dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.cpp

   1 //
   2 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3 //
   4 // Licensed under the Flora License, Version 1.0 (the License);
   5 // you may not use this file except in compliance with the License.
   6 // You may obtain a copy of the License at
   7 //
   8 //     http://floralicense.org/license/
   9 //
  10 // Unless required by applicable law or agreed to in writing, software
  11 // distributed under the License is distributed on an AS IS BASIS,
  12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 // See the License for the specific language governing permissions and
  14 // limitations under the License.
  15 //
  16
  17 // CLASS HEADER
  18 #include <dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.h>
  19
  20 // EXTERNAL INCLUDES
  21 #include <algorithm>
  22
  23 // INTERNAL INCLUDES
  24 #include <dali/public-api/events/mouse-wheel-event.h>
  25 #include <dali-toolkit/public-api/controls/scrollable/item-view/item-factory.h>
  26 #include <dali-toolkit/internal/controls/scrollable/scroll-connector-impl.h>
  27
  28 using namespace std;
  29 using namespace Dali;
  30
  31 namespace // unnamed namespace
  32 {
  33
  34 //Type registration
  35 TypeRegistration mType( typeid(Toolkit::ItemView), typeid(Toolkit::Scrollable), NULL );
  36
  37 const float DEFAULT_MINIMUM_SWIPE_SPEED = 1.0f;
  38 const float DEFAULT_MINIMUM_SWIPE_DISTANCE = 3.0f;
  39 const float DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION = 0.1f;
  40
  41 const int DEFAULT_REFRESH_INTERVAL_MILLISECONDS = 50; // 20 updates per second
  42 const int MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT = 500;  // 0.5 second
  43
  44 const float DEFAULT_ANCHORING_DURATION = 1.0f;  // 1 second
  45 const float DEFAULT_COLOR_VISIBILITY_REMOVE_TIME = 0.5f; // 0.5 second
  46
  47 const float MILLISECONDS_PER_SECONDS = 1000.0f;
  48
  49 const char* OVERSHOOT_OVERLAY_RIPPLE_IMAGE_PATH = DALI_IMAGE_DIR "overshoot_ripple.png";
  50 const Rect<int> OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA( 0, 0, 720, 58 );
  51 const Vector4 OVERSHOOT_OVERLAY_NINE_PATCH_BORDER(0.0f, 0.0f, 1.0f, 12.0f);
  52 const float MAXIMUM_OVERSHOOT_HEIGHT = 36.0f;  // 36 pixels
  53 const float DEFAULT_OVERSHOOT_ANIMATION_DURATION = 0.5f;  // 0.5 second
  54 const float DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION = 0.2f;
  55
  56 const string LAYOUT_POSITION_PROPERTY_NAME( "item-view-layout-position" );
  57 const string POSITION_PROPERTY_NAME( "item-view-position" );
  58 const string MINIMUM_LAYOUT_POSITION_PROPERTY_NAME( "item-view-minimum-layout-position" );
  59 const string SCROLL_SPEED_PROPERTY_NAME( "item-view-scroll-speed" );
  60 const string SCROLL_DIRECTION_PROPERTY_NAME( "item-view-scroll-direction" );
  61 const string OVERSHOOT_PROPERTY_NAME( "item-view-overshoot" );
  62
  63 // Functors which wrap constraint functions with stored item IDs
  64
  65 struct WrappedVector3Constraint
  66 {
  67   WrappedVector3Constraint(Toolkit::ItemLayout::Vector3Function wrapMe, unsigned int itemId)
  68   : mWrapMe(wrapMe),
  69     mItemId(itemId)
  70   {
  71   }
  72
  73   Vector3 operator()(const Vector3& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  74   {
  75     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
  76
  77     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
  78   }
  79
  80   Toolkit::ItemLayout::Vector3Function mWrapMe;
  81   unsigned int mItemId;
  82 };
  83
  84 struct WrappedQuaternionConstraint
  85 {
  86   WrappedQuaternionConstraint(Toolkit::ItemLayout::QuaternionFunction wrapMe, unsigned int itemId)
  87   : mWrapMe(wrapMe),
  88     mItemId(itemId)
  89   {
  90   }
  91
  92   Quaternion operator()(const Quaternion& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  93   {
  94     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
  95
  96     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
  97   }
  98
  99   Toolkit::ItemLayout::QuaternionFunction mWrapMe;
 100   unsigned int mItemId;
 101 };
 102
 103 struct WrappedVector4Constraint
 104 {
 105   WrappedVector4Constraint(Toolkit::ItemLayout::Vector4Function wrapMe, unsigned int itemId)
 106   : mWrapMe(wrapMe),
 107     mItemId(itemId)
 108   {
 109   }
 110
 111   Vector4 operator()(const Vector4& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 112   {
 113     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 114
 115     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 116   }
 117
 118   Toolkit::ItemLayout::Vector4Function mWrapMe;
 119   unsigned int mItemId;
 120 };
 121
 122 struct WrappedBoolConstraint
 123 {
 124   WrappedBoolConstraint(Toolkit::ItemLayout::BoolFunction wrapMe, unsigned int itemId)
 125   : mWrapMe(wrapMe),
 126     mItemId(itemId)
 127   {
 128   }
 129
 130   bool operator()(const bool& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 131   {
 132     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 133
 134     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 135   }
 136
 137   Toolkit::ItemLayout::BoolFunction mWrapMe;
 138   unsigned int mItemId;
 139 };
 140
 141 /**
 142  * Local helper to convert pan distance (in actor coordinates) to the layout-specific scrolling direction
 143  */
 144 float CalculateScrollDistance(Vector2 panDistance, Toolkit::ItemLayout& layout)
 145 {
 146   Radian scrollDirection(layout.GetScrollDirection());
 147
 148   float cosTheta = cosf(scrollDirection);
 149   float sinTheta = sinf(scrollDirection);
 150
 151   return panDistance.x * sinTheta + panDistance.y * cosTheta;
 152 }
 153
 154 // Overshoot overlay constraints
 155
 156 struct OvershootOverlaySizeConstraint
 157 {
 158   float operator()(const float& current,
 159                      const PropertyInput& parentScrollDirectionProperty,
 160                      const PropertyInput& parentOvershootProperty,
 161                      const PropertyInput& parentSizeProperty)
 162   {
 163     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 164     const Vector3 parentSize = parentSizeProperty.GetVector3();
 165     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 166
 167     float overlayWidth;
 168
 169     if(Toolkit::IsVertical(parentOrientation))
 170     {
 171       overlayWidth = fabsf(parentScrollDirection.y) > Math::MACHINE_EPSILON_1 ? parentSize.x : parentSize.y;
 172     }
 173     else
 174     {
 175       overlayWidth = fabsf(parentScrollDirection.x) > Math::MACHINE_EPSILON_1 ? parentSize.y : parentSize.x;
 176     }
 177
 178     return overlayWidth;
 179   }
 180 };
 181
 182 struct OvershootOverlayRotationConstraint
 183 {
 184   Quaternion operator()(const Quaternion& current,
 185                         const PropertyInput& parentScrollDirectionProperty,
 186                         const PropertyInput& parentOvershootProperty)
 187   {
 188     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 189     const float parentOvershoot = parentOvershootProperty.GetFloat();
 190     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 191
 192     Quaternion rotation;
 193
 194     if(Toolkit::IsVertical(parentOrientation))
 195     {
 196       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 197       {
 198         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 199             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 200         {
 201           rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 202         }
 203         else
 204         {
 205           rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 206         }
 207       }
 208       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 209             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 210       {
 211         rotation = Quaternion(0.0f, Vector3::ZAXIS);
 212       }
 213       else
 214       {
 215         rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 216       }
 217     }
 218     else
 219     {
 220       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 221       {
 222         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot > Math::MACHINE_EPSILON_0)
 223             ||(parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot < Math::MACHINE_EPSILON_0) )
 224         {
 225           rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 226         }
 227         else
 228         {
 229           rotation = Quaternion(0.0f, Vector3::ZAXIS);
 230         }
 231       }
 232       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 233             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 234       {
 235         rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 236       }
 237       else
 238       {
 239         rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 240       }
 241     }
 242
 243     return rotation;
 244   }
 245 };
 246
 247 struct OvershootOverlayPositionConstraint
 248 {
 249   Vector3 operator()(const Vector3&    current,
 250                      const PropertyInput& parentSizeProperty,
 251                      const PropertyInput& parentScrollDirectionProperty,
 252                      const PropertyInput& parentOvershootProperty)
 253   {
 254     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 255     const float parentOvershoot = parentOvershootProperty.GetFloat();
 256     const Vector3 parentSize = parentSizeProperty.GetVector3();
 257     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 258
 259     Vector3 relativeOffset;
 260
 261     if(Toolkit::IsVertical(parentOrientation))
 262     {
 263       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 264       {
 265         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 266             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 267         {
 268           relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 269         }
 270         else
 271         {
 272           relativeOffset =Vector3(0.0f, 1.0f, 0.0f);
 273         }
 274       }
 275       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 276             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 277       {
 278         relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 279       }
 280       else
 281       {
 282         relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 283       }
 284     }
 285     else
 286     {
 287       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 288       {
 289         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot < Math::MACHINE_EPSILON_0)
 290             || (parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot > Math::MACHINE_EPSILON_0) )
 291         {
 292           relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 293         }
 294         else
 295         {
 296           relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 297         }
 298       }
 299       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 300             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 301       {
 302         relativeOffset = Vector3(0.0f, 1.0f, 0.0f);
 303       }
 304       else
 305       {
 306         relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 307       }
 308     }
 309
 310     return relativeOffset * parentSize;
 311
 312   }
 313 };
 314
 315 struct OvershootOverlayVisibilityConstraint
 316 {
 317   bool operator()(const bool& current,
 318                   const PropertyInput& parentLayoutScrollableProperty)
 319   {
 320     const bool parentLayoutScrollable = parentLayoutScrollableProperty.GetBoolean();
 321
 322     return parentLayoutScrollable;
 323   }
 324 };
 325
 326 /**
 327  * Relative position Constraint
 328  * Generates the relative position value of the item view based on the layout position,
 329  * and it's relation to the layout domain. This is a value from 0.0f to 1.0f in each axis.
 330  */
 331 Vector3 RelativePositionConstraint(const Vector3& current,
 332                                    const PropertyInput& scrollPositionProperty,
 333                                    const PropertyInput& scrollMinProperty,
 334                                    const PropertyInput& scrollMaxProperty,
 335                                    const PropertyInput& layoutSizeProperty)
 336 {
 337   const Vector3& position = Vector3(0.0f, scrollPositionProperty.GetFloat(), 0.0f);
 338   const Vector3& min = scrollMinProperty.GetVector3();
 339   const Vector3& max = scrollMaxProperty.GetVector3();
 340
 341   Vector3 relativePosition;
 342   Vector3 domainSize = max - min;
 343
 344   relativePosition.x = fabsf(domainSize.x) > Math::MACHINE_EPSILON_1 ? ((min.x - position.x) / fabsf(domainSize.x)) : 0.0f;
 345   relativePosition.y = fabsf(domainSize.y) > Math::MACHINE_EPSILON_1 ? ((min.y - position.y) / fabsf(domainSize.y)) : 0.0f;
 346
 347   return relativePosition;
 348 }
 349
 350 } // unnamed namespace
 351
 352 namespace Dali
 353 {
 354
 355 namespace Toolkit
 356 {
 357
 358 namespace Internal
 359 {
 360
 361 ///////////////////////////////////////////////////////////////////////////////////////////////////
 362 // ItemPool
 363 ///////////////////////////////////////////////////////////////////////////////////////////////////
 364
 365 void ItemPool::AddItems(bool scrollingTowardsLast, ItemRange range, const Vector3& targetSize)
 366 {
 367   // Add new actors to the ItemPool.
 368   // The order of addition depends on the scroll direction.
 369   if (scrollingTowardsLast)
 370   {
 371     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 372     {
 373       AddItem(itemId, targetSize);
 374     }
 375   }
 376   else
 377   {
 378     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 379     {
 380       AddItem(itemId-1, targetSize);
 381     }
 382   }
 383 }
 384
 385 void ItemPool::RemoveItems(ItemRange range)
 386 {
 387   // Remove unwanted actors from the ItemView & ItemPool
 388   for (IDKeyIter iter = mIdKeyContainer.begin(); iter != mIdKeyContainer.end(); )
 389   {
 390     unsigned int current = iter->first;
 391
 392     if (!range.Within(current))
 393     {
 394       mItemView.ActorRemovedFromItemPool(iter->second, iter->first);
 395
 396       mActorKeyContainer.erase(iter->second);
 397       mIdKeyContainer.erase(iter++); // erase invalidates the current iter; the post-increment is important here
 398     }
 399     else
 400     {
 401       ++iter;
 402     }
 403   }
 404 }
 405
 406 void ItemPool::AddItem(unsigned int itemId, const Vector3& targetSize)
 407 {
 408   if (mIdKeyContainer.find(itemId) == mIdKeyContainer.end())
 409   {
 410     Actor actor = mItemView.CreateActor(itemId);
 411
 412     if (actor)
 413     {
 414       mIdKeyContainer.insert(IDKeyPair(itemId, actor));
 415       mActorKeyContainer.insert(ActorKeyPair(actor, itemId));
 416
 417       mItemView.ActorAddedToItemPool(actor, itemId, targetSize);
 418     }
 419   }
 420 }
 421
 422 bool ItemPool::RemoveItem(unsigned int itemId)
 423 {
 424   bool found = false;
 425
 426   IDKeyIter iter = mIdKeyContainer.find(itemId);
 427   if (iter != mIdKeyContainer.end())
 428   {
 429     mItemView.ActorRemovedFromItemPool(iter->second, iter->first);
 430
 431     mActorKeyContainer.erase(iter->second);
 432     for (ActorKeyIter iterActorKey = mActorKeyContainer.begin(); iterActorKey != mActorKeyContainer.end(); ++iterActorKey)
 433     {
 434       if(iterActorKey->second > itemId)
 435       {
 436         iterActorKey->second--;
 437       }
 438     }
 439
 440     for (IDKeyIter iterIDKey = iter; iterIDKey != mIdKeyContainer.end(); ++iterIDKey)
 441     {
 442       if(iterIDKey->first < mIdKeyContainer.rbegin()->first)
 443       {
 444         iterIDKey->second = mIdKeyContainer[iterIDKey->first + 1];
 445       }
 446       else
 447       {
 448         mIdKeyContainer.erase(iterIDKey);
 449         break;
 450       }
 451     }
 452
 453     found = true;
 454   }
 455
 456   return found;
 457 }
 458
 459 ///////////////////////////////////////////////////////////////////////////////////////////////////
 460 // ItemView
 461 ///////////////////////////////////////////////////////////////////////////////////////////////////
 462
 463 Dali::Toolkit::ItemView ItemView::New(ItemFactory& factory)
 464 {
 465   // Create the implementation
 466   ItemViewPtr itemView(new ItemView(factory));
 467
 468   // Pass ownership to CustomActor via derived handle
 469   Dali::Toolkit::ItemView handle(*itemView);
 470
 471   // Second-phase init of the implementation
 472   // This can only be done after the CustomActor connection has been made...
 473   itemView->Initialize();
 474
 475   return handle;
 476 }
 477
 478 ItemView::ItemView(ItemFactory& factory)
 479 : Scrollable(),
 480   mItemFactory(factory),
 481   mItemPool(*this),
 482   mActiveLayout(NULL),
 483   mAnimatingOvershootOn(false),
 484   mAnimateOvershootOff(false),
 485   mAnchoringEnabled(true),
 486   mAnchoringDuration(DEFAULT_ANCHORING_DURATION),
 487   mRefreshIntervalMilliseconds(DEFAULT_REFRESH_INTERVAL_MILLISECONDS),
 488   mRefreshOrderHint(true/*Refresh item 0 first*/),
 489   mMinimumSwipeSpeed(DEFAULT_MINIMUM_SWIPE_SPEED),
 490   mMinimumSwipeDistance(DEFAULT_MINIMUM_SWIPE_DISTANCE),
 491   mScrollDistance(0.0f),
 492   mScrollSpeed(0.0f),
 493   mTotalPanDisplacement(Vector2::ZERO),
 494   mScrollOvershoot(0.0f),
 495   mIsFlicking(false),
 496   mGestureState(Gesture::Clear)
 497 {
 498   SetRequiresMouseWheelEvents(true);
 499   SetKeyboardNavigationSupport(true);
 500 }
 501
 502 void ItemView::OnInitialize()
 503 {
 504   SetSizePolicy( Toolkit::Control::Fixed, Toolkit::Control::Fixed );
 505
 506   RegisterCommonProperties();
 507
 508   Actor self = Self();
 509
 510   mOvershootEffect = OvershootRippleEffect::New();
 511   Image overshootImage = Image::New( OVERSHOOT_OVERLAY_RIPPLE_IMAGE_PATH );
 512   mOvershootOverlay = ImageActor::New( overshootImage );
 513   mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
 514   mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
 515   mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
 516   mOvershootOverlay.SetShaderEffect(mOvershootEffect);
 517   mOvershootOverlay.SetPixelArea(OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA);
 518   self.Add(mOvershootOverlay);
 519
 520   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 521   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 522
 523   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 524   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 525   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 526   mPropertyOvershoot = self.RegisterProperty(OVERSHOOT_PROPERTY_NAME, 0.0f);
 527
 528   ApplyOvershootOverlayConstraints();
 529
 530   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 531                                                    LocalSource(mPropertyPosition),
 532                                                    LocalSource(mPropertyPositionMin),
 533                                                    LocalSource(mPropertyPositionMax),
 534                                                    LocalSource(Actor::SIZE),
 535                                                    RelativePositionConstraint);
 536   self.ApplyConstraint(constraint);
 537
 538   Vector2 stageSize = Stage::GetCurrent().GetSize();
 539   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 540
 541   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 542
 543   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 544   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 545 }
 546
 547 ItemView::~ItemView()
 548 {
 549 }
 550
 551 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 552 {
 553   return mScrollConnector;
 554 }
 555
 556 unsigned int ItemView::GetLayoutCount() const
 557 {
 558   return mLayouts.size();
 559 }
 560
 561 void ItemView::AddLayout(ItemLayout& layout)
 562 {
 563   mLayouts.push_back(ItemLayoutPtr(&layout));
 564 }
 565
 566 void ItemView::RemoveLayout(unsigned int layoutIndex)
 567 {
 568   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 569
 570   if (mActiveLayout == mLayouts[layoutIndex].Get())
 571   {
 572     mActiveLayout = NULL;
 573   }
 574
 575   mLayouts.erase(mLayouts.begin() + layoutIndex);
 576 }
 577
 578 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 579 {
 580   return mLayouts[layoutIndex];
 581 }
 582
 583 ItemLayoutPtr ItemView::GetActiveLayout() const
 584 {
 585   return ItemLayoutPtr(mActiveLayout);
 586 }
 587
 588 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 589 {
 590   return mScrollPositionObject.GetProperty<float>( ScrollConnector::SCROLL_POSITION ) + static_cast<float>( itemId );
 591 }
 592
 593 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 594 {
 595   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 596
 597   Actor self = Self();
 598
 599   // The ItemView size should match the active layout size
 600   self.SetSize(targetSize);
 601
 602   // Switch to the new layout
 603   ItemLayout* previousLayout = mActiveLayout;
 604   mActiveLayout = mLayouts[layoutIndex].Get();
 605
 606   // Calculate which items are within either layout
 607   ItemRange oldRange = previousLayout ? GetItemRange(*previousLayout, targetSize, false/*don't reserve extra*/) : ItemRange(0u, 0u);
 608   ItemRange newRange = GetItemRange(*mActiveLayout, targetSize, false/*don't reserve extra*/);
 609
 610   // Move the items to the new layout positions...
 611
 612   bool resizeAnimationNeeded(false);
 613
 614   const ItemPool::IDKeyContainer& itemPool = mItemPool.GetIDKeyContainer();
 615   for (ItemPool::IDKeyConstIter iter = itemPool.begin(); iter != itemPool.end(); ++iter)
 616   {
 617     unsigned int itemId = iter->first;
 618     Actor actor = iter->second;
 619
 620     // Immediately relayout items that aren't within either layout
 621     bool immediate = !oldRange.Within(itemId) &&
 622                      !newRange.Within(itemId);
 623
 624     // Remove constraints from previous layout
 625     actor.RemoveConstraints();
 626
 627     Vector3 size;
 628     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 629     {
 630       if (!immediate &&
 631           durationSeconds > 0.0f)
 632       {
 633         // Use a size animation
 634         if (!resizeAnimationNeeded)
 635         {
 636           resizeAnimationNeeded = true;
 637           RemoveAnimation(mResizeAnimation);
 638           mResizeAnimation = Animation::New(durationSeconds);
 639         }
 640
 641         // The layout provides its own resize animation
 642         mActiveLayout->GetResizeAnimation(mResizeAnimation, actor, size, durationSeconds);
 643       }
 644       else
 645       {
 646         // resize immediately
 647         actor.SetSize(size);
 648       }
 649     }
 650
 651     ApplyConstraints(actor, *mActiveLayout, itemId, immediate ? 0.0f : durationSeconds);
 652   }
 653
 654   if (resizeAnimationNeeded)
 655   {
 656     mResizeAnimation.Play();
 657   }
 658
 659   // Refresh the new layout
 660   ItemRange range = GetItemRange(*mActiveLayout, targetSize, true/*reserve extra*/);
 661   AddItems(*mActiveLayout, targetSize, range);
 662
 663   // Scroll to an appropriate layout position
 664
 665   bool scrollAnimationNeeded(false);
 666   float firstItemScrollPosition(0.0f);
 667
 668   float current = GetCurrentLayoutPosition(0);
 669   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 670   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 671
 672   if (current < minimum)
 673   {
 674     scrollAnimationNeeded = true;
 675     firstItemScrollPosition = minimum;
 676   }
 677   else if (mAnchoringEnabled)
 678   {
 679     scrollAnimationNeeded = true;
 680     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 681   }
 682
 683   if (scrollAnimationNeeded)
 684   {
 685     RemoveAnimation(mScrollAnimation);
 686     mScrollAnimation = Animation::New(mAnchoringDuration);
 687     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 688     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 689     mScrollAnimation.Play();
 690   }
 691
 692   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 693   AnimateScrollOvershoot(0.0f);
 694   mScrollOvershoot = 0.0f;
 695
 696   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 697   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 698   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 699
 700   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 701
 702   CalculateDomainSize(targetSize);
 703 }
 704
 705 void ItemView::DeactivateCurrentLayout()
 706 {
 707   if (mActiveLayout)
 708   {
 709     const ItemPool::IDKeyContainer& itemPool = mItemPool.GetIDKeyContainer();
 710     for (ItemPool::IDKeyConstIter iter = itemPool.begin(); iter != itemPool.end(); ++iter)
 711     {
 712       Actor actor = iter->second;
 713       actor.RemoveConstraints();
 714     }
 715
 716     mActiveLayout = NULL;
 717   }
 718
 719   CancelRefreshTimer();
 720 }
 721
 722 bool ItemView::OnRefreshTick()
 723 {
 724   // Short-circuit if there is no active layout
 725   if (!mActiveLayout)
 726   {
 727     return false;
 728   }
 729
 730   const Vector3 layoutSize = Self().GetCurrentSize();
 731
 732   ItemRange range = GetItemRange(*mActiveLayout, layoutSize, true/*reserve extra*/);
 733
 734   RemoveItems(range);
 735   AddItems(*mActiveLayout, layoutSize, range);
 736
 737   // Keep refreshing whilst the layout is moving
 738   return mScrollAnimation || (mGestureState == Gesture::Started || mGestureState == Gesture::Continuing);
 739 }
 740
 741 void ItemView::SetMinimumSwipeSpeed(float speed)
 742 {
 743   mMinimumSwipeSpeed = speed;
 744 }
 745
 746 float ItemView::GetMinimumSwipeSpeed() const
 747 {
 748   return mMinimumSwipeSpeed;
 749 }
 750
 751 void ItemView::SetMinimumSwipeDistance(float distance)
 752 {
 753   mMinimumSwipeDistance = distance;
 754 }
 755
 756 float ItemView::GetMinimumSwipeDistance() const
 757 {
 758   return mMinimumSwipeDistance;
 759 }
 760
 761 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 762 {
 763   mMouseWheelScrollDistanceStep = step;
 764 }
 765
 766 float ItemView::GetMouseWheelScrollDistanceStep() const
 767 {
 768   return mMouseWheelScrollDistanceStep;
 769 }
 770
 771 void ItemView::SetAnchoring(bool enabled)
 772 {
 773   mAnchoringEnabled = enabled;
 774 }
 775
 776 bool ItemView::GetAnchoring() const
 777 {
 778   return mAnchoringEnabled;
 779 }
 780
 781 void ItemView::SetAnchoringDuration(float durationSeconds)
 782 {
 783   mAnchoringDuration = durationSeconds;
 784 }
 785
 786 float ItemView::GetAnchoringDuration() const
 787 {
 788   return mAnchoringDuration;
 789 }
 790
 791 void ItemView::SetRefreshInterval(unsigned int intervalMilliseconds)
 792 {
 793   mRefreshIntervalMilliseconds = intervalMilliseconds;
 794 }
 795
 796 unsigned int ItemView::GetRefreshInterval() const
 797 {
 798   return mRefreshIntervalMilliseconds;
 799 }
 800
 801 Actor ItemView::GetItem(unsigned int itemId) const
 802 {
 803   Actor actor;
 804
 805   ItemPool::IDKeyConstIter found = mItemPool.GetIDKeyContainer().find(itemId);
 806   if (found != mItemPool.GetIDKeyContainer().end())
 807   {
 808     actor = found->second;
 809   }
 810
 811   return actor;
 812 }
 813
 814 unsigned int ItemView::GetItemId(Actor actor) const
 815 {
 816   unsigned int itemId(0);
 817
 818   ItemPool::ActorKeyConstIter found = mItemPool.GetActorKeyContainer().find(actor);
 819   if (found != mItemPool.GetActorKeyContainer().end())
 820   {
 821     itemId = found->second;
 822   }
 823
 824   return itemId;
 825 }
 826
 827 void ItemView::RemoveItem(unsigned int itemId, float durationSeconds)
 828 {
 829   if (mItemPool.RemoveItem(itemId))
 830   {
 831     const ItemPool::IDKeyContainer& itemPool = mItemPool.GetIDKeyContainer();
 832     for (ItemPool::IDKeyConstIter iter = itemPool.begin(); iter != itemPool.end(); ++iter)
 833     {
 834       unsigned int id = iter->first;
 835       Actor actor = iter->second;
 836
 837       // Reposition the items if necessary
 838       actor.RemoveConstraints();
 839       ApplyConstraints(actor, *mActiveLayout, id, durationSeconds);
 840     }
 841
 842     CalculateDomainSize(Self().GetCurrentSize());
 843   }
 844 }
 845
 846 Actor ItemView::CreateActor(unsigned int itemId)
 847 {
 848   return mItemFactory.NewItem(itemId);
 849 }
 850
 851 void ItemView::ActorAddedToItemPool(Actor actor, unsigned int itemId, const Vector3& targetSize)
 852 {
 853   Actor self = Self();
 854
 855   actor.SetParentOrigin(ParentOrigin::CENTER);
 856   actor.SetAnchorPoint(AnchorPoint::CENTER);
 857
 858   if (mActiveLayout)
 859   {
 860     Vector3 size;
 861     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 862     {
 863       actor.SetSize(size);
 864     }
 865
 866     ApplyConstraints(actor, *mActiveLayout, itemId, 0.0f/*immediate*/);
 867   }
 868
 869   self.Add(actor);
 870 }
 871
 872 void ItemView::ActorRemovedFromItemPool(Actor actor, unsigned int itemId)
 873 {
 874   Self().Remove(actor);
 875 }
 876
 877 void ItemView::RemoveItems(ItemRange range)
 878 {
 879   mItemPool.RemoveItems(range);
 880 }
 881
 882 void ItemView::AddItems(ItemLayout& layout, const Vector3& layoutSize, ItemRange range)
 883 {
 884   range.end = min(mItemFactory.GetNumberOfItems(), range.end);
 885
 886   mItemPool.AddItems(mRefreshOrderHint, range, layoutSize);
 887 }
 888
 889 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, bool reserveExtra)
 890 {
 891   unsigned int itemCount = mItemFactory.GetNumberOfItems();
 892
 893   ItemRange available(0u, itemCount);
 894
 895   ItemRange range = layout.GetItemsWithinArea( GetCurrentLayoutPosition(0), layoutSize );
 896
 897   if (reserveExtra)
 898   {
 899     // Add the reserve items for scrolling
 900     unsigned int extra = layout.GetReserveItemCount(layoutSize);
 901     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
 902     range.end += extra;
 903   }
 904
 905   return range.Intersection(available);
 906 }
 907
 908 bool ItemView::OnTouchEvent(const TouchEvent& event)
 909 {
 910   // Ignore events with multiple-touch points
 911   if (event.GetPointCount() != 1)
 912   {
 913     return false;
 914   }
 915
 916   if (event.GetPoint(0).state == TouchPoint::Down)
 917   {
 918     // Cancel ongoing scrolling etc.
 919     mGestureState = Gesture::Clear;
 920
 921     mScrollDistance = 0.0f;
 922     mScrollSpeed = 0.0f;
 923     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 924
 925     mScrollOvershoot = 0.0f;
 926     AnimateScrollOvershoot(0.0f);
 927
 928     mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
 929
 930     RemoveAnimation(mScrollAnimation);
 931   }
 932
 933   return true; // consume since we're potentially scrolling
 934 }
 935
 936 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
 937 {
 938   // Respond the mouse wheel event to scroll
 939   if (mActiveLayout)
 940   {
 941     Actor self = Self();
 942     const Vector3 layoutSize = Self().GetCurrentSize();
 943     float layoutPositionDelta = GetCurrentLayoutPosition(0) + (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
 944     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
 945
 946     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
 947     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
 948     mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
 949     StartRefreshTimer();
 950   }
 951
 952   if (mMouseWheelEventFinishedTimer.IsRunning())
 953   {
 954     mMouseWheelEventFinishedTimer.Stop();
 955   }
 956
 957   mMouseWheelEventFinishedTimer.Start();
 958
 959   return true;
 960 }
 961
 962 bool ItemView::OnMouseWheelEventFinished()
 963 {
 964   if (mActiveLayout)
 965   {
 966     RemoveAnimation(mScrollAnimation);
 967
 968     // No more mouse wheel events coming. Do the anchoring if enabled.
 969     mScrollAnimation = DoAnchoring();
 970     if (mScrollAnimation)
 971     {
 972       StartRefreshTimer();
 973
 974       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
 975       mScrollAnimation.Play();
 976     }
 977     else
 978     {
 979       mScrollOvershoot = 0.0f;
 980       AnimateScrollOvershoot(0.0f);
 981
 982       mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
 983     }
 984   }
 985
 986   return false;
 987 }
 988
 989 void ItemView::ApplyConstraints(Actor& actor, ItemLayout& layout, unsigned int itemId, float duration)
 990 {
 991   ItemLayout::Vector3Function positionConstraint;
 992   if (layout.GetPositionConstraint(itemId, positionConstraint))
 993   {
 994     WrappedVector3Constraint wrapped(positionConstraint, itemId);
 995
 996     Constraint constraint = Constraint::New<Vector3>( Actor::POSITION,
 997                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
 998                                                       ParentSource( mPropertyScrollSpeed ),
 999                                                       ParentSource( Actor::SIZE ),
1000                                                       wrapped );
1001     constraint.SetApplyTime(duration);
1002
1003     actor.ApplyConstraint(constraint);
1004   }
1005
1006   ItemLayout::QuaternionFunction rotationConstraint;
1007   if (layout.GetRotationConstraint(itemId, rotationConstraint))
1008   {
1009     WrappedQuaternionConstraint wrapped(rotationConstraint, itemId);
1010
1011     Constraint constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1012                                                          Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1013                                                          ParentSource( mPropertyScrollSpeed ),
1014                                                          ParentSource( Actor::SIZE ),
1015                                                          wrapped );
1016     constraint.SetApplyTime(duration);
1017
1018     actor.ApplyConstraint(constraint);
1019   }
1020
1021   ItemLayout::Vector3Function scaleConstraint;
1022   if (layout.GetScaleConstraint(itemId, scaleConstraint))
1023   {
1024     WrappedVector3Constraint wrapped(scaleConstraint, itemId);
1025
1026     Constraint constraint = Constraint::New<Vector3>( Actor::SCALE,
1027                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1028                                                       ParentSource( mPropertyScrollSpeed ),
1029                                                       ParentSource( Actor::SIZE ),
1030                                                       wrapped );
1031     constraint.SetApplyTime(duration);
1032
1033     actor.ApplyConstraint(constraint);
1034   }
1035
1036   ItemLayout::Vector4Function colorConstraint;
1037   if (layout.GetColorConstraint(itemId, colorConstraint))
1038   {
1039     WrappedVector4Constraint wrapped(colorConstraint, itemId);
1040
1041     Constraint constraint = Constraint::New<Vector4>( Actor::COLOR,
1042                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1043                                                       ParentSource( mPropertyScrollSpeed ),
1044                                                       ParentSource( Actor::SIZE ),
1045                                                       wrapped );
1046     constraint.SetApplyTime(duration);
1047
1048     // Release color constraints slowly; this allows ItemView to co-exist with ImageActor fade-in
1049     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1050     constraint.SetRemoveAction(Dali::Constraint::Discard);
1051
1052     actor.ApplyConstraint(constraint);
1053   }
1054
1055   ItemLayout::BoolFunction visibilityConstraint;
1056   if (layout.GetVisibilityConstraint(itemId, visibilityConstraint))
1057   {
1058     WrappedBoolConstraint wrapped(visibilityConstraint, itemId);
1059
1060     Constraint constraint = Constraint::New<bool>( Actor::VISIBLE,
1061                                                    Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1062                                                    ParentSource( mPropertyScrollSpeed ),
1063                                                    ParentSource( Actor::SIZE ),
1064                                                    wrapped );
1065     constraint.SetApplyTime(duration);
1066
1067     // Release visibility constraints the same time as the color constraint
1068     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1069     constraint.SetRemoveAction(Dali::Constraint::Discard);
1070
1071     actor.ApplyConstraint(constraint);
1072   }
1073 }
1074
1075 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1076 {
1077   Actor self = Self();
1078   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1079   float clamppedPosition = min(0.0f, max(minLayoutPosition, targetPosition));
1080   mScrollOvershoot = targetPosition - clamppedPosition;
1081   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1082
1083   return clamppedPosition;
1084 }
1085
1086 void ItemView::OnPan(PanGesture gesture)
1087 {
1088   Actor self = Self();
1089   const Vector3 layoutSize = Self().GetCurrentSize();
1090
1091   RemoveAnimation(mScrollAnimation);
1092
1093   // Short-circuit if there is no active layout
1094   if (!mActiveLayout)
1095   {
1096     mGestureState = Gesture::Clear;
1097     return;
1098   }
1099
1100   mGestureState = gesture.state;
1101
1102   switch (mGestureState)
1103   {
1104     case Gesture::Finished:
1105     {
1106       // Swipe Detection
1107       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1108           mScrollSpeed > mMinimumSwipeSpeed)
1109       {
1110         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1111
1112         mRefreshOrderHint = true;
1113
1114         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1115         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1116                                                                layoutSize,
1117                                                                *mActiveLayout);
1118
1119         if (mAnchoringEnabled)
1120         {
1121           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1122         }
1123
1124         RemoveAnimation(mScrollAnimation);
1125
1126         float flickAnimationDuration = mActiveLayout->GetItemFlickAnimationDuration() * max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)));
1127         mScrollAnimation = Animation::New(flickAnimationDuration);
1128         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1129         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1130         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1131
1132         mIsFlicking = true;
1133         // Check whether it has already scrolled to the end
1134         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1135         {
1136           AnimateScrollOvershoot(0.0f);
1137         }
1138       }
1139
1140       // Anchoring may be triggered when there was no swipe
1141       if (!mScrollAnimation)
1142       {
1143         mScrollAnimation = DoAnchoring();
1144       }
1145
1146       // Reset the overshoot if no scroll animation.
1147       if (!mScrollAnimation)
1148       {
1149         mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1150
1151         AnimateScrollOvershoot(0.0f, false);
1152       }
1153     }
1154     break;
1155
1156     case Gesture::Started: // Fall through
1157     {
1158       mTotalPanDisplacement = Vector2::ZERO;
1159     }
1160
1161     case Gesture::Continuing:
1162     {
1163       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1164       mScrollSpeed = Clamp((gesture.GetSpeed() * mActiveLayout->GetScrollSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1165
1166       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1167       mRefreshOrderHint = mScrollDistance < 0.0f;
1168
1169       RemoveAnimation(mScrollSpeedAnimation);
1170       mScrollSpeedAnimation = Animation::New(0.3f);
1171       mScrollSpeedAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), mScrollSpeed, AlphaFunctions::Linear );
1172       mScrollSpeedAnimation.Play();
1173
1174       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1175
1176       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1177
1178       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1179       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1180       mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1181
1182       mTotalPanDisplacement += gesture.displacement;
1183       mScrollOvershoot = layoutPositionDelta - firstItemScrollPosition;
1184       if( mScrollOvershoot > Math::MACHINE_EPSILON_1 )
1185       {
1186         AnimateScrollOvershoot(1.0f);
1187       }
1188       else if( mScrollOvershoot < -Math::MACHINE_EPSILON_1 )
1189       {
1190         AnimateScrollOvershoot(-1.0f);
1191       }
1192       else
1193       {
1194         AnimateScrollOvershoot(0.0f);
1195       }
1196
1197       StartRefreshTimer();
1198     }
1199     break;
1200
1201     case Gesture::Cancelled:
1202     {
1203       mScrollAnimation = DoAnchoring();
1204     }
1205     break;
1206
1207     default:
1208       break;
1209   }
1210
1211   if (mScrollAnimation)
1212   {
1213     StartRefreshTimer();
1214
1215     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1216     mScrollAnimation.Play();
1217   }
1218 }
1219
1220 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1221 {
1222   OnPan(gesture);
1223   return true;
1224 }
1225
1226 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1227 {
1228   Actor nextFocusActor;
1229   if(mActiveLayout)
1230   {
1231     int nextItemID = 0;
1232     if(!actor || actor == this->Self())
1233     {
1234       nextFocusActor = GetItem(nextItemID);
1235     }
1236     else if(actor && actor.GetParent() == this->Self())
1237     {
1238       int itemID = GetItemId(actor);
1239       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1240       nextFocusActor = GetItem(nextItemID);
1241       if(nextFocusActor == actor)
1242       {
1243         // need to pass NULL actor back to focus manager
1244         nextFocusActor.Reset();
1245         return nextFocusActor;
1246       }
1247     }
1248     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1249     Vector3 layoutSize = Self().GetCurrentSize();
1250     if(!nextFocusActor)
1251     {
1252       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1253       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1254       nextItemID = viewableItems.begin;
1255       nextFocusActor = GetItem(nextItemID);
1256     }
1257   }
1258   return nextFocusActor;
1259 }
1260
1261 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1262 {
1263   // only in this function if our chosen focus actor was actually used
1264   if(commitedFocusableActor)
1265   {
1266     int nextItemID = GetItemId(commitedFocusableActor);
1267     float layoutPosition = GetCurrentLayoutPosition(0);
1268     Vector3 layoutSize = Self().GetCurrentSize();
1269     Vector3 focusItemPosition = Vector3::ZERO;
1270     ItemLayout::Vector3Function itemPositionConstraint;
1271     if (mActiveLayout->GetPositionConstraint(nextItemID, itemPositionConstraint))
1272     {
1273       focusItemPosition = itemPositionConstraint(Vector3::ZERO, layoutPosition + nextItemID, 0.0f, layoutSize);
1274     }
1275
1276     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1277     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1278   }
1279 }
1280
1281 Animation ItemView::DoAnchoring()
1282 {
1283   Animation anchoringAnimation;
1284   Actor self = Self();
1285
1286   if (mActiveLayout && mAnchoringEnabled)
1287   {
1288     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1289
1290     anchoringAnimation = Animation::New(mAnchoringDuration);
1291     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1292     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1293     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1294     if(!mIsFlicking)
1295     {
1296       AnimateScrollOvershoot(0.0f);
1297     }
1298   }
1299
1300   return anchoringAnimation;
1301 }
1302
1303 void ItemView::OnScrollFinished(Animation& source)
1304 {
1305   Actor self = Self();
1306
1307   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1308
1309   mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1310
1311   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1312   {
1313     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1314   }
1315   else
1316   {
1317     // Reset the overshoot
1318     AnimateScrollOvershoot( 0.0f );
1319   }
1320   mIsFlicking = false;
1321
1322   mScrollOvershoot = 0.0f;
1323 }
1324
1325 void ItemView::OnOvershootOnFinished(Animation& animation)
1326 {
1327   mAnimatingOvershootOn = false;
1328   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1329   RemoveAnimation(mScrollOvershootAnimation);
1330   if(mAnimateOvershootOff)
1331   {
1332     AnimateScrollOvershoot(0.0f);
1333   }
1334 }
1335
1336 void ItemView::StartRefreshTimer()
1337 {
1338   if (!mRefreshTimer)
1339   {
1340     mRefreshTimer = Timer::New( mRefreshIntervalMilliseconds );
1341     mRefreshTimer.TickSignal().Connect( this, &ItemView::OnRefreshTick );
1342   }
1343
1344   if (!mRefreshTimer.IsRunning())
1345   {
1346     mRefreshTimer.Start();
1347   }
1348 }
1349
1350 void ItemView::CancelRefreshTimer()
1351 {
1352   if (mRefreshTimer)
1353   {
1354     mRefreshTimer.Stop();
1355   }
1356 }
1357
1358 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1359 {
1360   Actor self = Self();
1361   const Vector3 layoutSize = Self().GetCurrentSize();
1362   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1363
1364   StartRefreshTimer();
1365
1366   if(durationSeconds > 0.0f)
1367   {
1368     RemoveAnimation(mScrollAnimation);
1369     mScrollAnimation = Animation::New(durationSeconds);
1370     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1371     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1372     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1373     mScrollAnimation.Play();
1374   }
1375   else
1376   {
1377     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1378     AnimateScrollOvershoot(0.0f);
1379   }
1380
1381   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1382 }
1383
1384 void ItemView::RemoveAnimation(Animation& animation)
1385 {
1386   if(animation)
1387   {
1388     // Cease animating, and reset handle.
1389     animation.Clear();
1390     animation.Reset();
1391   }
1392 }
1393
1394 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1395 {
1396   Actor self = Self();
1397
1398   Vector3 firstItemPosition(Vector3::ZERO);
1399   Vector3 lastItemPosition(Vector3::ZERO);
1400
1401   if(mActiveLayout)
1402   {
1403     ItemLayout::Vector3Function firstItemPositionConstraint;
1404     if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1405     {
1406       firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, 0, 0.0f, layoutSize);
1407     }
1408
1409     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1410     ItemLayout::Vector3Function lastItemPositionConstraint;
1411     if (mActiveLayout->GetPositionConstraint(fabs(minLayoutPosition), lastItemPositionConstraint))
1412     {
1413       lastItemPosition = lastItemPositionConstraint(Vector3::ZERO, fabs(minLayoutPosition), 0.0f, layoutSize);
1414     }
1415
1416     if(IsHorizontal(mActiveLayout->GetOrientation()))
1417     {
1418       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1419       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1420     }
1421     else
1422     {
1423       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1424       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1425     }
1426
1427     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1428     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1429     self.SetProperty(mPropertyCanScrollHorizontal, false);
1430   }
1431 }
1432
1433 Vector3 ItemView::GetDomainSize() const
1434 {
1435   Actor self = Self();
1436
1437   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1438   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1439
1440   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1441 }
1442
1443 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1444 {
1445   Actor self = Self();
1446
1447   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1448   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1449   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1450
1451   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1452 }
1453
1454 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1455 {
1456   Vector3 firstItemPosition(Vector3::ZERO);
1457   ItemLayout::Vector3Function firstItemPositionConstraint;
1458   if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1459   {
1460     firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, layoutPosition, 0.0f, layoutSize);
1461   }
1462
1463   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1464 }
1465
1466 Vector3 ItemView::GetCurrentScrollPosition() const
1467 {
1468   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1469   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1470 }
1471
1472 void ItemView::AddOverlay(Actor actor)
1473 {
1474   Self().Add(actor);
1475 }
1476
1477 void ItemView::RemoveOverlay(Actor actor)
1478 {
1479   Self().Remove(actor);
1480 }
1481
1482 void ItemView::ScrollTo(const Vector3& position, float duration)
1483 {
1484   Actor self = Self();
1485   const Vector3 layoutSize = Self().GetCurrentSize();
1486
1487   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1488
1489   StartRefreshTimer();
1490
1491   if(duration > 0.0f)
1492   {
1493     RemoveAnimation(mScrollAnimation);
1494     mScrollAnimation = Animation::New(duration);
1495     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1496     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1497     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1498     mScrollAnimation.Play();
1499   }
1500   else
1501   {
1502     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1503     AnimateScrollOvershoot(0.0f);
1504   }
1505
1506   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1507 }
1508
1509 void ItemView::ApplyOvershootOverlayConstraints()
1510 {
1511   Constraint constraint = Constraint::New<float>( Actor::SIZE_WIDTH,
1512                                                     ParentSource( mPropertyScrollDirection ),
1513                                                     ParentSource( mPropertyOvershoot ),
1514                                                     ParentSource( Actor::SIZE ),
1515                                                     OvershootOverlaySizeConstraint() );
1516   mOvershootOverlay.ApplyConstraint(constraint);
1517   mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.width, OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.height);
1518
1519   constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1520                                             ParentSource( mPropertyScrollDirection ),
1521                                             ParentSource( mPropertyOvershoot ),
1522                                             OvershootOverlayRotationConstraint() );
1523   mOvershootOverlay.ApplyConstraint(constraint);
1524
1525   constraint = Constraint::New<Vector3>( Actor::POSITION,
1526                                          ParentSource( Actor::SIZE ),
1527                                          ParentSource( mPropertyScrollDirection ),
1528                                          ParentSource( mPropertyOvershoot ),
1529                                          OvershootOverlayPositionConstraint() );
1530   mOvershootOverlay.ApplyConstraint(constraint);
1531
1532   constraint = Constraint::New<bool>( Actor::VISIBLE,
1533                                       ParentSource( mPropertyCanScrollVertical ),
1534                                       OvershootOverlayVisibilityConstraint() );
1535   mOvershootOverlay.ApplyConstraint(constraint);
1536
1537   int effectOvershootPropertyIndex = mOvershootEffect.GetPropertyIndex(mOvershootEffect.GetOvershootPropertyName());
1538   Actor self = Self();
1539   constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1540                                        Source( self, mPropertyOvershoot ),
1541                                        EqualToConstraint() );
1542   mOvershootEffect.ApplyConstraint(constraint);
1543 }
1544
1545 float ItemView::CalculateScrollOvershoot()
1546 {
1547   float overshoot = 0.0f;
1548
1549   if(mActiveLayout)
1550   {
1551     // The overshoot must be calculated from the accumulated pan gesture displacement
1552     // since the pan gesture starts.
1553     Actor self = Self();
1554     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1555     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1556     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1557     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1558     float clamppedPosition = min(0.0f, max(minLayoutPosition, positionDelta));
1559     overshoot = positionDelta - clamppedPosition;
1560   }
1561
1562   return overshoot;
1563 }
1564
1565 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1566 {
1567   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1568
1569   // make sure we animate back if needed
1570   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1571
1572   if( mAnimatingOvershootOn )
1573   {
1574     // animating on, do not allow animate off
1575     return;
1576   }
1577
1578   Actor self = Self();
1579   float currentOvershoot = self.GetProperty<float>(mPropertyOvershoot);
1580   float duration = DEFAULT_OVERSHOOT_ANIMATION_DURATION * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot));
1581
1582   RemoveAnimation(mScrollOvershootAnimation);
1583   mScrollOvershootAnimation = Animation::New(duration);
1584   mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1585   mScrollOvershootAnimation.AnimateTo( Property(self, mPropertyOvershoot), overshootAmount, TimePeriod(0.0f, duration) );
1586   mScrollOvershootAnimation.Play();
1587
1588   mAnimatingOvershootOn = animatingOn;
1589 }
1590
1591 } // namespace Internal
1592
1593 } // namespace Toolkit
1594
1595 } // namespace Dali