Windows re-open in the same position

gridbugs · gridbugs · commit 92087b7088e6 · 2025-09-19T17:43:23.000+10:00
diff --git a/Cargo.toml b/Cargo.toml
@@ -28,4 +28,5 @@ members = [
     "viz-udp-app",
     "viz-udp-app-lib",
     "widgets",
+    "window-utils",
 ]
diff --git a/viz-udp-app-lib/src/blink.rs b/viz-udp-app-lib/src/blink.rs
@@ -22,8 +22,8 @@ impl Default for Config {
             width: 100,
             height: 100,
             red: 127,
-            green: 0,
-            blue: 0,
+            green: 127,
+            blue: 127,
         }
     }
 }
diff --git a/viz-udp-app/Cargo.toml b/viz-udp-app/Cargo.toml
@@ -16,3 +16,5 @@ line_2d = "0.5"
 clap = { version = "4", features = ["derive"] }
 caw_viz_udp_app_lib = { version = "0.1", path = "../viz-udp-app-lib" }
 lazy_static = "1.5"
+log = "0.4"
+caw_window_utils = { version = "0.1", path = "../window-utils" }
diff --git a/viz-udp-app/src/main.rs b/viz-udp-app/src/main.rs
@@ -5,6 +5,7 @@ use caw_viz_udp_app_lib::{
     blink,
     oscilloscope::{self, OscilloscopeStyle},
 };
+use caw_window_utils::persisten_window_position;
 use clap::{Parser, Subcommand, ValueEnum};
 use lazy_static::lazy_static;
 use line_2d::Coord;
@@ -85,11 +86,11 @@ struct BlinkCommand {
     width: u32,
     #[arg(long, default_value_t = 100)]
     height: u32,
-    #[arg(long, short, default_value_t = 0)]
+    #[arg(long, short, default_value_t = 127)]
     red: u8,
     #[arg(long, short, default_value_t = 127)]
     green: u8,
-    #[arg(long, short, default_value_t = 0)]
+    #[arg(long, short, default_value_t = 127)]
     blue: u8,
 }
 
@@ -141,9 +142,25 @@ struct App {
     server: String,
     canvas: Canvas<Window>,
     event_pump: EventPump,
+    title: String,
 }
 
 impl App {
+    fn handle_event_common(event: Event, title: &str) {
+        match event {
+            Event::Quit { .. } => std::process::exit(0),
+            Event::Window {
+                win_event: WindowEvent::Moved(x, y),
+                ..
+            } => {
+                if let Err(e) = persisten_window_position::save(title, x, y) {
+                    log::warn!("{}", e);
+                }
+            }
+            _ => (),
+        }
+    }
+
     fn run_oscilloscope(
         mut self,
         mut args: OscilloscopeCommand,
@@ -152,8 +169,8 @@ impl App {
         let mut scope_state = ScopeState::default();
         loop {
             for event in self.event_pump.poll_iter() {
+                Self::handle_event_common(event.clone(), self.title.as_str());
                 match event {
-                    Event::Quit { .. } => std::process::exit(0),
                     Event::MouseWheel { y, .. } => {
                         let ratio = 1.1;
                         if y > 0 {
@@ -381,10 +398,7 @@ impl App {
         let mut prev_mean = 0.0;
         loop {
             for event in self.event_pump.poll_iter() {
-                match event {
-                    Event::Quit { .. } => std::process::exit(0),
-                    _ => (),
-                }
+                Self::handle_event_common(event.clone(), self.title.as_str());
             }
             let mut total = 0.0;
             let mut count = 0;
@@ -433,17 +447,30 @@ fn main() -> anyhow::Result<()> {
     } = Cli::parse();
     let sdl_context = sdl2::init().map_err(|e| anyhow!(e))?;
     let video_subsystem = sdl_context.video().map_err(|e| anyhow!(e))?;
-    let window = match command {
-        Command::Oscilloscope(_) => video_subsystem
-            .window(title.as_str(), command.width(), command.height())
-            .always_on_top()
-            .resizable()
-            .build()?,
-        Command::Blink(_) => video_subsystem
-            .window("", command.width(), command.height())
-            .always_on_top()
-            .build()?,
+    let mut window_builder = match command {
+        Command::Oscilloscope(_) => {
+            let mut wb = video_subsystem.window(
+                title.as_str(),
+                command.width(),
+                command.height(),
+            );
+            wb.resizable();
+            wb
+        }
+        Command::Blink(_) => {
+            let mut wb =
+                video_subsystem.window("", command.width(), command.height());
+            wb.always_on_top();
+            wb
+        }
     };
+    match persisten_window_position::load(&title) {
+        Err(e) => log::warn!("{}", e),
+        Ok((x, y)) => {
+            window_builder.position(x, y);
+        }
+    }
+    let window = window_builder.build()?;
     let mut canvas = window
         .into_canvas()
         .target_texture()
@@ -455,6 +482,7 @@ fn main() -> anyhow::Result<()> {
         server,
         event_pump,
         canvas,
+        title: title.clone(),
     };
     match command {
         Command::Oscilloscope(oscilloscope_command) => {
diff --git a/widgets/Cargo.toml b/widgets/Cargo.toml
@@ -18,7 +18,9 @@ midly = "0.5"
 caw_computer_keyboard = { version = "0.4", path = "../computer-keyboard" }
 caw_keyboard = { version = "0.4", path = "../keyboard" }
 caw_sdl2 = { version = "0.1", path = "../sdl2" }
+caw_window_utils = { version = "0.1", path = "../window-utils" }
 itertools = "0.14"
+log = "0.4"
 
 [dev-dependencies]
 env_logger = "0.11"
diff --git a/widgets/src/button.rs b/widgets/src/button.rs
@@ -23,8 +23,11 @@ impl Button {
     fn handle_events(&mut self) {
         for event in self.window.event_pump.poll_iter() {
             use sdl2::event::Event;
+            Window::handle_event_common(
+                event.clone(),
+                self.window.title.as_ref(),
+            );
             match event {
-                Event::Quit { .. } => std::process::exit(0),
                 Event::MouseButtonDown { .. } => {
                     self.pressed = true;
                 }
diff --git a/widgets/src/computer_keyboard.rs b/widgets/src/computer_keyboard.rs
@@ -72,8 +72,11 @@ impl ComputerKeyboard {
     fn handle_events(&mut self, buf: &mut Vec<MidiMessage>) {
         for event in self.window.event_pump.poll_iter() {
             use sdl2::event::Event;
+            Window::handle_event_common(
+                event.clone(),
+                self.window.title.as_ref(),
+            );
             match event {
-                Event::Quit { .. } => std::process::exit(0),
                 Event::KeyDown {
                     scancode: Some(Scancode::Space),
                     ..
diff --git a/widgets/src/knob.rs b/widgets/src/knob.rs
@@ -2,7 +2,10 @@ use crate::window::Window;
 use anyhow::anyhow;
 use line_2d::Coord;
 use midly::num::u7;
-use sdl2::{keyboard::Scancode, mouse::MouseButton, pixels::Color, rect::Rect};
+use sdl2::{
+    event::Event, keyboard::Scancode, mouse::MouseButton, pixels::Color,
+    rect::Rect,
+};
 use std::time::Instant;
 
 const WIDTH_PX: u32 = 128;
@@ -32,9 +35,11 @@ impl Knob {
 
     fn handle_events(&mut self) {
         for event in self.window.event_pump.poll_iter() {
-            use sdl2::event::Event;
+            Window::handle_event_common(
+                event.clone(),
+                self.window.title.as_ref(),
+            );
             match event {
-                Event::Quit { .. } => std::process::exit(0),
                 Event::KeyDown { scancode, .. } => {
                     let value_01 = match scancode {
                         Some(Scancode::Grave) => 0.0,
diff --git a/widgets/src/window.rs b/widgets/src/window.rs
@@ -1,7 +1,9 @@
 use anyhow::anyhow;
+use caw_window_utils::persisten_window_position;
 use lazy_static::lazy_static;
 use sdl2::{
     EventPump,
+    event::{Event, WindowEvent},
     pixels::Color,
     rect::Rect,
     render::{Canvas, TextureCreator},
@@ -48,10 +50,18 @@ impl Window {
     ) -> anyhow::Result<Self> {
         let sdl_context = sdl2::init().map_err(|e| anyhow!(e))?;
         let video_subsystem = sdl_context.video().map_err(|e| anyhow!(e))?;
-        let window = video_subsystem
-            .window("", width_px, height_px)
-            .always_on_top()
-            .build()?;
+        let mut window_builder =
+            video_subsystem.window("", width_px, height_px);
+        window_builder.always_on_top();
+        if let Some(title) = title {
+            match persisten_window_position::load(title) {
+                Err(e) => log::warn!("{}", e),
+                Ok((x, y)) => {
+                    window_builder.position(x, y);
+                }
+            }
+        }
+        let window = window_builder.build()?;
         let canvas = window
             .into_canvas()
             .target_texture()
@@ -112,7 +122,26 @@ impl Window {
     pub fn width_px(&self) -> u32 {
         self.width_px
     }
+
     pub fn height_px(&self) -> u32 {
         self.height_px
     }
+
+    pub fn handle_event_common(event: Event, title: Option<&String>) {
+        match event {
+            Event::Quit { .. } => std::process::exit(0),
+            Event::Window {
+                win_event: WindowEvent::Moved(x, y),
+                ..
+            } => {
+                if let Some(title) = title {
+                    if let Err(e) = persisten_window_position::save(title, x, y)
+                    {
+                        log::warn!("{}", e);
+                    }
+                }
+            }
+            _ => (),
+        }
+    }
 }
diff --git a/widgets/src/xy.rs b/widgets/src/xy.rs
@@ -26,8 +26,11 @@ impl Xy {
     fn handle_events(&mut self) {
         for event in self.window.event_pump.poll_iter() {
             use sdl2::event::Event;
+            Window::handle_event_common(
+                event.clone(),
+                self.window.title.as_ref(),
+            );
             match event {
-                Event::Quit { .. } => std::process::exit(0),
                 Event::MouseButtonDown { x, y, .. } => {
                     self.x_px = x.clamp(0, WIDTH_PX as i32) as u32;
                     self.y_px = y.clamp(0, HEIGHT_PX as i32) as u32;
diff --git a/window-utils/Cargo.toml b/window-utils/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "caw_window_utils"
+version = "0.1.0"
+edition = "2024"
+description = "Helpers for working with windows within the CAW synthesizer framework"
+authors = ["Stephen Sherratt <stephen@sherra.tt>"]
+license = "MIT"
+homepage = "https://github.com/gridbugs/caw.git"
+repository = "https://github.com/gridbugs/caw.git"
+documentation = "https://docs.rs/caw_window_utils"
+
+
+[dependencies]
+serde_json = "1.0"
+serde = { version = "1.0", features = ["serde_derive"] }
+hex = "0.4"
+anyhow = "1"
diff --git a/window-utils/src/lib.rs b/window-utils/src/lib.rs
@@ -0,0 +1,45 @@
+use std::path::PathBuf;
+
+fn caw_tmp_dir() -> PathBuf {
+    let tmp_dir = std::env::temp_dir();
+    tmp_dir.join("caw")
+}
+
+pub mod persisten_window_position {
+    use super::*;
+    use serde::{Deserialize, Serialize};
+    use std::fs::{self, File};
+
+    #[derive(Serialize, Deserialize)]
+    struct WindowPosition {
+        x: i32,
+        y: i32,
+    }
+
+    fn window_position_dir() -> PathBuf {
+        caw_tmp_dir().join("window_positions")
+    }
+
+    fn file_path(title: impl AsRef<str>) -> PathBuf {
+        let hexxed_title = hex::encode(title.as_ref());
+        window_position_dir().join(format!("{}.json", hexxed_title))
+    }
+
+    pub fn save(title: impl AsRef<str>, x: i32, y: i32) -> anyhow::Result<()> {
+        use std::io::Write;
+        fs::create_dir_all(&window_position_dir())?;
+        // Hex the title so we can safely use it as part of a file path (ie. so it contains no
+        // slashes or other characters that have meaning within a file path).
+        let json_string = serde_json::to_string(&WindowPosition { x, y })?;
+        let mut file = File::create(file_path(title))?;
+        write!(file, "{}", json_string)?;
+        Ok(())
+    }
+
+    pub fn load(title: impl AsRef<str>) -> anyhow::Result<(i32, i32)> {
+        let json_string = fs::read_to_string(file_path(title))?;
+        let WindowPosition { x, y } =
+            serde_json::from_str(json_string.as_str())?;
+        Ok((x, y))
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -28,4 +28,5 @@ members = [`
`28`	`28`	`"viz-udp-app",`
`29`	`29`	`"viz-udp-app-lib",`
`30`	`30`	`"widgets",`
	`31`	`+ "window-utils",`
`31`	`32`	`]`
Original file line number	Diff line number	Diff line change
`@@ -22,8 +22,8 @@ impl Default for Config {`
`22`	`22`	`width: 100,`
`23`	`23`	`height: 100,`
`24`	`24`	`red: 127,`
`25`		`- green: 0,`
`26`		`- blue: 0,`
	`25`	`+ green: 127,`
	`26`	`+ blue: 127,`
`27`	`27`	`}`
`28`	`28`	`}`
`29`	`29`	`}`