feat(linux): add drawing behavior builder methods, closes #567 (#572)

* feat(linux): add drawing behavior builder methods, closes #567

* changefile

* fix docs

.changes/painting-builder.md

@@ -0,0 +1,5 @@
+---
+"tao": minor
+---
+
+Add builder methods on Linux to control the drawing behavior of the window. `WindowBuilderExtUnix::with_double_buffered`, `WindowBuilderExtUnix::with_rgba_visual` and `WindowBuilderExtUnix::with_app_paintable`

src/platform/unix.rs

@@ -57,6 +57,23 @@ pub trait WindowBuilderExtUnix {
   /// For anyone who wants to draw the background themselves, set this to `false`.
   /// Default is `true`.
   fn with_transparent_draw(self, draw: bool) -> WindowBuilder;
+
+  /// Whether to enable or disable the double buffered rendering of the window.
+  ///
+  /// Default is `true`.
+  fn with_double_buffered(self, double_buffered: bool) -> WindowBuilder;
+
+  /// Whether to enable the rgba visual for the window.
+  ///
+  /// Default is `false` but is always `true` if [`WindowAttributes::transparent`](crate::window::WindowAttributes::transparent) is `true`
+  fn with_rgba_visual(self, rgba_visual: bool) -> WindowBuilder;
+
+  /// Wether to set this window as app paintable
+  ///
+  /// <https://docs.gtk.org/gtk3/method.Widget.set_app_paintable.html>
+  ///
+  /// Default is `false` but is always `true` if [`WindowAttributes::transparent`](crate::window::WindowAttributes::transparent) is `true`
+  fn with_app_paintable(self, app_paintable: bool) -> WindowBuilder;
 }
 
 impl WindowBuilderExtUnix for WindowBuilder {
@@ -74,6 +91,21 @@ impl WindowBuilderExtUnix for WindowBuilder {
     self.platform_specific.auto_transparent = draw;
     self
   }
+
+  fn with_double_buffered(mut self, double_buffered: bool) -> WindowBuilder {
+    self.platform_specific.double_buffered = double_buffered;
+    self
+  }
+
+  fn with_rgba_visual(mut self, rgba_visual: bool) -> WindowBuilder {
+    self.platform_specific.rgba_visual = rgba_visual;
+    self
+  }
+
+  fn with_app_paintable(mut self, app_paintable: bool) -> WindowBuilder {
+    self.platform_specific.app_paintable = app_paintable;
+    self
+  }
 }
 
 /// Additional methods on `EventLoop` that are specific to Unix.

src/platform_impl/linux/mod.rs

@@ -62,6 +62,9 @@ pub struct PlatformSpecificWindowBuilderAttributes {
   pub parent: Parent,
   pub skip_taskbar: bool,
   pub auto_transparent: bool,
+  pub double_buffered: bool,
+  pub app_paintable: bool,
+  pub rgba_visual: bool,
 }
 
 impl Default for PlatformSpecificWindowBuilderAttributes {
@@ -70,6 +73,9 @@ impl Default for PlatformSpecificWindowBuilderAttributes {
       parent: Default::default(),
       skip_taskbar: Default::default(),
       auto_transparent: true,
+      double_buffered: true,
+      app_paintable: false,
+      rgba_visual: false,
     }
   }
 }

src/platform_impl/linux/window.rs

@@ -139,20 +139,27 @@ impl Window {
     }
 
     // Set GDK Visual
-    if let Some(screen) = window.screen() {
-      if let Some(visual) = screen.rgba_visual() {
-        window.set_visual(Some(&visual));
+    if pl_attribs.rgba_visual || attributes.transparent {
+      if let Some(screen) = window.screen() {
+        if let Some(visual) = screen.rgba_visual() {
+          window.set_visual(Some(&visual));
+        }
       }
     }
 
-    // Set a few attributes to make the window can be painted.
-    // See Gtk drawing model for more info:
-    // https://docs.gtk.org/gtk3/drawing-model.html
-    window.set_app_paintable(true);
-    let widget = window.upcast_ref::<gtk::Widget>();
-    if !event_loop_window_target.is_wayland() {
-      unsafe {
-        gtk::ffi::gtk_widget_set_double_buffered(widget.to_glib_none().0, 0);
+    if pl_attribs.app_paintable || attributes.transparent {
+      // Set a few attributes to make the window can be painted.
+      // See Gtk drawing model for more info:
+      // https://docs.gtk.org/gtk3/drawing-model.html
+      window.set_app_paintable(true);
+    }
+
+    if !pl_attribs.double_buffered {
+      let widget = window.upcast_ref::<gtk::Widget>();
+      if !event_loop_window_target.is_wayland() {
+        unsafe {
+          gtk::ffi::gtk_widget_set_double_buffered(widget.to_glib_none().0, 0);
+        }
       }
     }
 

src/window.rs

@@ -918,7 +918,7 @@ impl Window {
   /// ## Platform-specific
   ///
   /// - **iOS / Android / Linux:** Unsupported.
-  pub fn set_content_protection(&self, enabled: bool) {
+  pub fn set_content_protection(&self, #[allow(unused)] enabled: bool) {
     #[cfg(any(target_os = "macos", target_os = "windows"))]
     self.window.set_content_protection(enabled);
   }