1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
// Copyright 2013 The Servo Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std;
use std::fmt;
use std::marker::PhantomData;
use std::mem;
use std::mem::ManuallyDrop;
use std::ops::{Deref, DerefMut};
use std::os::raw::c_void;

pub use core_foundation_sys::base::*;

use string::CFString;
use ConcreteCFType;

pub trait CFIndexConvertible {
    /// Always use this method to construct a `CFIndex` value. It performs bounds checking to
    /// ensure the value is in range.
    fn to_CFIndex(self) -> CFIndex;
}

impl CFIndexConvertible for usize {
    #[inline]
    fn to_CFIndex(self) -> CFIndex {
        let max_CFIndex = CFIndex::max_value();
        if self > (max_CFIndex as usize) {
            panic!("value out of range")
        }
        self as CFIndex
    }
}

declare_TCFType!{
    /// Superclass of all Core Foundation objects.
    CFType, CFTypeRef
}

impl CFType {
    /// Try to downcast the `CFType` to a subclass. Checking if the instance is the
    /// correct subclass happens at runtime and `None` is returned if it is not the correct type.
    /// Works similar to [`Box::downcast`] and [`CFPropertyList::downcast`].
    ///
    /// # Examples
    ///
    /// ```
    /// # use core_foundation::string::CFString;
    /// # use core_foundation::boolean::CFBoolean;
    /// # use core_foundation::base::{CFType, TCFType};
    /// #
    /// // Create a string.
    /// let string: CFString = CFString::from_static_string("FooBar");
    /// // Cast it up to a CFType.
    /// let cf_type: CFType = string.as_CFType();
    /// // Cast it down again.
    /// assert_eq!(cf_type.downcast::<CFString>().unwrap().to_string(), "FooBar");
    /// // Casting it to some other type will yield `None`
    /// assert!(cf_type.downcast::<CFBoolean>().is_none());
    /// ```
    ///
    /// ```compile_fail
    /// # use core_foundation::array::CFArray;
    /// # use core_foundation::base::TCFType;
    /// # use core_foundation::boolean::CFBoolean;
    /// # use core_foundation::string::CFString;
    /// #
    /// let boolean_array = CFArray::from_CFTypes(&[CFBoolean::true_value()]).into_CFType();
    ///
    /// // This downcast is not allowed and causes compiler error, since it would cause undefined
    /// // behavior to access the elements of the array as a CFString:
    /// let invalid_string_array = boolean_array
    ///     .downcast_into::<CFArray<CFString>>()
    ///     .unwrap();
    /// ```
    ///
    /// [`Box::downcast`]: https://doc.rust-lang.org/std/boxed/struct.Box.html#method.downcast
    /// [`CFPropertyList::downcast`]: ../propertylist/struct.CFPropertyList.html#method.downcast
    #[inline]
    pub fn downcast<T: ConcreteCFType>(&self) -> Option<T> {
        if self.instance_of::<T>() {
            unsafe {
                let reference = T::Ref::from_void_ptr(self.0);
                Some(T::wrap_under_get_rule(reference))
            }
        } else {
            None
        }
    }

    /// Similar to [`downcast`], but consumes self and can thus avoid touching the retain count.
    ///
    /// [`downcast`]: #method.downcast
    #[inline]
    pub fn downcast_into<T: ConcreteCFType>(self) -> Option<T> {
        if self.instance_of::<T>() {
            unsafe {
                let reference = T::Ref::from_void_ptr(self.0);
                mem::forget(self);
                Some(T::wrap_under_create_rule(reference))
            }
        } else {
            None
        }
    }
}

impl fmt::Debug for CFType {
   /// Formats the value using [`CFCopyDescription`].
   ///
   /// [`CFCopyDescription`]: https://developer.apple.com/documentation/corefoundation/1521252-cfcopydescription?language=objc
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let desc = unsafe {
            CFString::wrap_under_create_rule(CFCopyDescription(self.0))
        };
        desc.fmt(f)
    }
}

impl Clone for CFType {
    #[inline]
    fn clone(&self) -> CFType {
        unsafe {
            TCFType::wrap_under_get_rule(self.0)
        }
    }
}

impl PartialEq for CFType {
    #[inline]
    fn eq(&self, other: &CFType) -> bool {
        unsafe {
            CFEqual(self.as_CFTypeRef(), other.as_CFTypeRef()) != 0
        }
    }
}

declare_TCFType!(CFAllocator, CFAllocatorRef);
impl_TCFType!(CFAllocator, CFAllocatorRef, CFAllocatorGetTypeID);

impl CFAllocator {
    #[inline]
    pub fn new(mut context: CFAllocatorContext) -> CFAllocator {
        unsafe {
            let allocator_ref = CFAllocatorCreate(kCFAllocatorDefault, &mut context);
            TCFType::wrap_under_create_rule(allocator_ref)
        }
    }
}


/// All Core Foundation types implement this trait. The associated type `Ref` specifies the
/// associated Core Foundation type: e.g. for `CFType` this is `CFTypeRef`; for `CFArray` this is
/// `CFArrayRef`.
///
/// Most structs that implement this trait will do so via the [`impl_TCFType`] macro.
///
/// [`impl_TCFType`]: ../macro.impl_TCFType.html
pub trait TCFType {
    /// The reference type wrapped inside this type.
    type Ref: TCFTypeRef;

    /// Returns the object as its concrete TypeRef.
    fn as_concrete_TypeRef(&self) -> Self::Ref;

    /// Returns an instance of the object, wrapping the underlying `CFTypeRef` subclass. Use this
    /// when following Core Foundation's "Create Rule". The reference count is *not* bumped.
    unsafe fn wrap_under_create_rule(obj: Self::Ref) -> Self;

    /// Returns the type ID for this class.
    fn type_id() -> CFTypeID;

    /// Returns the object as a wrapped `CFType`. The reference count is incremented by one.
    #[inline]
    fn as_CFType(&self) -> CFType {
        unsafe {
            TCFType::wrap_under_get_rule(self.as_CFTypeRef())
        }
    }

    /// Returns the object as a wrapped `CFType`. Consumes self and avoids changing the reference
    /// count.
    #[inline]
    fn into_CFType(self) -> CFType
    where
        Self: Sized,
    {
        let reference = self.as_CFTypeRef();
        mem::forget(self);
        unsafe { TCFType::wrap_under_create_rule(reference) }
    }

    /// Returns the object as a raw `CFTypeRef`. The reference count is not adjusted.
    fn as_CFTypeRef(&self) -> CFTypeRef;

    /// Returns an instance of the object, wrapping the underlying `CFTypeRef` subclass. Use this
    /// when following Core Foundation's "Get Rule". The reference count *is* bumped.
    unsafe fn wrap_under_get_rule(reference: Self::Ref) -> Self;

    /// Returns the reference count of the object. It is unwise to do anything other than test
    /// whether the return value of this method is greater than zero.
    #[inline]
    fn retain_count(&self) -> CFIndex {
        unsafe {
            CFGetRetainCount(self.as_CFTypeRef())
        }
    }

    /// Returns the type ID of this object.
    #[inline]
    fn type_of(&self) -> CFTypeID {
        unsafe {
            CFGetTypeID(self.as_CFTypeRef())
        }
    }

    /// Writes a debugging version of this object on standard error.
    fn show(&self) {
        unsafe {
            CFShow(self.as_CFTypeRef())
        }
    }

    /// Returns true if this value is an instance of another type.
    #[inline]
    fn instance_of<OtherCFType: TCFType>(&self) -> bool {
        self.type_of() == OtherCFType::type_id()
    }
}

impl TCFType for CFType {
    type Ref = CFTypeRef;

    #[inline]
    fn as_concrete_TypeRef(&self) -> CFTypeRef {
        self.0
    }

    #[inline]
    unsafe fn wrap_under_get_rule(reference: CFTypeRef) -> CFType {
        let reference: CFTypeRef = CFRetain(reference);
        TCFType::wrap_under_create_rule(reference)
    }

    #[inline]
    fn as_CFTypeRef(&self) -> CFTypeRef {
        self.as_concrete_TypeRef()
    }

    #[inline]
    unsafe fn wrap_under_create_rule(obj: CFTypeRef) -> CFType {
        CFType(obj)
    }

    #[inline]
    fn type_id() -> CFTypeID {
        // FIXME(pcwalton): Is this right?
        0
    }
}

/// A reference to an element inside a container
pub struct ItemRef<'a, T: 'a>(ManuallyDrop<T>, PhantomData<&'a T>);

impl<'a, T> Deref for ItemRef<'a, T> {
    type Target = T;

    fn deref(&self) -> &T {
        &self.0
    }
}

impl<'a, T: fmt::Debug> fmt::Debug for ItemRef<'a, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        self.0.fmt(f)
    }
}

impl<'a, T: PartialEq> PartialEq for ItemRef<'a, T> {
    fn eq(&self, other: &Self) -> bool {
        self.0.eq(&other.0)
    }
}

/// A reference to a mutable element inside a container
pub struct ItemMutRef<'a, T: 'a>(ManuallyDrop<T>, PhantomData<&'a T>);

impl<'a, T> Deref for ItemMutRef<'a, T> {
    type Target = T;

    fn deref(&self) -> &T {
        &self.0
    }
}

impl<'a, T> DerefMut for ItemMutRef<'a, T> {
    fn deref_mut(&mut self) -> &mut T {
        &mut self.0
    }
}

impl<'a, T: fmt::Debug> fmt::Debug for ItemMutRef<'a, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        self.0.fmt(f)
    }
}

impl<'a, T: PartialEq> PartialEq for ItemMutRef<'a, T> {
    fn eq(&self, other: &Self) -> bool {
        self.0.eq(&other.0)
    }
}

/// A trait describing how to convert from the stored *mut c_void to the desired T
pub unsafe trait FromMutVoid {
    unsafe fn from_mut_void<'a>(x: *mut c_void) -> ItemMutRef<'a, Self> where Self: std::marker::Sized;
}

unsafe impl FromMutVoid for u32 {
    unsafe fn from_mut_void<'a>(x: *mut c_void) -> ItemMutRef<'a, Self> {
        ItemMutRef(ManuallyDrop::new(x as u32), PhantomData)
    }
}

unsafe impl FromMutVoid for *const c_void {
    unsafe fn from_mut_void<'a>(x: *mut c_void) -> ItemMutRef<'a, Self> {
        ItemMutRef(ManuallyDrop::new(x), PhantomData)
    }
}

unsafe impl<T: TCFType> FromMutVoid for T {
    unsafe fn from_mut_void<'a>(x: *mut c_void) -> ItemMutRef<'a, Self> {
        ItemMutRef(ManuallyDrop::new(TCFType::wrap_under_create_rule(T::Ref::from_void_ptr(x))), PhantomData)
    }
}

/// A trait describing how to convert from the stored *const c_void to the desired T
pub unsafe trait FromVoid {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> where Self: std::marker::Sized;
}

unsafe impl FromVoid for u32 {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> {
        // Functions like CGFontCopyTableTags treat the void*'s as u32's
        // so we convert by casting directly
        ItemRef(ManuallyDrop::new(x as u32), PhantomData)
    }
}

unsafe impl FromVoid for *const c_void {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> {
        ItemRef(ManuallyDrop::new(x), PhantomData)
    }
}

unsafe impl<T: TCFType> FromVoid for T {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> {
        ItemRef(ManuallyDrop::new(TCFType::wrap_under_create_rule(T::Ref::from_void_ptr(x))), PhantomData)
    }
}

/// A trait describing how to convert from the stored *const c_void to the desired T
pub unsafe trait ToVoid<T> {
    fn to_void(&self) -> *const c_void;
}

unsafe impl ToVoid<*const c_void> for *const c_void {
    fn to_void(&self) -> *const c_void {
        *self
    }
}

unsafe impl<'a> ToVoid<CFType> for &'a CFType {
    fn to_void(&self) -> *const ::std::os::raw::c_void {
        self.as_concrete_TypeRef().as_void_ptr()
    }
}

unsafe impl ToVoid<CFType> for CFType {
    fn to_void(&self) -> *const ::std::os::raw::c_void {
        self.as_concrete_TypeRef().as_void_ptr()
    }
}

unsafe impl ToVoid<CFType> for CFTypeRef {
    fn to_void(&self) -> *const ::std::os::raw::c_void {
        self.as_void_ptr()
    }
}


#[cfg(test)]
mod tests {
    use super::*;
    use std::mem;
    use boolean::CFBoolean;

    #[test]
    fn cftype_instance_of() {
        let string = CFString::from_static_string("foo");
        let cftype = string.as_CFType();

        assert!(cftype.instance_of::<CFString>());
        assert!(!cftype.instance_of::<CFBoolean>());
    }

    #[test]
    fn as_cftype_retain_count() {
        let string = CFString::from_static_string("bar");
        assert_eq!(string.retain_count(), 1);
        let cftype = string.as_CFType();
        assert_eq!(cftype.retain_count(), 2);
        mem::drop(string);
        assert_eq!(cftype.retain_count(), 1);
    }

    #[test]
    fn into_cftype_retain_count() {
        let string = CFString::from_static_string("bar");
        assert_eq!(string.retain_count(), 1);
        let cftype = string.into_CFType();
        assert_eq!(cftype.retain_count(), 1);
    }

    #[test]
    fn as_cftype_and_downcast() {
        let string = CFString::from_static_string("bar");
        let cftype = string.as_CFType();
        let string2 = cftype.downcast::<CFString>().unwrap();
        assert_eq!(string2.to_string(), "bar");

        assert_eq!(string.retain_count(), 3);
        assert_eq!(cftype.retain_count(), 3);
        assert_eq!(string2.retain_count(), 3);
    }

    #[test]
    fn into_cftype_and_downcast_into() {
        let string = CFString::from_static_string("bar");
        let cftype = string.into_CFType();
        let string2 = cftype.downcast_into::<CFString>().unwrap();
        assert_eq!(string2.to_string(), "bar");
        assert_eq!(string2.retain_count(), 1);
    }
}