Add the Password dialog box

5 files changed, 80 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 11dc234..8759e6e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# Unreleased
+- Add the `Password` dialog box.
+
 # v0.1.0 (2019-01-08)
 - Initial release with the `Input`, `Message` and `Question` dialog boxes and
   the `Dialog` backend.
diff --git a/examples/password.rs b/examples/password.rs
new file mode 100644
index 0000000..7504bdd
--- /dev/null
+++ b/examples/password.rs
@@ -0,0 +1,15 @@
+// Copyright (C) 2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
+use dialog::DialogBox;
+
+fn main() -> dialog::Result<()> {
+    let password = dialog::Password::new("Please enter a new password")
+        .title("Password")
+        .show()?;
+    match password {
+        Some(password) => println!("Your new password is: {}", password),
+        None => println!("You do not want to have a password."),
+    };
+    Ok(())
+}
diff --git a/src/backends/dialog.rs b/src/backends/dialog.rs
index da17ad1..939b8f3 100644
--- a/src/backends/dialog.rs
+++ b/src/backends/dialog.rs
@@ -3,7 +3,7 @@
 
 use std::process;
 
-use crate::{Choice, Error, Input, Message, Question, Result};
+use crate::{Choice, Error, Input, Message, Password, Question, Result};
 
 /// The `dialog` backend.
 ///
@@ -135,6 +135,12 @@ impl super::Backend for Dialog {
             .map(|_| ())
     }
 
+    fn show_password(&self, password: &Password) -> Result<Option<String>> {
+        let args = vec!["--passwordbox", &password.text];
+        self.execute(args, vec![], &password.title)
+            .and_then(get_stderr)
+    }
+
     fn show_question(&self, question: &Question) -> Result<Choice> {
         let args = vec!["--yesno", &question.text];
         self.execute(args, vec![], &question.title)
diff --git a/src/backends/mod.rs b/src/backends/mod.rs
index fd0ddcc..1d555e3 100644
--- a/src/backends/mod.rs
+++ b/src/backends/mod.rs
@@ -23,6 +23,9 @@ pub trait Backend {
     /// Shows the given message dialog.
     fn show_message(&self, message: &super::Message) -> Result<()>;
 
+    /// Shows the given password dialog and returns the password.
+    fn show_password(&self, password: &super::Password) -> Result<Option<String>>;
+
     /// Shows the given question dialog and returns the choice.
     fn show_question(&self, question: &super::Question) -> Result<super::Choice>;
 }
diff --git a/src/lib.rs b/src/lib.rs
index 422252b..dd255d9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,7 @@
 //! are:
 //! - [`Input`][]: a text input dialog
 //! - [`Message`][]: a simple message box
+//! - [`Password`][]: a password input dialog
 //! - [`Question`][]: a question dialog box
 //!
 //! These dialog boxes can be displayed using various backends:
@@ -65,6 +66,7 @@
 //! [`Dialog`]: backends/struct.Dialog.html
 //! [`Input`]: struct.Input.html
 //! [`Message`]: struct.Message.html
+//! [`Password`]: struct.Password.html
 //! [`Question`]: struct.Question.html
 //! [`default_backend`]: fn.default_backend.html
 //! [`show`]: trait.DialogBox.html#method.show
@@ -258,6 +260,56 @@ impl DialogBox for Input {
     }
 }
 
+/// A dialog box with a password input field.
+///
+/// This dialog box displays a text and a password input field.  It returns the password entered by
+/// the user or `None` if the user cancelled the dialog.
+///
+/// # Example
+///
+/// ```no_run
+/// use dialog::DialogBox;
+///
+/// let password = dialog::Password::new("Please enter a new password")
+///     .title("Password")
+///     .show()
+///     .expect("Could not display dialog box");
+/// match password {
+///     Some(password) => println!("Your new password is: {}", password),
+///     None => println!("You do not want to have a password."),
+/// };
+/// ```
+pub struct Password {
+    text: String,
+    title: Option<String>,
+}
+
+impl Password {
+    /// Creates a new password dialog box with the given text.
+    pub fn new(text: impl Into<String>) -> Password {
+        Password {
+            text: text.into(),
+            title: None,
+        }
+    }
+
+    /// Sets the title of this password dialog box.
+    ///
+    /// This method returns a reference to `self` to enable chaining.
+    pub fn title(&mut self, title: impl Into<String>) -> &mut Password {
+        self.title = Some(title.into());
+        self
+    }
+}
+
+impl DialogBox for Password {
+    type Output = Option<String>;
+
+    fn show_with(&self, backend: &impl backends::Backend) -> Result<Self::Output> {
+        backend.show_password(self)
+    }
+}
+
 /// A user choise in a dialog box.
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum Choice {