Move WindowSettings from egui_glium to egui-winit

egui-winit/Cargo.toml

@@ -26,6 +26,7 @@ epi = { version = "0.14.0", path = "../epi" }
 winit = "0.25"
 
 copypasta = { version = "0.7", optional = true }
+serde = { version = "1.0", optional = true, features = ["derive"] }
 webbrowser = { version = "0.5", optional = true }
 
 # feature screen_reader
@@ -43,3 +44,5 @@ links = ["webbrowser"]
 
 # experimental support for a screen reader
 screen_reader = ["tts"]
+
+serialize = ["egui/serialize", "serde"]

egui-winit/src/lib.rs

@@ -76,6 +76,9 @@ pub use winit;
 
 pub mod clipboard;
 pub mod screen_reader;
+mod window_settings;
+
+pub use window_settings::WindowSettings;
 
 pub fn native_pixels_per_point(window: &winit::window::Window) -> f32 {
     window.scale_factor() as f32

egui-winit/src/window_settings.rs

@@ -0,0 +1,55 @@
+/// Can be used to store window settings (position and size).
+#[derive(Clone, Copy, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+pub struct WindowSettings {
+    /// outer position of window in physical pixels
+    pos: Option<egui::Pos2>,
+    /// Inner size of window in logical pixels
+    inner_size_points: Option<egui::Vec2>,
+}
+
+impl WindowSettings {
+    pub fn from_display(window: &winit::window::Window) -> Self {
+        let inner_size_points = window.inner_size().to_logical::<f32>(window.scale_factor());
+
+        Self {
+            pos: window
+                .outer_position()
+                .ok()
+                .map(|p| egui::pos2(p.x as f32, p.y as f32)),
+
+            inner_size_points: Some(egui::vec2(
+                inner_size_points.width as f32,
+                inner_size_points.height as f32,
+            )),
+        }
+    }
+
+    pub fn initialize_window(
+        &self,
+        mut window: winit::window::WindowBuilder,
+    ) -> winit::window::WindowBuilder {
+        if !cfg!(target_os = "windows") {
+            // If the app last ran on two monitors and only one is now connected, then
+            // the given position is invalid.
+            // If this happens on Mac, the window is clamped into valid area.
+            // If this happens on Windows, the window is hidden and impossible to bring to get at.
+            // So we don't restore window positions on Windows.
+            if let Some(pos) = self.pos {
+                window = window.with_position(winit::dpi::PhysicalPosition {
+                    x: pos.x as f64,
+                    y: pos.y as f64,
+                });
+            }
+        }
+
+        if let Some(inner_size_points) = self.inner_size_points {
+            window.with_inner_size(winit::dpi::LogicalSize {
+                width: inner_size_points.x as f64,
+                height: inner_size_points.y as f64,
+            })
+        } else {
+            window
+        }
+    }
+}