feat(Windows): resize borderless window

.changes/borderless-resize.md

@@ -0,0 +1,5 @@
+---
+"wry": patch
+---
+
+Allow resizing of borderless window on Windows

examples/custom_titlebar.rs

@@ -50,7 +50,9 @@ fn main() -> wry::Result<()> {
 
       document.addEventListener('mousedown', (e) => {
         if (e.target.classList.contains('drag-region') && e.buttons === 1) {
-          window.rpc.notify('drag_window');
+          e.detail === 2
+            ? window.rpc.notify('maximize')
+            : window.rpc.notify('drag_window');
         }
       })
 

src/webview/webkitgtk/mod.rs

@@ -4,7 +4,7 @@
 
 use std::rc::Rc;
 
-use gdk::{WindowEdge, WindowExt, RGBA};
+use gdk::{WindowEdge, RGBA};
 use gio::Cancellable;
 use glib::{signal::Inhibit, Bytes, Cast, FileError};
 use gtk::{BoxExt, ContainerExt, GtkWindowExt, WidgetExt};
@@ -101,26 +101,33 @@ impl InnerWebView {
     webview.connect_button_press_event(|webview, event| {
       if event.get_button() == 1 {
         let (cx, cy) = event.get_root();
-        if let Some(window) = webview.get_parent_window() {
-          let result = crate::application::platform::unix::hit_test(&window, cx, cy);
+        // This one should be GtkBox
+        if let Some(widget) = webview.get_parent() {
+          // This one should be GtkWindow
+          if let Some(window) = widget.get_parent() {
+            // Safe to unwrap unless this is not from tao
+            let window: gtk::Window = window.downcast().unwrap();
+            if !window.get_decorated() && window.get_resizable() {
+              // Safe to unwrap since it's a valide GtkWindow
+              let result = hit_test(&window.get_window().unwrap(), cx, cy);
 
-          // this check is necessary, otherwise the webview won't recieve the click properly when resize isn't needed
-          if result != WindowEdge::__Unknown(8) {
-            window.begin_resize_drag(result, 1, cx as i32, cy as i32, event.get_time());
+              // this check is necessary, otherwise the webview won't recieve the click properly when resize isn't needed
+              if result != WindowEdge::__Unknown(8) {
+                window.begin_resize_drag(result, 1, cx as i32, cy as i32, event.get_time());
+              }
+            }
           }
         }
       }
       Inhibit(false)
     });
 
     // Gtk application window can only contain one widget at a time.
-    // In tao, we add a gtk box if menu bar is required. So we check if
+    // In tao, we add a GtkBox to pack menu bar. So we check if
     // there's a box widget here.
     if let Some(widget) = window.get_children().pop() {
       let vbox = widget.downcast::<gtk::Box>().unwrap();
       vbox.pack_start(&*webview, true, true, 0);
-    } else {
-      window.add(&*webview);
     }
     webview.grab_focus();
 

src/webview/webview2/win32/mod.rs

@@ -103,7 +103,14 @@ impl InnerWebView {
 
         // Initialize scripts
         w.add_script_to_execute_on_document_created(
-          "window.external={invoke:s=>window.chrome.webview.postMessage(s)}",
+          r#"
+            window.external={invoke:s=>window.chrome.webview.postMessage(s)};
+
+            window.addEventListener('mousedown', (e) => {
+              if (e.buttons === 1) window.chrome.webview.postMessage('__WEBVIEW_LEFT_MOUSE_DOWN__')
+            });
+            window.addEventListener('mousemove', () => window.chrome.webview.postMessage('__WEBVIEW_MOUSE_MOVE__'));
+          "#,
           |_| (Ok(())),
         )?;
         for js in attributes.initialization_scripts {
@@ -116,6 +123,46 @@ impl InnerWebView {
         let rpc_handler = attributes.rpc_handler.take();
         w.add_web_message_received(move |webview, args| {
           let js = args.try_get_web_message_as_string()?;
+          if js == "__WEBVIEW_LEFT_MOUSE_DOWN__" || js == "__WEBVIEW_MOUSE_MOVE__" {
+            if !window_.is_decorated() && window_.is_resizable() {
+              use winapi::um::winuser::{
+                HTBOTTOM, HTBOTTOMLEFT, HTBOTTOMRIGHT, HTLEFT, HTRIGHT,
+                HTTOP, HTTOPLEFT, HTTOPRIGHT, HTCLIENT, GetCursorPos,
+              };
+              use crate::application::{window::CursorIcon,platform::windows::hit_test};
+
+              let (cx, cy);
+              unsafe {
+                let mut point = std::mem::zeroed();
+                GetCursorPos(&mut point);
+                cx = point.x;
+                cy = point.y;
+              };
+              let result = hit_test(window_.hwnd() as _, cx, cy);
+              let cursor = match result {
+                    HTLEFT => CursorIcon::WResize,
+                    HTTOP => CursorIcon::NResize,
+                    HTRIGHT => CursorIcon::EResize,
+                    HTBOTTOM => CursorIcon::SResize,
+                    HTTOPLEFT => CursorIcon::NwResize,
+                    HTTOPRIGHT => CursorIcon::NeResize,
+                    HTBOTTOMLEFT => CursorIcon::SwResize,
+                    HTBOTTOMRIGHT => CursorIcon::SeResize,
+                    _ => CursorIcon::Arrow,
+              };
+              window_.set_cursor_icon(cursor);
+
+              if js == "__WEBVIEW_LEFT_MOUSE_DOWN__"  {
+                // this check is necessary, otherwise any window dragging implementation won't work
+                if result != HTCLIENT {
+                  window_.begin_resize_drag(result);
+                }
+              }
+            }
+            // these are internal messages, rpc_handlers don't need it so exit early
+            return Ok(());
+          }
+
           if let Some(rpc_handler) = &rpc_handler {
             match super::rpc_proxy(&window_, js, rpc_handler) {
               Ok(result) => {
@@ -240,6 +287,7 @@ impl InnerWebView {
         }
       }
     });
+    // TODO: OnceCell into_inner for controller
 
     Ok(Self {
       controller,
@@ -263,17 +311,14 @@ impl InnerWebView {
     let hwnd = hwnd as HWND;
 
     // Safety: System calls are unsafe
+    // XXX: Resizing on Windows is usually sluggish. Many other applications share same behavior.
     unsafe {
       let mut rect = std::mem::zeroed();
       GetClientRect(hwnd, &mut rect);
       if let Some(c) = self.controller.get() {
-        rect.left = rect.left + 1;
-        c.put_bounds(rect)?;
-        rect.left = rect.left - 1;
         c.put_bounds(rect)?;
       }
     }
-
     Ok(())
   }