expose platform-native monitor identifier

src/android/mod.rs

@@ -14,6 +14,7 @@ use std::collections::VecDeque;
 use Api;
 use BuilderAttribs;
 use GlRequest;
+use NativeMonitorID;
 
 pub struct Window {
     display: ffi::egl::types::EGLDisplay,
@@ -41,6 +42,10 @@ impl MonitorID {
         Some("Primary".to_string())
     }
 
+    pub fn get_native_identifier(&self) -> NativeMonitorID {
+        NativeMonitorID::Unavailable
+    }
+
     pub fn get_dimensions(&self) -> (u32, u32) {
         unimplemented!()
     }

src/cocoa/monitor.rs

@@ -1,5 +1,6 @@
 use core_graphics::display;
 use std::collections::VecDeque;
+use window::NativeMonitorID;
 
 pub struct MonitorID(u32);
 
@@ -35,6 +36,11 @@ impl MonitorID {
         Some(format!("Monitor #{}", screen_num))
     }
 
+    pub fn get_native_identifier(&self) -> NativeMonitorID {
+        let MonitorID(display_id) = *self;
+        NativeMonitorID::Numeric(display_id)
+    }
+
     pub fn get_dimensions(&self) -> (u32, u32) {
         let MonitorID(display_id) = *self;
         let dimension = unsafe {

src/lib.rs

@@ -50,7 +50,7 @@ pub use headless::{HeadlessRendererBuilder, HeadlessContext};
 #[cfg(feature = "window")]
 pub use window::{WindowBuilder, Window, WindowProxy, PollEventsIterator, WaitEventsIterator};
 #[cfg(feature = "window")]
-pub use window::{AvailableMonitorsIter, MonitorID, get_available_monitors, get_primary_monitor};
+pub use window::{AvailableMonitorsIter, NativeMonitorID, MonitorID, get_available_monitors, get_primary_monitor};
 
 #[cfg(all(not(target_os = "windows"), not(target_os = "linux"), not(target_os = "macos"), not(target_os = "android")))]
 use this_platform_is_not_supported;

src/win32/monitor.rs

@@ -3,6 +3,8 @@ use user32;
 
 use std::collections::VecDeque;
 
+use NativeMonitorID;
+
 /// Win32 implementation of the main `MonitorID` object.
 pub struct MonitorID {
     /// The system name of the monitor.
@@ -113,6 +115,11 @@ impl MonitorID {
         Some(self.readable_name.clone())
     }
 
+    /// See the docs of the crate root file.
+    pub fn get_native_identifier(&self) -> NativeMonitorID {
+        NativeMonitorID::Name(self.readable_name.clone())
+    }
+
     /// See the docs if the crate root file.
     pub fn get_dimensions(&self) -> (u32, u32) {
         // TODO: retreive the dimensions every time this is called

src/window.rs

@@ -500,6 +500,19 @@ pub fn get_primary_monitor() -> MonitorID {
     MonitorID(winimpl::get_primary_monitor())
 }
 
+/// Native platform identifier for a monitor. Different platforms use fundamentally different types
+/// to represent a monitor ID.
+pub enum NativeMonitorID {
+    /// Cocoa and X11 use a numeric identifier to represent a monitor.
+    Numeric(u32),
+
+    /// Win32 uses a Unicode string to represent a monitor.
+    Name(String),
+
+    /// Other platforms (Android) don't support monitor identification.
+    Unavailable
+}
+
 /// Identifier for a monitor.
 pub struct MonitorID(winimpl::MonitorID);
 
@@ -510,6 +523,12 @@ impl MonitorID {
         id.get_name()
     }
 
+    /// Returns the native platform identifier for this monitor.
+    pub fn get_native_identifier(&self) -> NativeMonitorID {
+        let &MonitorID(ref id) = self;
+        id.get_native_identifier()
+    }
+
     /// Returns the number of pixels currently displayed on the monitor.
     pub fn get_dimensions(&self) -> (u32, u32) {
         let &MonitorID(ref id) = self;

src/x11/window/monitor.rs

@@ -43,6 +43,11 @@ impl MonitorID {
         Some(format!("Monitor #{}", screen_num))
     }
 
+    pub fn get_native_identifier(&self) -> NativeMonitorID {
+        let MonitorID(screen_num) = *self;
+        NativeMonitorID::Numeric(screen_num)
+    }
+
     pub fn get_dimensions(&self) -> (u32, u32) {
         let dimensions = unsafe {
             let display = ffi::XOpenDisplay(ptr::null());