Source code
Revision control
Copy as Markdown
Other Tools
// Copyright © 2017 winapi-rs developers
// Licensed under the Apache License, Version 2.0
// All files in the project carrying such notice may not be copied, modified, or distributed
// except according to those terms.
#![allow(unused)]
use crate::windows::{
winapi::{IUnknown, Interface},
windows_sys::{
CoInitializeEx, SysFreeString, SysStringLen, BSTR, COINIT_MULTITHREADED, HRESULT, S_FALSE,
S_OK,
},
};
use std::{
convert::TryInto,
ffi::{OsStr, OsString},
mem::ManuallyDrop,
ops::Deref,
os::windows::ffi::{OsStrExt, OsStringExt},
ptr::{null, null_mut},
slice::from_raw_parts,
};
pub fn initialize() -> Result<(), HRESULT> {
let err = unsafe { CoInitializeEx(null(), COINIT_MULTITHREADED.try_into().unwrap()) };
if err != S_OK && err != S_FALSE {
// S_FALSE just means COM is already initialized
Err(err)
} else {
Ok(())
}
}
pub struct ComPtr<T>(*mut T)
where
T: Interface;
impl<T> ComPtr<T>
where
T: Interface,
{
/// Creates a `ComPtr` to wrap a raw pointer.
/// It takes ownership over the pointer which means it does __not__ call `AddRef`.
/// `T` __must__ be a COM interface that inherits from `IUnknown`.
pub unsafe fn from_raw(ptr: *mut T) -> ComPtr<T> {
assert!(!ptr.is_null());
ComPtr(ptr)
}
/// Casts up the inheritance chain
pub fn up<U>(self) -> ComPtr<U>
where
T: Deref<Target = U>,
U: Interface,
{
ComPtr(self.into_raw() as *mut U)
}
/// Extracts the raw pointer.
/// You are now responsible for releasing it yourself.
pub fn into_raw(self) -> *mut T {
ManuallyDrop::new(self).0
}
/// For internal use only.
fn as_unknown(&self) -> &IUnknown {
unsafe { &*(self.0 as *mut IUnknown) }
}
/// Performs `QueryInterface` fun.
pub fn cast<U>(&self) -> Result<ComPtr<U>, i32>
where
U: Interface,
{
let mut obj = null_mut();
let err = unsafe { self.as_unknown().QueryInterface(&U::uuidof(), &mut obj) };
if err < 0 {
return Err(err);
}
Ok(unsafe { ComPtr::from_raw(obj as *mut U) })
}
}
impl<T> Deref for ComPtr<T>
where
T: Interface,
{
type Target = T;
fn deref(&self) -> &T {
unsafe { &*self.0 }
}
}
impl<T> Clone for ComPtr<T>
where
T: Interface,
{
fn clone(&self) -> Self {
unsafe {
self.as_unknown().AddRef();
ComPtr::from_raw(self.0)
}
}
}
impl<T> Drop for ComPtr<T>
where
T: Interface,
{
fn drop(&mut self) {
unsafe {
self.as_unknown().Release();
}
}
}
pub struct BStr(BSTR);
impl BStr {
pub unsafe fn from_raw(s: BSTR) -> BStr {
BStr(s)
}
pub fn to_osstring(&self) -> OsString {
let len = unsafe { SysStringLen(self.0) };
let slice = unsafe { from_raw_parts(self.0, len as usize) };
OsStringExt::from_wide(slice)
}
}
impl Drop for BStr {
fn drop(&mut self) {
unsafe { SysFreeString(self.0) };
}
}
pub trait ToWide {
fn to_wide(&self) -> Vec<u16>;
fn to_wide_null(&self) -> Vec<u16>;
}
impl<T> ToWide for T
where
T: AsRef<OsStr>,
{
fn to_wide(&self) -> Vec<u16> {
self.as_ref().encode_wide().collect()
}
fn to_wide_null(&self) -> Vec<u16> {
self.as_ref().encode_wide().chain(Some(0)).collect()
}
}
pub trait FromWide
where
Self: Sized,
{
fn from_wide(wide: &[u16]) -> Self;
fn from_wide_null(wide: &[u16]) -> Self {
let len = wide.iter().take_while(|&&c| c != 0).count();
Self::from_wide(&wide[..len])
}
}
impl FromWide for OsString {
fn from_wide(wide: &[u16]) -> OsString {
OsStringExt::from_wide(wide)
}
}