Files
readest/apps/readest-app/extensions/windows-thumbnail/src/com_provider.rs
T

507 lines
17 KiB
Rust

/// Windows COM Thumbnail Provider for Readest
///
/// Implements IThumbnailProvider and IInitializeWithItem for Windows Shell integration.
/// This allows Windows Explorer to show book covers as thumbnails for eBook files.
///
/// **Important**: Thumbnails are only shown when Readest.exe is the default application
/// for the file type.
///
/// ## CLSID: {A1B2C3D4-E5F6-7890-ABCD-EF1234567890}
use std::cell::UnsafeCell;
use std::ffi::c_void;
use std::path::PathBuf;
use std::sync::atomic::{AtomicIsize, AtomicU32, Ordering};
use windows::core::{IUnknown, Interface, GUID, HRESULT, PCWSTR, PWSTR};
use windows::Win32::Foundation::{
CLASS_E_NOAGGREGATION, E_FAIL, E_INVALIDARG, E_NOINTERFACE, HMODULE, S_FALSE, S_OK,
};
use windows::Win32::Graphics::Gdi::{
CreateDIBSection, BITMAPINFO, BITMAPINFOHEADER, BI_RGB, DIB_RGB_COLORS, HBITMAP,
};
use windows::Win32::System::Com::{CoTaskMemFree, IClassFactory, IClassFactory_Impl};
use windows::Win32::System::LibraryLoader::GetModuleFileNameW;
use windows::Win32::System::Registry::{
RegCloseKey, RegCreateKeyExW, RegDeleteTreeW, RegSetValueExW, HKEY, HKEY_CLASSES_ROOT,
KEY_WRITE, REG_OPTION_NON_VOLATILE, REG_SZ,
};
use windows::Win32::UI::Shell::{
AssocQueryStringW, IInitializeWithItem, IInitializeWithItem_Impl, IShellItem,
IThumbnailProvider, IThumbnailProvider_Impl, ASSOCF_NONE, ASSOCSTR_EXECUTABLE,
SIGDN_FILESYSPATH, WTSAT_ARGB, WTS_ALPHATYPE,
};
use windows_core::BOOL;
use windows_core::{implement, Ref};
use super::cached_thumbnail_for_path;
// ─────────────────────────────────────────────────────────────────────────────
// CLSID for Readest Thumbnail Provider
// ─────────────────────────────────────────────────────────────────────────────
/// CLSID: {A1B2C3D4-E5F6-7890-ABCD-EF1234567890}
pub const CLSID_READEST_THUMBNAIL: GUID = GUID::from_u128(0xA1B2C3D4_E5F6_7890_ABCD_EF1234567890);
/// Supported file extensions
pub const SUPPORTED_EXTENSIONS: &[&str] = &[
".epub", ".mobi", ".azw", ".azw3", ".kf8", ".prc", ".fb2", ".cbz", ".cbr", ".txt",
];
// DLL reference counting
static DLL_REF_COUNT: AtomicU32 = AtomicU32::new(0);
static DLL_MODULE_PTR: AtomicIsize = AtomicIsize::new(0);
fn dll_add_ref() {
DLL_REF_COUNT.fetch_add(1, Ordering::SeqCst);
}
fn dll_release() {
DLL_REF_COUNT.fetch_sub(1, Ordering::SeqCst);
}
fn set_dll_module(h: HMODULE) {
DLL_MODULE_PTR.store(h.0 as isize, Ordering::SeqCst);
}
fn get_dll_module() -> Option<HMODULE> {
let ptr = DLL_MODULE_PTR.load(Ordering::SeqCst);
if ptr == 0 {
None
} else {
Some(HMODULE(ptr as *mut c_void))
}
}
// ─────────────────────────────────────────────────────────────────────────────
// File Association Check
// ─────────────────────────────────────────────────────────────────────────────
/// Check if Readest.exe is the default application for a given file extension.
fn is_readest_default_for_extension(ext: &str) -> bool {
let ext_wide: Vec<u16> = ext.encode_utf16().chain(std::iter::once(0)).collect();
let mut buffer = [0u16; 260];
let mut buffer_size = buffer.len() as u32;
unsafe {
let result = AssocQueryStringW(
ASSOCF_NONE,
ASSOCSTR_EXECUTABLE,
PCWSTR(ext_wide.as_ptr()),
None,
Some(PWSTR(buffer.as_mut_ptr())),
&mut buffer_size,
);
if result.is_ok() {
let len = buffer.iter().position(|&c| c == 0).unwrap_or(buffer.len());
let path = String::from_utf16_lossy(&buffer[..len]).to_lowercase();
return path.contains("readest");
}
}
false
}
/// Check if Readest is the default app for a specific file path.
fn is_readest_default_for_file(path: &PathBuf) -> bool {
if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
let ext_with_dot = format!(".{}", ext.to_lowercase());
return is_readest_default_for_extension(&ext_with_dot);
}
false
}
// ─────────────────────────────────────────────────────────────────────────────
// ThumbnailProvider
// ─────────────────────────────────────────────────────────────────────────────
/// Interior mutability wrapper for COM single-threaded apartment
struct ComCell<T>(UnsafeCell<T>);
impl<T> ComCell<T> {
fn new(value: T) -> Self {
Self(UnsafeCell::new(value))
}
fn get(&self) -> &T {
unsafe { &*self.0.get() }
}
fn set(&self, value: T) {
unsafe {
*self.0.get() = value;
}
}
}
// SAFETY: COM thumbnail providers run in single-threaded apartment (STA)
unsafe impl<T> Sync for ComCell<T> {}
unsafe impl<T> Send for ComCell<T> {}
#[implement(IThumbnailProvider, IInitializeWithItem)]
pub struct ThumbnailProvider {
file_path: ComCell<Option<PathBuf>>,
file_ext: ComCell<Option<String>>,
should_provide: ComCell<bool>,
}
impl ThumbnailProvider {
pub fn new() -> Self {
dll_add_ref();
Self {
file_path: ComCell::new(None),
file_ext: ComCell::new(None),
should_provide: ComCell::new(false),
}
}
}
impl Default for ThumbnailProvider {
fn default() -> Self {
Self::new()
}
}
impl Drop for ThumbnailProvider {
fn drop(&mut self) {
dll_release();
}
}
impl IInitializeWithItem_Impl for ThumbnailProvider_Impl {
fn Initialize(&self, psi: Ref<'_, IShellItem>, _grfmode: u32) -> windows::core::Result<()> {
let item = psi.ok()?;
unsafe {
let path_pwstr = item.GetDisplayName(SIGDN_FILESYSPATH)?;
let mut len = 0usize;
let mut ptr = path_pwstr.0;
while *ptr != 0 {
len += 1;
ptr = ptr.add(1);
}
let slice = std::slice::from_raw_parts(path_pwstr.0, len);
let path_str = String::from_utf16_lossy(slice);
let path = PathBuf::from(&path_str);
CoTaskMemFree(Some(path_pwstr.0 as *const c_void));
let is_default = is_readest_default_for_file(&path);
self.should_provide.set(is_default);
if !is_default {
return Ok(());
}
let ext = path
.extension()
.and_then(|e| e.to_str())
.map(|s| s.to_lowercase())
.unwrap_or_default();
self.file_path.set(Some(path));
self.file_ext.set(Some(ext));
}
Ok(())
}
}
impl IThumbnailProvider_Impl for ThumbnailProvider_Impl {
fn GetThumbnail(
&self,
cx: u32,
phbmp: *mut HBITMAP,
pdwalpha: *mut WTS_ALPHATYPE,
) -> windows::core::Result<()> {
if !*self.should_provide.get() {
return Err(E_FAIL.into());
}
let path = self.file_path.get().as_ref().ok_or(E_FAIL)?;
let ext = self.file_ext.get().as_ref().ok_or(E_FAIL)?;
let png_bytes = cached_thumbnail_for_path(path, ext, cx).map_err(|_| E_FAIL)?;
let img = image::load_from_memory(&png_bytes).map_err(|_| E_FAIL)?;
let rgba = img.to_rgba8();
let (width, height) = (rgba.width(), rgba.height());
let bmi = BITMAPINFO {
bmiHeader: BITMAPINFOHEADER {
biSize: std::mem::size_of::<BITMAPINFOHEADER>() as u32,
biWidth: width as i32,
biHeight: -(height as i32),
biPlanes: 1,
biBitCount: 32,
biCompression: BI_RGB.0,
..Default::default()
},
..Default::default()
};
let mut bits: *mut c_void = std::ptr::null_mut();
unsafe {
let hbmp = CreateDIBSection(None, &bmi, DIB_RGB_COLORS, &mut bits, None, 0)
.map_err(|_| E_FAIL)?;
if bits.is_null() {
return Err(E_FAIL.into());
}
// RGBA -> BGRA
let dst =
std::slice::from_raw_parts_mut(bits as *mut u8, (width * height * 4) as usize);
let src = rgba.as_raw();
for i in 0..(width * height) as usize {
let si = i * 4;
dst[si] = src[si + 2]; // B
dst[si + 1] = src[si + 1]; // G
dst[si + 2] = src[si]; // R
dst[si + 3] = src[si + 3]; // A
}
*phbmp = hbmp;
*pdwalpha = WTSAT_ARGB;
}
Ok(())
}
}
// ─────────────────────────────────────────────────────────────────────────────
// ClassFactory
// ─────────────────────────────────────────────────────────────────────────────
#[implement(IClassFactory)]
pub struct ThumbnailProviderFactory;
impl ThumbnailProviderFactory {
pub fn new() -> Self {
dll_add_ref();
Self
}
}
impl Default for ThumbnailProviderFactory {
fn default() -> Self {
Self::new()
}
}
impl Drop for ThumbnailProviderFactory {
fn drop(&mut self) {
dll_release();
}
}
impl IClassFactory_Impl for ThumbnailProviderFactory_Impl {
fn CreateInstance(
&self,
punkouter: Ref<'_, IUnknown>,
riid: *const GUID,
ppvobject: *mut *mut c_void,
) -> windows::core::Result<()> {
unsafe {
if ppvobject.is_null() {
return Err(E_INVALIDARG.into());
}
*ppvobject = std::ptr::null_mut();
if !punkouter.is_null() {
return Err(CLASS_E_NOAGGREGATION.into());
}
let provider: IThumbnailProvider = ThumbnailProvider::new().into();
provider.query(&*riid, ppvobject).ok()
}
}
fn LockServer(&self, flock: BOOL) -> windows::core::Result<()> {
if flock.as_bool() {
dll_add_ref();
} else {
dll_release();
}
Ok(())
}
}
// ─────────────────────────────────────────────────────────────────────────────
// DLL Exports
// ─────────────────────────────────────────────────────────────────────────────
#[no_mangle]
pub extern "system" fn DllMain(hinstance: HMODULE, reason: u32, _reserved: *mut c_void) -> BOOL {
const DLL_PROCESS_ATTACH: u32 = 1;
if reason == DLL_PROCESS_ATTACH {
set_dll_module(hinstance);
}
BOOL::from(true)
}
#[no_mangle]
pub extern "system" fn DllCanUnloadNow() -> HRESULT {
if DLL_REF_COUNT.load(Ordering::SeqCst) == 0 {
S_OK
} else {
S_FALSE
}
}
#[no_mangle]
pub unsafe extern "system" fn DllGetClassObject(
rclsid: *const GUID,
riid: *const GUID,
ppv: *mut *mut c_void,
) -> HRESULT {
if ppv.is_null() || rclsid.is_null() || riid.is_null() {
return E_INVALIDARG;
}
*ppv = std::ptr::null_mut();
if *rclsid != CLSID_READEST_THUMBNAIL {
return E_NOINTERFACE;
}
if *riid != IClassFactory::IID && *riid != IUnknown::IID {
return E_NOINTERFACE;
}
let factory: IClassFactory = ThumbnailProviderFactory::new().into();
factory.query(&*riid, ppv)
}
#[no_mangle]
pub unsafe extern "system" fn DllRegisterServer() -> HRESULT {
match register_server_impl() {
Ok(()) => S_OK,
Err(e) => e,
}
}
#[no_mangle]
pub unsafe extern "system" fn DllUnregisterServer() -> HRESULT {
let _ = unregister_server_impl();
S_OK
}
// ─────────────────────────────────────────────────────────────────────────────
// Registry helpers
// ─────────────────────────────────────────────────────────────────────────────
fn get_dll_path() -> Option<String> {
let module = get_dll_module()?;
let mut buffer = [0u16; 260];
unsafe {
let len = GetModuleFileNameW(Some(module), &mut buffer);
if len == 0 {
None
} else {
Some(String::from_utf16_lossy(&buffer[..len as usize]))
}
}
}
fn clsid_string() -> String {
format!(
"{{{:08X}-{:04X}-{:04X}-{:02X}{:02X}-{:02X}{:02X}{:02X}{:02X}{:02X}{:02X}}}",
CLSID_READEST_THUMBNAIL.data1,
CLSID_READEST_THUMBNAIL.data2,
CLSID_READEST_THUMBNAIL.data3,
CLSID_READEST_THUMBNAIL.data4[0],
CLSID_READEST_THUMBNAIL.data4[1],
CLSID_READEST_THUMBNAIL.data4[2],
CLSID_READEST_THUMBNAIL.data4[3],
CLSID_READEST_THUMBNAIL.data4[4],
CLSID_READEST_THUMBNAIL.data4[5],
CLSID_READEST_THUMBNAIL.data4[6],
CLSID_READEST_THUMBNAIL.data4[7]
)
}
fn to_wide(s: &str) -> Vec<u16> {
s.encode_utf16().chain(std::iter::once(0)).collect()
}
unsafe fn set_reg_value(key: HKEY, name: &str, value: &str) -> Result<(), HRESULT> {
let name_w = to_wide(name);
let value_w = to_wide(value);
let bytes: &[u8] = std::slice::from_raw_parts(value_w.as_ptr() as *const u8, value_w.len() * 2);
if RegSetValueExW(key, PCWSTR(name_w.as_ptr()), Some(0), REG_SZ, Some(bytes)).is_err() {
Err(E_FAIL)
} else {
Ok(())
}
}
unsafe fn create_reg_key(parent: HKEY, subkey: &str) -> Result<HKEY, HRESULT> {
let subkey_w = to_wide(subkey);
let mut hkey = HKEY::default();
let result = RegCreateKeyExW(
parent,
PCWSTR(subkey_w.as_ptr()),
Some(0),
None,
REG_OPTION_NON_VOLATILE,
KEY_WRITE,
None,
&mut hkey,
None,
);
if result.is_err() {
Err(E_FAIL)
} else {
Ok(hkey)
}
}
unsafe fn register_server_impl() -> Result<(), HRESULT> {
let dll_path = get_dll_path().ok_or(E_FAIL)?;
let clsid = clsid_string();
// CLSID key
let clsid_key = create_reg_key(HKEY_CLASSES_ROOT, &format!("CLSID\\{}", clsid))?;
set_reg_value(clsid_key, "", "Readest Thumbnail Provider")?;
// CRITICAL: DisableProcessIsolation = 1
let disable_isolation_name = to_wide("DisableProcessIsolation");
let value: u32 = 1;
let _ = windows::Win32::System::Registry::RegSetValueExW(
clsid_key,
PCWSTR(disable_isolation_name.as_ptr()),
Some(0),
windows::Win32::System::Registry::REG_DWORD,
Some(std::slice::from_raw_parts(
&value as *const u32 as *const u8,
4,
)),
);
let inproc_key = create_reg_key(clsid_key, "InprocServer32")?;
set_reg_value(inproc_key, "", &dll_path)?;
set_reg_value(inproc_key, "ThreadingModel", "Apartment")?;
let _ = RegCloseKey(inproc_key);
let _ = RegCloseKey(clsid_key);
// Register ShellEx thumbnail handler for each extension
for ext in SUPPORTED_EXTENSIONS {
let ext_shellex_path =
format!("{}\\ShellEx\\{{e357fccd-a995-4576-b01f-234630154e96}}", ext);
if let Ok(ext_shellex_key) = create_reg_key(HKEY_CLASSES_ROOT, &ext_shellex_path) {
let _ = set_reg_value(ext_shellex_key, "", &clsid);
let _ = RegCloseKey(ext_shellex_key);
}
}
Ok(())
}
unsafe fn unregister_server_impl() -> Result<(), HRESULT> {
let clsid = clsid_string();
let clsid_path = to_wide(&format!("CLSID\\{}", clsid));
let _ = RegDeleteTreeW(HKEY_CLASSES_ROOT, PCWSTR(clsid_path.as_ptr()));
for ext in SUPPORTED_EXTENSIONS {
let ext_path = to_wide(&format!(
"{}\\ShellEx\\{{e357fccd-a995-4576-b01f-234630154e96}}",
ext
));
let _ = RegDeleteTreeW(HKEY_CLASSES_ROOT, PCWSTR(ext_path.as_ptr()));
}
Ok(())
}