1 #ifndef __DALI_CONSTRAINT_H__
2 #define __DALI_CONSTRAINT_H__
5 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/public-api/animation/constraint-source.h>
23 #include <dali/public-api/common/dali-vector.h>
24 #include <dali/public-api/object/base-handle.h>
25 #include <dali/public-api/object/property.h>
26 #include <dali/public-api/object/property-input.h>
27 #include <dali/public-api/signals/callback.h>
32 * @addtogroup dali_core_animation
38 namespace Internal DALI_INTERNAL
43 typedef Vector< PropertyInput* > PropertyInputContainer;
46 * @brief An abstract base class for Constraints.
48 * This can be used to constrain a property of an object, after animations have been applied.
49 * Constraints are applied in the following order:
50 * - Constraints are applied to on-stage actors in a depth-first traversal.
51 * - For each actor, the constraints are applied in the same order as the calls to Apply().
52 * - Constraints are not applied to off-stage actors.
54 * Create a constraint using one of the New methods depending on the type of callback function used.
55 * Try to use a C function unless some data needs to be stored, otherwise functors and class methods
58 * A constraint can be applied to an object in the following manner:
61 * Handle handle = CreateMyObject();
62 * Constraint constraint = Constraint::New< Vector3 >( handle, CONSTRAINING_PROPERTY_INDEX, &MyFunction );
63 * constraint.AddSource( LocalSource( INPUT_PROPERTY_INDEX ) );
68 class DALI_IMPORT_API Constraint : public BaseHandle
73 * @brief Template for the Function that is called by the Constraint system.
77 * - Static member methods of an object
78 * - Member functions of a particular class
79 * - Functors of a particular class
80 * - If a functor or method is provided, then a copy of the object is made.
82 * The expected signature of the callback should be:
84 * void Function( P&, const PropertyInputContainer& );
87 * The P& parameter is an in,out parameter which stores the current value of the property. The callback
88 * should change this value to the desired one. The PropertyInputContainer is a const reference to the property inputs
89 * added to the Constraint in the order they were added via AddSource().
91 * @tparam P The property type to constrain.
94 template< typename P >
95 class DALI_INTERNAL Function : public CallbackBase
100 * @brief Constructor which connects to the provided C function (or a static member function).
102 * The expected signature of the function is:
104 * void MyFunction( P&, const PropertyInputContainer& );
108 * @param[in] function The function to call.
110 Function( void( *function )( P&, const PropertyInputContainer& ) )
111 : CallbackBase( reinterpret_cast< CallbackBase::Function >( function ) ),
112 mCopyConstructorDispatcher( NULL )
117 * @brief Constructor which copies a function object and connects to the functor of that object.
119 * The function object should have a functor with the following signature:
121 * void operator()( P&, const PropertyInputContainer& );
125 * @param[in] object The object to copy.
127 * @tparam T The type of the object.
130 Function( const T& object )
131 : CallbackBase( reinterpret_cast< void* >( new T( object ) ), // copy the object
132 NULL, // uses operator() instead of member function
133 reinterpret_cast< CallbackBase::Dispatcher >( &FunctorDispatcher2< T, P&, const PropertyInputContainer& >::Dispatch ),
134 reinterpret_cast< CallbackBase::Destructor >( &Destroyer< T >::Delete ) ),
135 mCopyConstructorDispatcher( reinterpret_cast< CopyConstructorDispatcher >( &ObjectCopyConstructorDispatcher< T >::Copy ) )
140 * @brief Constructor which copies a function object and allows a connection to a member method.
142 * The object should have a method with the signature:
144 * void MyObject::MyMethod( P&, const PropertyInputContainer& );
148 * @param[in] object The object to copy.
149 * @param[in] memberFunction The member function to call. This has to be a member of the same class.
151 * @tparam T The type of the object.
154 Function( const T& object, void ( T::*memberFunction ) ( P&, const PropertyInputContainer& ) )
155 : CallbackBase( reinterpret_cast< void* >( new T( object ) ), // copy the object
156 reinterpret_cast< CallbackBase::MemberFunction >( memberFunction ),
157 reinterpret_cast< CallbackBase::Dispatcher >( &Dispatcher2< T, P&, const PropertyInputContainer& >::Dispatch ),
158 reinterpret_cast< CallbackBase::Destructor >( &Destroyer< T >::Delete ) ),
159 mCopyConstructorDispatcher( reinterpret_cast< CopyConstructorDispatcher >( &ObjectCopyConstructorDispatcher< T >::Copy ) )
164 * @brief Clones the Function object.
166 * The object, if held by this object, is also copied.
169 * @return A pointer to a newly-allocation Function.
171 CallbackBase* Clone()
173 CallbackBase* callback = NULL;
174 if ( mImpl && mImpl->mObjectPointer && mCopyConstructorDispatcher )
176 callback = new Function( mCopyConstructorDispatcher( reinterpret_cast< UndefinedClass* >( mImpl->mObjectPointer ) ) /* Copy the object */,
178 mImpl->mMemberFunctionDispatcher,
179 mImpl->mDestructorDispatcher,
180 mCopyConstructorDispatcher );
184 callback = new Function( mFunction );
192 * @brief Must not be declared.
194 * This is used so that no optimisations are done by the compiler when using void*.
196 class UndefinedClass;
199 * @brief Used to call the function to copy the stored object
202 typedef UndefinedClass* (*CopyConstructorDispatcher) ( UndefinedClass* object );
205 * @brief Copies the actual object in Constraint::Function.
207 * @tparam T The type of the object.
211 struct ObjectCopyConstructorDispatcher
214 * @brief Copy the object stored in Constraint::Function.
217 * @param[in] object The object to copy.
219 * @return Newly allocated clone of the object.
221 static UndefinedClass* Copy( const UndefinedClass* object )
223 T* copy = new T( *( reinterpret_cast< const T* >( object ) ) );
224 return reinterpret_cast< UndefinedClass* >( copy );
229 * @brief Undefined copy constructor
232 Function( const Function& );
235 * @brief Undefined assignment operator
238 Function& operator=( const Function& );
241 * @brief Constructor used when copying the stored object.
244 * @param[in] object A newly copied object
245 * @param[in] memberFunction The member function of the object.
246 * @param[in] dispatcher Used to call the actual object.
247 * @param[in] destructor Used to delete the owned object.
248 * @param[in] copyConstructorDispatcher Used to create a copy of the owned object.
250 Function( void* object,
251 CallbackBase::MemberFunction memberFunction,
252 CallbackBase::Dispatcher dispatcher,
253 CallbackBase::Destructor destructor,
254 CopyConstructorDispatcher copyConstructorDispatcher )
255 : CallbackBase( object, memberFunction, dispatcher, destructor ),
256 mCopyConstructorDispatcher( copyConstructorDispatcher )
261 * @brief Constructor used when copying a simple stored function.
264 * @param[in] function The function to call.
266 Function( CallbackBase::Function function )
267 : CallbackBase( function ),
268 mCopyConstructorDispatcher( NULL )
274 CopyConstructorDispatcher mCopyConstructorDispatcher; ///< Function to call to copy the stored object
278 * @brief The action that will happen when the constraint is removed.
280 * The final value may be "baked" i.e. saved permanently.
281 * Alternatively the constrained value may be discarded when the constraint is removed.
286 Bake, ///< When the constraint is fully-applied, the constrained value is saved. @SINCE_1_0.0
287 Discard ///< When the constraint is removed, the constrained value is discarded. @SINCE_1_0.0
290 static const RemoveAction DEFAULT_REMOVE_ACTION; ///< Bake
293 * @brief Create an uninitialized Constraint; this can be initialized with Constraint::New().
295 * Calling member functions with an uninitialized Dali::Object is not allowed.
301 * @brief Create a constraint which targets a property using a function or a static class member.
303 * The expected signature, for a Vector3 type for example, of the function is:
305 * void MyFunction( Vector3&, const PropertyInputContainer& );
308 * Create the constraint with this function as follows:
310 * Constraint constraint = Constraint::New< Vector3 >( handle, CONSTRAINING_PROPERTY_INDEX, &MyFunction );
314 * @param[in] handle The handle to the property-owning object.
315 * @param[in] targetIndex The index of the property to constrain.
316 * @param[in] function The function to call to set the constrained property value.
317 * @return The new constraint.
319 * @tparam P The type of the property to constrain.
322 static Constraint New( Handle handle, Property::Index targetIndex, void( *function )( P&, const PropertyInputContainer& ) )
324 CallbackBase* callback = new Constraint::Function< P >( function );
325 return New( handle, targetIndex, PropertyTypes::Get< P >(), callback );
329 * @brief Create a constraint which targets a property using a functor object.
331 * The expected structure, for a Vector3 type for example, of the functor object is:
335 * void operator() ( Vector3&, const PropertyInputContainer& );
339 * Create the constraint with this object as follows:
341 * Constraint constraint = Constraint::New< Vector3 >( handle, CONSTRAINING_PROPERTY_INDEX, MyObject() );
345 * @param[in] handle The handle to the property-owning object.
346 * @param[in] targetIndex The index of the property to constrain.
347 * @param[in] object The functor object whose functor is called to set the constrained property value.
348 * @return The new constraint.
350 * @tparam P The type of the property to constrain.
351 * @tparam T The type of the object.
353 template< class P, class T >
354 static Constraint New( Handle handle, Property::Index targetIndex, const T& object )
356 CallbackBase* function = new Constraint::Function< P >( object );
357 return New( handle, targetIndex, PropertyTypes::Get< P >(), function );
361 * @brief Create a constraint which targets a property using an object method.
363 * The expected structure, for a Vector3 type for example, of the object is:
367 * void MyMethod( Vector3&, const PropertyInputContainer& );
371 * Create the constraint with this object as follows:
373 * Constraint constraint = Constraint::New< Vector3 >( handle, CONSTRAINING_PROPERTY_INDEX, MyObject(), &MyObject::MyMethod );
377 * @param[in] handle The handle to the property-owning object.
378 * @param[in] targetIndex The index of the property to constrain.
379 * @param[in] object The object whose member function is called to set the constrained property value.
380 * @param[in] memberFunction The member function to call to set the constrained property value.
381 * @return The new constraint.
383 * @tparam P The type of the property to constrain.
384 * @tparam T The type of the object.
386 template< class P, class T >
387 static Constraint New( Handle handle, Property::Index targetIndex, const T& object, void ( T::*memberFunction ) ( P&, const PropertyInputContainer& ) )
389 CallbackBase* function = new Constraint::Function< P >( object, memberFunction );
390 return New( handle, targetIndex, PropertyTypes::Get< P >(), function );
394 * @brief Creates a clones of this constraint for another object.
397 * @param[in] handle The handle to the property-owning object this constraint is to be cloned for.
399 * @return The new constraint.
401 Constraint Clone( Handle handle );
406 * This is non-virtual since derived Handle types must not contain data or virtual methods.
412 * @brief This copy constructor is required for (smart) pointer semantics.
415 * @param [in] constraint A reference to the copied handle
417 Constraint( const Constraint& constraint );
420 * @brief This assignment operator is required for (smart) pointer semantics.
423 * @param [in] rhs A reference to the copied handle
424 * @return A reference to this
426 Constraint& operator=( const Constraint& rhs );
429 * @brief Downcast an Object handle to Constraint handle.
431 * If handle points to a Constraint object the
432 * downcast produces valid handle. If not the returned handle is left uninitialized.
434 * @param[in] baseHandle to An object
435 * @return handle to a Constraint object or an uninitialized handle
437 static Constraint DownCast( BaseHandle baseHandle );
440 * @brief Adds a constraint source to the constraint
443 * @param[in] source The constraint source input to add
445 void AddSource( ConstraintSource source );
448 * @brief Applies this constraint.
451 * @pre The constraint must be initialized
452 * @pre The target object must still be alive
453 * @pre The source inputs should not have been destroyed
458 * @brief Removes this constraint.
464 * @brief Retrieve the object which this constraint is targeting.
467 * @return The target object.
469 Handle GetTargetObject();
472 * @brief Retrieve the property which this constraint is targeting.
475 * @return The target property.
477 Dali::Property::Index GetTargetProperty();
480 * @brief Set whether the constraint will "bake" a value when fully-applied.
482 * Otherwise the constrained value will be discarded, when the constraint is removed.
483 * The default value is Constraint::Bake.
485 * @param[in] action The remove-action.
487 void SetRemoveAction( RemoveAction action );
490 * @brief Query whether the constraint will "bake" a value when fully-applied.
492 * Otherwise the constrained value will be discarded, when the constraint is removed.
494 * @return The apply-action.
496 RemoveAction GetRemoveAction() const;
499 * @brief Set a tag for the constraint so it can be identified later
502 * @param[in] tag An integer to identify the constraint
504 void SetTag( const unsigned int tag );
512 unsigned int GetTag() const;
514 public: // Not intended for use by Application developers
517 * @brief This constructor is used by Dali New() methods
519 * @param [in] constraint A pointer to a newly allocated Dali resource
521 explicit DALI_INTERNAL Constraint( Internal::ConstraintBase* constraint );
523 private: // Not intended for use by Application developers
526 * @brief Construct a new constraint which targets a property.
529 * @param[in] handle The handle to the property-owning object.
530 * @param[in] targetIndex The index of the property to constrain.
531 * @param[in] targetType Type The type of the constrained property.
532 * @param[in] function The constraint function.
533 * @return The new constraint.
535 static Constraint New( Handle handle, Property::Index targetIndex, Property::Type targetType, CallbackBase* function );
543 #endif // __DALI_CONSTRAINT_H__