1 #ifndef __DALI_TOOLKIT_ITEM_LAYOUT_H__
2 #define __DALI_TOOLKIT_ITEM_LAYOUT_H__
5 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <boost/function.hpp>
23 #include <dali/public-api/animation/alpha-function.h>
26 #include <dali-toolkit/public-api/enums.h>
27 #include <dali-toolkit/public-api/controls/control.h>
37 typedef IntrusivePtr<ItemLayout> ItemLayoutPtr; ///< Pointer to a Dali::Toolkit::ItemLayout object
40 * @brief A support class for managing ranges of items.
45 * @brief Create a range of item identifiers.
47 * @param[in] beginItem The first item within the range.
48 * @param[in] endItem The past-the-end item.
50 ItemRange(unsigned int beginItem, unsigned int endItem)
57 * @brief Copy Constructor.
59 * @param[in] copy ItemRange we should copy from.
61 ItemRange(const ItemRange& copy)
68 * @brief Assignment operator.
70 * @param[in] range The Range to assign from.
71 * @return The updated range.
73 ItemRange& operator=(const ItemRange& range)
81 * @brief Test whether an item is within the range.
83 * @param[in] itemId The item identifier.
84 * @return True if the item is within the range.
86 bool Within(unsigned int itemId)
88 return itemId >= begin &&
93 * @brief Create the intersection of two ranges.
95 * @param[in] second The second range.
96 * @return The intersection.
98 ItemRange Intersection(const ItemRange& second)
100 ItemRange intersection(0u, 0u);
102 // If the ranges intersect
103 if ( (begin < second.end && end > second.begin) ||
104 (second.begin < end && second.end > begin) )
106 intersection.begin = std::max(begin, second.begin);
107 intersection.end = std::min(end, second.end);
113 unsigned int begin; ///< The start of the range
114 unsigned int end; ///< The end of the range
118 * @brief An ItemLayout describes the constraints which are imposed on items in the layout.
120 * - Potentially visible items are represented by Actors, created for ItemView by the ItemFactory.
121 * - Constraints are applied after ItemView activates a layout.
123 * An ItemLayout also describes the direction of input gestures, used to scroll through the layout.
124 * Whilst scrolling, the layout provides a range of items that are within a layout-area (3D bounding volume).
126 class DALI_IMPORT_API ItemLayout : public RefObject
130 /// @brief Function signature of a boolean constraint
131 typedef boost::function<bool (const bool& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> BoolFunction;
133 /// @brief Function signature of a Vector3 constraint
134 typedef boost::function<Vector3 (const Vector3& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector3Function;
136 /// @brief Function signature of a Vector4 constraint
137 typedef boost::function<Vector4 (const Vector4& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector4Function;
139 /// @brief Function signature of a Quaternion constraint
140 typedef boost::function<Quaternion (const Quaternion& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> QuaternionFunction;
143 * @brief Virtual destructor.
145 DALI_IMPORT_API virtual ~ItemLayout();
148 * @brief Set the orientation of the layout.
150 * @param[in] orientation The orientation of the layout.
152 DALI_IMPORT_API void SetOrientation(ControlOrientation::Type orientation);
155 * @brief Query the orientation of the layout.
157 * @return the orientation of the layout.
159 DALI_IMPORT_API ControlOrientation::Type GetOrientation() const;
162 * @brief Query the minimum valid layout position; this is a negative value.
164 * When scrolling, the first item will move within the range 0 to GetMinimumLayoutPosition().
165 * @param[in] numberOfItems The current number of items in the layout.
166 * @param[in] layoutSize The size of the layout area.
167 * @return The minimum layout position.
169 virtual float GetMinimumLayoutPosition(unsigned int numberOfItems, Vector3 layoutSize) const = 0;
172 * @brief Query the closest anchor position for the given layout position.
174 * This anchor position is the position where all the items in the layout are aligned to
175 * their rounded layout positions in integer.
176 * @param[in] layoutPosition The layout position.
177 * @return The closest anchor position for the given layout position.
179 virtual float GetClosestAnchorPosition(float layoutPosition) const = 0;
182 * @brief Query the layout position for the first item in the layout to move to when the layout
183 * needs to scroll to a particular item.
185 * @param[in] itemId The ID of an item in the layout.
186 * @return The layout position for the first item in the layout to move to.
188 virtual float GetItemScrollToPosition(unsigned int itemId) const = 0;
191 * @brief Query the items within a given layout-area.
193 * @param[in] firstItemPosition The layout-position of the first item in the layout.
194 * @param[in] layoutSize The size of the layout area.
195 * @return The ID of the first & last visible item.
197 virtual ItemRange GetItemsWithinArea(float firstItemPosition, Vector3 layoutSize) const = 0;
200 * @brief Get the closest layout position to bring an item onto the screen.
202 * If the item is already fully on the screen this function will
203 * return the current layout position.
205 * This function is used by systems such as KeyboardFocusManager to
206 * bring the next focusable item into view and all layout
207 * implementations should provide their own version of this function
208 * to ensure proper functionality of internal toolkit systems.
210 * @param[in] itemID id of the item to bring within the viewable screen area
211 * @param[in] currentLayoutPosition the current layout position of the item view instance
212 * @param[in] layoutSize the current size of the item view instance
213 * @return The layout position
215 DALI_IMPORT_API virtual float GetClosestOnScreenLayoutPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize);
218 * @brief Query the number of items that should be reserved, for scrolling purposes.
220 * @param[in] layoutSize The size of the layout area.
221 * @return The number of extra items. ItemView will populate itself with actors within the layout-area
222 * (see GetItemsWithinArea), plus this number of additional items on either-side.
224 virtual unsigned int GetReserveItemCount(Vector3 layoutSize) const = 0;
227 * @brief Retrieve the target size of an item in the layout.
229 * @note layout-position is not provided as a parameter, since applying size constraints is not recommended.
230 * Animating to target-sizes is preferable, since this allows controls to perform layouting without constraints.
231 * @param[in] itemId The ID of an item in the layout.
232 * @param[in] layoutSize The layout size
233 * @param[out] itemSize The target size of an item, or an uninitialized value.
234 * @return Whether the item size is available or not
236 virtual bool GetItemSize(unsigned int itemId, Vector3 layoutSize, Vector3& itemSize) const = 0;
239 * @brief Retrieve the resize animation in the layout.
241 * @note This allows the layout to provide its own resize animation.
242 * @param[in] animation The resize animation, not owned by the layout
243 * @param[in] actor The actor to animate
244 * @param [in] size The target size.
245 * @param [in] durationSeconds The duration of the resizing.
247 virtual void GetResizeAnimation(Animation& animation, Actor actor, Vector3 size, float durationSeconds) const = 0;
250 * @brief Retrieve the position constraint function of an item in the layout.
252 * The constraint will be applied when the item is created or the layout is activated.
253 * @param[in] itemId The ID of an item in the layout.
254 * @param[out] constraint The position constraint function of an item, or an uninitialized function pointer.
255 * @return Whether the position constraint function of an item is available or not
257 virtual bool GetPositionConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
260 * @brief Retrieve the rotation constraint function of an item in the layout.
262 * The constraint will be applied when the item is created or the layout is activated.
263 * @param[in] itemId The ID of an item in the layout.
264 * @param[out] constraint The rotation constraint function of an item, or an uninitialized function pointer.
265 * @return Whether the rotation constraint function of an item is available or not
267 virtual bool GetRotationConstraint(unsigned int itemId, QuaternionFunction& constraint) const = 0;
270 * @brief Retrieve the scale constraint function of an item in the layout.
272 * The constraint will be applied when the item is created or the layout is activated.
273 * @param[in] itemId The ID of an item in the layout.
274 * @param[out] constraint The scale constraint function of an item, or an uninitialized function pointer.
275 * @return Whether the scale constraint function of an item is available or not
277 virtual bool GetScaleConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
280 * @brief Retrieve the color constraint function of an item in the layout.
282 * The constraint will be applied when the item is created or the layout is activated.
283 * @param[in] itemId The ID of an item in the layout.
284 * @param[out] constraint The color constraint function of an item, or an uninitialized function pointer.
285 * @return Whether the color constraint function of an item is available or not
287 virtual bool GetColorConstraint(unsigned int itemId, Vector4Function& constraint) const = 0;
290 * @brief Retrieve the visibility constraint function of an item in the layout.
292 * The constraint will be applied when the item is created or the layout is activated.
293 * @param[in] itemId The ID of an item in the layout.
294 * @param[out] constraint The visibility constraint function of an item, or an uninitialized function pointer.
295 * @return Whether the visibility constraint function of an item is available or not
297 virtual bool GetVisibilityConstraint(unsigned int itemId, BoolFunction& constraint) const = 0;
300 * @brief Query the scroll direction of the layout.
302 * When an input gesture follows this direction, the layout-position of items will be increased.
303 * If the input gesture points in the opposite direction, then the layout-positions will decrease.
304 * @return The scroll direction in degrees.
306 virtual Degree GetScrollDirection() const = 0;
309 * @brief Query the scroll speed factor of the layout while dragging.
311 * This factor is used by the layout to customise its scroll speed while dragging.
312 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
313 * and the layout position of the actors in ItemView will be moved by this result.
314 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
315 * position of actors will be moved by 1.
316 * Therefore, the bigger the factor is, the faster the scroll speed will be.
318 * @return The scroll speed factor of the layout.
320 virtual float GetScrollSpeedFactor() const = 0;
323 * @brief Query the maximum swipe speed in pixels per second.
325 * Swipe gestures will be clamped when exceeding this speed limit.
326 * @return speed The maximum swipe speed.
328 virtual float GetMaximumSwipeSpeed() const = 0;
331 * @brief Get the duration of the flick animation in second.
333 * This is the time taken to animate each
334 * item to its next layout position (e.g. from 1.0 to 2.0) when a flick animation is triggered
335 * by a swipe gesture.
336 * @return The duration of the flick animation.
338 virtual float GetItemFlickAnimationDuration() const = 0;
341 * @brief Gets the id of the next item for KeyboardFocusManager to focus on depending on the inputted item ID.
343 * @param[in] itemID The current focused item
344 * @param[in] maxItems The maximum number of items in the list
345 * @param[in] direction The directional key pressed on the keyboard
346 * @param[in] loopEnabled Whether the KeyboardFocusManager is set to wrap around between first and last item
347 * @return The next item ID.
349 DALI_IMPORT_API virtual int GetNextFocusItemID(int itemID, int maxItems, Dali::Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled);
352 * @brief Query the flick speed factor of the layout while swipping.
354 * This factor is used by the layout to customise its scroll speed while swiping.
355 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
356 * and the layout position of the actors in ItemView will be moved by this result.
357 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
358 * position of actors will be moved by 1.
359 * Therefore, the bigger the factor is, the faster the flick speed will be.
361 * @return The scroll speed factor of the layout.
363 DALI_IMPORT_API virtual float GetFlickSpeedFactor() const;
366 * @brief Applies constraints defined by the layout to an actor.
368 * @param[in] actor The actor to constrain.
369 * @param[in] itemId The ID of the item represented by the actor.
370 * @param[in] durationSeconds The time taken to fully constrain the actors.
371 * @param[in] itemViewActor The item view instance which requests the application of constraints.
373 DALI_IMPORT_API virtual void ApplyConstraints( Actor& actor, const int itemId, const float durationSeconds, const Actor& itemViewActor );
376 * @brief Gets the position of a given item
378 * @param[in] itemID id of the item we want to get its position
379 * @param[in] currentLayoutPosition the current layout position of the item view instance
380 * @param[in] layoutSize the current size of the item view instance
381 * @return The item position (x,y,z)
383 DALI_IMPORT_API virtual Vector3 GetItemPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize) const;
386 * @brief Set the alpha function used when applying constraints
388 * @param[in] func The alpha function to use.
390 DALI_IMPORT_API void SetAlphaFunction(AlphaFunction func);
393 * @brief Retrieve the alpha function used when applying constraints
395 * @return The alpha function.
397 DALI_IMPORT_API AlphaFunction GetAlphaFunction() const;
402 * @brief Create a new ItemLayout; Only derived versions are instantiatable.
404 DALI_IMPORT_API ItemLayout();
408 ControlOrientation::Type mOrientation; ///< the orientation of the layout.
409 AlphaFunction mAlphaFunction; ///< Alpha function to be applied when removing/adding constraints
410 Handle mWeightObject; ///< Weight object gets created to apply the constraints over a certain time
413 } // namespace Toolkit
417 #endif // __DALI_TOOLKIT_ITEM_LAYOUT_H__