1 #ifndef __DALI_TOOLKIT_ITEM_LAYOUT_H__
2 #define __DALI_TOOLKIT_ITEM_LAYOUT_H__
5 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/public-api/animation/alpha-function.h>
23 #include <dali/public-api/object/property-key.h>
24 #include <dali/public-api/object/property-map.h>
27 #include <dali-toolkit/public-api/enums.h>
28 #include <dali-toolkit/public-api/controls/control.h>
36 * @addtogroup dali_toolkit_controls_item_view
42 typedef IntrusivePtr<ItemLayout> ItemLayoutPtr; ///< Pointer to a Dali::Toolkit::ItemLayout object @SINCE_1_0.0
45 * @brief A support class for managing ranges of items.
51 * @brief Create a range of item identifiers.
54 * @param[in] beginItem The first item within the range.
55 * @param[in] endItem The past-the-end item.
57 ItemRange(unsigned int beginItem, unsigned int endItem)
64 * @brief Copy Constructor.
67 * @param[in] copy ItemRange we should copy from.
69 ItemRange(const ItemRange& copy)
76 * @brief Assignment operator.
79 * @param[in] range The Range to assign from.
80 * @return The updated range.
82 ItemRange& operator=(const ItemRange& range)
93 * @brief Test whether an item is within the range.
96 * @param[in] itemId The item identifier.
97 * @return True if the item is within the range.
99 bool Within(unsigned int itemId)
101 return itemId >= begin &&
106 * @brief Create the intersection of two ranges.
109 * @param[in] second The second range.
110 * @return The intersection.
112 ItemRange Intersection(const ItemRange& second)
114 ItemRange intersection(0u, 0u);
116 // If the ranges intersect
117 if ( (begin < second.end && end > second.begin) ||
118 (second.begin < end && second.end > begin) )
120 intersection.begin = std::max(begin, second.begin);
121 intersection.end = std::min(end, second.end);
127 unsigned int begin; ///< The start of the range
128 unsigned int end; ///< The end of the range
132 * @brief An ItemLayout describes the constraints which are imposed on items in the layout.
134 * - Potentially visible items are represented by Actors, created for ItemView by the ItemFactory.
135 * - Constraints are applied after ItemView activates a layout.
137 * An ItemLayout also describes the direction of input gestures, used to scroll through the layout.
138 * Whilst scrolling, the layout provides a range of items that are within a layout-area (3D bounding volume).
141 class DALI_IMPORT_API ItemLayout : public RefObject
145 class Extension; ///< Forward declare future extension interface
148 * @brief Virtual destructor.
151 DALI_IMPORT_API virtual ~ItemLayout();
154 * @brief Set the orientation of the layout.
157 * @param[in] orientation The orientation of the layout.
159 DALI_IMPORT_API void SetOrientation(ControlOrientation::Type orientation);
162 * @brief Query the orientation of the layout.
165 * @return the orientation of the layout.
167 DALI_IMPORT_API ControlOrientation::Type GetOrientation() const;
170 * @brief Apply the layout Properties.
172 * @param[in] properties The properties the layout.
174 void SetLayoutProperties(const Property::Map& properties);
177 * @brief Get the layout Properties.
179 * @return the property of the layout.
181 Property::Map GetLayoutProperties();
184 * @brief Check if the Property has been changed.
186 * @return whether the layout has been changed or not.if changed, return true.
188 bool HasLayoutChanged();
191 * @brief Set the layout changed flag to false.
194 void ResetLayoutChangedFlag();
197 * @brief Retrieve the target size of an item in the layout.
199 * This will return the default size for the layout unless overridden by calling SetItemSize().
202 * @param[in] itemId The ID of an item in the layout.
203 * @param[in] layoutSize The layout size
204 * @param[out] itemSize The target size of an item.
205 * @note layout-position is not provided as a parameter, since applying size constraints is not recommended.
206 * Animating to target-sizes is preferable, since this allows controls to perform layouting without constraints.
208 DALI_IMPORT_API void GetItemSize( unsigned int itemId, const Vector3& layoutSize, Vector3& itemSize ) const;
211 * @brief Overrides the default size for the layout.
214 * @param[in] itemSize The size of each item.
216 DALI_IMPORT_API void SetItemSize( const Vector3& itemSize );
219 * @brief Query the minimum valid layout position; this is a negative value.
221 * When scrolling, the first item will move within the range 0 to GetMinimumLayoutPosition().
223 * @param[in] numberOfItems The current number of items in the layout.
224 * @param[in] layoutSize The size of the layout area.
225 * @return The minimum layout position.
227 virtual float GetMinimumLayoutPosition(unsigned int numberOfItems, Vector3 layoutSize) const = 0;
230 * @brief Query the closest anchor position for the given layout position.
232 * This anchor position is the position where all the items in the layout are aligned to
233 * their rounded layout positions in integer.
235 * @param[in] layoutPosition The layout position.
236 * @return The closest anchor position for the given layout position.
238 virtual float GetClosestAnchorPosition(float layoutPosition) const = 0;
241 * @brief Query the layout position for the first item in the layout to move to when the layout
242 * needs to scroll to a particular item.
245 * @param[in] itemId The ID of an item in the layout.
246 * @return The layout position for the first item in the layout to move to.
248 virtual float GetItemScrollToPosition(unsigned int itemId) const = 0;
251 * @brief Query the items within a given layout-area.
254 * @param[in] firstItemPosition The layout-position of the first item in the layout.
255 * @param[in] layoutSize The size of the layout area.
256 * @return The ID of the first & last visible item.
258 virtual ItemRange GetItemsWithinArea(float firstItemPosition, Vector3 layoutSize) const = 0;
261 * @brief Get the closest layout position to bring an item onto the screen.
263 * If the item is already fully on the screen this function will
264 * return the current layout position.
266 * This function is used by systems such as KeyboardFocusManager to
267 * bring the next focusable item into view and all layout
268 * implementations should provide their own version of this function
269 * to ensure proper functionality of internal toolkit systems.
272 * @param[in] itemID id of the item to bring within the viewable screen area
273 * @param[in] currentLayoutPosition the current layout position of the item view instance
274 * @param[in] layoutSize the current size of the item view instance
275 * @return The layout position
277 DALI_IMPORT_API virtual float GetClosestOnScreenLayoutPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize);
280 * @brief Query the number of items that should be reserved, for scrolling purposes.
283 * @param[in] layoutSize The size of the layout area.
284 * @return The number of extra items. ItemView will populate itself with actors within the layout-area
285 * (see GetItemsWithinArea), plus this number of additional items on either-side.
287 virtual unsigned int GetReserveItemCount(Vector3 layoutSize) const = 0;
290 * @brief Retrieve the default size of an item in the layout.
293 * @param[in] itemId The ID of an item in the layout.
294 * @param[in] layoutSize The layout size
295 * @param[out] itemSize The target size of an item.
296 * @note layout-position is not provided as a parameter, since applying size constraints is not recommended.
297 * Animating to target-sizes is preferable, since this allows controls to perform layouting without constraints.
299 virtual void GetDefaultItemSize( unsigned int itemId, const Vector3& layoutSize, Vector3& itemSize ) const = 0;
302 * @brief Query the scroll direction of the layout.
304 * When an input gesture follows this direction, the layout-position of items will be increased.
305 * If the input gesture points in the opposite direction, then the layout-positions will decrease.
307 * @return The scroll direction in degrees.
309 virtual Degree GetScrollDirection() const = 0;
312 * @brief Query the scroll speed factor of the layout while dragging.
314 * This factor is used by the layout to customise its scroll speed while dragging.
315 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
316 * and the layout position of the actors in ItemView will be moved by this result.
317 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
318 * position of actors will be moved by 1.
319 * Therefore, the bigger the factor is, the faster the scroll speed will be.
322 * @return The scroll speed factor of the layout.
324 virtual float GetScrollSpeedFactor() const = 0;
327 * @brief Query the maximum swipe speed in pixels per second.
329 * Swipe gestures will be clamped when exceeding this speed limit.
331 * @return speed The maximum swipe speed.
333 virtual float GetMaximumSwipeSpeed() const = 0;
336 * @brief Get the duration of the flick animation in second.
338 * This is the time taken to animate each
339 * item to its next layout position (e.g. from 1.0 to 2.0) when a flick animation is triggered
340 * by a swipe gesture.
342 * @return The duration of the flick animation.
344 virtual float GetItemFlickAnimationDuration() const = 0;
347 * @brief Gets the id of the next item for KeyboardFocusManager to focus on depending on the inputted item ID.
350 * @param[in] itemID The current focused item
351 * @param[in] maxItems The maximum number of items in the list
352 * @param[in] direction The directional key pressed on the keyboard
353 * @param[in] loopEnabled Whether the KeyboardFocusManager is set to wrap around between first and last item
354 * @return The next item ID.
356 DALI_IMPORT_API virtual int GetNextFocusItemID(int itemID, int maxItems, Dali::Toolkit::Control::KeyboardFocus::Direction direction, bool loopEnabled);
359 * @brief Query the flick speed factor of the layout while swipping.
361 * This factor is used by the layout to customise its scroll speed while swiping.
362 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
363 * and the layout position of the actors in ItemView will be moved by this result.
364 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
365 * position of actors will be moved by 1.
366 * Therefore, the bigger the factor is, the faster the flick speed will be.
369 * @return The scroll speed factor of the layout.
371 DALI_IMPORT_API virtual float GetFlickSpeedFactor() const;
374 * @brief Applies constraints defined by the layout to an actor.
376 * @param[in] actor The actor to constrain.
377 * @param[in] itemId The ID of the item represented by the actor.
378 * @param[in] layoutSize The current size of the item view instance.
379 * @param[in] itemViewActor The item view instance which requests the application of constraints.
381 DALI_IMPORT_API virtual void ApplyConstraints( Actor& actor, const int itemId, const Vector3& layoutSize, const Actor& itemViewActor ) = 0;
384 * @brief Gets the position of a given item
387 * @param[in] itemID The id of the item we want to get its position
388 * @param[in] currentLayoutPosition The current layout position of the item view instance
389 * @param[in] layoutSize The current size of the item view instance
390 * @return The item position (x,y,z)
392 DALI_IMPORT_API virtual Vector3 GetItemPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize) const = 0;
395 * @brief Retrieve the extension for this layout.
398 * @return The extension if available, NULL otherwise
400 virtual Extension* GetExtension()
408 * @brief Create a new ItemLayout; Only derived versions are instantiatable.
411 DALI_IMPORT_API ItemLayout();
416 * @brief Don't allow copy constructor
419 ItemLayout( const ItemLayout& handle );
422 * @brief Don't allow copy operator
425 ItemLayout& operator=( const ItemLayout& handle );
436 } // namespace Toolkit
440 #endif // __DALI_TOOLKIT_ITEM_LAYOUT_H__