Refine function names and type signatures (#886)

* First name consistency pass. More to come!

* Remove multitouch variable (hopefully this compiles!)

* Remove CreationError::NotSupported

* Add new error handling types

* Remove `get_` prefix from getters.

This is as per the Rust naming conventions recommended in
https://rust-lang-nursery.github.io/api-guidelines/naming.html#getter-names-follow-rust-convention-c-getter

* Make changes to Window position and size function signatures

* Remove CreationError in favor of OsError

* Begin updating iOS backend

* Change MonitorHandle::outer_position to just position

* Fix build on Windows and Linux

* Add Display and Error implementations to Error types

* Attempt to fix iOS build.

I can't actually check that this works since I can't cross-compile to
iOS on a Windows machine (thanks apple :/) but this should be one of
several commits to get it working.

* Attempt to fix iOS errors, and muck up Travis to make debugging easier

* More iOS fixins

* Add Debug and Display impls to OsError

* Fix Display impl

* Fix unused code warnings and travis

* Rename set_ime_spot to set_ime_position

* Add CHANGELOG entry

* Rename set_cursor to set_cursor_icon and MouseCursor to CursorIcon

* Organize Window functions into multiple, categorized impls

* Improve clarity of function ordering and docs in EventLoop

src/platform_impl/windows/monitor.rs

@@ -3,7 +3,7 @@ use winapi::shared::windef::{HDC, HMONITOR, HWND, LPRECT, POINT};
 use winapi::um::winnt::LONG;
 use winapi::um::winuser;
 
-use std::{mem, ptr};
+use std::{mem, ptr, io};
 use std::collections::VecDeque;
 
 use super::{EventLoop, util};
@@ -50,7 +50,7 @@ unsafe extern "system" fn monitor_enum_proc(
     TRUE // continue enumeration
 }
 
-pub fn get_available_monitors() -> VecDeque<MonitorHandle> {
+pub fn available_monitors() -> VecDeque<MonitorHandle> {
     let mut monitors: VecDeque<MonitorHandle> = VecDeque::new();
     unsafe {
         winuser::EnumDisplayMonitors(
@@ -63,7 +63,7 @@ pub fn get_available_monitors() -> VecDeque<MonitorHandle> {
     monitors
 }
 
-pub fn get_primary_monitor() -> MonitorHandle {
+pub fn primary_monitor() -> MonitorHandle {
     const ORIGIN: POINT = POINT { x: 0, y: 0 };
     let hmonitor = unsafe {
         winuser::MonitorFromPoint(ORIGIN, winuser::MONITOR_DEFAULTTOPRIMARY)
@@ -71,7 +71,7 @@ pub fn get_primary_monitor() -> MonitorHandle {
     MonitorHandle::from_hmonitor(hmonitor)
 }
 
-pub fn get_current_monitor(hwnd: HWND) -> MonitorHandle {
+pub fn current_monitor(hwnd: HWND) -> MonitorHandle {
     let hmonitor = unsafe {
         winuser::MonitorFromWindow(hwnd, winuser::MONITOR_DEFAULTTONEAREST)
     };
@@ -80,26 +80,26 @@ pub fn get_current_monitor(hwnd: HWND) -> MonitorHandle {
 
 impl<T> EventLoop<T> {
     // TODO: Investigate opportunities for caching
-    pub fn get_available_monitors(&self) -> VecDeque<MonitorHandle> {
-        get_available_monitors()
+    pub fn available_monitors(&self) -> VecDeque<MonitorHandle> {
+        available_monitors()
     }
 
-    pub fn get_primary_monitor(&self) -> MonitorHandle {
-        get_primary_monitor()
+    pub fn primary_monitor(&self) -> MonitorHandle {
+        primary_monitor()
     }
 }
 
 impl Window {
-    pub fn get_available_monitors(&self) -> VecDeque<MonitorHandle> {
-        get_available_monitors()
+    pub fn available_monitors(&self) -> VecDeque<MonitorHandle> {
+        available_monitors()
     }
 
-    pub fn get_primary_monitor(&self) -> MonitorHandle {
-        get_primary_monitor()
+    pub fn primary_monitor(&self) -> MonitorHandle {
+        primary_monitor()
     }
 }
 
-pub(crate) fn get_monitor_info(hmonitor: HMONITOR) -> Result<winuser::MONITORINFOEXW, util::WinError> {
+pub(crate) fn get_monitor_info(hmonitor: HMONITOR) -> Result<winuser::MONITORINFOEXW, io::Error> {
     let mut monitor_info: winuser::MONITORINFOEXW = unsafe { mem::uninitialized() };
     monitor_info.cbSize = mem::size_of::<winuser::MONITORINFOEXW>() as DWORD;
     let status = unsafe {
@@ -109,7 +109,7 @@ pub(crate) fn get_monitor_info(hmonitor: HMONITOR) -> Result<winuser::MONITORINF
         )
     };
     if status == 0 {
-        Err(util::WinError::from_last_error())
+        Err(io::Error::last_os_error())
     } else {
         Ok(monitor_info)
     }
@@ -142,32 +142,32 @@ impl MonitorHandle {
     }
 
     #[inline]
-    pub fn get_name(&self) -> Option<String> {
+    pub fn name(&self) -> Option<String> {
         Some(self.monitor_name.clone())
     }
 
     #[inline]
-    pub fn get_native_identifier(&self) -> String {
+    pub fn native_identifier(&self) -> String {
         self.monitor_name.clone()
     }
 
     #[inline]
-    pub fn get_hmonitor(&self) -> HMONITOR {
+    pub fn hmonitor(&self) -> HMONITOR {
         self.hmonitor.0
     }
 
     #[inline]
-    pub fn get_dimensions(&self) -> PhysicalSize {
+    pub fn dimensions(&self) -> PhysicalSize {
         self.dimensions.into()
     }
 
     #[inline]
-    pub fn get_position(&self) -> PhysicalPosition {
+    pub fn position(&self) -> PhysicalPosition {
         self.position.into()
     }
 
     #[inline]
-    pub fn get_hidpi_factor(&self) -> f64 {
+    pub fn hidpi_factor(&self) -> f64 {
         self.hidpi_factor
     }
 }