Windows taskbar icon: .exe icon id for the MSI shortcut + icon regression tests (#248) (#269) (#269)

apps/photocraft/src/app_icon.rs

@@ -0,0 +1,122 @@
+//! The app icon, everywhere Windows, macOS and Linux show one (#248).
+//!
+//! - **Executable:** `build.rs` embeds `assets/app-icon/photocraft.ico` (16–256 px) as icon
+//!   resource 1, which Explorer, Alt+Tab and an unpinned taskbar button fall back to.
+//! - **Window:** [`window_icon`] sets the title-bar and taskbar icon at runtime (`WM_SETICON` on
+//!   Windows, `_NET_WM_ICON` on X11, the Dock when running unbundled on macOS).
+//! - **Start Menu shortcut (MSI):** the taskbar matches a running window to the shortcut that
+//!   launches its executable and shows that shortcut's icon. Windows Installer caches an advertised
+//!   shortcut's icon under its `<Icon Id>`, so that id must carry the target's `.exe` extension
+//!   (ICE50); an extensionless id showed a blank page on the taskbar. The tests below check it.
+//!
+//! The process keeps Windows' implicit AppUserModelID (derived from the executable path), which
+//! is what makes that matching work for both the MSI shortcut and the portable exe. An explicit
+//! ID would need a Win32 call (`unsafe`, which the workspace forbids) and would then also have to
+//! be stamped on the shortcut, or the taskbar would stop matching the two.
+
+/// Window, taskbar and (when running unbundled) Dock icon. macOS gets the padded 1024 px render
+/// on Apple's icon grid; elsewhere the tighter 256 px hicolor render reads better at small sizes.
+pub fn window_icon() -> egui::IconData {
+    match eframe::icon_data::from_png_bytes(PNG) {
+        Ok(icon) => icon,
+        Err(e) => {
+            log::warn!("app icon: {e}");
+            egui::IconData::default()
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+const PNG: &[u8] = include_bytes!("../../../assets/app-icon/photocraft-1024.png");
+#[cfg(not(target_os = "macos"))]
+const PNG: &[u8] = include_bytes!("../../../assets/app-icon/hicolor/256x256/apps/ai.storyteller.photocraft.png");
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const ICO: &[u8] = include_bytes!("../../../assets/app-icon/photocraft.ico");
+    const WXS: &str = include_str!("../../../packaging/windows/photocraft.wxs");
+
+    fn u16_at(b: &[u8], i: usize) -> usize {
+        u16::from_le_bytes([b[i], b[i + 1]]) as usize
+    }
+    fn u32_at(b: &[u8], i: usize) -> usize {
+        u32::from_le_bytes([b[i], b[i + 1], b[i + 2], b[i + 3]]) as usize
+    }
+
+    #[test]
+    fn window_icon_decodes() {
+        let icon = window_icon();
+        assert!(icon.width >= 256 && icon.width == icon.height, "{}x{}", icon.width, icon.height);
+        assert_eq!(icon.rgba.len(), icon.width as usize * icon.height as usize * 4);
+        assert!(icon.rgba.chunks(4).any(|p| p[3] > 0), "the icon isn't blank");
+    }
+
+    /// The `.ico` build.rs embeds: every size Windows asks for, each a valid PNG or BMP image.
+    #[test]
+    fn exe_icon_has_every_shell_size() {
+        assert_eq!((u16_at(ICO, 0), u16_at(ICO, 2)), (0, 1), "ICONDIR header, type 1 (icon)");
+        let n = u16_at(ICO, 4);
+        let mut sizes = Vec::new();
+        for i in 0..n {
+            let e = 6 + i * 16;
+            let w = if ICO[e] == 0 { 256 } else { ICO[e] as usize };
+            let h = if ICO[e + 1] == 0 { 256 } else { ICO[e + 1] as usize };
+            assert_eq!(w, h);
+            let (len, off) = (u32_at(ICO, e + 8), u32_at(ICO, e + 12));
+            let data = ICO.get(off..off + len).expect("image data inside the file");
+            let png = data.starts_with(b"\x89PNG\r\n\x1a\n");
+            let bmp = data.len() >= 40 && u32_at(data, 0) == 40;
+            assert!(png || bmp, "{w}px entry is neither PNG nor BMP");
+            if png {
+                // IHDR width/height match the directory entry.
+                let pw = u32::from_be_bytes([data[16], data[17], data[18], data[19]]) as usize;
+                assert_eq!(pw, w, "{w}px entry holds a {pw}px PNG");
+            }
+            sizes.push(w);
+        }
+        for want in [16, 24, 32, 48, 64, 256] {
+            assert!(sizes.contains(&want), "photocraft.ico lacks {want}px (has {sizes:?})");
+        }
+    }
+
+    /// The value of `attr="…"` inside `element`.
+    fn attr<'a>(element: &'a str, attr: &str) -> Option<&'a str> {
+        let key = format!(" {attr}=\"");
+        let start = element.find(&key)? + key.len();
+        element[start..].split('"').next()
+    }
+
+    /// Each `<tag …>` element's text up to its closing `>`.
+    fn elements<'a>(xml: &'a str, tag: &str) -> Vec<&'a str> {
+        let open = format!("<{tag} ");
+        xml.match_indices(&open).map(|(i, _)| &xml[i..i + xml[i..].find('>').unwrap()]).collect()
+    }
+
+    /// ICE50 (#248): advertised shortcut icons are cached under their `<Icon Id>`; without the
+    /// target's extension the shell shows a blank page on the Start Menu and the taskbar.
+    #[test]
+    fn msi_shortcut_icons_keep_the_exe_extension() {
+        let icons: Vec<&str> = elements(WXS, "Icon").iter().filter_map(|e| attr(e, "Id")).collect();
+        assert!(!icons.is_empty());
+        for id in &icons {
+            assert!(id.ends_with(".exe") || id.ends_with(".ico"), "<Icon Id=\"{id}\"> needs an .exe or .ico extension");
+        }
+        let shortcuts = elements(WXS, "Shortcut");
+        assert!(!shortcuts.is_empty());
+        for s in shortcuts {
+            let icon = attr(s, "Icon").expect("shortcuts name their icon");
+            assert!(icons.contains(&icon), "shortcut icon {icon} isn't an <Icon>");
+            if attr(s, "Advertise") == Some("yes") {
+                // Every shortcut in the MSI targets photocraft.exe.
+                assert!(icon.ends_with(".exe"), "advertised shortcut icon {icon} must end in .exe like its target (ICE50)");
+            }
+        }
+        let arp = WXS.split("Id=\"ARPPRODUCTICON\" Value=\"").nth(1).and_then(|r| r.split('"').next()).expect("ARPPRODUCTICON");
+        assert!(icons.contains(&arp), "ARPPRODUCTICON {arp} isn't an <Icon>");
+        // The Start Menu shortcut must not set its own AppUserModelID: the process keeps the
+        // implicit one, and a mismatch would split the taskbar button from the shortcut.
+        assert!(!WXS.contains("System.AppUserModel.ID"));
+    }
+}

apps/photocraft/src/main.rs

@@ -17,6 +17,7 @@
 #![cfg_attr(all(windows, not(debug_assertions)), windows_subsystem = "windows")]
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 
+mod app_icon;
 #[cfg(target_os = "macos")]
 mod apple_events;
 mod control_server;
@@ -37,16 +38,6 @@ use photocraft_ui_egui::PhotocraftApp;
 /// Matches the `.desktop` file and hicolor icon name, so Wayland docks pick up the icon.
 const APP_ID: &str = "ai.storyteller.photocraft";
 
-/// Window, taskbar and (when running unbundled) Dock icon. macOS gets the padded 1024 px render
-/// on Apple's icon grid; elsewhere the tighter 256 px hicolor render reads better at small sizes.
-fn app_icon() -> egui::IconData {
-    #[cfg(target_os = "macos")]
-    const PNG: &[u8] = include_bytes!("../../../assets/app-icon/photocraft-1024.png");
-    #[cfg(not(target_os = "macos"))]
-    const PNG: &[u8] = include_bytes!("../../../assets/app-icon/hicolor/256x256/apps/ai.storyteller.photocraft.png");
-    eframe::icon_data::from_png_bytes(PNG).unwrap_or_default()
-}
-
 fn main() -> eframe::Result {
     crash_guard::install_hook();
     let mut control_port: Option<u16> = std::env::var("PHOTOCRAFT_CONTROL_PORT").ok().and_then(|p| p.parse().ok());
@@ -130,7 +121,7 @@ fn main() -> eframe::Result {
     let presets = services::presets_dir().map(photocraft_engine::preset_store::open_dir_async);
     let mut options = eframe::NativeOptions {
         viewport: egui::ViewportBuilder::default()
-            .with_icon(app_icon())
+            .with_icon(app_icon::window_icon())
             .with_app_id(APP_ID)
             .with_title("PhotoCraft")
             .with_inner_size([1440.0, 900.0])

assets/app-icon/README.md

@@ -36,7 +36,10 @@ craftrules at `assets/app-icons/photocraft/source.png`. License: see `LICENSE.tx
 - `hicolor/<size>/apps/ai.storyteller.photocraft.png` (16–512) and `hicolor/scalable/...svg`:
   Linux icon theme.
 
-The app also sets the window icon and Wayland app ID at runtime (`apps/photocraft/src/main.rs`).
+The app also sets the window icon and Wayland app ID at runtime (`apps/photocraft/src/app_icon.rs`,
+`main.rs`). On Windows the taskbar shows the icon of the Start Menu shortcut that launches the
+exe, so the MSI's `<Icon Id>` keeps the `.exe` extension (ICE50); `app_icon.rs` documents the
+details and tests the `.ico` sizes and the WiX icon references.
 
 ## Regenerate