feat: add MacOS print options (#1259)

* feat: add MacOS print options

Currently, when printing on a MacOS, it defaults to a quite big margin, which does not reflect the side of
it when printing on the web. The current code just creates a new NSPrintInfo from the default, which for some
reason has a large margin.

This changes so that the default margin is 0 and add the option to change it when printing the webview on MacOs.
This is not a field that can be changed by the user on the appkit modal, so it has to be defined before the modal is open.

Other options could be added on top of these ones, but for this initial commit/PR decided to go with adding the margins
since it seems to be the one with bigger discrepancy compared to the web version.

References:
- https://developer.apple.com/documentation/appkit/nsprintinfo

.changes/macos_default_print_margins.md

@@ -0,0 +1,5 @@
+---
+"wry": minor
+---
+
+Default the margin when printing on MacOS to 0 so it is closer to the behavior of when printing on the web.

.changes/macos_print_margin_options.md

@@ -0,0 +1,5 @@
+---
+"wry": minor
+---
+
+Add `WebViewExtMacOS::print_with_options` which allows to modify the margins that will be used on the print dialog.

src/lib.rs

@@ -232,6 +232,8 @@ use webkitgtk::*;
 pub(crate) mod wkwebview;
 #[cfg(any(target_os = "macos", target_os = "ios"))]
 use wkwebview::*;
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+pub use wkwebview::{PrintMargin, PrintOptions};
 
 #[cfg(target_os = "windows")]
 pub(crate) mod webview2;
@@ -1598,6 +1600,8 @@ pub trait WebViewExtMacOS {
   fn ns_window(&self) -> cocoa::base::id;
   /// Attaches this webview to the given NSWindow and removes it from the current one.
   fn reparent(&self, window: cocoa::base::id) -> Result<()>;
+  // Prints with extra options
+  fn print_with_options(&self, options: &PrintOptions) -> Result<()>;
 }
 
 #[cfg(target_os = "macos")]
@@ -1620,6 +1624,10 @@ impl WebViewExtMacOS for WebView {
   fn reparent(&self, window: cocoa::base::id) -> Result<()> {
     self.webview.reparent(window)
   }
+
+  fn print_with_options(&self, options: &PrintOptions) -> Result<()> {
+    self.webview.print_with_options(options)
+  }
 }
 
 /// Additional methods on `WebView` that are specific to iOS.

src/wkwebview/mod.rs

@@ -32,7 +32,9 @@ use std::{
   sync::{Arc, Mutex},
 };
 
+use core_graphics::base::CGFloat;
 use core_graphics::geometry::{CGPoint, CGRect, CGSize};
+
 use objc::{
   declare::ClassDecl,
   runtime::{Class, Object, Sel, BOOL},
@@ -79,6 +81,19 @@ const NS_JSON_WRITING_FRAGMENTS_ALLOWED: u64 = 4;
 static COUNTER: Counter = Counter::new();
 static WEBVIEW_IDS: Lazy<Mutex<HashSet<u32>>> = Lazy::new(Default::default);
 
+#[derive(Debug, Default, Copy, Clone)]
+pub struct PrintMargin {
+  pub top: f32,
+  pub right: f32,
+  pub bottom: f32,
+  pub left: f32,
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct PrintOptions {
+  pub margins: PrintMargin,
+}
+
 pub(crate) struct InnerWebView {
   pub webview: id,
   pub manager: id,
@@ -1128,6 +1143,10 @@ r#"Object.defineProperty(window, 'ipc', {
   }
 
   pub fn print(&self) -> crate::Result<()> {
+    self.print_with_options(&PrintOptions::default())
+  }
+
+  pub fn print_with_options(&self, options: &PrintOptions) -> crate::Result<()> {
     // Safety: objc runtime calls are unsafe
     #[cfg(target_os = "macos")]
     unsafe {
@@ -1139,6 +1158,10 @@ r#"Object.defineProperty(window, 'ipc', {
         // Create a shared print info
         let print_info: id = msg_send![class!(NSPrintInfo), sharedPrintInfo];
         let print_info: id = msg_send![print_info, init];
+        let () = msg_send![print_info, setTopMargin:CGFloat::from(options.margins.top)];
+        let () = msg_send![print_info, setRightMargin:CGFloat::from(options.margins.right)];
+        let () = msg_send![print_info, setBottomMargin:CGFloat::from(options.margins.bottom)];
+        let () = msg_send![print_info, setLeftMargin:CGFloat::from(options.margins.left)];
         // Create new print operation from the webview content
         let print_operation: id = msg_send![self.webview, printOperationWithPrintInfo: print_info];
         // Allow the modal to detach from the current thread and be non-blocker