base/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
  24 // INTERNAL INCLUDES
  25 #include <dali/public-api/events/mouse-wheel-event.h>
  26 #include <dali-toolkit/public-api/controls/scrollable/item-view/item-factory.h>
  27 #include <dali-toolkit/internal/controls/scrollable/scroll-connector-impl.h>
  28 #include <dali-toolkit/internal/controls/scrollable/bouncing-effect-actor.h>
  29
  30 using namespace std;
  31 using namespace Dali;
  32
  33 namespace // unnamed namespace
  34 {
  35
  36 //Type registration
  37 TypeRegistration mType( typeid(Toolkit::ItemView), typeid(Toolkit::Scrollable), NULL );
  38
  39 const float DEFAULT_MINIMUM_SWIPE_SPEED = 1.0f;
  40 const float DEFAULT_MINIMUM_SWIPE_DISTANCE = 3.0f;
  41 const float DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION = 0.1f;
  42
  43 const float DEFAULT_MINIMUM_SWIPE_DURATION = 0.45f;
  44 const float DEFAULT_MAXIMUM_SWIPE_DURATION = 2.6f;
  45
  46
  47 const float DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS = 20.0f; // 1 updates per 20 items
  48 const int MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT = 500;  // 0.5 second
  49
  50 const float DEFAULT_ANCHORING_DURATION = 1.0f;  // 1 second
  51 const float DEFAULT_COLOR_VISIBILITY_REMOVE_TIME = 0.5f; // 0.5 second
  52
  53 const float MILLISECONDS_PER_SECONDS = 1000.0f;
  54
  55 const Vector2 OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE( 720.0f, 42.0f );
  56 const float OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD = 180.0f;
  57 const Vector4 OVERSHOOT_OVERLAY_NINE_PATCH_BORDER(0.0f, 0.0f, 1.0f, 12.0f);
  58 const float MAXIMUM_OVERSHOOT_HEIGHT = 36.0f;  // 36 pixels
  59 const float DEFAULT_OVERSHOOT_ANIMATION_DURATION = 0.5f;  // 0.5 second
  60 const float DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION = 0.2f;
  61
  62 const string LAYOUT_POSITION_PROPERTY_NAME( "item-view-layout-position" );
  63 const string POSITION_PROPERTY_NAME( "item-view-position" );
  64 const string MINIMUM_LAYOUT_POSITION_PROPERTY_NAME( "item-view-minimum-layout-position" );
  65 const string SCROLL_SPEED_PROPERTY_NAME( "item-view-scroll-speed" );
  66 const string SCROLL_DIRECTION_PROPERTY_NAME( "item-view-scroll-direction" );
  67 const string OVERSHOOT_PROPERTY_NAME( "item-view-overshoot" );
  68
  69 // Functors which wrap constraint functions with stored item IDs
  70
  71 struct WrappedVector3Constraint
  72 {
  73   WrappedVector3Constraint(Toolkit::ItemLayout::Vector3Function wrapMe, unsigned int itemId)
  74   : mWrapMe(wrapMe),
  75     mItemId(itemId)
  76   {
  77   }
  78
  79   Vector3 operator()(const Vector3& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  80   {
  81     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
  82
  83     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
  84   }
  85
  86   Toolkit::ItemLayout::Vector3Function mWrapMe;
  87   unsigned int mItemId;
  88 };
  89
  90 struct WrappedQuaternionConstraint
  91 {
  92   WrappedQuaternionConstraint(Toolkit::ItemLayout::QuaternionFunction wrapMe, unsigned int itemId)
  93   : mWrapMe(wrapMe),
  94     mItemId(itemId)
  95   {
  96   }
  97
  98   Quaternion operator()(const Quaternion& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  99   {
 100     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 101
 102     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 103   }
 104
 105   Toolkit::ItemLayout::QuaternionFunction mWrapMe;
 106   unsigned int mItemId;
 107 };
 108
 109 struct WrappedVector4Constraint
 110 {
 111   WrappedVector4Constraint(Toolkit::ItemLayout::Vector4Function wrapMe, unsigned int itemId)
 112   : mWrapMe(wrapMe),
 113     mItemId(itemId)
 114   {
 115   }
 116
 117   Vector4 operator()(const Vector4& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 118   {
 119     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 120
 121     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 122   }
 123
 124   Toolkit::ItemLayout::Vector4Function mWrapMe;
 125   unsigned int mItemId;
 126 };
 127
 128 struct WrappedBoolConstraint
 129 {
 130   WrappedBoolConstraint(Toolkit::ItemLayout::BoolFunction wrapMe, unsigned int itemId)
 131   : mWrapMe(wrapMe),
 132     mItemId(itemId)
 133   {
 134   }
 135
 136   bool operator()(const bool& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 137   {
 138     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 139
 140     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 141   }
 142
 143   Toolkit::ItemLayout::BoolFunction mWrapMe;
 144   unsigned int mItemId;
 145 };
 146
 147 /**
 148  * Local helper to convert pan distance (in actor coordinates) to the layout-specific scrolling direction
 149  */
 150 float CalculateScrollDistance(Vector2 panDistance, Toolkit::ItemLayout& layout)
 151 {
 152   Radian scrollDirection(layout.GetScrollDirection());
 153
 154   float cosTheta = cosf(scrollDirection);
 155   float sinTheta = sinf(scrollDirection);
 156
 157   return panDistance.x * sinTheta + panDistance.y * cosTheta;
 158 }
 159
 160 // Overshoot overlay constraints
 161
 162 struct OvershootOverlaySizeConstraint
 163 {
 164   Vector3 operator()(const Vector3& current,
 165                      const PropertyInput& parentScrollDirectionProperty,
 166                      const PropertyInput& parentOvershootProperty,
 167                      const PropertyInput& parentSizeProperty)
 168   {
 169     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 170     const Vector3 parentSize = parentSizeProperty.GetVector3();
 171     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 172
 173     float overlayWidth;
 174
 175     if(Toolkit::IsVertical(parentOrientation))
 176     {
 177       overlayWidth = fabsf(parentScrollDirection.y) > Math::MACHINE_EPSILON_1 ? parentSize.x : parentSize.y;
 178     }
 179     else
 180     {
 181       overlayWidth = fabsf(parentScrollDirection.x) > Math::MACHINE_EPSILON_1 ? parentSize.y : parentSize.x;
 182     }
 183
 184     float overlayHeight = (overlayWidth > OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD) ? OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height : OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height*0.5f;
 185
 186     return Vector3( overlayWidth, overlayHeight, current.depth );
 187   }
 188 };
 189
 190 struct OvershootOverlayRotationConstraint
 191 {
 192   Quaternion operator()(const Quaternion& current,
 193                         const PropertyInput& parentScrollDirectionProperty,
 194                         const PropertyInput& parentOvershootProperty)
 195   {
 196     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 197     const float parentOvershoot = parentOvershootProperty.GetFloat();
 198     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 199
 200     Quaternion rotation;
 201
 202     if(Toolkit::IsVertical(parentOrientation))
 203     {
 204       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 205       {
 206         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 207             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 208         {
 209           rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 210         }
 211         else
 212         {
 213           rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 214         }
 215       }
 216       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 217             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 218       {
 219         rotation = Quaternion(0.0f, Vector3::ZAXIS);
 220       }
 221       else
 222       {
 223         rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 224       }
 225     }
 226     else
 227     {
 228       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 229       {
 230         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot > Math::MACHINE_EPSILON_0)
 231             ||(parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot < Math::MACHINE_EPSILON_0) )
 232         {
 233           rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 234         }
 235         else
 236         {
 237           rotation = Quaternion(0.0f, Vector3::ZAXIS);
 238         }
 239       }
 240       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 241             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 242       {
 243         rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 244       }
 245       else
 246       {
 247         rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 248       }
 249     }
 250
 251     return rotation;
 252   }
 253 };
 254
 255 struct OvershootOverlayPositionConstraint
 256 {
 257   Vector3 operator()(const Vector3&    current,
 258                      const PropertyInput& parentSizeProperty,
 259                      const PropertyInput& parentScrollDirectionProperty,
 260                      const PropertyInput& parentOvershootProperty)
 261   {
 262     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 263     const float parentOvershoot = parentOvershootProperty.GetFloat();
 264     const Vector3 parentSize = parentSizeProperty.GetVector3();
 265     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 266
 267     Vector3 relativeOffset;
 268
 269     if(Toolkit::IsVertical(parentOrientation))
 270     {
 271       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 272       {
 273         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 274             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 275         {
 276           relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 277         }
 278         else
 279         {
 280           relativeOffset =Vector3(0.0f, 1.0f, 0.0f);
 281         }
 282       }
 283       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 284             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 285       {
 286         relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 287       }
 288       else
 289       {
 290         relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 291       }
 292     }
 293     else
 294     {
 295       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 296       {
 297         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot < Math::MACHINE_EPSILON_0)
 298             || (parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot > Math::MACHINE_EPSILON_0) )
 299         {
 300           relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 301         }
 302         else
 303         {
 304           relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 305         }
 306       }
 307       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 308             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 309       {
 310         relativeOffset = Vector3(0.0f, 1.0f, 0.0f);
 311       }
 312       else
 313       {
 314         relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 315       }
 316     }
 317
 318     return relativeOffset * parentSize;
 319
 320   }
 321 };
 322
 323 struct OvershootOverlayVisibilityConstraint
 324 {
 325   bool operator()(const bool& current,
 326                   const PropertyInput& parentLayoutScrollableProperty)
 327   {
 328     const bool parentLayoutScrollable = parentLayoutScrollableProperty.GetBoolean();
 329
 330     return parentLayoutScrollable;
 331   }
 332 };
 333
 334 /**
 335  * Relative position Constraint
 336  * Generates the relative position value of the item view based on the layout position,
 337  * and it's relation to the layout domain. This is a value from 0.0f to 1.0f in each axis.
 338  */
 339 Vector3 RelativePositionConstraint(const Vector3& current,
 340                                    const PropertyInput& scrollPositionProperty,
 341                                    const PropertyInput& scrollMinProperty,
 342                                    const PropertyInput& scrollMaxProperty,
 343                                    const PropertyInput& layoutSizeProperty)
 344 {
 345   const Vector3& position = Vector3(0.0f, scrollPositionProperty.GetFloat(), 0.0f);
 346   const Vector3& min = scrollMinProperty.GetVector3();
 347   const Vector3& max = scrollMaxProperty.GetVector3();
 348
 349   Vector3 relativePosition;
 350   Vector3 domainSize = max - min;
 351
 352   relativePosition.x = fabsf(domainSize.x) > Math::MACHINE_EPSILON_1 ? ((min.x - position.x) / fabsf(domainSize.x)) : 0.0f;
 353   relativePosition.y = fabsf(domainSize.y) > Math::MACHINE_EPSILON_1 ? ((min.y - position.y) / fabsf(domainSize.y)) : 0.0f;
 354
 355   return relativePosition;
 356 }
 357
 358 } // unnamed namespace
 359
 360 namespace Dali
 361 {
 362
 363 namespace Toolkit
 364 {
 365
 366 namespace Internal
 367 {
 368
 369 namespace // unnamed namespace
 370 {
 371
 372 bool FindById( const ItemContainer& items, ItemId id )
 373 {
 374   for( ConstItemIter iter = items.begin(); items.end() != iter; ++iter )
 375   {
 376     if( iter->first == id )
 377     {
 378       return true;
 379     }
 380   }
 381
 382   return false;
 383 }
 384
 385 } // unnamed namespace
 386
 387 Dali::Toolkit::ItemView ItemView::New(ItemFactory& factory)
 388 {
 389   // Create the implementation
 390   ItemViewPtr itemView(new ItemView(factory));
 391
 392   // Pass ownership to CustomActor via derived handle
 393   Dali::Toolkit::ItemView handle(*itemView);
 394
 395   // Second-phase init of the implementation
 396   // This can only be done after the CustomActor connection has been made...
 397   itemView->Initialize();
 398
 399   return handle;
 400 }
 401
 402 ItemView::ItemView(ItemFactory& factory)
 403 : Scrollable(),
 404   mItemFactory(factory),
 405   mActiveLayout(NULL),
 406   mDefaultAlphaFunction(Dali::Constraint::DEFAULT_ALPHA_FUNCTION),
 407   mAnimatingOvershootOn(false),
 408   mAnimateOvershootOff(false),
 409   mAnchoringEnabled(true),
 410   mAnchoringDuration(DEFAULT_ANCHORING_DURATION),
 411   mRefreshIntervalLayoutPositions(0.0f),
 412   mRefreshOrderHint(true/*Refresh item 0 first*/),
 413   mMinimumSwipeSpeed(DEFAULT_MINIMUM_SWIPE_SPEED),
 414   mMinimumSwipeDistance(DEFAULT_MINIMUM_SWIPE_DISTANCE),
 415   mScrollDistance(0.0f),
 416   mScrollSpeed(0.0f),
 417   mTotalPanDisplacement(Vector2::ZERO),
 418   mScrollOvershoot(0.0f),
 419   mIsFlicking(false),
 420   mGestureState(Gesture::Clear),
 421   mAddingItems(false),
 422   mRefreshEnabled(true),
 423   mItemsParentOrigin( ParentOrigin::CENTER),
 424   mItemsAnchorPoint( AnchorPoint::CENTER)
 425 {
 426   SetRequiresMouseWheelEvents(true);
 427   SetKeyboardNavigationSupport(true);
 428 }
 429
 430 void ItemView::OnInitialize()
 431 {
 432   SetSizePolicy( Toolkit::Control::Fixed, Toolkit::Control::Fixed );
 433
 434   RegisterCommonProperties();
 435
 436   Actor self = Self();
 437
 438   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 439   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 440   mScrollConnector.ScrollPositionChangedSignal().Connect( this, &ItemView::OnScrollPositionChanged );
 441
 442   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 443   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 444   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 445
 446   EnableScrollComponent(Toolkit::Scrollable::OvershootIndicator);
 447
 448   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 449                                                    LocalSource(mPropertyPosition),
 450                                                    LocalSource(mPropertyPositionMin),
 451                                                    LocalSource(mPropertyPositionMax),
 452                                                    LocalSource(Actor::SIZE),
 453                                                    RelativePositionConstraint);
 454   self.ApplyConstraint(constraint);
 455
 456   Vector2 stageSize = Stage::GetCurrent().GetSize();
 457   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 458
 459   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 460
 461   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 462   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 463
 464   SetRefreshInterval(DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS);
 465 }
 466
 467 ItemView::~ItemView()
 468 {
 469 }
 470
 471 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 472 {
 473   return mScrollConnector;
 474 }
 475
 476 unsigned int ItemView::GetLayoutCount() const
 477 {
 478   return mLayouts.size();
 479 }
 480
 481 void ItemView::AddLayout(ItemLayout& layout)
 482 {
 483   mLayouts.push_back(ItemLayoutPtr(&layout));
 484 }
 485
 486 void ItemView::RemoveLayout(unsigned int layoutIndex)
 487 {
 488   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 489
 490   if (mActiveLayout == mLayouts[layoutIndex].Get())
 491   {
 492     mActiveLayout = NULL;
 493   }
 494
 495   mLayouts.erase(mLayouts.begin() + layoutIndex);
 496 }
 497
 498 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 499 {
 500   return mLayouts[layoutIndex];
 501 }
 502
 503 ItemLayoutPtr ItemView::GetActiveLayout() const
 504 {
 505   return ItemLayoutPtr(mActiveLayout);
 506 }
 507
 508 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 509 {
 510   return mScrollConnector.GetScrollPosition() + static_cast<float>( itemId );
 511 }
 512
 513 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 514 {
 515   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 516
 517   mRefreshEnabled = false;
 518
 519   Actor self = Self();
 520
 521   // The ItemView size should match the active layout size
 522   self.SetSize(targetSize);
 523   mActiveLayoutTargetSize = targetSize;
 524
 525   // Switch to the new layout
 526   mActiveLayout = mLayouts[layoutIndex].Get();
 527
 528   // Move the items to the new layout positions...
 529
 530   bool resizeAnimationNeeded(false);
 531
 532   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 533   {
 534     unsigned int itemId = iter->first;
 535     Actor actor = iter->second;
 536
 537     // Remove constraints from previous layout
 538     actor.RemoveConstraints();
 539
 540     Vector3 size;
 541     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 542     {
 543       if( durationSeconds > 0.0f )
 544       {
 545         // Use a size animation
 546         if (!resizeAnimationNeeded)
 547         {
 548           resizeAnimationNeeded = true;
 549           RemoveAnimation(mResizeAnimation);
 550           mResizeAnimation = Animation::New(durationSeconds);
 551         }
 552
 553         // The layout provides its own resize animation
 554         mActiveLayout->GetResizeAnimation(mResizeAnimation, actor, size, durationSeconds);
 555       }
 556       else
 557       {
 558         // resize immediately
 559         actor.SetSize(size);
 560       }
 561     }
 562
 563     ApplyConstraints(actor, *mActiveLayout, itemId, durationSeconds);
 564   }
 565
 566   if (resizeAnimationNeeded)
 567   {
 568     mResizeAnimation.Play();
 569   }
 570
 571   // Refresh the new layout
 572   ItemRange range = GetItemRange(*mActiveLayout, targetSize, GetCurrentLayoutPosition(0), false/* don't reserve extra*/);
 573   AddActorsWithinRange( range, durationSeconds );
 574
 575   // Scroll to an appropriate layout position
 576
 577   bool scrollAnimationNeeded(false);
 578   float firstItemScrollPosition(0.0f);
 579
 580   float current = GetCurrentLayoutPosition(0);
 581   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 582   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 583
 584   if (current < minimum)
 585   {
 586     scrollAnimationNeeded = true;
 587     firstItemScrollPosition = minimum;
 588   }
 589   else if (mAnchoringEnabled)
 590   {
 591     scrollAnimationNeeded = true;
 592     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 593   }
 594
 595   if (scrollAnimationNeeded)
 596   {
 597     RemoveAnimation(mScrollAnimation);
 598     mScrollAnimation = Animation::New(durationSeconds);
 599     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 600     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 601     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnLayoutActivationScrollFinished);
 602     mScrollAnimation.Play();
 603   }
 604
 605   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 606   AnimateScrollOvershoot(0.0f);
 607   mScrollOvershoot = 0.0f;
 608
 609   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 610   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 611   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 612
 613   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 614
 615   CalculateDomainSize(targetSize);
 616 }
 617
 618 void ItemView::DeactivateCurrentLayout()
 619 {
 620   if (mActiveLayout)
 621   {
 622     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 623     {
 624       Actor actor = iter->second;
 625       actor.RemoveConstraints();
 626     }
 627
 628     mActiveLayout = NULL;
 629   }
 630 }
 631
 632 void ItemView::SetDefaultAlphaFunction(AlphaFunction func)
 633 {
 634   mDefaultAlphaFunction = func;
 635 }
 636
 637 AlphaFunction ItemView::GetDefaultAlphaFunction() const
 638 {
 639   return mDefaultAlphaFunction;
 640 }
 641
 642 void ItemView::OnRefreshNotification(PropertyNotification& source)
 643 {
 644   if(mRefreshEnabled || mScrollAnimation)
 645   {
 646     // Only refresh the cache during normal scrolling
 647     DoRefresh(GetCurrentLayoutPosition(0), true);
 648   }
 649 }
 650
 651 void ItemView::DoRefresh(float currentLayoutPosition, bool cacheExtra)
 652 {
 653   if (mActiveLayout)
 654   {
 655     ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, currentLayoutPosition, cacheExtra/*reserve extra*/);
 656     RemoveActorsOutsideRange( range );
 657     AddActorsWithinRange( range, 0.0f/*immediate*/ );
 658
 659     mScrollUpdatedSignalV2.Emit( Vector3(0.0f, currentLayoutPosition, 0.0f) );
 660   }
 661 }
 662
 663 void ItemView::SetMinimumSwipeSpeed(float speed)
 664 {
 665   mMinimumSwipeSpeed = speed;
 666 }
 667
 668 float ItemView::GetMinimumSwipeSpeed() const
 669 {
 670   return mMinimumSwipeSpeed;
 671 }
 672
 673 void ItemView::SetMinimumSwipeDistance(float distance)
 674 {
 675   mMinimumSwipeDistance = distance;
 676 }
 677
 678 float ItemView::GetMinimumSwipeDistance() const
 679 {
 680   return mMinimumSwipeDistance;
 681 }
 682
 683 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 684 {
 685   mMouseWheelScrollDistanceStep = step;
 686 }
 687
 688 float ItemView::GetMouseWheelScrollDistanceStep() const
 689 {
 690   return mMouseWheelScrollDistanceStep;
 691 }
 692
 693 void ItemView::SetAnchoring(bool enabled)
 694 {
 695   mAnchoringEnabled = enabled;
 696 }
 697
 698 bool ItemView::GetAnchoring() const
 699 {
 700   return mAnchoringEnabled;
 701 }
 702
 703 void ItemView::SetAnchoringDuration(float durationSeconds)
 704 {
 705   mAnchoringDuration = durationSeconds;
 706 }
 707
 708 float ItemView::GetAnchoringDuration() const
 709 {
 710   return mAnchoringDuration;
 711 }
 712
 713 void ItemView::SetRefreshInterval(float intervalLayoutPositions)
 714 {
 715   if(mRefreshIntervalLayoutPositions != intervalLayoutPositions)
 716   {
 717     mRefreshIntervalLayoutPositions = intervalLayoutPositions;
 718
 719     if(mRefreshNotification)
 720     {
 721       mScrollPositionObject.RemovePropertyNotification(mRefreshNotification);
 722     }
 723     mRefreshNotification = mScrollPositionObject.AddPropertyNotification( ScrollConnector::SCROLL_POSITION, StepCondition(mRefreshIntervalLayoutPositions, 0.0f) );
 724     mRefreshNotification.NotifySignal().Connect( this, &ItemView::OnRefreshNotification );
 725   }
 726 }
 727
 728 float ItemView::GetRefreshInterval() const
 729 {
 730   return mRefreshIntervalLayoutPositions;
 731 }
 732
 733 void ItemView::SetRefreshEnabled(bool enabled)
 734 {
 735   mRefreshEnabled = enabled;
 736 }
 737
 738 Actor ItemView::GetItem(unsigned int itemId) const
 739 {
 740   Actor actor;
 741
 742   ConstItemPoolIter iter = mItemPool.find( itemId );
 743   if( iter != mItemPool.end() )
 744   {
 745     actor = iter->second;
 746   }
 747
 748   return actor;
 749 }
 750
 751 unsigned int ItemView::GetItemId( Actor actor ) const
 752 {
 753   unsigned int itemId( 0 );
 754
 755   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 756   {
 757     if( iter->second == actor )
 758     {
 759       itemId = iter->first;
 760       break;
 761     }
 762   }
 763
 764   return itemId;
 765 }
 766
 767 void ItemView::InsertItem( Item newItem, float durationSeconds )
 768 {
 769   mAddingItems = true;
 770
 771   SetupActor( newItem, durationSeconds );
 772   Self().Add( newItem.second );
 773
 774   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 775   if( mItemPool.end() != foundIter )
 776   {
 777     Actor moveMe = foundIter->second;
 778     foundIter->second = newItem.second;
 779
 780     // Move the existing actors to make room
 781     for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 782     {
 783       Actor temp = iter->second;
 784       iter->second = moveMe;
 785       moveMe = temp;
 786
 787       iter->second.RemoveConstraints();
 788       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 789     }
 790
 791     // Create last item
 792     ItemId lastId = mItemPool.rbegin()->first;
 793     Item lastItem( lastId + 1, moveMe );
 794     mItemPool.insert( lastItem );
 795
 796     lastItem.second.RemoveConstraints();
 797     ApplyConstraints( lastItem.second, *mActiveLayout, lastItem.first, durationSeconds );
 798   }
 799   else
 800   {
 801     mItemPool.insert( newItem );
 802   }
 803
 804   CalculateDomainSize(Self().GetCurrentSize());
 805
 806   mAddingItems = false;
 807 }
 808
 809 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 810 {
 811   mAddingItems = true;
 812
 813   // Insert from lowest id to highest
 814   set<Item> sortedItems;
 815   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 816   {
 817     sortedItems.insert( *iter );
 818   }
 819
 820   for( set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 821   {
 822     Self().Add( iter->second );
 823
 824     cout << "inserting item: " << iter->first << endl;
 825
 826     ItemPoolIter foundIter = mItemPool.find( iter->first );
 827     if( mItemPool.end() != foundIter )
 828     {
 829       Actor moveMe = foundIter->second;
 830       foundIter->second = iter->second;
 831
 832       // Move the existing actors to make room
 833       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 834       {
 835         Actor temp = iter->second;
 836         iter->second = moveMe;
 837         moveMe = temp;
 838       }
 839
 840       // Create last item
 841       ItemId lastId = mItemPool.rbegin()->first;
 842       Item lastItem( lastId + 1, moveMe );
 843       mItemPool.insert( lastItem );
 844     }
 845     else
 846     {
 847       mItemPool.insert( *iter );
 848     }
 849   }
 850
 851   // Relayout everything
 852   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 853   {
 854     // If newly inserted
 855     if( FindById( newItems, iter->first ) )
 856     {
 857       SetupActor( *iter, durationSeconds );
 858     }
 859     else
 860     {
 861       iter->second.RemoveConstraints();
 862       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 863     }
 864   }
 865
 866   CalculateDomainSize(Self().GetCurrentSize());
 867
 868   mAddingItems = false;
 869 }
 870
 871 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 872 {
 873   bool actorRemoved = RemoveActor( itemId );
 874   if( actorRemoved )
 875   {
 876     ReapplyAllConstraints( durationSeconds );
 877   }
 878 }
 879
 880 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 881 {
 882   bool actorRemoved( false );
 883
 884   // Remove from highest id to lowest
 885   set<ItemId> sortedItems;
 886   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 887   {
 888     sortedItems.insert( *iter );
 889   }
 890
 891   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 892   {
 893     if( RemoveActor( *iter ) )
 894     {
 895       actorRemoved = true;
 896     }
 897   }
 898
 899   if( actorRemoved )
 900   {
 901     ReapplyAllConstraints( durationSeconds );
 902   }
 903 }
 904
 905 bool ItemView::RemoveActor(unsigned int itemId)
 906 {
 907   bool removed( false );
 908
 909   const ItemPoolIter removeIter = mItemPool.find( itemId );
 910
 911   if( removeIter != mItemPool.end() )
 912   {
 913     ReleaseActor(itemId, removeIter->second);
 914
 915     removed = true;
 916
 917     // Adjust the remaining item IDs, for example if item 2 is removed:
 918     //   Initial actors:     After insert:
 919     //     ID 1 - ActorA       ID 1 - ActorA
 920     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 921     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 922     //     ID 4 - ActorD
 923     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 924     {
 925       if( iter->first < mItemPool.rbegin()->first )
 926       {
 927         iter->second = mItemPool[ iter->first + 1 ];
 928       }
 929       else
 930       {
 931         mItemPool.erase( iter );
 932         break;
 933       }
 934     }
 935   }
 936
 937   return removed;
 938 }
 939
 940 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 941 {
 942   mAddingItems = true;
 943
 944   SetupActor( replacementItem, durationSeconds );
 945   Self().Add( replacementItem.second );
 946
 947   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 948   if( mItemPool.end() != iter )
 949   {
 950     ReleaseActor(iter->first, iter->second);
 951     iter->second = replacementItem.second;
 952   }
 953   else
 954   {
 955     mItemPool.insert( replacementItem );
 956   }
 957
 958   CalculateDomainSize(Self().GetCurrentSize());
 959
 960   mAddingItems = false;
 961 }
 962
 963 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 964 {
 965   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 966   {
 967     ReplaceItem( *iter, durationSeconds );
 968   }
 969 }
 970
 971 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 972 {
 973   // Remove unwanted actors from the ItemView & ItemPool
 974   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 975   {
 976     unsigned int current = iter->first;
 977
 978     if( ! range.Within( current ) )
 979     {
 980       ReleaseActor(iter->first, iter->second);
 981
 982       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 983     }
 984     else
 985     {
 986       ++iter;
 987     }
 988   }
 989 }
 990
 991 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 992 {
 993   range.end = min(mItemFactory.GetNumberOfItems(), range.end);
 994
 995   // The order of addition depends on the scroll direction.
 996   if (mRefreshOrderHint)
 997   {
 998     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 999     {
1000       AddNewActor( itemId, durationSeconds );
1001     }
1002   }
1003   else
1004   {
1005     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
1006     {
1007       AddNewActor( itemId-1, durationSeconds );
1008     }
1009   }
1010
1011   // Total number of items may change dynamically.
1012   // Always recalculate the domain size to reflect that.
1013   CalculateDomainSize(Self().GetCurrentSize());
1014 }
1015
1016 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
1017 {
1018   mAddingItems = true;
1019
1020   if( mItemPool.end() == mItemPool.find( itemId ) )
1021   {
1022     Actor actor = mItemFactory.NewItem( itemId );
1023
1024     if( actor )
1025     {
1026       Item newItem( itemId, actor );
1027
1028       mItemPool.insert( newItem );
1029
1030       SetupActor( newItem, durationSeconds );
1031       Self().Add( actor );
1032     }
1033   }
1034
1035   mAddingItems = false;
1036 }
1037
1038 void ItemView::SetupActor( Item item, float durationSeconds )
1039 {
1040   item.second.SetParentOrigin( mItemsParentOrigin );
1041   item.second.SetAnchorPoint( mItemsAnchorPoint );
1042
1043   if( mActiveLayout )
1044   {
1045     Vector3 size;
1046     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
1047     {
1048       item.second.SetSize( size );
1049     }
1050
1051     ApplyConstraints( item.second, *mActiveLayout, item.first, durationSeconds );
1052   }
1053 }
1054
1055 void ItemView::ReleaseActor( ItemId item, Actor actor )
1056 {
1057   Self().Remove( actor );
1058   mItemFactory.ItemReleased(item, actor);
1059 }
1060
1061 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, float layoutPosition, bool reserveExtra)
1062 {
1063   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1064
1065   ItemRange available(0u, itemCount);
1066
1067   ItemRange range = layout.GetItemsWithinArea( layoutPosition, layoutSize );
1068
1069   if (reserveExtra)
1070   {
1071     // Add the reserve items for scrolling
1072     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1073     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1074     range.end += extra;
1075   }
1076
1077   return range.Intersection(available);
1078 }
1079
1080 void ItemView::OnChildAdd(Actor& child)
1081 {
1082   if(!mAddingItems)
1083   {
1084     // We don't want to do this downcast check for any item added by ItemView itself.
1085     Dali::Toolkit::ScrollComponent scrollComponent = Dali::Toolkit::ScrollComponent::DownCast(child);
1086     if(scrollComponent)
1087     {
1088       // Set the scroll connector when scroll bar is being added
1089       scrollComponent.SetScrollConnector(mScrollConnector);
1090     }
1091   }
1092 }
1093
1094 bool ItemView::OnTouchEvent(const TouchEvent& event)
1095 {
1096   // Ignore events with multiple-touch points
1097   if (event.GetPointCount() != 1)
1098   {
1099     return false;
1100   }
1101
1102   if (event.GetPoint(0).state == TouchPoint::Down)
1103   {
1104     // Cancel ongoing scrolling etc.
1105     mGestureState = Gesture::Clear;
1106
1107     mScrollDistance = 0.0f;
1108     mScrollSpeed = 0.0f;
1109     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1110
1111     mScrollOvershoot = 0.0f;
1112     AnimateScrollOvershoot(0.0f);
1113
1114     if(mScrollAnimation)
1115     {
1116       mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1117     }
1118
1119     RemoveAnimation(mScrollAnimation);
1120   }
1121
1122   return true; // consume since we're potentially scrolling
1123 }
1124
1125 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1126 {
1127   // Respond the mouse wheel event to scroll
1128   if (mActiveLayout)
1129   {
1130     Actor self = Self();
1131     const Vector3 layoutSize = Self().GetCurrentSize();
1132     float layoutPositionDelta = GetCurrentLayoutPosition(0) - (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1133     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1134
1135     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1136     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1137     mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1138     mRefreshEnabled = true;
1139   }
1140
1141   if (mMouseWheelEventFinishedTimer.IsRunning())
1142   {
1143     mMouseWheelEventFinishedTimer.Stop();
1144   }
1145
1146   mMouseWheelEventFinishedTimer.Start();
1147
1148   return true;
1149 }
1150
1151 bool ItemView::OnMouseWheelEventFinished()
1152 {
1153   if (mActiveLayout)
1154   {
1155     RemoveAnimation(mScrollAnimation);
1156
1157     // No more mouse wheel events coming. Do the anchoring if enabled.
1158     mScrollAnimation = DoAnchoring();
1159     if (mScrollAnimation)
1160     {
1161       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1162       mScrollAnimation.Play();
1163     }
1164     else
1165     {
1166       mScrollOvershoot = 0.0f;
1167       AnimateScrollOvershoot(0.0f);
1168
1169       mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1170     }
1171   }
1172
1173   return false;
1174 }
1175
1176 void ItemView::ApplyConstraints(Actor& actor, ItemLayout& layout, unsigned int itemId, float duration)
1177 {
1178   ItemLayout::Vector3Function positionConstraint;
1179   if (layout.GetPositionConstraint(itemId, positionConstraint))
1180   {
1181     WrappedVector3Constraint wrapped(positionConstraint, itemId);
1182
1183     Constraint constraint = Constraint::New<Vector3>( Actor::POSITION,
1184                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1185                                                       ParentSource( mPropertyScrollSpeed ),
1186                                                       ParentSource( Actor::SIZE ),
1187                                                       wrapped );
1188     constraint.SetApplyTime(duration);
1189     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1190
1191     actor.ApplyConstraint(constraint);
1192   }
1193
1194   ItemLayout::QuaternionFunction rotationConstraint;
1195   if (layout.GetRotationConstraint(itemId, rotationConstraint))
1196   {
1197     WrappedQuaternionConstraint wrapped(rotationConstraint, itemId);
1198
1199     Constraint constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1200                                                          Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1201                                                          ParentSource( mPropertyScrollSpeed ),
1202                                                          ParentSource( Actor::SIZE ),
1203                                                          wrapped );
1204     constraint.SetApplyTime(duration);
1205     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1206
1207     actor.ApplyConstraint(constraint);
1208   }
1209
1210   ItemLayout::Vector3Function scaleConstraint;
1211   if (layout.GetScaleConstraint(itemId, scaleConstraint))
1212   {
1213     WrappedVector3Constraint wrapped(scaleConstraint, itemId);
1214
1215     Constraint constraint = Constraint::New<Vector3>( Actor::SCALE,
1216                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1217                                                       ParentSource( mPropertyScrollSpeed ),
1218                                                       ParentSource( Actor::SIZE ),
1219                                                       wrapped );
1220     constraint.SetApplyTime(duration);
1221     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1222
1223     actor.ApplyConstraint(constraint);
1224   }
1225
1226   ItemLayout::Vector4Function colorConstraint;
1227   if (layout.GetColorConstraint(itemId, colorConstraint))
1228   {
1229     WrappedVector4Constraint wrapped(colorConstraint, itemId);
1230
1231     Constraint constraint = Constraint::New<Vector4>( Actor::COLOR,
1232                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1233                                                       ParentSource( mPropertyScrollSpeed ),
1234                                                       ParentSource( Actor::SIZE ),
1235                                                       wrapped );
1236     constraint.SetApplyTime(duration);
1237     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1238
1239     // Release color constraints slowly; this allows ItemView to co-exist with ImageActor fade-in
1240     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1241     constraint.SetRemoveAction(Dali::Constraint::Discard);
1242
1243     actor.ApplyConstraint(constraint);
1244   }
1245
1246   ItemLayout::BoolFunction visibilityConstraint;
1247   if (layout.GetVisibilityConstraint(itemId, visibilityConstraint))
1248   {
1249     WrappedBoolConstraint wrapped(visibilityConstraint, itemId);
1250
1251     Constraint constraint = Constraint::New<bool>( Actor::VISIBLE,
1252                                                    Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1253                                                    ParentSource( mPropertyScrollSpeed ),
1254                                                    ParentSource( Actor::SIZE ),
1255                                                    wrapped );
1256     constraint.SetApplyTime(duration);
1257     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1258
1259     // Release visibility constraints the same time as the color constraint
1260     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1261     constraint.SetRemoveAction(Dali::Constraint::Discard);
1262
1263     actor.ApplyConstraint(constraint);
1264   }
1265 }
1266
1267 void ItemView::ReapplyAllConstraints( float durationSeconds )
1268 {
1269   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1270   {
1271     unsigned int id = iter->first;
1272     Actor actor = iter->second;
1273
1274     actor.RemoveConstraints();
1275     ApplyConstraints(actor, *mActiveLayout, id, durationSeconds);
1276   }
1277
1278   CalculateDomainSize(Self().GetCurrentSize());
1279 }
1280
1281 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1282 {
1283   Actor self = Self();
1284   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1285   float clamppedPosition = min(0.0f, max(minLayoutPosition, targetPosition));
1286   mScrollOvershoot = targetPosition - clamppedPosition;
1287   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1288
1289   return clamppedPosition;
1290 }
1291
1292 void ItemView::OnPan(PanGesture gesture)
1293 {
1294   Actor self = Self();
1295   const Vector3 layoutSize = Self().GetCurrentSize();
1296
1297   RemoveAnimation(mScrollAnimation);
1298
1299   // Short-circuit if there is no active layout
1300   if (!mActiveLayout)
1301   {
1302     mGestureState = Gesture::Clear;
1303     return;
1304   }
1305
1306   mGestureState = gesture.state;
1307
1308   switch (mGestureState)
1309   {
1310     case Gesture::Finished:
1311     {
1312       // Swipe Detection
1313       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1314           mScrollSpeed > mMinimumSwipeSpeed)
1315       {
1316         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1317
1318         mRefreshOrderHint = true;
1319
1320         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1321         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1322                                                                layoutSize,
1323                                                                *mActiveLayout);
1324
1325         if (mAnchoringEnabled)
1326         {
1327           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1328         }
1329
1330         RemoveAnimation(mScrollAnimation);
1331
1332         float flickAnimationDuration = Clamp( mActiveLayout->GetItemFlickAnimationDuration() * max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)))
1333                                        , DEFAULT_MINIMUM_SWIPE_DURATION, DEFAULT_MAXIMUM_SWIPE_DURATION);
1334
1335         mScrollAnimation = Animation::New(flickAnimationDuration);
1336         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1337         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1338         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1339
1340         mIsFlicking = true;
1341         // Check whether it has already scrolled to the end
1342         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1343         {
1344           AnimateScrollOvershoot(0.0f);
1345         }
1346       }
1347
1348       // Anchoring may be triggered when there was no swipe
1349       if (!mScrollAnimation)
1350       {
1351         mScrollAnimation = DoAnchoring();
1352       }
1353
1354       // Reset the overshoot if no scroll animation.
1355       if (!mScrollAnimation)
1356       {
1357         mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1358
1359         AnimateScrollOvershoot(0.0f, false);
1360       }
1361     }
1362     break;
1363
1364     case Gesture::Started: // Fall through
1365     {
1366       mTotalPanDisplacement = Vector2::ZERO;
1367       mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1368       mRefreshEnabled = true;
1369     }
1370
1371     case Gesture::Continuing:
1372     {
1373       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1374       mScrollSpeed = Clamp((gesture.GetSpeed() * gesture.GetSpeed() * mActiveLayout->GetFlickSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1375
1376       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1377       mRefreshOrderHint = mScrollDistance < 0.0f;
1378
1379       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1380
1381       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1382
1383       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1384       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1385
1386       mTotalPanDisplacement += gesture.displacement;
1387       mScrollOvershoot = layoutPositionDelta - firstItemScrollPosition;
1388       if( mScrollOvershoot > Math::MACHINE_EPSILON_1 )
1389       {
1390         AnimateScrollOvershoot(1.0f);
1391       }
1392       else if( mScrollOvershoot < -Math::MACHINE_EPSILON_1 )
1393       {
1394         AnimateScrollOvershoot(-1.0f);
1395       }
1396       else
1397       {
1398         AnimateScrollOvershoot(0.0f);
1399       }
1400     }
1401     break;
1402
1403     case Gesture::Cancelled:
1404     {
1405       mScrollAnimation = DoAnchoring();
1406     }
1407     break;
1408
1409     default:
1410       break;
1411   }
1412
1413   if (mScrollAnimation)
1414   {
1415     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1416     mScrollAnimation.Play();
1417   }
1418 }
1419
1420 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1421 {
1422   OnPan(gesture);
1423   return true;
1424 }
1425
1426 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1427 {
1428   Actor nextFocusActor;
1429   if(mActiveLayout)
1430   {
1431     int nextItemID = 0;
1432     if(!actor || actor == this->Self())
1433     {
1434       nextFocusActor = GetItem(nextItemID);
1435     }
1436     else if(actor && actor.GetParent() == this->Self())
1437     {
1438       int itemID = GetItemId(actor);
1439       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1440       nextFocusActor = GetItem(nextItemID);
1441       if(nextFocusActor == actor)
1442       {
1443         // need to pass NULL actor back to focus manager
1444         nextFocusActor.Reset();
1445         return nextFocusActor;
1446       }
1447     }
1448     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1449     Vector3 layoutSize = Self().GetCurrentSize();
1450     if(!nextFocusActor)
1451     {
1452       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1453       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1454       nextItemID = viewableItems.begin;
1455       nextFocusActor = GetItem(nextItemID);
1456     }
1457   }
1458   return nextFocusActor;
1459 }
1460
1461 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1462 {
1463   // only in this function if our chosen focus actor was actually used
1464   if(commitedFocusableActor)
1465   {
1466     int nextItemID = GetItemId(commitedFocusableActor);
1467     float layoutPosition = GetCurrentLayoutPosition(0);
1468     Vector3 layoutSize = Self().GetCurrentSize();
1469     Vector3 focusItemPosition = Vector3::ZERO;
1470     ItemLayout::Vector3Function itemPositionConstraint;
1471     if (mActiveLayout->GetPositionConstraint(nextItemID, itemPositionConstraint))
1472     {
1473       focusItemPosition = itemPositionConstraint(Vector3::ZERO, layoutPosition + nextItemID, 0.0f, layoutSize);
1474     }
1475
1476     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1477     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1478   }
1479 }
1480
1481 Animation ItemView::DoAnchoring()
1482 {
1483   Animation anchoringAnimation;
1484   Actor self = Self();
1485
1486   if (mActiveLayout && mAnchoringEnabled)
1487   {
1488     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1489
1490     anchoringAnimation = Animation::New(mAnchoringDuration);
1491     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1492     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1493     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1494     if(!mIsFlicking)
1495     {
1496       AnimateScrollOvershoot(0.0f);
1497     }
1498   }
1499
1500   return anchoringAnimation;
1501 }
1502
1503 void ItemView::OnScrollFinished(Animation& source)
1504 {
1505   Actor self = Self();
1506
1507   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1508
1509   mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1510
1511   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1512   {
1513     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1514   }
1515   else
1516   {
1517     // Reset the overshoot
1518     AnimateScrollOvershoot( 0.0f );
1519   }
1520   mIsFlicking = false;
1521
1522   mScrollOvershoot = 0.0f;
1523 }
1524
1525 void ItemView::OnLayoutActivationScrollFinished(Animation& source)
1526 {
1527   RemoveAnimation(mScrollAnimation);
1528   mRefreshEnabled = true;
1529   DoRefresh(GetCurrentLayoutPosition(0), true);
1530 }
1531
1532 void ItemView::OnOvershootOnFinished(Animation& animation)
1533 {
1534   mAnimatingOvershootOn = false;
1535   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1536   RemoveAnimation(mScrollOvershootAnimation);
1537   if(mAnimateOvershootOff)
1538   {
1539     AnimateScrollOvershoot(0.0f);
1540   }
1541 }
1542
1543 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1544 {
1545   Actor self = Self();
1546   const Vector3 layoutSize = Self().GetCurrentSize();
1547   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1548
1549   if(durationSeconds > 0.0f)
1550   {
1551     RemoveAnimation(mScrollAnimation);
1552     mScrollAnimation = Animation::New(durationSeconds);
1553     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1554     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1555     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1556     mScrollAnimation.Play();
1557   }
1558   else
1559   {
1560     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1561     AnimateScrollOvershoot(0.0f);
1562   }
1563
1564   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1565   mRefreshEnabled = true;
1566 }
1567
1568 void ItemView::RemoveAnimation(Animation& animation)
1569 {
1570   if(animation)
1571   {
1572     // Cease animating, and reset handle.
1573     animation.Clear();
1574     animation.Reset();
1575   }
1576 }
1577
1578 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1579 {
1580   Actor self = Self();
1581
1582   Vector3 firstItemPosition(Vector3::ZERO);
1583   Vector3 lastItemPosition(Vector3::ZERO);
1584
1585   if(mActiveLayout)
1586   {
1587     ItemLayout::Vector3Function firstItemPositionConstraint;
1588     if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1589     {
1590       firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, 0, 0.0f, layoutSize);
1591     }
1592
1593     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1594     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1595
1596     ItemLayout::Vector3Function lastItemPositionConstraint;
1597     if (mActiveLayout->GetPositionConstraint(fabs(minLayoutPosition), lastItemPositionConstraint))
1598     {
1599       lastItemPosition = lastItemPositionConstraint(Vector3::ZERO, fabs(minLayoutPosition), 0.0f, layoutSize);
1600     }
1601
1602     float domainSize;
1603
1604     if(IsHorizontal(mActiveLayout->GetOrientation()))
1605     {
1606       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1607       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1608       domainSize = fabs(firstItemPosition.x - lastItemPosition.x);
1609     }
1610     else
1611     {
1612       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1613       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1614       domainSize = fabs(firstItemPosition.y - lastItemPosition.y);
1615     }
1616
1617     mScrollConnector.SetScrollDomain(minLayoutPosition, 0.0f, domainSize);
1618
1619     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1620     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1621     self.SetProperty(mPropertyCanScrollHorizontal, false);
1622   }
1623 }
1624
1625 Vector3 ItemView::GetDomainSize() const
1626 {
1627   Actor self = Self();
1628
1629   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1630   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1631
1632   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1633 }
1634
1635 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1636 {
1637   Actor self = Self();
1638
1639   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1640   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1641   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1642
1643   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1644 }
1645
1646 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1647 {
1648   Vector3 firstItemPosition(Vector3::ZERO);
1649   ItemLayout::Vector3Function firstItemPositionConstraint;
1650   if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1651   {
1652     firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, layoutPosition, 0.0f, layoutSize);
1653   }
1654
1655   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1656 }
1657
1658 Vector3 ItemView::GetCurrentScrollPosition() const
1659 {
1660   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1661   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1662 }
1663
1664 void ItemView::AddOverlay(Actor actor)
1665 {
1666   Self().Add(actor);
1667 }
1668
1669 void ItemView::RemoveOverlay(Actor actor)
1670 {
1671   Self().Remove(actor);
1672 }
1673
1674 void ItemView::ScrollTo(const Vector3& position, float duration)
1675 {
1676   Actor self = Self();
1677   const Vector3 layoutSize = Self().GetCurrentSize();
1678
1679   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1680
1681   if(duration > 0.0f)
1682   {
1683     RemoveAnimation(mScrollAnimation);
1684     mScrollAnimation = Animation::New(duration);
1685     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1686     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1687     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1688     mScrollAnimation.Play();
1689   }
1690   else
1691   {
1692     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1693     AnimateScrollOvershoot(0.0f);
1694   }
1695
1696   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1697   mRefreshEnabled = true;
1698 }
1699
1700 void ItemView::SetOvershootEffectColor( const Vector4& color )
1701 {
1702   mOvershootEffectColor = color;
1703   if( mOvershootOverlay )
1704   {
1705     mOvershootOverlay.SetColor( color );
1706   }
1707 }
1708
1709 void ItemView::SetOvershootEnabled( bool enable )
1710 {
1711   Actor self = Self();
1712   if( enable )
1713   {
1714     Property::Index effectOvershootPropertyIndex = Property::INVALID_INDEX;
1715     mOvershootOverlay = CreateBouncingEffectActor( effectOvershootPropertyIndex );
1716     mOvershootOverlay.SetColor(mOvershootEffectColor);
1717     mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
1718     mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
1719     mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
1720     self.Add(mOvershootOverlay);
1721
1722     Constraint constraint = Constraint::New<Vector3>( Actor::SIZE,
1723                                                       ParentSource( mPropertyScrollDirection ),
1724                                                       Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1725                                                       ParentSource( Actor::SIZE ),
1726                                                       OvershootOverlaySizeConstraint() );
1727     mOvershootOverlay.ApplyConstraint(constraint);
1728     mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.width, OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height);
1729
1730     constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1731                                               ParentSource( mPropertyScrollDirection ),
1732                                               Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1733                                               OvershootOverlayRotationConstraint() );
1734     mOvershootOverlay.ApplyConstraint(constraint);
1735
1736     constraint = Constraint::New<Vector3>( Actor::POSITION,
1737                                            ParentSource( Actor::SIZE ),
1738                                            ParentSource( mPropertyScrollDirection ),
1739                                            Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1740                                            OvershootOverlayPositionConstraint() );
1741     mOvershootOverlay.ApplyConstraint(constraint);
1742
1743     constraint = Constraint::New<bool>( Actor::VISIBLE,
1744                                         ParentSource( mPropertyCanScrollVertical ),
1745                                         OvershootOverlayVisibilityConstraint() );
1746     mOvershootOverlay.ApplyConstraint(constraint);
1747
1748     Actor self = Self();
1749     constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1750                                          Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1751                                          EqualToConstraint() );
1752     mOvershootOverlay.ApplyConstraint(constraint);
1753   }
1754   else
1755   {
1756     if( mOvershootOverlay )
1757     {
1758       self.Remove(mOvershootOverlay);
1759       mOvershootOverlay.Reset();
1760     }
1761   }
1762 }
1763
1764 float ItemView::CalculateScrollOvershoot()
1765 {
1766   float overshoot = 0.0f;
1767
1768   if(mActiveLayout)
1769   {
1770     // The overshoot must be calculated from the accumulated pan gesture displacement
1771     // since the pan gesture starts.
1772     Actor self = Self();
1773     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1774     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1775     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1776     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1777     float clamppedPosition = min(0.0f, max(minLayoutPosition, positionDelta));
1778     overshoot = positionDelta - clamppedPosition;
1779   }
1780
1781   return overshoot;
1782 }
1783
1784 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1785 {
1786   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1787
1788   // make sure we animate back if needed
1789   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1790
1791   if( mAnimatingOvershootOn )
1792   {
1793     // animating on, do not allow animate off
1794     return;
1795   }
1796
1797   Actor self = Self();
1798   float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1799   float duration = DEFAULT_OVERSHOOT_ANIMATION_DURATION * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot));
1800
1801   RemoveAnimation(mScrollOvershootAnimation);
1802   mScrollOvershootAnimation = Animation::New(duration);
1803   mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1804   mScrollOvershootAnimation.AnimateTo( Property(mScrollPositionObject, ScrollConnector::OVERSHOOT), overshootAmount, TimePeriod(0.0f, duration) );
1805   mScrollOvershootAnimation.Play();
1806
1807   mAnimatingOvershootOn = animatingOn;
1808 }
1809
1810 void ItemView::SetItemsParentOrigin( const Vector3& parentOrigin )
1811 {
1812   if( parentOrigin != mItemsParentOrigin )
1813   {
1814     mItemsParentOrigin = parentOrigin;
1815     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1816     {
1817       iter->second.SetParentOrigin(parentOrigin);
1818     }
1819   }
1820 }
1821
1822 Vector3 ItemView::GetItemsParentOrigin() const
1823 {
1824   return mItemsParentOrigin;
1825 }
1826
1827 void ItemView::SetItemsAnchorPoint( const Vector3& anchorPoint )
1828 {
1829   if( anchorPoint != mItemsAnchorPoint )
1830   {
1831     mItemsAnchorPoint = anchorPoint;
1832     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1833     {
1834       iter->second.SetAnchorPoint(anchorPoint);
1835     }
1836   }
1837 }
1838
1839 Vector3 ItemView::GetItemsAnchorPoint() const
1840 {
1841   return mItemsAnchorPoint;
1842 }
1843
1844 void ItemView::GetItemsRange(ItemRange& range)
1845 {
1846   range.begin = mItemPool.begin()->first;
1847   range.end = mItemPool.rbegin()->first + 1;
1848 }
1849
1850 void ItemView::OnScrollPositionChanged( float position )
1851 {
1852   // Cancel scroll animation to prevent any fighting of setting the scroll position property.
1853   RemoveAnimation(mScrollAnimation);
1854
1855   // Refresh the cache immediately when the scroll position is changed.
1856   DoRefresh(position, false); // No need to cache extra items.
1857 }
1858
1859 } // namespace Internal
1860
1861 } // namespace Toolkit
1862
1863 } // namespace Dali