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 Apache License, Version 2.0 (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://www.apache.org/licenses/LICENSE-2.0
   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
  18 // CLASS HEADER
  19 #include <dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <algorithm>
  23 #include <dali/public-api/animation/constraints.h>
  24 #include <dali/public-api/common/set-wrapper.h>
  25 #include <dali/public-api/common/stage.h>
  26 #include <dali/public-api/events/mouse-wheel-event.h>
  27 #include <dali/public-api/events/touch-event.h>
  28 #include <dali/public-api/object/type-registry.h>
  29
  30 // INTERNAL INCLUDES
  31 #include <dali-toolkit/public-api/controls/scrollable/item-view/item-factory.h>
  32 #include <dali-toolkit/internal/controls/scrollable/scroll-connector-impl.h>
  33 #include <dali-toolkit/internal/controls/scrollable/bouncing-effect-actor.h>
  34
  35 using std::string;
  36 using std::set;
  37 using namespace Dali;
  38
  39 namespace // unnamed namespace
  40 {
  41
  42 //Type registration
  43 TypeRegistration mType( typeid(Toolkit::ItemView), typeid(Toolkit::Scrollable), NULL );
  44
  45 const float DEFAULT_MINIMUM_SWIPE_SPEED = 1.0f;
  46 const float DEFAULT_MINIMUM_SWIPE_DISTANCE = 3.0f;
  47 const float DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION = 0.1f;
  48
  49 const float DEFAULT_MINIMUM_SWIPE_DURATION = 0.45f;
  50 const float DEFAULT_MAXIMUM_SWIPE_DURATION = 2.6f;
  51
  52 const float DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS = 20.0f; // 1 updates per 20 items
  53 const int MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT = 500;  // 0.5 second
  54
  55 const float DEFAULT_ANCHORING_DURATION = 1.0f;  // 1 second
  56
  57 const float MILLISECONDS_PER_SECONDS = 1000.0f;
  58
  59 const Vector2 OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE( 720.0f, 42.0f );
  60 const float OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD = 180.0f;
  61 const Vector4 OVERSHOOT_OVERLAY_NINE_PATCH_BORDER(0.0f, 0.0f, 1.0f, 12.0f);
  62 const float DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION = 0.2f;
  63
  64 const string LAYOUT_POSITION_PROPERTY_NAME( "item-view-layout-position" );
  65 const string POSITION_PROPERTY_NAME( "item-view-position" );
  66 const string MINIMUM_LAYOUT_POSITION_PROPERTY_NAME( "item-view-minimum-layout-position" );
  67 const string SCROLL_SPEED_PROPERTY_NAME( "item-view-scroll-speed" );
  68 const string SCROLL_DIRECTION_PROPERTY_NAME( "item-view-scroll-direction" );
  69 const string OVERSHOOT_PROPERTY_NAME( "item-view-overshoot" );
  70
  71 /**
  72  * Local helper to convert pan distance (in actor coordinates) to the layout-specific scrolling direction
  73  */
  74 float CalculateScrollDistance(Vector2 panDistance, Toolkit::ItemLayout& layout)
  75 {
  76   Radian scrollDirection(layout.GetScrollDirection());
  77
  78   float cosTheta = cosf(scrollDirection);
  79   float sinTheta = sinf(scrollDirection);
  80
  81   return panDistance.x * sinTheta + panDistance.y * cosTheta;
  82 }
  83
  84 // Overshoot overlay constraints
  85
  86 struct OvershootOverlaySizeConstraint
  87 {
  88   Vector3 operator()(const Vector3& current,
  89                      const PropertyInput& parentScrollDirectionProperty,
  90                      const PropertyInput& parentOvershootProperty,
  91                      const PropertyInput& parentSizeProperty)
  92   {
  93     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
  94     const Vector3 parentSize = parentSizeProperty.GetVector3();
  95     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
  96
  97     float overlayWidth;
  98
  99     if(Toolkit::IsVertical(parentOrientation))
 100     {
 101       overlayWidth = fabsf(parentScrollDirection.y) > Math::MACHINE_EPSILON_1 ? parentSize.x : parentSize.y;
 102     }
 103     else
 104     {
 105       overlayWidth = fabsf(parentScrollDirection.x) > Math::MACHINE_EPSILON_1 ? parentSize.y : parentSize.x;
 106     }
 107
 108     float overlayHeight = (overlayWidth > OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD) ? OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height : OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height*0.5f;
 109
 110     return Vector3( overlayWidth, overlayHeight, current.depth );
 111   }
 112 };
 113
 114 struct OvershootOverlayRotationConstraint
 115 {
 116   Quaternion operator()(const Quaternion& current,
 117                         const PropertyInput& parentScrollDirectionProperty,
 118                         const PropertyInput& parentOvershootProperty)
 119   {
 120     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 121     const float parentOvershoot = parentOvershootProperty.GetFloat();
 122     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 123
 124     Quaternion rotation;
 125
 126     if(Toolkit::IsVertical(parentOrientation))
 127     {
 128       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 129       {
 130         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 131             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 132         {
 133           rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 134         }
 135         else
 136         {
 137           rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 138         }
 139       }
 140       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 141             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 142       {
 143         rotation = Quaternion(0.0f, Vector3::ZAXIS);
 144       }
 145       else
 146       {
 147         rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 148       }
 149     }
 150     else
 151     {
 152       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 153       {
 154         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot > Math::MACHINE_EPSILON_0)
 155             ||(parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot < Math::MACHINE_EPSILON_0) )
 156         {
 157           rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 158         }
 159         else
 160         {
 161           rotation = Quaternion(0.0f, Vector3::ZAXIS);
 162         }
 163       }
 164       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 165             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 166       {
 167         rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 168       }
 169       else
 170       {
 171         rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 172       }
 173     }
 174
 175     return rotation;
 176   }
 177 };
 178
 179 struct OvershootOverlayPositionConstraint
 180 {
 181   Vector3 operator()(const Vector3&    current,
 182                      const PropertyInput& parentSizeProperty,
 183                      const PropertyInput& parentScrollDirectionProperty,
 184                      const PropertyInput& parentOvershootProperty)
 185   {
 186     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 187     const float parentOvershoot = parentOvershootProperty.GetFloat();
 188     const Vector3 parentSize = parentSizeProperty.GetVector3();
 189     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 190
 191     Vector3 relativeOffset;
 192
 193     if(Toolkit::IsVertical(parentOrientation))
 194     {
 195       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 196       {
 197         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 198             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 199         {
 200           relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 201         }
 202         else
 203         {
 204           relativeOffset =Vector3(0.0f, 1.0f, 0.0f);
 205         }
 206       }
 207       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 208             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 209       {
 210         relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 211       }
 212       else
 213       {
 214         relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 215       }
 216     }
 217     else
 218     {
 219       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 220       {
 221         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot < Math::MACHINE_EPSILON_0)
 222             || (parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot > Math::MACHINE_EPSILON_0) )
 223         {
 224           relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 225         }
 226         else
 227         {
 228           relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 229         }
 230       }
 231       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 232             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 233       {
 234         relativeOffset = Vector3(0.0f, 1.0f, 0.0f);
 235       }
 236       else
 237       {
 238         relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 239       }
 240     }
 241
 242     return relativeOffset * parentSize;
 243
 244   }
 245 };
 246
 247 struct OvershootOverlayVisibilityConstraint
 248 {
 249   bool operator()(const bool& current,
 250                   const PropertyInput& parentLayoutScrollableProperty)
 251   {
 252     const bool parentLayoutScrollable = parentLayoutScrollableProperty.GetBoolean();
 253
 254     return parentLayoutScrollable;
 255   }
 256 };
 257
 258 /**
 259  * Relative position Constraint
 260  * Generates the relative position value of the item view based on the layout position,
 261  * and it's relation to the layout domain. This is a value from 0.0f to 1.0f in each axis.
 262  */
 263 Vector3 RelativePositionConstraint(const Vector3& current,
 264                                    const PropertyInput& scrollPositionProperty,
 265                                    const PropertyInput& scrollMinProperty,
 266                                    const PropertyInput& scrollMaxProperty,
 267                                    const PropertyInput& layoutSizeProperty)
 268 {
 269   const Vector3& position = Vector3(0.0f, scrollPositionProperty.GetFloat(), 0.0f);
 270   const Vector3& min = scrollMinProperty.GetVector3();
 271   const Vector3& max = scrollMaxProperty.GetVector3();
 272
 273   Vector3 relativePosition;
 274   Vector3 domainSize = max - min;
 275
 276   relativePosition.x = fabsf(domainSize.x) > Math::MACHINE_EPSILON_1 ? ((min.x - position.x) / fabsf(domainSize.x)) : 0.0f;
 277   relativePosition.y = fabsf(domainSize.y) > Math::MACHINE_EPSILON_1 ? ((min.y - position.y) / fabsf(domainSize.y)) : 0.0f;
 278
 279   return relativePosition;
 280 }
 281
 282 } // unnamed namespace
 283
 284 namespace Dali
 285 {
 286
 287 namespace Toolkit
 288 {
 289
 290 namespace Internal
 291 {
 292
 293 namespace // unnamed namespace
 294 {
 295
 296 bool FindById( const ItemContainer& items, ItemId id )
 297 {
 298   for( ConstItemIter iter = items.begin(); items.end() != iter; ++iter )
 299   {
 300     if( iter->first == id )
 301     {
 302       return true;
 303     }
 304   }
 305
 306   return false;
 307 }
 308
 309 } // unnamed namespace
 310
 311 Dali::Toolkit::ItemView ItemView::New(ItemFactory& factory)
 312 {
 313   // Create the implementation
 314   ItemViewPtr itemView(new ItemView(factory));
 315
 316   // Pass ownership to CustomActor via derived handle
 317   Dali::Toolkit::ItemView handle(*itemView);
 318
 319   // Second-phase init of the implementation
 320   // This can only be done after the CustomActor connection has been made...
 321   itemView->Initialize();
 322
 323   return handle;
 324 }
 325
 326 ItemView::ItemView(ItemFactory& factory)
 327 : Scrollable(),
 328   mItemFactory(factory),
 329   mActiveLayout(NULL),
 330   mAnimatingOvershootOn(false),
 331   mAnimateOvershootOff(false),
 332   mAnchoringEnabled(true),
 333   mAnchoringDuration(DEFAULT_ANCHORING_DURATION),
 334   mRefreshIntervalLayoutPositions(0.0f),
 335   mRefreshOrderHint(true/*Refresh item 0 first*/),
 336   mMinimumSwipeSpeed(DEFAULT_MINIMUM_SWIPE_SPEED),
 337   mMinimumSwipeDistance(DEFAULT_MINIMUM_SWIPE_DISTANCE),
 338   mMouseWheelScrollDistanceStep(0.0f),
 339   mScrollDistance(0.0f),
 340   mScrollSpeed(0.0f),
 341   mTotalPanDisplacement(Vector2::ZERO),
 342   mScrollOvershoot(0.0f),
 343   mIsFlicking(false),
 344   mGestureState(Gesture::Clear),
 345   mAddingItems(false),
 346   mPropertyPosition(Property::INVALID_INDEX),
 347   mPropertyMinimumLayoutPosition(Property::INVALID_INDEX),
 348   mPropertyScrollSpeed(Property::INVALID_INDEX),
 349   mRefreshEnabled(true),
 350   mItemsParentOrigin( ParentOrigin::CENTER),
 351   mItemsAnchorPoint( AnchorPoint::CENTER)
 352 {
 353   SetRequiresMouseWheelEvents(true);
 354   SetKeyboardNavigationSupport(true);
 355 }
 356
 357 void ItemView::OnInitialize()
 358 {
 359   SetSizePolicy( Toolkit::Control::Fixed, Toolkit::Control::Fixed );
 360
 361   RegisterCommonProperties();
 362
 363   Actor self = Self();
 364
 365   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 366   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 367   mScrollConnector.ScrollPositionChangedSignal().Connect( this, &ItemView::OnScrollPositionChanged );
 368
 369   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 370   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 371   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 372
 373   EnableScrollComponent(Toolkit::Scrollable::OvershootIndicator);
 374
 375   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 376                                                    LocalSource(mPropertyPosition),
 377                                                    LocalSource(mPropertyPositionMin),
 378                                                    LocalSource(mPropertyPositionMax),
 379                                                    LocalSource(Actor::SIZE),
 380                                                    RelativePositionConstraint);
 381   self.ApplyConstraint(constraint);
 382
 383   Vector2 stageSize = Stage::GetCurrent().GetSize();
 384   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 385
 386   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 387
 388   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 389   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 390
 391   SetRefreshInterval(DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS);
 392 }
 393
 394 ItemView::~ItemView()
 395 {
 396 }
 397
 398 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 399 {
 400   return mScrollConnector;
 401 }
 402
 403 unsigned int ItemView::GetLayoutCount() const
 404 {
 405   return mLayouts.size();
 406 }
 407
 408 void ItemView::AddLayout(ItemLayout& layout)
 409 {
 410   mLayouts.push_back(ItemLayoutPtr(&layout));
 411 }
 412
 413 void ItemView::RemoveLayout(unsigned int layoutIndex)
 414 {
 415   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 416
 417   if (mActiveLayout == mLayouts[layoutIndex].Get())
 418   {
 419     mActiveLayout = NULL;
 420   }
 421
 422   mLayouts.erase(mLayouts.begin() + layoutIndex);
 423 }
 424
 425 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 426 {
 427   return mLayouts[layoutIndex];
 428 }
 429
 430 ItemLayoutPtr ItemView::GetActiveLayout() const
 431 {
 432   return ItemLayoutPtr(mActiveLayout);
 433 }
 434
 435 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 436 {
 437   return mScrollConnector.GetScrollPosition() + static_cast<float>( itemId );
 438 }
 439
 440 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 441 {
 442   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 443
 444   mRefreshEnabled = false;
 445
 446   Actor self = Self();
 447
 448   // The ItemView size should match the active layout size
 449   self.SetSize(targetSize);
 450   mActiveLayoutTargetSize = targetSize;
 451
 452   // Switch to the new layout
 453   mActiveLayout = mLayouts[layoutIndex].Get();
 454
 455   // Move the items to the new layout positions...
 456
 457   bool resizeAnimationNeeded(false);
 458   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 459   {
 460     unsigned int itemId = iter->first;
 461     Actor actor = iter->second;
 462
 463     // Remove constraints from previous layout
 464     actor.RemoveConstraints();
 465
 466     Vector3 size;
 467     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 468     {
 469       if( durationSeconds > 0.0f )
 470       {
 471         // Use a size animation
 472         if (!resizeAnimationNeeded)
 473         {
 474           resizeAnimationNeeded = true;
 475           RemoveAnimation(mResizeAnimation);
 476           mResizeAnimation = Animation::New(durationSeconds);
 477         }
 478
 479         // The layout provides its own resize animation
 480         mActiveLayout->GetResizeAnimation(mResizeAnimation, actor, size, durationSeconds);
 481       }
 482       else
 483       {
 484         // resize immediately
 485         actor.SetSize(size);
 486       }
 487     }
 488
 489     mActiveLayout->ApplyConstraints(actor, itemId, durationSeconds, mScrollPositionObject, Self() );
 490   }
 491
 492   if (resizeAnimationNeeded)
 493   {
 494     mResizeAnimation.Play();
 495   }
 496
 497   // Refresh the new layout
 498   ItemRange range = GetItemRange(*mActiveLayout, targetSize, GetCurrentLayoutPosition(0), false/* don't reserve extra*/);
 499   AddActorsWithinRange( range, durationSeconds );
 500
 501   // Scroll to an appropriate layout position
 502
 503   bool scrollAnimationNeeded(false);
 504   float firstItemScrollPosition(0.0f);
 505
 506   float current = GetCurrentLayoutPosition(0);
 507   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 508   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 509
 510   if (current < minimum)
 511   {
 512     scrollAnimationNeeded = true;
 513     firstItemScrollPosition = minimum;
 514   }
 515   else if (mAnchoringEnabled)
 516   {
 517     scrollAnimationNeeded = true;
 518     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 519   }
 520
 521   if (scrollAnimationNeeded)
 522   {
 523     RemoveAnimation(mScrollAnimation);
 524     mScrollAnimation = Animation::New(durationSeconds);
 525     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 526     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 527     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnLayoutActivationScrollFinished);
 528     mScrollAnimation.Play();
 529   }
 530
 531   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 532   AnimateScrollOvershoot(0.0f);
 533   mScrollOvershoot = 0.0f;
 534
 535   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 536   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 537   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 538
 539   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 540
 541   CalculateDomainSize(targetSize);
 542 }
 543
 544 void ItemView::DeactivateCurrentLayout()
 545 {
 546   if (mActiveLayout)
 547   {
 548     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 549     {
 550       Actor actor = iter->second;
 551       actor.RemoveConstraints();
 552     }
 553
 554     mActiveLayout = NULL;
 555   }
 556 }
 557
 558 void ItemView::OnRefreshNotification(PropertyNotification& source)
 559 {
 560   if(mRefreshEnabled || mScrollAnimation)
 561   {
 562     // Only refresh the cache during normal scrolling
 563     DoRefresh(GetCurrentLayoutPosition(0), true);
 564   }
 565 }
 566
 567 void ItemView::DoRefresh(float currentLayoutPosition, bool cacheExtra)
 568 {
 569   if (mActiveLayout)
 570   {
 571     ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, currentLayoutPosition, cacheExtra/*reserve extra*/);
 572     RemoveActorsOutsideRange( range );
 573     AddActorsWithinRange( range, 0.0f/*immediate*/ );
 574
 575     mScrollUpdatedSignal.Emit( Vector3(0.0f, currentLayoutPosition, 0.0f) );
 576   }
 577 }
 578
 579 void ItemView::SetMinimumSwipeSpeed(float speed)
 580 {
 581   mMinimumSwipeSpeed = speed;
 582 }
 583
 584 float ItemView::GetMinimumSwipeSpeed() const
 585 {
 586   return mMinimumSwipeSpeed;
 587 }
 588
 589 void ItemView::SetMinimumSwipeDistance(float distance)
 590 {
 591   mMinimumSwipeDistance = distance;
 592 }
 593
 594 float ItemView::GetMinimumSwipeDistance() const
 595 {
 596   return mMinimumSwipeDistance;
 597 }
 598
 599 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 600 {
 601   mMouseWheelScrollDistanceStep = step;
 602 }
 603
 604 float ItemView::GetMouseWheelScrollDistanceStep() const
 605 {
 606   return mMouseWheelScrollDistanceStep;
 607 }
 608
 609 void ItemView::SetAnchoring(bool enabled)
 610 {
 611   mAnchoringEnabled = enabled;
 612 }
 613
 614 bool ItemView::GetAnchoring() const
 615 {
 616   return mAnchoringEnabled;
 617 }
 618
 619 void ItemView::SetAnchoringDuration(float durationSeconds)
 620 {
 621   mAnchoringDuration = durationSeconds;
 622 }
 623
 624 float ItemView::GetAnchoringDuration() const
 625 {
 626   return mAnchoringDuration;
 627 }
 628
 629 void ItemView::SetRefreshInterval(float intervalLayoutPositions)
 630 {
 631   if( !Equals(mRefreshIntervalLayoutPositions, intervalLayoutPositions) )
 632   {
 633     mRefreshIntervalLayoutPositions = intervalLayoutPositions;
 634
 635     if(mRefreshNotification)
 636     {
 637       mScrollPositionObject.RemovePropertyNotification(mRefreshNotification);
 638     }
 639     mRefreshNotification = mScrollPositionObject.AddPropertyNotification( ScrollConnector::SCROLL_POSITION, StepCondition(mRefreshIntervalLayoutPositions, 0.0f) );
 640     mRefreshNotification.NotifySignal().Connect( this, &ItemView::OnRefreshNotification );
 641   }
 642 }
 643
 644 float ItemView::GetRefreshInterval() const
 645 {
 646   return mRefreshIntervalLayoutPositions;
 647 }
 648
 649 void ItemView::SetRefreshEnabled(bool enabled)
 650 {
 651   mRefreshEnabled = enabled;
 652 }
 653
 654 Actor ItemView::GetItem(unsigned int itemId) const
 655 {
 656   Actor actor;
 657
 658   ConstItemPoolIter iter = mItemPool.find( itemId );
 659   if( iter != mItemPool.end() )
 660   {
 661     actor = iter->second;
 662   }
 663
 664   return actor;
 665 }
 666
 667 unsigned int ItemView::GetItemId( Actor actor ) const
 668 {
 669   unsigned int itemId( 0 );
 670
 671   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 672   {
 673     if( iter->second == actor )
 674     {
 675       itemId = iter->first;
 676       break;
 677     }
 678   }
 679
 680   return itemId;
 681 }
 682
 683 void ItemView::InsertItem( Item newItem, float durationSeconds )
 684 {
 685   mAddingItems = true;
 686
 687   Actor displacedActor;
 688   ItemPoolIter afterDisplacedIter = mItemPool.end();
 689
 690   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 691   if( mItemPool.end() != foundIter )
 692   {
 693     SetupActor( newItem, durationSeconds );
 694     Self().Add( newItem.second );
 695
 696     displacedActor = foundIter->second;
 697     foundIter->second = newItem.second;
 698
 699     afterDisplacedIter = ++foundIter;
 700   }
 701   else
 702   {
 703     // Inserting before the existing item range?
 704     ItemPoolIter iter = mItemPool.begin();
 705     if( iter != mItemPool.end() &&
 706         iter->first > newItem.first )
 707     {
 708       displacedActor = iter->second;
 709       mItemPool.erase( iter++ ); // iter is still valid after the erase
 710
 711       afterDisplacedIter = iter;
 712     }
 713   }
 714
 715   if( displacedActor )
 716   {
 717     // Move the existing actors to make room
 718     for( ItemPoolIter iter = afterDisplacedIter; mItemPool.end() != iter; ++iter )
 719     {
 720       Actor temp = iter->second;
 721       iter->second = displacedActor;
 722       displacedActor = temp;
 723
 724       iter->second.RemoveConstraints();
 725       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 726     }
 727
 728     // Create last item
 729     ItemPool::reverse_iterator lastIter = mItemPool.rbegin();
 730     if ( lastIter != mItemPool.rend() )
 731     {
 732       ItemId lastId = lastIter->first;
 733       Item lastItem( lastId + 1, displacedActor );
 734       mItemPool.insert( lastItem );
 735
 736       lastItem.second.RemoveConstraints();
 737       mActiveLayout->ApplyConstraints( lastItem.second, lastItem.first, durationSeconds, mScrollPositionObject, Self() );
 738     }
 739   }
 740
 741   CalculateDomainSize(Self().GetCurrentSize());
 742
 743   mAddingItems = false;
 744 }
 745
 746 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 747 {
 748   mAddingItems = true;
 749
 750   // Insert from lowest id to highest
 751   std::set<Item> sortedItems;
 752   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 753   {
 754     sortedItems.insert( *iter );
 755   }
 756
 757   for( std::set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 758   {
 759     Self().Add( iter->second );
 760
 761     ItemPoolIter foundIter = mItemPool.find( iter->first );
 762     if( mItemPool.end() != foundIter )
 763     {
 764       Actor moveMe = foundIter->second;
 765       foundIter->second = iter->second;
 766
 767       // Move the existing actors to make room
 768       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 769       {
 770         Actor temp = iter->second;
 771         iter->second = moveMe;
 772         moveMe = temp;
 773       }
 774
 775       // Create last item
 776       ItemId lastId = mItemPool.rbegin()->first;
 777       Item lastItem( lastId + 1, moveMe );
 778       mItemPool.insert( lastItem );
 779     }
 780     else
 781     {
 782       mItemPool.insert( *iter );
 783     }
 784   }
 785
 786   // Relayout everything
 787   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 788   {
 789     // If newly inserted
 790     if( FindById( newItems, iter->first ) )
 791     {
 792       SetupActor( *iter, durationSeconds );
 793     }
 794     else
 795     {
 796       iter->second.RemoveConstraints();
 797       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 798     }
 799   }
 800
 801   CalculateDomainSize(Self().GetCurrentSize());
 802
 803   mAddingItems = false;
 804 }
 805
 806 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 807 {
 808   bool actorsReordered = RemoveActor( itemId );
 809   if( actorsReordered )
 810   {
 811     ReapplyAllConstraints( durationSeconds );
 812
 813     OnItemsRemoved();
 814   }
 815 }
 816
 817 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 818 {
 819   bool actorsReordered( false );
 820
 821   // Remove from highest id to lowest
 822   set<ItemId> sortedItems;
 823   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 824   {
 825     sortedItems.insert( *iter );
 826   }
 827
 828   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 829   {
 830     if( RemoveActor( *iter ) )
 831     {
 832       actorsReordered = true;
 833     }
 834   }
 835
 836   if( actorsReordered )
 837   {
 838     ReapplyAllConstraints( durationSeconds );
 839
 840     OnItemsRemoved();
 841   }
 842 }
 843
 844 bool ItemView::RemoveActor(unsigned int itemId)
 845 {
 846   bool reordered( false );
 847
 848   ItemPoolIter removeIter = mItemPool.find( itemId );
 849   if( removeIter != mItemPool.end() )
 850   {
 851     ReleaseActor(itemId, removeIter->second);
 852   }
 853   else
 854   {
 855     // Removing before the existing item range?
 856     ItemPoolIter iter = mItemPool.begin();
 857     if( iter != mItemPool.end() &&
 858         iter->first > itemId )
 859     {
 860       // In order to decrement the first visible item ID
 861       mItemPool.insert( Item(iter->first - 1, Actor()) );
 862
 863       removeIter = mItemPool.begin();
 864     }
 865   }
 866
 867   if( removeIter != mItemPool.end() )
 868   {
 869     reordered = true;
 870
 871     // Adjust the remaining item IDs, for example if item 2 is removed:
 872     //   Initial actors:     After insert:
 873     //     ID 1 - ActorA       ID 1 - ActorA
 874     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 875     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 876     //     ID 4 - ActorD
 877     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 878     {
 879       if( iter->first < mItemPool.rbegin()->first )
 880       {
 881         iter->second = mItemPool[ iter->first + 1 ];
 882       }
 883       else
 884       {
 885         mItemPool.erase( iter );
 886         break;
 887       }
 888     }
 889   }
 890
 891   return reordered;
 892 }
 893
 894 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 895 {
 896   mAddingItems = true;
 897
 898   SetupActor( replacementItem, durationSeconds );
 899   Self().Add( replacementItem.second );
 900
 901   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 902   if( mItemPool.end() != iter )
 903   {
 904     ReleaseActor(iter->first, iter->second);
 905     iter->second = replacementItem.second;
 906   }
 907   else
 908   {
 909     mItemPool.insert( replacementItem );
 910   }
 911
 912   CalculateDomainSize(Self().GetCurrentSize());
 913
 914   mAddingItems = false;
 915 }
 916
 917 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 918 {
 919   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 920   {
 921     ReplaceItem( *iter, durationSeconds );
 922   }
 923 }
 924
 925 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 926 {
 927   // Remove unwanted actors from the ItemView & ItemPool
 928   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 929   {
 930     unsigned int current = iter->first;
 931
 932     if( ! range.Within( current ) )
 933     {
 934       ReleaseActor(iter->first, iter->second);
 935
 936       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 937     }
 938     else
 939     {
 940       ++iter;
 941     }
 942   }
 943 }
 944
 945 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 946 {
 947   range.end = std::min(mItemFactory.GetNumberOfItems(), range.end);
 948
 949   // The order of addition depends on the scroll direction.
 950   if (mRefreshOrderHint)
 951   {
 952     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 953     {
 954       AddNewActor( itemId, durationSeconds );
 955     }
 956   }
 957   else
 958   {
 959     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 960     {
 961       AddNewActor( itemId-1, durationSeconds );
 962     }
 963   }
 964
 965   // Total number of items may change dynamically.
 966   // Always recalculate the domain size to reflect that.
 967   CalculateDomainSize(Self().GetCurrentSize());
 968 }
 969
 970 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 971 {
 972   mAddingItems = true;
 973
 974   if( mItemPool.end() == mItemPool.find( itemId ) )
 975   {
 976     Actor actor = mItemFactory.NewItem( itemId );
 977
 978     if( actor )
 979     {
 980       Item newItem( itemId, actor );
 981
 982       mItemPool.insert( newItem );
 983
 984       SetupActor( newItem, durationSeconds );
 985       Self().Add( actor );
 986     }
 987   }
 988
 989   mAddingItems = false;
 990 }
 991
 992 void ItemView::SetupActor( Item item, float durationSeconds )
 993 {
 994   item.second.SetParentOrigin( mItemsParentOrigin );
 995   item.second.SetAnchorPoint( mItemsAnchorPoint );
 996
 997   if( mActiveLayout )
 998   {
 999     Vector3 size;
1000     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
1001     {
1002       item.second.SetSize( size );
1003     }
1004
1005     mActiveLayout->ApplyConstraints( item.second, item.first, durationSeconds, mScrollPositionObject, Self() );
1006   }
1007 }
1008
1009 void ItemView::ReleaseActor( ItemId item, Actor actor )
1010 {
1011   Self().Remove( actor );
1012   mItemFactory.ItemReleased(item, actor);
1013 }
1014
1015 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, float layoutPosition, bool reserveExtra)
1016 {
1017   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1018
1019   ItemRange available(0u, itemCount);
1020
1021   ItemRange range = layout.GetItemsWithinArea( layoutPosition, layoutSize );
1022
1023   if (reserveExtra)
1024   {
1025     // Add the reserve items for scrolling
1026     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1027     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1028     range.end += extra;
1029   }
1030
1031   return range.Intersection(available);
1032 }
1033
1034 void ItemView::OnChildAdd(Actor& child)
1035 {
1036   if(!mAddingItems)
1037   {
1038     // We don't want to do this downcast check for any item added by ItemView itself.
1039     Dali::Toolkit::ScrollComponent scrollComponent = Dali::Toolkit::ScrollComponent::DownCast(child);
1040     if(scrollComponent)
1041     {
1042       // Set the scroll connector when scroll bar is being added
1043       scrollComponent.SetScrollConnector(mScrollConnector);
1044     }
1045   }
1046 }
1047
1048 bool ItemView::OnTouchEvent(const TouchEvent& event)
1049 {
1050   // Ignore events with multiple-touch points
1051   if (event.GetPointCount() != 1)
1052   {
1053     return false;
1054   }
1055
1056   if (event.GetPoint(0).state == TouchPoint::Down)
1057   {
1058     // Cancel ongoing scrolling etc.
1059     mGestureState = Gesture::Clear;
1060
1061     mScrollDistance = 0.0f;
1062     mScrollSpeed = 0.0f;
1063     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1064
1065     mScrollOvershoot = 0.0f;
1066     AnimateScrollOvershoot(0.0f);
1067
1068     if(mScrollAnimation)
1069     {
1070       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1071     }
1072
1073     RemoveAnimation(mScrollAnimation);
1074   }
1075
1076   return true; // consume since we're potentially scrolling
1077 }
1078
1079 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1080 {
1081   // Respond the mouse wheel event to scroll
1082   if (mActiveLayout)
1083   {
1084     Actor self = Self();
1085     const Vector3 layoutSize = Self().GetCurrentSize();
1086     float layoutPositionDelta = GetCurrentLayoutPosition(0) - (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1087     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1088
1089     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1090     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1091     mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1092     mRefreshEnabled = true;
1093   }
1094
1095   if (mMouseWheelEventFinishedTimer.IsRunning())
1096   {
1097     mMouseWheelEventFinishedTimer.Stop();
1098   }
1099
1100   mMouseWheelEventFinishedTimer.Start();
1101
1102   return true;
1103 }
1104
1105 bool ItemView::OnMouseWheelEventFinished()
1106 {
1107   if (mActiveLayout)
1108   {
1109     RemoveAnimation(mScrollAnimation);
1110
1111     // No more mouse wheel events coming. Do the anchoring if enabled.
1112     mScrollAnimation = DoAnchoring();
1113     if (mScrollAnimation)
1114     {
1115       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1116       mScrollAnimation.Play();
1117     }
1118     else
1119     {
1120       mScrollOvershoot = 0.0f;
1121       AnimateScrollOvershoot(0.0f);
1122
1123       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1124     }
1125   }
1126
1127   return false;
1128 }
1129
1130 void ItemView::ReapplyAllConstraints( float durationSeconds )
1131 {
1132   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1133   {
1134     unsigned int id = iter->first;
1135     Actor actor = iter->second;
1136
1137     actor.RemoveConstraints();
1138     mActiveLayout->ApplyConstraints(actor, id, durationSeconds, mScrollPositionObject, Self());
1139   }
1140 }
1141
1142 void ItemView::OnItemsRemoved()
1143 {
1144   CalculateDomainSize(Self().GetCurrentSize());
1145
1146   // Adjust scroll-position after an item is removed
1147   if( mActiveLayout )
1148   {
1149     float firstItemScrollPosition = ClampFirstItemPosition(GetCurrentLayoutPosition(0), Self().GetCurrentSize(), *mActiveLayout);
1150
1151     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1152   }
1153 }
1154
1155 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1156 {
1157   Actor self = Self();
1158   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1159   float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, targetPosition));
1160   mScrollOvershoot = targetPosition - clamppedPosition;
1161   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1162
1163   return clamppedPosition;
1164 }
1165
1166 void ItemView::OnPan( const PanGesture& gesture )
1167 {
1168   Actor self = Self();
1169   const Vector3 layoutSize = Self().GetCurrentSize();
1170
1171   RemoveAnimation(mScrollAnimation);
1172
1173   // Short-circuit if there is no active layout
1174   if (!mActiveLayout)
1175   {
1176     mGestureState = Gesture::Clear;
1177     return;
1178   }
1179
1180   mGestureState = gesture.state;
1181
1182   switch (mGestureState)
1183   {
1184     case Gesture::Finished:
1185     {
1186       // Swipe Detection
1187       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1188           mScrollSpeed > mMinimumSwipeSpeed)
1189       {
1190         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1191
1192         mRefreshOrderHint = true;
1193
1194         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1195         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1196                                                                layoutSize,
1197                                                                *mActiveLayout);
1198
1199         if (mAnchoringEnabled)
1200         {
1201           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1202         }
1203
1204         RemoveAnimation(mScrollAnimation);
1205
1206         float flickAnimationDuration = Clamp( mActiveLayout->GetItemFlickAnimationDuration() * std::max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)))
1207                                        , DEFAULT_MINIMUM_SWIPE_DURATION, DEFAULT_MAXIMUM_SWIPE_DURATION);
1208
1209         mScrollAnimation = Animation::New(flickAnimationDuration);
1210         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1211         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1212         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1213
1214         mIsFlicking = true;
1215         // Check whether it has already scrolled to the end
1216         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1217         {
1218           AnimateScrollOvershoot(0.0f);
1219         }
1220       }
1221
1222       // Anchoring may be triggered when there was no swipe
1223       if (!mScrollAnimation)
1224       {
1225         mScrollAnimation = DoAnchoring();
1226       }
1227
1228       // Reset the overshoot if no scroll animation.
1229       if (!mScrollAnimation)
1230       {
1231         mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1232
1233         AnimateScrollOvershoot(0.0f, false);
1234       }
1235     }
1236     break;
1237
1238     case Gesture::Started: // Fall through
1239     {
1240       mTotalPanDisplacement = Vector2::ZERO;
1241       mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1242       mRefreshEnabled = true;
1243     }
1244
1245     case Gesture::Continuing:
1246     {
1247       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1248       mScrollSpeed = Clamp((gesture.GetSpeed() * gesture.GetSpeed() * mActiveLayout->GetFlickSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1249
1250       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1251       mRefreshOrderHint = mScrollDistance < 0.0f;
1252
1253       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1254
1255       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1256
1257       float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1258
1259       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1260       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1261
1262       if( (firstItemScrollPosition >= 0.0f && currentOvershoot < 1.0f) || (firstItemScrollPosition <= mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize) && currentOvershoot > -1.0f) )
1263       {
1264         mTotalPanDisplacement += gesture.displacement;
1265       }
1266
1267       mScrollOvershoot = CalculateScrollOvershoot();
1268       mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, mScrollOvershoot );
1269     }
1270     break;
1271
1272     case Gesture::Cancelled:
1273     {
1274       mScrollAnimation = DoAnchoring();
1275     }
1276     break;
1277
1278     default:
1279       break;
1280   }
1281
1282   if (mScrollAnimation)
1283   {
1284     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1285     mScrollAnimation.Play();
1286   }
1287 }
1288
1289 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1290 {
1291   OnPan(gesture);
1292   return true;
1293 }
1294
1295 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1296 {
1297   Actor nextFocusActor;
1298   if(mActiveLayout)
1299   {
1300     int nextItemID = 0;
1301     if(!actor || actor == this->Self())
1302     {
1303       nextFocusActor = GetItem(nextItemID);
1304     }
1305     else if(actor && actor.GetParent() == this->Self())
1306     {
1307       int itemID = GetItemId(actor);
1308       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1309       nextFocusActor = GetItem(nextItemID);
1310       if(nextFocusActor == actor)
1311       {
1312         // need to pass NULL actor back to focus manager
1313         nextFocusActor.Reset();
1314         return nextFocusActor;
1315       }
1316     }
1317     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1318     Vector3 layoutSize = Self().GetCurrentSize();
1319     if(!nextFocusActor)
1320     {
1321       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1322       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1323       nextItemID = viewableItems.begin;
1324       nextFocusActor = GetItem(nextItemID);
1325     }
1326   }
1327   return nextFocusActor;
1328 }
1329
1330 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1331 {
1332   // only in this function if our chosen focus actor was actually used
1333   if(commitedFocusableActor)
1334   {
1335     int nextItemID = GetItemId(commitedFocusableActor);
1336     float layoutPosition = GetCurrentLayoutPosition(0);
1337     Vector3 layoutSize = Self().GetCurrentSize();
1338
1339     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1340     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1341   }
1342 }
1343
1344 Animation ItemView::DoAnchoring()
1345 {
1346   Animation anchoringAnimation;
1347   Actor self = Self();
1348
1349   if (mActiveLayout && mAnchoringEnabled)
1350   {
1351     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1352
1353     anchoringAnimation = Animation::New(mAnchoringDuration);
1354     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1355     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1356     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1357     if(!mIsFlicking)
1358     {
1359       AnimateScrollOvershoot(0.0f);
1360     }
1361   }
1362
1363   return anchoringAnimation;
1364 }
1365
1366 void ItemView::OnScrollFinished(Animation& source)
1367 {
1368   Actor self = Self();
1369
1370   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1371
1372   mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1373
1374   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1375   {
1376     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1377   }
1378   else
1379   {
1380     // Reset the overshoot
1381     AnimateScrollOvershoot( 0.0f );
1382   }
1383   mIsFlicking = false;
1384
1385   mScrollOvershoot = 0.0f;
1386 }
1387
1388 void ItemView::OnLayoutActivationScrollFinished(Animation& source)
1389 {
1390   RemoveAnimation(mScrollAnimation);
1391   mRefreshEnabled = true;
1392   DoRefresh(GetCurrentLayoutPosition(0), true);
1393 }
1394
1395 void ItemView::OnOvershootOnFinished(Animation& animation)
1396 {
1397   mAnimatingOvershootOn = false;
1398   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1399   RemoveAnimation(mScrollOvershootAnimation);
1400   if(mAnimateOvershootOff)
1401   {
1402     AnimateScrollOvershoot(0.0f);
1403   }
1404 }
1405
1406 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1407 {
1408   Actor self = Self();
1409   const Vector3 layoutSize = Self().GetCurrentSize();
1410   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1411
1412   if(durationSeconds > 0.0f)
1413   {
1414     RemoveAnimation(mScrollAnimation);
1415     mScrollAnimation = Animation::New(durationSeconds);
1416     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1417     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1418     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1419     mScrollAnimation.Play();
1420   }
1421   else
1422   {
1423     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1424     AnimateScrollOvershoot(0.0f);
1425   }
1426
1427   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1428   mRefreshEnabled = true;
1429 }
1430
1431 void ItemView::RemoveAnimation(Animation& animation)
1432 {
1433   if(animation)
1434   {
1435     // Cease animating, and reset handle.
1436     animation.Clear();
1437     animation.Reset();
1438   }
1439 }
1440
1441 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1442 {
1443   Actor self = Self();
1444
1445   Vector3 firstItemPosition(Vector3::ZERO);
1446   Vector3 lastItemPosition(Vector3::ZERO);
1447
1448   if(mActiveLayout)
1449   {
1450     firstItemPosition = mActiveLayout->GetItemPosition( 0,0,layoutSize );
1451
1452     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1453     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1454     lastItemPosition = mActiveLayout->GetItemPosition( fabs(minLayoutPosition),fabs(minLayoutPosition),layoutSize );
1455
1456     float domainSize;
1457
1458     if(IsHorizontal(mActiveLayout->GetOrientation()))
1459     {
1460       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1461       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1462       domainSize = fabs(firstItemPosition.x - lastItemPosition.x);
1463     }
1464     else
1465     {
1466       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1467       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1468       domainSize = fabs(firstItemPosition.y - lastItemPosition.y);
1469     }
1470
1471     mScrollConnector.SetScrollDomain(minLayoutPosition, 0.0f, domainSize);
1472
1473     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1474     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1475     self.SetProperty(mPropertyCanScrollHorizontal, false);
1476   }
1477 }
1478
1479 Vector3 ItemView::GetDomainSize() const
1480 {
1481   Actor self = Self();
1482
1483   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1484   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1485
1486   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1487 }
1488
1489 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1490 {
1491   Actor self = Self();
1492
1493   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1494   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1495   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1496
1497   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1498 }
1499
1500 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1501 {
1502   Vector3 firstItemPosition( mActiveLayout->GetItemPosition(0, layoutPosition, layoutSize ) );
1503   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1504 }
1505
1506 Vector3 ItemView::GetCurrentScrollPosition() const
1507 {
1508   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1509   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1510 }
1511
1512 void ItemView::AddOverlay(Actor actor)
1513 {
1514   Self().Add(actor);
1515 }
1516
1517 void ItemView::RemoveOverlay(Actor actor)
1518 {
1519   Self().Remove(actor);
1520 }
1521
1522 void ItemView::ScrollTo(const Vector3& position, float duration)
1523 {
1524   Actor self = Self();
1525   const Vector3 layoutSize = Self().GetCurrentSize();
1526
1527   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1528
1529   if(duration > 0.0f)
1530   {
1531     RemoveAnimation(mScrollAnimation);
1532     mScrollAnimation = Animation::New(duration);
1533     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1534     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1535     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1536     mScrollAnimation.Play();
1537   }
1538   else
1539   {
1540     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1541     AnimateScrollOvershoot(0.0f);
1542   }
1543
1544   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1545   mRefreshEnabled = true;
1546 }
1547
1548 void ItemView::SetOvershootEffectColor( const Vector4& color )
1549 {
1550   mOvershootEffectColor = color;
1551   if( mOvershootOverlay )
1552   {
1553     mOvershootOverlay.SetColor( color );
1554   }
1555 }
1556
1557 void ItemView::SetOvershootEnabled( bool enable )
1558 {
1559   Actor self = Self();
1560   if( enable )
1561   {
1562     Property::Index effectOvershootPropertyIndex = Property::INVALID_INDEX;
1563     mOvershootOverlay = CreateBouncingEffectActor( effectOvershootPropertyIndex );
1564     mOvershootOverlay.SetColor(mOvershootEffectColor);
1565     mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
1566     mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
1567     mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
1568     self.Add(mOvershootOverlay);
1569
1570     Constraint constraint = Constraint::New<Vector3>( Actor::SIZE,
1571                                                       ParentSource( mPropertyScrollDirection ),
1572                                                       Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1573                                                       ParentSource( Actor::SIZE ),
1574                                                       OvershootOverlaySizeConstraint() );
1575     mOvershootOverlay.ApplyConstraint(constraint);
1576     mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.width, OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height);
1577
1578     constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1579                                               ParentSource( mPropertyScrollDirection ),
1580                                               Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1581                                               OvershootOverlayRotationConstraint() );
1582     mOvershootOverlay.ApplyConstraint(constraint);
1583
1584     constraint = Constraint::New<Vector3>( Actor::POSITION,
1585                                            ParentSource( Actor::SIZE ),
1586                                            ParentSource( mPropertyScrollDirection ),
1587                                            Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1588                                            OvershootOverlayPositionConstraint() );
1589     mOvershootOverlay.ApplyConstraint(constraint);
1590
1591     constraint = Constraint::New<bool>( Actor::VISIBLE,
1592                                         ParentSource( mPropertyCanScrollVertical ),
1593                                         OvershootOverlayVisibilityConstraint() );
1594     mOvershootOverlay.ApplyConstraint(constraint);
1595
1596     constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1597                                          Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1598                                          EqualToConstraint() );
1599     mOvershootOverlay.ApplyConstraint(constraint);
1600   }
1601   else
1602   {
1603     if( mOvershootOverlay )
1604     {
1605       self.Remove(mOvershootOverlay);
1606       mOvershootOverlay.Reset();
1607     }
1608   }
1609 }
1610
1611 float ItemView::CalculateScrollOvershoot()
1612 {
1613   float overshoot = 0.0f;
1614
1615   if(mActiveLayout)
1616   {
1617     // The overshoot must be calculated from the accumulated pan gesture displacement
1618     // since the pan gesture starts.
1619     Actor self = Self();
1620     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1621     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1622     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1623     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1624     float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, positionDelta));
1625     overshoot = positionDelta - clamppedPosition;
1626   }
1627
1628   return overshoot > 0.0f ? std::min(overshoot, 1.0f) : std::max(overshoot, -1.0f);
1629 }
1630
1631 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1632 {
1633   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1634
1635   // make sure we animate back if needed
1636   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1637
1638   if( mAnimatingOvershootOn )
1639   {
1640     // animating on, do not allow animate off
1641     return;
1642   }
1643
1644   if(mOvershootAnimationSpeed > Math::MACHINE_EPSILON_0)
1645   {
1646     float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1647     float duration = mOvershootOverlay.GetCurrentSize().height * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot)) / mOvershootAnimationSpeed;
1648
1649     RemoveAnimation(mScrollOvershootAnimation);
1650     mScrollOvershootAnimation = Animation::New(duration);
1651     mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1652     mScrollOvershootAnimation.AnimateTo( Property(mScrollPositionObject, ScrollConnector::OVERSHOOT), overshootAmount, TimePeriod(0.0f, duration) );
1653     mScrollOvershootAnimation.Play();
1654
1655     mAnimatingOvershootOn = animatingOn;
1656   }
1657   else
1658   {
1659     mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, overshootAmount );
1660   }
1661 }
1662
1663 void ItemView::SetItemsParentOrigin( const Vector3& parentOrigin )
1664 {
1665   if( parentOrigin != mItemsParentOrigin )
1666   {
1667     mItemsParentOrigin = parentOrigin;
1668     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1669     {
1670       iter->second.SetParentOrigin(parentOrigin);
1671     }
1672   }
1673 }
1674
1675 Vector3 ItemView::GetItemsParentOrigin() const
1676 {
1677   return mItemsParentOrigin;
1678 }
1679
1680 void ItemView::SetItemsAnchorPoint( const Vector3& anchorPoint )
1681 {
1682   if( anchorPoint != mItemsAnchorPoint )
1683   {
1684     mItemsAnchorPoint = anchorPoint;
1685     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1686     {
1687       iter->second.SetAnchorPoint(anchorPoint);
1688     }
1689   }
1690 }
1691
1692 Vector3 ItemView::GetItemsAnchorPoint() const
1693 {
1694   return mItemsAnchorPoint;
1695 }
1696
1697 void ItemView::GetItemsRange(ItemRange& range)
1698 {
1699   if( !mItemPool.empty() )
1700   {
1701     range.begin = mItemPool.begin()->first;
1702     range.end = mItemPool.rbegin()->first + 1;
1703   }
1704   else
1705   {
1706     range.begin = 0;
1707     range.end = 0;
1708   }
1709 }
1710
1711 void ItemView::OnScrollPositionChanged( float position )
1712 {
1713   // Cancel scroll animation to prevent any fighting of setting the scroll position property.
1714   RemoveAnimation(mScrollAnimation);
1715
1716   // Refresh the cache immediately when the scroll position is changed.
1717   DoRefresh(position, false); // No need to cache extra items.
1718 }
1719
1720 } // namespace Internal
1721
1722 } // namespace Toolkit
1723
1724 } // namespace Dali