Make the events module an optional feature (#776)

.github/workflows/crossterm_test.yml

@@ -57,7 +57,7 @@ jobs:
       run: cargo test --lib --features serde -- --nocapture --test-threads 1
       continue-on-error: ${{ matrix.can-fail }}
     - name: Test event-stream feature
-      run: cargo test --lib --features event-stream -- --nocapture --test-threads 1
+      run: cargo test --lib --features "event-stream,events" -- --nocapture --test-threads 1
       continue-on-error: ${{ matrix.can-fail }}
     - name: Test all features
       run: cargo test --all-features -- --nocapture --test-threads 1
@@ -68,7 +68,7 @@ jobs:
       continue-on-error: ${{ matrix.can-fail }}
     - name: Test no default features with windows feature enabled
       if: matrix.os == 'windows-2019'
-      run: cargo test --no-default-features --features windows -- --nocapture --test-threads 1
+      run: cargo test --no-default-features --features "windows" -- --nocapture --test-threads 1
     - name: Test Packaging
       if: matrix.rust == 'stable'
       run: cargo package

Cargo.toml

@@ -26,12 +26,12 @@ all-features = true
 # Features
 #
 [features]
-default = ["bracketed-paste", "windows"]
+default = ["bracketed-paste", "windows", "events"]
 windows = ["winapi", "crossterm_winapi"]
 bracketed-paste = []
-event-stream = ["futures-core"]
+event-stream = ["futures-core", "events"]
 use-dev-tty = ["filedescriptor"]
-
+events = ["mio", "signal-hook", "signal-hook-mio"]
 #
 # Shared dependencies
 #
@@ -59,10 +59,10 @@ crossterm_winapi = { version = "0.9", optional = true }
 #
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
-signal-hook = { version = "0.3.13" }
+signal-hook = { version = "0.3.13", optional = true }
 filedescriptor = { version = "0.8", optional = true }
-mio = { version = "0.8", features = ["os-poll"] }
-signal-hook-mio = { version = "0.2.3", features = ["support-v0_8"] }
+mio = { version = "0.8", features = ["os-poll"], optional = true }
+signal-hook-mio = { version = "0.2.3", features = ["support-v0_8"], optional = true }
 
 #
 # Dev dependencies (examples, ...)
@@ -79,12 +79,28 @@ serde_json = "1.0"
 #
 [[example]]
 name = "event-read"
-required-features = ["bracketed-paste"]
+required-features = ["bracketed-paste", "events"]
+
+[[example]]
+name = "event-match-modifiers"
+required-features = ["bracketed-paste", "events"]
+
+[[example]]
+name = "event-poll-read"
+required-features = ["bracketed-paste", "events"]
 
 [[example]]
 name = "event-stream-async-std"
-required-features = ["event-stream"]
+required-features = ["event-stream", "events"]
 
 [[example]]
 name = "event-stream-tokio"
-required-features = ["event-stream"]
+required-features = ["event-stream", "events"]
+
+[[example]]
+name = "event-read-char-line"
+required-features = ["events"]
+
+[[example]]
+name = "stderr"
+required-features = ["events"]

README.md

@@ -144,16 +144,22 @@ features = ["event-stream"]
 |:---------------|:---------------------------------------------|
 | `event-stream` | `futures::Stream` producing `Result<Event>`. |
 | `serde`        | (De)serializing of events.                   |
+| `events`        | Reading input/system events (enabled by default) |
+| `filedescriptor` | Use raw filedescriptor for all events rather then mio dependency |
+
+
+To use crossterm as a very tin layer you can disable the `events` feature or use `filedescriptor` feature. 
+This can disable `mio` / `signal-hook` / `signal-hook-mio` dependencies.
 
 ### Dependency Justification
 
 | Dependency     | Used for                                                                         | Included                              |
 |:---------------|:---------------------------------------------------------------------------------|:--------------------------------------|
 | `bitflags`     | `KeyModifiers`, those are differ based on input.                                 | always                                |
 | `parking_lot`  | locking `RwLock`s with a timeout, const mutexes.                                 | always                                |
-| `libc`         | UNIX terminal_size/raw modes/set_title and several other low level functionality. | UNIX only                             |
-| `Mio`          | event readiness polling, waking up poller                                        | UNIX only                             |
-| `signal-hook`  | signal-hook is used to handle terminal resize SIGNAL with Mio.                    | UNIX only                             |
+| `libc`         | UNIX terminal_size/raw modes/set_title and several other low level functionality. | optional (`events` feature), UNIX only |
+| `Mio`          | event readiness polling, waking up poller                                        | optional (`events` feature), UNIX only |
+| `signal-hook`  | signal-hook is used to handle terminal resize SIGNAL with Mio.                   |  optional (`events` feature),UNIX only |
 | `winapi`       | Used for low-level windows system calls which ANSI codes can't replace           | windows only                          |
 | `futures-core` | For async stream of events                                                       | only with `event-stream` feature flag |
 | `serde`        | ***ser***ializing and ***de***serializing of events                              | only with `serde` feature flag        |

src/cursor.rs

@@ -48,10 +48,11 @@ use std::fmt;
 use crate::Result;
 use crate::{csi, impl_display, Command};
 
-pub use sys::position;
-
 pub(crate) mod sys;
 
+#[cfg(feature = "events")]
+pub use sys::position;
+
 /// A command that moves the terminal cursor to the given position (column, row).
 ///
 /// # Notes
@@ -426,13 +427,14 @@ impl_display!(for DisableBlinking);
 impl_display!(for SetCursorStyle);
 
 #[cfg(test)]
+#[cfg(feature = "events")]
 mod tests {
     use std::io::{self, stdout};
 
     use crate::execute;
 
     use super::{
-        position, MoveDown, MoveLeft, MoveRight, MoveTo, MoveUp, RestorePosition, SavePosition,
+        sys::position, MoveDown, MoveLeft, MoveRight, MoveTo, MoveUp, RestorePosition, SavePosition,
     };
 
     // Test is disabled, because it's failing on Travis

src/cursor/sys.rs

@@ -1,6 +1,7 @@
 //! This module provides platform related functions.
 
 #[cfg(unix)]
+#[cfg(feature = "events")]
 pub use self::unix::position;
 #[cfg(windows)]
 pub use self::windows::position;
@@ -14,4 +15,5 @@ pub(crate) use self::windows::{
 pub(crate) mod windows;
 
 #[cfg(unix)]
+#[cfg(feature = "events")]
 pub(crate) mod unix;