зеркало из https://github.com/mozilla/gecko-dev.git
262 строки
9.0 KiB
C++
262 строки
9.0 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* ***** BEGIN LICENSE BLOCK *****
|
|
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version
|
|
* 1.1 (the "License"); you may not use this file except in compliance with
|
|
* the License. You may obtain a copy of the License at
|
|
* http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the
|
|
* License.
|
|
*
|
|
* The Original Code is Mozilla Corporation code.
|
|
*
|
|
* The Initial Developer of the Original Code is Mozilla Foundation.
|
|
* Portions created by the Initial Developer are Copyright (C) 2010
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Robert O'Callahan <robert@ocallahan.org>
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either the GNU General Public License Version 2 or later (the "GPL"), or
|
|
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
|
* in which case the provisions of the GPL or the LGPL are applicable instead
|
|
* of those above. If you wish to allow use of your version of this file only
|
|
* under the terms of either the GPL or the LGPL, and not to allow others to
|
|
* use your version of this file under the terms of the MPL, indicate your
|
|
* decision by deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL or the LGPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this file under
|
|
* the terms of any one of the MPL, the GPL or the LGPL.
|
|
*
|
|
* ***** END LICENSE BLOCK ***** */
|
|
|
|
#ifndef FRAMEPROPERTYTABLE_H_
|
|
#define FRAMEPROPERTYTABLE_H_
|
|
|
|
#include "nsTHashtable.h"
|
|
#include "nsHashKeys.h"
|
|
|
|
class nsIFrame;
|
|
|
|
namespace mozilla {
|
|
|
|
struct FramePropertyDescriptor;
|
|
|
|
typedef void (*FramePropertyDestructor)(void* aPropertyValue);
|
|
typedef void (*FramePropertyDestructorWithFrame)(nsIFrame* aFrame,
|
|
void* aPropertyValue);
|
|
|
|
/**
|
|
* A pointer to a FramePropertyDescriptor serves as a unique property ID.
|
|
* The FramePropertyDescriptor stores metadata about the property.
|
|
* Currently the only metadata is a destructor function. The destructor
|
|
* function is called on property values when they are overwritten or
|
|
* deleted.
|
|
*
|
|
* To use this class, declare a global (i.e., file, class or function-scope
|
|
* static member) FramePropertyDescriptor and pass its address as
|
|
* aProperty in the FramePropertyTable methods.
|
|
*/
|
|
struct FramePropertyDescriptor {
|
|
/**
|
|
* mDestructor will be called if it's non-null.
|
|
*/
|
|
FramePropertyDestructor mDestructor;
|
|
/**
|
|
* mDestructorWithFrame will be called if it's non-null and mDestructor
|
|
* is null. WARNING: The frame passed to mDestructorWithFrame may
|
|
* be a dangling frame pointer, if this is being called during
|
|
* presshell teardown. Do not use it except to compare against
|
|
* other frame pointers. No frame will have been allocated with
|
|
* the same address yet.
|
|
*/
|
|
FramePropertyDestructorWithFrame mDestructorWithFrame;
|
|
/**
|
|
* mDestructor and mDestructorWithFrame may both be null, in which case
|
|
* no value destruction is a no-op.
|
|
*/
|
|
};
|
|
|
|
/**
|
|
* The FramePropertyTable is optimized for storing 0 or 1 properties on
|
|
* a given frame. Storing very large numbers of properties on a single
|
|
* frame will not be efficient.
|
|
*
|
|
* Property values are passed as void* but do not actually have to be
|
|
* valid pointers. You can use NS_INT32_TO_PTR/NS_PTR_TO_INT32 to
|
|
* store PRInt32 values. Null/zero values can be stored and retrieved.
|
|
* Of course, the destructor function (if any) must handle such values
|
|
* correctly.
|
|
*/
|
|
class FramePropertyTable {
|
|
public:
|
|
FramePropertyTable() : mLastFrame(nsnull), mLastEntry(nsnull)
|
|
{
|
|
mEntries.Init();
|
|
}
|
|
~FramePropertyTable()
|
|
{
|
|
DeleteAll();
|
|
}
|
|
|
|
/**
|
|
* Set a property value on a frame. This requires one hashtable
|
|
* lookup (using the frame as the key) and a linear search through
|
|
* the properties of that frame. Any existing value for the property
|
|
* is destroyed.
|
|
*/
|
|
void Set(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty,
|
|
void* aValue);
|
|
/**
|
|
* Get a property value for a frame. This requires one hashtable
|
|
* lookup (using the frame as the key) and a linear search through
|
|
* the properties of that frame. If the frame has no such property,
|
|
* returns null.
|
|
* @param aFoundResult if non-null, receives a value 'true' iff
|
|
* the frame has a value for the property. This lets callers
|
|
* disambiguate a null result, which can mean 'no such property' or
|
|
* 'property value is null'.
|
|
*/
|
|
void* Get(const nsIFrame* aFrame, const FramePropertyDescriptor* aProperty,
|
|
PRBool* aFoundResult = nsnull);
|
|
/**
|
|
* Remove a property value for a frame. This requires one hashtable
|
|
* lookup (using the frame as the key) and a linear search through
|
|
* the properties of that frame. The old property value is returned
|
|
* (and not destroyed). If the frame has no such property,
|
|
* returns null.
|
|
* @param aFoundResult if non-null, receives a value 'true' iff
|
|
* the frame had a value for the property. This lets callers
|
|
* disambiguate a null result, which can mean 'no such property' or
|
|
* 'property value is null'.
|
|
*/
|
|
void* Remove(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty,
|
|
PRBool* aFoundResult = nsnull);
|
|
/**
|
|
* Remove and destroy a property value for a frame. This requires one
|
|
* hashtable lookup (using the frame as the key) and a linear search
|
|
* through the properties of that frame. If the frame has no such
|
|
* property, nothing happens.
|
|
*/
|
|
void Delete(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty);
|
|
/**
|
|
* Remove and destroy all property values for a frame. This requires one
|
|
* hashtable lookup (using the frame as the key).
|
|
*/
|
|
void DeleteAllFor(nsIFrame* aFrame);
|
|
/**
|
|
* Remove and destroy all property values for all frames.
|
|
*/
|
|
void DeleteAll();
|
|
|
|
protected:
|
|
/**
|
|
* Stores a property descriptor/value pair. It can also be used to
|
|
* store an nsTArray of PropertyValues.
|
|
*/
|
|
struct PropertyValue {
|
|
PropertyValue() : mProperty(nsnull), mValue(nsnull) {}
|
|
PropertyValue(const FramePropertyDescriptor* aProperty, void* aValue)
|
|
: mProperty(aProperty), mValue(aValue) {}
|
|
|
|
PRBool IsArray() { return !mProperty && mValue; }
|
|
nsTArray<PropertyValue>* ToArray()
|
|
{
|
|
NS_ASSERTION(IsArray(), "Must be array");
|
|
return reinterpret_cast<nsTArray<PropertyValue>*>(&mValue);
|
|
}
|
|
|
|
void DestroyValueFor(nsIFrame* aFrame) {
|
|
if (mProperty->mDestructor) {
|
|
mProperty->mDestructor(mValue);
|
|
} else if (mProperty->mDestructorWithFrame) {
|
|
mProperty->mDestructorWithFrame(aFrame, mValue);
|
|
}
|
|
}
|
|
|
|
const FramePropertyDescriptor* mProperty;
|
|
void* mValue;
|
|
};
|
|
|
|
/**
|
|
* Used with an array of PropertyValues to allow lookups that compare
|
|
* only on the FramePropertyDescriptor.
|
|
*/
|
|
class PropertyComparator {
|
|
public:
|
|
PRBool Equals(const PropertyValue& a, const PropertyValue& b) const {
|
|
return a.mProperty == b.mProperty;
|
|
}
|
|
PRBool Equals(const FramePropertyDescriptor* a, const PropertyValue& b) const {
|
|
return a == b.mProperty;
|
|
}
|
|
PRBool Equals(const PropertyValue& a, const FramePropertyDescriptor* b) const {
|
|
return a.mProperty == b;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Our hashtable entry. The key is an nsIFrame*, the value is a
|
|
* PropertyValue representing one or more property/value pairs.
|
|
*/
|
|
class Entry : public nsPtrHashKey<nsIFrame>
|
|
{
|
|
public:
|
|
Entry(KeyTypePointer aKey) : nsPtrHashKey<nsIFrame>(aKey) {}
|
|
Entry(const Entry &toCopy) :
|
|
nsPtrHashKey<nsIFrame>(toCopy), mProp(toCopy.mProp) {}
|
|
|
|
PropertyValue mProp;
|
|
};
|
|
|
|
static void DeleteAllForEntry(Entry* aEntry);
|
|
static PLDHashOperator DeleteEnumerator(Entry* aEntry, void* aArg);
|
|
|
|
nsTHashtable<Entry> mEntries;
|
|
nsIFrame* mLastFrame;
|
|
Entry* mLastEntry;
|
|
};
|
|
|
|
/**
|
|
* This class encapsulates the properties of a frame.
|
|
*/
|
|
class FrameProperties {
|
|
public:
|
|
FrameProperties(FramePropertyTable* aTable, nsIFrame* aFrame)
|
|
: mTable(aTable), mFrame(aFrame) {}
|
|
FrameProperties(FramePropertyTable* aTable, const nsIFrame* aFrame)
|
|
: mTable(aTable), mFrame(const_cast<nsIFrame*>(aFrame)) {}
|
|
|
|
void Set(const FramePropertyDescriptor* aProperty, void* aValue) const
|
|
{
|
|
mTable->Set(mFrame, aProperty, aValue);
|
|
}
|
|
void* Get(const FramePropertyDescriptor* aProperty,
|
|
PRBool* aFoundResult = nsnull) const
|
|
{
|
|
return mTable->Get(mFrame, aProperty, aFoundResult);
|
|
}
|
|
void* Remove(const FramePropertyDescriptor* aProperty,
|
|
PRBool* aFoundResult = nsnull) const
|
|
{
|
|
return mTable->Remove(mFrame, aProperty, aFoundResult);
|
|
}
|
|
void Delete(const FramePropertyDescriptor* aProperty)
|
|
{
|
|
mTable->Delete(mFrame, aProperty);
|
|
}
|
|
|
|
private:
|
|
FramePropertyTable* mTable;
|
|
nsIFrame* mFrame;
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* FRAMEPROPERTYTABLE_H_ */
|