = "android")]
/// Additional methods on `WebView` that are specific to Android
pub trait WebviewExtAndroid {
  fn handle(&self) -> JniHandle;
}

#[cfg(target_os = "android")]
impl WebviewExtAndroid for WebView {
  fn handle(&self) -> JniHandle {
    JniHandle
  }
}

#[derive(Debug, Clone, Copy)]
pub enum Theme {
  Dark,
  Light,
  Auto,
}

#[cfg(test)]
mod tests {
  use super::*;

  #[test]
  fn should_get_webview_version() {
    if let Err(error) = webview_version() {
      panic!("{}", error);
    }
  }
}