Initial software keyboard support

3 files changed, 195 insertions, 0 deletions

diff --git a/ctru-rs/src/applet/mod.rs b/ctru-rs/src/applet/mod.rs
new file mode 100644
index 0000000..73469a3
--- /dev/null
+++ b/ctru-rs/src/applet/mod.rs
@@ -0,0 +1 @@
+pub mod swkbd;
diff --git a/ctru-rs/src/applet/swkbd.rs b/ctru-rs/src/applet/swkbd.rs
new file mode 100644
index 0000000..27b08ee
--- /dev/null
+++ b/ctru-rs/src/applet/swkbd.rs
@@ -0,0 +1,193 @@
+use std::mem;
+use std::str;
+
+use libctru::{self, SwkbdState, swkbdInit, swkbdSetFeatures, swkbdInputText};
+
+use libc;
+
+/// An instance of the software keyboard.
+pub struct Swkbd {
+    state: Box<SwkbdState>,
+}
+
+/// The kind of keyboard to be initialized.
+///
+/// Normal is the full keyboard with several pages (QUERTY/accents/symbol/mobile)
+/// Querty is a QUERTY-only keyboard.
+/// Numpad is a number pad.
+/// Western is a text keyboard without japanese symbols (only applies to JPN systems). For other
+/// systems it's the same as a Normal keyboard.
+#[derive(Copy, Clone, Debug)]
+pub enum Kind {
+    Normal,
+    Querty,
+    Numpad,
+    Western,
+}
+
+/// Represents which button the user pressed to close the software keyboard.
+#[derive(Copy, Clone, Debug)]
+pub enum Button {
+    Left,
+    Middle,
+    Right,
+}
+
+/// Error type for the software keyboard.
+#[derive(Copy, Clone, Debug)]
+pub enum Error {
+    InvalidInput,
+    OutOfMem,
+    HomePressed,
+    ResetPressed,
+    PowerPressed,
+    ParentalOk,
+    ParentalFail,
+    BannedInput,
+}
+
+/// Restrictions on keyboard input
+#[derive(Copy, Clone, Debug)]
+pub enum ValidInput {
+    Anything,
+    NotEmpty,
+    NotEmptyNotBlank,
+    NotBlank,
+    FixedLen,
+}
+
+/// Keyboard feature flags
+bitflags! {
+    pub struct Features: u32 {
+        const PARENTAL_PIN      = 1 << 0;
+        const DARKEN_TOP_SCREEN = 1 << 1;
+        const PREDICTIVE_INPUT  = 1 << 2;
+        const MULTILINE         = 1 << 3;
+        const FIXED_WIDTH       = 1 << 4;
+        const ALLOW_HOME        = 1 << 5;
+        const ALLOW_RESET       = 1 << 6;
+        const ALLOW_POWER       = 1 << 7;
+        const DEFAULT_QUERTY    = 1 << 8;
+    }
+}
+
+/// Keyboard input filtering flags
+bitflags! {
+    pub struct Filters: u32 {
+        const DIGITS    = 1 << 0;
+        const AT        = 1 << 1;
+        const PERCENT   = 1 << 2;
+        const BACKSLASH = 1 << 3;
+        const PROFANITY = 1 << 4;
+        const CALLBACK  = 1 << 5;
+    }
+}
+
+impl Swkbd {
+    /// Initializes a software keyboard of the specified type and the chosen number of buttons
+    /// (from 1-3).
+    pub fn init(keyboard_type: Kind, num_buttons: i32) -> Self {
+        unsafe {
+            let mut state = Box::new(mem::uninitialized::<SwkbdState>());
+            swkbdInit(state.as_mut(), keyboard_type as u32, num_buttons, -1);
+            Swkbd { state }
+        }
+    }
+
+    /// Gets input from this keyboard and appends it to the provided string.
+    ///
+    /// The text received from the keyboard can be up to 2048 bytes in length.
+    pub fn get_utf8(&mut self, buf: &mut String) -> Result<Button, Error> {
+        // Unfortunately the libctru API doesn't really provide a way to get the exact length
+        // of the string that it receieves from the software keyboard. Instead it expects you
+        // to pass in a buffer and hope that it's big enough to fit the entire string, so
+        // you have to set some upper limit on the potential size of the user's input.
+        const MAX_BYTES: usize = 2048;
+        let mut tmp = [0u8; MAX_BYTES];
+        let button = unsafe { self.get_bytes(&mut tmp)? };
+
+        // Make sure we haven't overflowed our buffer. libctru might already check this,
+        // but we'll do it here too just in case
+        let len = unsafe { libc::strlen(tmp.as_ptr()) };
+        assert!(len <= MAX_BYTES);
+
+        // Not sure if this is falliable or not in this stage of the process,
+        // but catch any decoding errors to be sure
+        let utf8 = match str::from_utf8(&tmp[..len]) {
+            Ok(parsed) => parsed,
+            Err(_) => return Err(Error::InvalidInput),
+        };
+
+        // Finally, copy the validated input into the user's `String`
+        *buf += utf8;
+        Ok(button)
+    }
+
+    /// Fills the provided buffer with a NUL-terminated sequence of bytes from the software
+    /// keyboard
+    /// 
+    /// # Unsafety
+    ///
+    /// The received bytes are nominally UTF-8 formatted, but the provided buffer must be large
+    /// enough to receive both the text from the software keyboard along with a NUL-terminator.
+    /// Otherwise undefined behavior can result.
+    pub unsafe fn get_bytes(&mut self, buf: &mut [u8]) -> Result<Button, Error> {
+        match swkbdInputText(self.state.as_mut(), buf.as_mut_ptr(), buf.len()) {
+            libctru::SWKBD_BUTTON_NONE => Err(self.parse_swkbd_error()),
+            libctru::SWKBD_BUTTON_LEFT => Ok(Button::Left),
+            libctru::SWKBD_BUTTON_MIDDLE => Ok(Button::Middle),
+            libctru::SWKBD_BUTTON_RIGHT => Ok(Button::Right),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Sets special features for this keyboard
+    pub fn set_features(&mut self, features: Features) {
+        unsafe {
+            swkbdSetFeatures(self.state.as_mut(), features.bits)
+        }
+    }
+
+    /// Configures input validation for this keyboard
+    pub fn set_validation(&mut self, validation: ValidInput,
+                          filters: Filters) {
+        self.state.valid_input = validation as i32;
+        self.state.filter_flags = filters.bits;
+    }
+
+    /// Configures the maximum number of digits that can be entered in the keyboard when the
+    /// `Filters::DIGITS` flag is enabled
+    pub fn set_max_digits(&mut self, digits: u16) {
+        self.state.max_digits = digits;
+    }
+
+    /// Configures the maximum number of UTF-16 code units that can be entered into the software
+    /// keyboard. By default the limit is 0xFDE8 code units.
+    /// 
+    /// Note that keyboard input is converted from UTF-16 to UTF-8 before being handed to Rust,
+    /// so this code point limit does not necessarily equal the max number of UTF-8 code points
+    /// receivable by the `get_utf8` and `get_bytes` functions.
+    pub fn set_max_text_len(&mut self, len: u16) {
+        self.state.max_text_len = len;
+    }
+
+    fn parse_swkbd_error(&self) -> Error {
+        match self.state.result {
+            libctru::SWKBD_INVALID_INPUT => Error::InvalidInput,
+            libctru::SWKBD_OUTOFMEM => Error::OutOfMem,
+            libctru::SWKBD_HOMEPRESSED => Error::HomePressed,
+            libctru::SWKBD_RESETPRESSED => Error::ResetPressed,
+            libctru::SWKBD_POWERPRESSED => Error::PowerPressed,
+            libctru::SWKBD_PARENTAL_OK => Error::ParentalOk,
+            libctru::SWKBD_PARENTAL_FAIL => Error::ParentalFail,
+            libctru::SWKBD_BANNED_INPUT => Error::BannedInput,
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl Default for Swkbd {
+    fn default() -> Self {
+        Swkbd::init(Kind::Normal, 2)
+    }
+}
diff --git a/ctru-rs/src/lib.rs b/ctru-rs/src/lib.rs
index 56ac370..c98ca65 100644
--- a/ctru-rs/src/lib.rs
+++ b/ctru-rs/src/lib.rs
@@ -11,6 +11,7 @@ extern crate widestring;
 
 extern crate ctru_sys as libctru;
 
+pub mod applet;
 pub mod console;
 pub mod error;
 pub mod srv;