1 #ifndef __DALI_TOOLKIT_ITEM_LAYOUT_H__
2 #define __DALI_TOOLKIT_ITEM_LAYOUT_H__
5 * Copyright (c) 2014 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/common/vector-wrapper.h>
25 #include <dali-toolkit/public-api/enums.h>
26 #include <dali-toolkit/public-api/controls/control.h>
36 typedef IntrusivePtr<ItemLayout> ItemLayoutPtr; ///< Pointer to a Dali::Toolkit::ItemLayout object
38 typedef std::vector<ItemLayoutPtr> ItemLayoutContainer; ///< Container of Dali::Toolkit::ItemLayout objects
39 typedef ItemLayoutContainer::iterator ItemLayoutIter; ///< Iterator for Dali::Toolkit::ItemLayoutContainer
40 typedef ItemLayoutContainer::const_iterator ItemLayoutConstIter; ///< Const Iterator for Dali::Toolkit::ItemLayoutContainer
44 * @brief A support class for managing ranges of items.
49 * @brief Create a range of item identifiers.
51 * @param[in] beginItem The first item within the range.
52 * @param[in] endItem The past-the-end item.
54 ItemRange(unsigned int beginItem, unsigned int endItem)
61 * @brief Copy Constructor.
63 * @param[in] copy ItemRange we should copy from.
65 ItemRange(const ItemRange& copy)
72 * @brief Assignment operator.
74 * @param[in] range The Range to assign from.
75 * @return The updated range.
77 ItemRange& operator=(const ItemRange& range)
85 * @brief Test whether an item is within the range.
87 * @param[in] itemId The item identifier.
88 * @return True if the item is within the range.
90 bool Within(unsigned int itemId)
92 return itemId >= begin &&
97 * @brief Create the intersection of two ranges.
99 * @param[in] second The second range.
100 * @return The intersection.
102 ItemRange Intersection(const ItemRange& second)
104 ItemRange intersection(0u, 0u);
106 // If the ranges intersect
107 if ( (begin < second.end && end > second.begin) ||
108 (second.begin < end && second.end > begin) )
110 intersection.begin = std::max(begin, second.begin);
111 intersection.end = std::min(end, second.end);
117 unsigned int begin; ///< The start of the range
118 unsigned int end; ///< The end of the range
122 * @brief An ItemLayout describes the constraints which are imposed on items in the layout.
124 * - Potentially visible items are represented by Actors, created for ItemView by the ItemFactory.
125 * - Constraints are applied after ItemView activates a layout.
127 * An ItemLayout also describes the direction of input gestures, used to scroll through the layout.
128 * Whilst scrolling, the layout provides a range of items that are within a layout-area (3D bounding volume).
130 class ItemLayout : public RefObject
134 /// @brief Function signature of a boolean constraint
135 typedef boost::function<bool (const bool& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> BoolFunction;
137 /// @brief Function signature of a Vector3 constraint
138 typedef boost::function<Vector3 (const Vector3& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector3Function;
140 /// @brief Function signature of a Vector4 constraint
141 typedef boost::function<Vector4 (const Vector4& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector4Function;
143 /// @brief Function signature of a Quaternion constraint
144 typedef boost::function<Quaternion (const Quaternion& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> QuaternionFunction;
147 * @brief Virtual destructor.
149 DALI_IMPORT_API virtual ~ItemLayout();
152 * @brief Set the orientation of the layout.
154 * @param[in] orientation The orientation of the layout.
156 DALI_IMPORT_API void SetOrientation(ControlOrientation::Type orientation);
159 * @brief Query the orientation of the layout.
161 * @return the orientation of the layout.
163 DALI_IMPORT_API ControlOrientation::Type GetOrientation() const;
166 * @brief Query the minimum valid layout position; this is a negative value.
168 * When scrolling, the first item will move within the range 0 to GetMinimumLayoutPosition().
169 * @param[in] numberOfItems The current number of items in the layout.
170 * @param[in] layoutSize The size of the layout area.
171 * @return The minimum layout position.
173 virtual float GetMinimumLayoutPosition(unsigned int numberOfItems, Vector3 layoutSize) const = 0;
176 * @brief Query the closest anchor position for the given layout position.
178 * This anchor position is the position where all the items in the layout are aligned to
179 * their rounded layout positions in integer.
180 * @param[in] layoutPosition The layout position.
181 * @return The closest anchor position for the given layout position.
183 virtual float GetClosestAnchorPosition(float layoutPosition) const = 0;
186 * @brief Query the layout position for the first item in the layout to move to when the layout
187 * needs to scroll to a particular item.
189 * @param[in] itemId The ID of an item in the layout.
190 * @return The layout position for the first item in the layout to move to.
192 virtual float GetItemScrollToPosition(unsigned int itemId) const = 0;
195 * @brief Query the items within a given layout-area.
197 * @param[in] firstItemPosition The layout-position of the first item in the layout.
198 * @param[in] layoutSize The size of the layout area.
199 * @return The ID of the first & last visible item.
201 virtual ItemRange GetItemsWithinArea(float firstItemPosition, Vector3 layoutSize) const = 0;
204 * @brief Get the closest layout position to bring an item onto the screen.
206 * If the item is already fully on the screen this function will
207 * return the current layout position.
209 * This function is used by systems such as KeyboardFocusManager to
210 * bring the next focusable item into view and all layout
211 * implementations should provide their own version of this function
212 * to ensure proper functionality of internal toolkit systems.
214 * @param[in] itemID id of the item to bring within the viewable screen area
215 * @param[in] currentLayoutPosition the current layout position of the item view instance
216 * @param[in] layoutSize the current size of the item view instance
217 * @return The layout position
219 DALI_IMPORT_API virtual float GetClosestOnScreenLayoutPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize);
222 * @brief Query the number of items that should be reserved, for scrolling purposes.
224 * @param[in] layoutSize The size of the layout area.
225 * @return The number of extra items. ItemView will populate itself with actors within the layout-area
226 * (see GetItemsWithinArea), plus this number of additional items on either-side.
228 virtual unsigned int GetReserveItemCount(Vector3 layoutSize) const = 0;
231 * @brief Retrieve the target size of an item in the layout.
233 * @note layout-position is not provided as a parameter, since applying size constraints is not recommended.
234 * Animating to target-sizes is preferable, since this allows controls to perform layouting without constraints.
235 * @param[in] itemId The ID of an item in the layout.
236 * @param[in] layoutSize The layout size
237 * @param[out] itemSize The target size of an item, or an uninitialized value.
238 * @return Whether the item size is available or not
240 virtual bool GetItemSize(unsigned int itemId, Vector3 layoutSize, Vector3& itemSize) const = 0;
243 * @brief Retrieve the resize animation in the layout.
245 * @note This allows the layout to provide its own resize animation.
246 * @param[in] animation The resize animation, not owned by the layout
247 * @param[in] actor The actor to animate
248 * @param [in] size The target size.
249 * @param [in] durationSeconds The duration of the resizing.
251 virtual void GetResizeAnimation(Animation& animation, Actor actor, Vector3 size, float durationSeconds) const = 0;
254 * @brief Retrieve the position constraint function of an item in the layout.
256 * The constraint will be applied when the item is created or the layout is activated.
257 * @param[in] itemId The ID of an item in the layout.
258 * @param[out] constraint The position constraint function of an item, or an uninitialized function pointer.
259 * @return Whether the position constraint function of an item is available or not
261 virtual bool GetPositionConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
264 * @brief Retrieve the rotation constraint function of an item in the layout.
266 * The constraint will be applied when the item is created or the layout is activated.
267 * @param[in] itemId The ID of an item in the layout.
268 * @param[out] constraint The rotation constraint function of an item, or an uninitialized function pointer.
269 * @return Whether the rotation constraint function of an item is available or not
271 virtual bool GetRotationConstraint(unsigned int itemId, QuaternionFunction& constraint) const = 0;
274 * @brief Retrieve the scale constraint function of an item in the layout.
276 * The constraint will be applied when the item is created or the layout is activated.
277 * @param[in] itemId The ID of an item in the layout.
278 * @param[out] constraint The scale constraint function of an item, or an uninitialized function pointer.
279 * @return Whether the scale constraint function of an item is available or not
281 virtual bool GetScaleConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
284 * @brief Retrieve the color constraint function of an item in the layout.
286 * The constraint will be applied when the item is created or the layout is activated.
287 * @param[in] itemId The ID of an item in the layout.
288 * @param[out] constraint The color constraint function of an item, or an uninitialized function pointer.
289 * @return Whether the color constraint function of an item is available or not
291 virtual bool GetColorConstraint(unsigned int itemId, Vector4Function& constraint) const = 0;
294 * @brief Retrieve the visibility constraint function of an item in the layout.
296 * The constraint will be applied when the item is created or the layout is activated.
297 * @param[in] itemId The ID of an item in the layout.
298 * @param[out] constraint The visibility constraint function of an item, or an uninitialized function pointer.
299 * @return Whether the visibility constraint function of an item is available or not
301 virtual bool GetVisibilityConstraint(unsigned int itemId, BoolFunction& constraint) const = 0;
304 * @brief Query the scroll direction of the layout.
306 * When an input gesture follows this direction, the layout-position of items will be increased.
307 * If the input gesture points in the opposite direction, then the layout-positions will decrease.
308 * @return The scroll direction in degrees.
310 virtual Degree GetScrollDirection() const = 0;
313 * @brief Tells scroll components how to interpolate our logical scroll position as a screen x/y direction.
315 * Application developer wants to use -ve y, +ve x as up direction and +ve y, -ve x as down direction scroll values in a
316 * vertical scroll type effect (SpiralLayout). This means that scroll bar/overshoot indicator should be affected by y-axis.
317 * Returning (0.0f, 0.0f) for x and (0.0f, -1.0f) for y tells us that we need to use the y scroll value to move the scroll bar
318 * along y axis with y scroll of 0 starting at bottom (due to -1.0f on y), a value of (0.0f, 1.0f) on x axis mask would mean using y scroll value to move scroll bar along x axis
320 * This function is used by numerous objects such as scroll indicators and scroll overshoot indicators and all
321 * layout implementations should provide their own version of this function to ensure proper functionality of
322 * internal toolkit systems.
324 * @param[out] scrollHint Vector2 describing how x and y scroll values should be used for x-axis scrolling
326 DALI_IMPORT_API virtual void GetXAxisScrollHint(Vector2& scrollHint) const;
329 * @brief Tells scroll components how to interpolate our logical scroll position as a screen x/y direction.
331 * Application developer wants to use -ve y, +ve x as up direction and +ve y, -ve x as down direction scroll values in a
332 * vertical scroll type effect (SpiralLayout). This means that scroll bar/overshoot indicator should be affected by y-axis.
333 * Returning (0.0f, 0.0f) for x and (0.0f, -1.0f) for y tells us that we need to use the y scroll value to move the scroll bar
334 * along y axis with y scroll of 0 starting at bottom (due to -1.0f on y), a value of (0.0f, 1.0f) on x axis mask would mean using y scroll value to move scroll bar along x axis
336 * This function is used by numerous objects such as scroll indicators and scroll overshoot indicators and all
337 * layout implementations should provide their own version of this function to ensure proper functionality of
338 * internal toolkit systems.
340 * @param[out] scrollHint Vector2 describing how x and y scroll values should be used for y-axis scrolling
342 DALI_IMPORT_API virtual void GetYAxisScrollHint(Vector2& scrollHint) const;
345 * @brief Query the scroll speed factor of the layout while dragging.
347 * This factor is used by the layout to customise its scroll speed while dragging.
348 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
349 * and the layout position of the actors in ItemView will be moved by this result.
350 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
351 * position of actors will be moved by 1.
352 * Therefore, the bigger the factor is, the faster the scroll speed will be.
354 * @return The scroll speed factor of the layout.
356 virtual float GetScrollSpeedFactor() const = 0;
359 * @brief Query the maximum swipe speed in pixels per second.
361 * Swipe gestures will be clamped when exceeding this speed limit.
362 * @return speed The maximum swipe speed.
364 virtual float GetMaximumSwipeSpeed() const = 0;
367 * @brief Get the duration of the flick animation in second.
369 * This is the time taken to animate each
370 * item to its next layout position (e.g. from 1.0 to 2.0) when a flick animation is triggered
371 * by a swipe gesture.
372 * @return The duration of the flick animation.
374 virtual float GetItemFlickAnimationDuration() const = 0;
377 * @brief Gets the id of the next item for KeyboardFocusManager to focus on depending on the inputted item ID.
379 * @param[in] itemID The current focused item
380 * @param[in] maxItems The maximum number of items in the list
381 * @param[in] direction The directional key pressed on the keyboard
382 * @param[in] loopEnabled Whether the KeyboardFocusManager is set to wrap around between first and last item
383 * @return The next item ID.
385 DALI_IMPORT_API virtual int GetNextFocusItemID(int itemID, int maxItems, Dali::Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled);
388 * @brief Query the flick speed factor of the layout while swipping.
390 * This factor is used by the layout to customise its scroll speed while swiping.
391 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
392 * and the layout position of the actors in ItemView will be moved by this result.
393 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
394 * position of actors will be moved by 1.
395 * Therefore, the bigger the factor is, the faster the flick speed will be.
397 * @return The scroll speed factor of the layout.
399 DALI_IMPORT_API virtual float GetFlickSpeedFactor() const;
402 * @brief Applies constraints defined by the layout to an actor.
404 * @param[in] actor The actor to constrain.
405 * @param[in] itemId The ID of the item represented by the actor.
406 * @param[in] durationSeconds The time taken to fully constrain the actors.
407 * @param[in] scrollPositionObject The object which provides the layout position property.
408 * @param[in] itemViewActor The item view instance which requests the application of constraints.
410 DALI_IMPORT_API virtual void ApplyConstraints( Actor& actor, const int itemId, const float durationSeconds, Constrainable scrollPositionObject, const Actor& itemViewActor );
413 * @brief Gets the position of a given item
415 * @param[in] itemID id of the item we want to get its position
416 * @param[in] currentLayoutPosition the current layout position of the item view instance
417 * @param[in] layoutSize the current size of the item view instance
418 * @return The item position (x,y,z)
420 DALI_IMPORT_API virtual Vector3 GetItemPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize) const;
423 * @brief Set the alpha function used when applying constraints
425 * @param[in] func The alpha function to use.
427 DALI_IMPORT_API void SetAlphaFunction(AlphaFunction func);
430 * @brief Retrieve the alpha function used when applying constraints
432 * @return The alpha function.
434 DALI_IMPORT_API AlphaFunction GetAlphaFunction() const;
439 * @brief Create a new ItemLayout; Only derived versions are instantiatable.
441 DALI_IMPORT_API ItemLayout();
445 ControlOrientation::Type mOrientation; ///< the orientation of the layout.
446 AlphaFunction mAlphaFunction; ///<Alpha function to be applied when removing/adding constraints
449 } // namespace Toolkit
453 #endif // __DALI_TOOLKIT_ITEM_LAYOUT_H__