Add Windows shell sample illustrating VARIANT support (#2789)

.github/workflows/clippy.yml

@@ -60,6 +60,7 @@ jobs:
           cargo clippy -p sample_privileges &&
           cargo clippy -p sample_privileges_sys &&
           cargo clippy -p sample_rss &&
+          cargo clippy -p sample_shell &&
           cargo clippy -p sample_simple &&
           cargo clippy -p sample_spellchecker &&
           cargo clippy -p sample_thread_pool_work &&

.github/workflows/test.yml

@@ -67,6 +67,7 @@ jobs:
           cargo test -p sample_privileges &&
           cargo test -p sample_privileges_sys &&
           cargo test -p sample_rss &&
+          cargo test -p sample_shell &&
           cargo test -p sample_simple &&
           cargo test -p sample_spellchecker &&
           cargo test -p sample_thread_pool_work &&
@@ -100,8 +101,8 @@ jobs:
           cargo test -p test_enums &&
           cargo test -p test_error &&
           cargo test -p test_event &&
-          cargo test -p test_extensions &&
           cargo clean &&
+          cargo test -p test_extensions &&
           cargo test -p test_handles &&
           cargo test -p test_helpers &&
           cargo test -p test_implement &&

crates/libs/core/src/variant.rs

@@ -229,6 +229,18 @@ impl From<BSTR> for PROPVARIANT {
     }
 }
 
+impl From<&str> for VARIANT {
+    fn from(value: &str) -> Self {
+        BSTR::from(value).into()
+    }
+}
+
+impl From<&str> for PROPVARIANT {
+    fn from(value: &str) -> Self {
+        BSTR::from(value).into()
+    }
+}
+
 impl TryFrom<&VARIANT> for BSTR {
     type Error = Error;
     fn try_from(from: &VARIANT) -> Result<Self> {

crates/samples/windows/shell/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "sample_shell"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies.windows]
+path = "../../../libs/windows"
+features = [
+    "Win32_System_Com",
+    "Win32_System_Ole",
+    "Win32_UI_Shell",
+    "Win32_UI_WindowsAndMessaging",
+]

crates/samples/windows/shell/src/main.rs

@@ -0,0 +1,63 @@
+use windows::{
+    core::*, Win32::System::Com::*, Win32::UI::Shell::*, Win32::UI::WindowsAndMessaging::*,
+};
+
+fn main() -> Result<()> {
+    unsafe { CoInitialize(None)? };
+
+    shell_execute_from_explorer(
+        "https://github.com/microsoft/windows-rs",
+        "",
+        "",
+        "",
+        SW_SHOWNORMAL,
+    )
+}
+
+// Ported from https://devblogs.microsoft.com/oldnewthing/20131118-00/?p=2643
+fn shell_execute_from_explorer(
+    file: &str,
+    args: &str,
+    directory: &str,
+    operation: &str,
+    show: SHOW_WINDOW_CMD,
+) -> Result<()> {
+    unsafe {
+        let view: IShellView = find_desktop_folder_view()?;
+        let background: IDispatch = view.GetItemObject(SVGIO_BACKGROUND)?;
+        let folder: IShellFolderViewDual = background.cast()?;
+        let shell: IShellDispatch2 = folder.Application()?.cast()?;
+
+        shell.ShellExecute(
+            &BSTR::from(file),
+            &VARIANT::from(args),
+            &VARIANT::from(directory),
+            &VARIANT::from(operation),
+            &VARIANT::from(show.0),
+        )
+    }
+}
+
+// Ported from https://devblogs.microsoft.com/oldnewthing/20130318-00/?p=4933
+fn find_desktop_folder_view<T: Interface>() -> Result<T> {
+    unsafe {
+        let windows: IShellWindows = CoCreateInstance(&ShellWindows, None, CLSCTX_ALL)?;
+        let mut dispatch = None;
+        let mut handle = 0;
+
+        // TODO: find out why this retval isn't kicking in
+        windows.FindWindowSW(
+            &VARIANT::from(CSIDL_DESKTOP),
+            &VARIANT::default(),
+            SWC_DESKTOP,
+            &mut handle,
+            SWFO_NEEDDISPATCH,
+            &mut dispatch,
+        )?;
+
+        let provider: IServiceProvider = dispatch.unwrap().cast()?;
+        let browser: IShellBrowser = provider.QueryService(&SID_STopLevelBrowser)?;
+        let view = browser.QueryActiveShellView()?;
+        view.cast()
+    }
+}

crates/tests/variant/tests/tests.rs

@@ -94,6 +94,11 @@ fn test_variant() -> Result<()> {
         VARIANT::from(BSTR::from("goodbye"))
     );
 
+    let v = VARIANT::from("hello");
+    assert_eq!(BSTR::try_from(&v)?, "hello");
+    assert_eq!(VARIANT::from("hello"), VARIANT::from("hello"));
+    assert_ne!(VARIANT::from("hello"), VARIANT::from("goodbye"));
+
     let v = VARIANT::from(3.5f64);
     assert_eq!(BSTR::try_from(&v)?, "3.5");
 
@@ -205,6 +210,11 @@ fn test_propvariant() -> Result<()> {
         PROPVARIANT::from(BSTR::from("goodbye"))
     );
 
+    let v = PROPVARIANT::from("hello");
+    assert_eq!(BSTR::try_from(&v)?, "hello");
+    assert_eq!(PROPVARIANT::from("hello"), PROPVARIANT::from("hello"));
+    assert_ne!(PROPVARIANT::from("hello"), PROPVARIANT::from("goodbye"));
+
     let v = PROPVARIANT::from(3.5f64);
     assert_eq!(BSTR::try_from(&v)?, "3.5");