[PM-22790] Adds SendInput() Functionality to the Autotype Crate (#15751)

* [PM-22790] Adds SendInput() functionality to the autotype crate

* [PM-22790] Fixes unused variable linting errors

* [PM-22790] Updated autotype lib.rs comment

apps/desktop/desktop_native/autotype/src/lib.rs

@@ -10,3 +10,13 @@ mod windowing;
 pub fn get_foreground_window_title() -> std::result::Result<String, ()> {
     windowing::get_foreground_window_title()
 }
+
+/// Attempts to type the input text wherever the user's cursor is.
+///
+/// `input` must be an array of utf-16 encoded characters to insert.
+///
+/// TODO: The error handling will be improved in a future PR: PM-23615
+#[allow(clippy::result_unit_err)]
+pub fn type_input(input: Vec<u16>) -> std::result::Result<(), ()> {
+    windowing::type_input(input)
+}

apps/desktop/desktop_native/autotype/src/linux.rs

@@ -1,3 +1,7 @@
 pub fn get_foreground_window_title() -> std::result::Result<String, ()> {
     todo!("Bitwarden does not yet support Linux autotype");
 }
+
+pub fn type_input(_input: Vec<u16>) -> std::result::Result<(), ()> {
+    todo!("Bitwarden does not yet support Linux autotype");
+}

apps/desktop/desktop_native/autotype/src/macos.rs

@@ -1,3 +1,7 @@
 pub fn get_foreground_window_title() -> std::result::Result<String, ()> {
     todo!("Bitwarden does not yet support Mac OS autotype");
 }
+
+pub fn type_input(_input: Vec<u16>) -> std::result::Result<(), ()> {
+    todo!("Bitwarden does not yet support Mac OS autotype");
+}

apps/desktop/desktop_native/autotype/src/windows.rs

@@ -1,7 +1,11 @@
 use std::ffi::OsString;
 use std::os::windows::ffi::OsStringExt;
 
-use windows::Win32::Foundation::HWND;
+use windows::Win32::Foundation::{GetLastError, HWND};
+use windows::Win32::UI::Input::KeyboardAndMouse::{
+    BlockInput, SendInput, INPUT, INPUT_0, INPUT_KEYBOARD, KEYBDINPUT, KEYEVENTF_KEYUP,
+    KEYEVENTF_UNICODE,
+};
 use windows::Win32::UI::WindowsAndMessaging::{
     GetForegroundWindow, GetWindowTextLengthW, GetWindowTextW,
 };
@@ -18,6 +22,29 @@ pub fn get_foreground_window_title() -> std::result::Result<String, ()> {
     Ok(window_title)
 }
 
+/// Attempts to type the input text wherever the user's cursor is.
+///
+/// `input` must be an array of utf-16 encoded characters to insert.
+///
+/// https://learn.microsoft.com/en-in/windows/win32/api/winuser/nf-winuser-sendinput
+pub fn type_input(input: Vec<u16>) -> Result<(), ()> {
+    let mut keyboard_inputs: Vec<INPUT> = Vec::new();
+
+    for i in input {
+        let next_down_input = build_input(InputKeyPress::Down, i);
+        let next_up_input = build_input(InputKeyPress::Up, i);
+
+        keyboard_inputs.push(next_down_input);
+        keyboard_inputs.push(next_up_input);
+    }
+
+    let _ = block_input(true);
+    let result = send_input(keyboard_inputs);
+    let _ = block_input(false);
+
+    result
+}
+
 /// Gets the foreground window handle.
 ///
 /// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getforegroundwindow
@@ -33,8 +60,6 @@ fn get_foreground_window() -> Result<HWND, ()> {
 
 /// Gets the length of the window title bar text.
 ///
-/// TODO: Future improvement is to use GetLastError for better error handling
-///
 /// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getwindowtextlengthw
 fn get_window_title_length(window_handle: HWND) -> Result<usize, ()> {
     if window_handle.is_invalid() {
@@ -49,8 +74,6 @@ fn get_window_title_length(window_handle: HWND) -> Result<usize, ()> {
 
 /// Gets the window title bar title.
 ///
-/// TODO: Future improvement is to use GetLastError for better error handling
-///
 /// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getwindowtextw
 fn get_window_title(window_handle: HWND) -> Result<Option<String>, ()> {
     if window_handle.is_invalid() {
@@ -73,3 +96,71 @@ fn get_window_title(window_handle: HWND) -> Result<Option<String>, ()> {
 
     Ok(Some(window_title.to_string_lossy().into_owned()))
 }
+
+/// Used in build_input() to specify if an input key is being pressed (down) or released (up).
+enum InputKeyPress {
+    Down,
+    Up,
+}
+
+/// A function for easily building keyboard INPUT structs used in SendInput().
+///
+/// Before modifying this function, make sure you read the SendInput() documentation:
+/// https://learn.microsoft.com/en-in/windows/win32/api/winuser/nf-winuser-sendinput
+fn build_input(key_press: InputKeyPress, character: u16) -> INPUT {
+    match key_press {
+        InputKeyPress::Down => INPUT {
+            r#type: INPUT_KEYBOARD,
+            Anonymous: INPUT_0 {
+                ki: KEYBDINPUT {
+                    wVk: Default::default(),
+                    wScan: character,
+                    dwFlags: KEYEVENTF_UNICODE,
+                    time: 0,
+                    dwExtraInfo: 0,
+                },
+            },
+        },
+        InputKeyPress::Up => INPUT {
+            r#type: INPUT_KEYBOARD,
+            Anonymous: INPUT_0 {
+                ki: KEYBDINPUT {
+                    wVk: Default::default(),
+                    wScan: character,
+                    dwFlags: KEYEVENTF_KEYUP | KEYEVENTF_UNICODE,
+                    time: 0,
+                    dwExtraInfo: 0,
+                },
+            },
+        },
+    }
+}
+
+/// Block keyboard and mouse input events. This prevents the hotkey
+/// key presses from interfering with the input sent via SendInput().
+///
+/// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-blockinput
+fn block_input(block: bool) -> Result<(), ()> {
+    match unsafe { BlockInput(block) } {
+        Ok(()) => Ok(()),
+        Err(_) => Err(()),
+    }
+}
+
+/// Attempts to type the provided input wherever the user's cursor is.
+///
+/// https://learn.microsoft.com/en-in/windows/win32/api/winuser/nf-winuser-sendinput
+fn send_input(inputs: Vec<INPUT>) -> Result<(), ()> {
+    let insert_count = unsafe { SendInput(&inputs, std::mem::size_of::<INPUT>() as i32) };
+
+    let e = unsafe { GetLastError().to_hresult().message() };
+    println!("type_input() called, GetLastError() is: {:?}", e);
+
+    if insert_count == 0 {
+        return Err(()); // input was blocked by another thread
+    } else if insert_count != inputs.len() as u32 {
+        return Err(()); // input insertion not completed
+    }
+
+    Ok(())
+}

apps/desktop/desktop_native/napi/index.d.ts

@@ -210,4 +210,5 @@ export declare namespace logging {
 }
 export declare namespace autotype {
   export function getForegroundWindowTitle(): string
+  export function typeInput(input: Array<number>): void
 }

apps/desktop/desktop_native/napi/src/lib.rs

@@ -872,8 +872,15 @@ pub mod autotype {
     pub fn get_foreground_window_title() -> napi::Result<String, napi::Status> {
         autotype::get_foreground_window_title().map_err(|_| {
             napi::Error::from_reason(
-                "Autotype Error: faild to get foreground window title".to_string(),
+                "Autotype Error: failed to get foreground window title".to_string(),
             )
         })
     }
+
+    #[napi]
+    pub fn type_input(input: Vec<u16>) -> napi::Result<(), napi::Status> {
+        autotype::type_input(input).map_err(|_| {
+            napi::Error::from_reason("Autotype Error: failed to type input".to_string())
+        })
+    }
 }