# OHOS::UIAbstractScroll ## **Overview** **Related Modules:** [Graphic](Graphic.md) **Description:** Defines the attributes of a scroll, including the scroll direction, blank size of a scroll view, velocity and effects of a scroll animation. **Since:** 1.0 **Version:** 1.0 ## **Summary** ## Public Member Functions

Public Member Function Name

Description

UIAbstractScroll ()

 

A constructor used to create a UIAbstractScroll instance.

~UIAbstractScroll ()

virtual 

A destructor used to delete the UIAbstractScroll instance.

GetViewType () const override

UIViewType 

Obtains the view type.

GetDirection () const

uint8_t 

Obtains the scroll direction.

SetScrollBlankSize (uint16_t size)

void 

Sets the blank size for this scroll view.

SetMaxScrollDistance (uint16_t distance)

void 

Sets the maximum scroll distance after a finger lifts the screen.

SetReboundSize (uint16_t size)

void 

Sets the rebound size, which is the distance a knob moves after being released when it reaches the end of a scrollbar.

GetMaxScrollDistance () const

uint16_t 

Obtains the maximum scroll distance after a finger lifts the screen.

SetDragFunc (EasingFunc func)

void 

Sets the easing function that specifies a scroll animation after a finger lifts the screen.

SetThrowDrag (bool throwDrag)

void 

Sets whether to continue scrolling after a finger lifts the screen.

MoveChildByOffset (int16_t offsetX, int16_t offsetY) override

void 

Moves the position of all child views.

SetDragACCLevel (uint16_t value)

void 

Sets the drag acceleration.

GetDragACCLevel () const

uint8_t 

Obtains the drag acceleration.

SetSwipeACCLevel (uint16_t value)

void 

Sets the compensation distance after a finger lifts the screen.

GetSwipeACCLevel () const

uint8_t 

Obtains the compensation distance after a finger lifts the screen.

UIViewGroup ()

 

A default constructor used to create a UIViewGroup instance.

~UIViewGroup ()

virtual 

A destructor used to delete the UIViewGroup instance.

GetViewType () const override

UIViewType 

Obtains the view type.

Add (UIView *view)

virtual void 

Adds a child view.

Insert (UIView *prevView, UIView *insertView)

virtual void 

Inserts a new child view behind the current one.

Remove (UIView *view)

virtual void 

Removes a child view.

RemoveAll ()

virtual void 

Removes all child views.

GetTargetView (const Point &point, UIView **last) override

virtual void 

Obtains the target child view that is visible and can respond to touch events based on given coordinates.

GetChildrenHead () const

UIView * 

Obtains the first child view in this view group.

GetChildrenTail () const

UIView * 

Obtains the last child view in this view group.

SetDisallowIntercept (bool flag)

void 

Sets whether this view group is intercepted upon touch events.

GetChildById (const char *id) const override

UIView * 

Obtains the target child view with a specified ID.

SetAutoSize (bool state)

void 

Sets whether the size of this view group is adaptive to that of all child views.

UIView ()

 

A default constructor used to create an UIView instance.

UIView (const char *id)

 

A constructor used to create an UIView instance.

~UIView ()

virtual 

A destructor used to delete the UIView instance.

OnPreDraw (const Rect &invalidatedArea)

virtual bool 

Called before a view is drawn. This function is used to check whether the parent view of this view needs to be redrawn so as to optimize the drawing process.

OnDraw (const Rect &invalidatedArea)

virtual void 

Called when a view is drawn.

OnPostDraw (const Rect &invalidatedArea)

virtual void 

Called after a view is drawn.

ReMeasure ()

virtual void 

Remeasures the view size.

Invalidate ()

void 

Refreshes the invalidated area of the view.

InvalidateRect (const Rect &invalidatedArea)

void 

Refreshes a view in a specified invalidated area.

OnLongPressEvent (const LongPressEvent &event)

virtual bool 

Called when the view is long pressed.

OnDragStartEvent (const DragEvent &event)

virtual bool 

Called when the view starts to drag.

OnDragEvent (const DragEvent &event)

virtual bool 

Called when the view is being dragged.

OnDragEndEvent (const DragEvent &event)

virtual bool 

Called when the view stops dragging.

OnClickEvent (const ClickEvent &event)

virtual void 

Called when the view is clicked.

OnPressEvent (const PressEvent &event)

virtual void 

Called when the view is pressed.

OnReleaseEvent (const ReleaseEvent &event)

virtual void 

Called when the view is released.

OnCancelEvent (const CancelEvent &event)

virtual void 

Called when a click event on the view is canceled.

SetOnDragListener (OnDragListener *onDragListener)

void 

Sets a drag event listener for the view.

GetOnDragListener ()

OnDragListener *& 

Obtains the drag event listener for the view.

SetOnClickListener (OnClickListener *onClickListener)

void 

Sets a click event listener for the view.

GetOnClickListener ()

OnClickListener *& 

Obtains the click event listener for the view.

SetOnLongPressListener (OnLongPressListener *onLongPressListener)

void 

Sets a long-press event listener for the view.

GetOnLongPressListener ()

OnLongPressListener *& 

Obtains the long-press event listener for the view.

SetOnTouchListener (OnTouchListener *onTouchListener)

void 

Sets a touch event listener for the view.

GetTouchListener ()

OnTouchListener *& 

Obtains the touch event listener for the view.

SetParent (UIView *parent)

void 

Sets the parent view for the view.

GetParent () const

UIView * 

Obtains the parent view of the view.

SetNextSibling (UIView *sibling)

void 

Sets the next sibling view for the view.

GetNextSibling () const

UIView * 

Obtains the next sibling view of the view.

SetVisible (bool visible)

virtual void 

Sets whether the view is visible.

IsVisible () const

bool 

Checks whether the view is visible.

SetTouchable (bool touch)

void 

Sets whether the view is touchable.

IsTouchable () const

bool 

Checks whether the view is touchable.

SetDraggable (bool draggable)

void 

Sets whether the view is draggable.

IsDraggable () const

bool 

Checks whether the view is draggable.

SetDragParentInstead (bool dragParentInstead)

void 

Sets whether to transfer the drag event to the parent view for processing when the view is being dragged.

IsDragParentInstead () const

bool 

Obtains whether the view transfers a drag event to the parent view for processing.

GetRect () const

Rect 

Obtains the absolute rectangle area of the view. When the view has deformation such as rotation, the rectangle area is the intersection set of the absolute rectangle area and deformation matrix.

GetVisibleRect () const

Rect 

Obtains the visible absolute rectangle area of the view.

GetMaskedRect () const

Rect 

Obtains the valid absolute rectangle area of the view. The valid area refers to the area where the view can be displayed. Generally, the valid area is the same as the visible view area, but they may be different in the grid layout.

GetOrigRect () const

Rect 

Obtains the absolute rectangle area of the view.

GetContentRect ()

virtual Rect 

Obtains the content of the absolute rectangle area of the view. This area excludes padding.

GetRelativeRect () const

Rect 

Obtains the rectangular area of the view relative to the parent view, that is, the rectangular area relative to the coordinates of the parent view.

ResizeVisibleArea (int16_t x, int16_t y, int16_t width, int16_t height)

void 

Adjusts the size of the visible area. This operation may affect the final display size.

SetWidth (int16_t width)

virtual void 

Sets the width for the view.

GetWidth ()

virtual int16_t 

Obtains the width for the view.

SetHeight (int16_t height)

virtual void 

Sets the height for the view.

GetHeight ()

virtual int16_t 

Obtains the height for the view.

Resize (int16_t width, int16_t height)

virtual void 

Adjusts the size of the view.

SetX (int16_t x)

virtual void 

Sets the x-coordinate for the view.

GetX () const

int16_t 

Obtains the x-coordinate for the view.

SetY (int16_t y)

virtual void 

Sets the y-coordinate for the view.

GetY () const

int16_t 

Obtains the y-coordinate for the view.

SetPosition (int16_t x, int16_t y)

virtual void 

Sets the position for the view.

SetPosition (int16_t x, int16_t y, int16_t width, int16_t height)

virtual void 

Adjusts the position and size of the view.

IsViewGroup () const

bool 

Checks whether the view is a container view.

SetIntercept (bool isIntercept)

void 

Sets whether to intercept the drag event. If intercepted, the view does not transfer the drag event to the parent view after local processing.

SetTransformMap (const TransformMap &transMap)

void 

Sets the affine transformation matrix.

GetTransformMap ()

TransformMap & 

Obtains an affine transformation matrix.

SetViewId (const char *id)

void 

Sets the view ID.

GetViewId () const

const char * 

Obtains the view ID.

SetViewIndex (int16_t index)

void 

Sets the view index.

GetViewIndex () const

int16_t 

Obtains the view index.

LayoutChildren (bool neeInvalidate=false)

virtual void 

Lays out all child views according to the preset arrangement mode.

LayoutCenterOfParent (int16_t xOffSet=0, int16_t yOffset=0)

void 

Lays out the view in the center of the parent view.

LayoutLeftOfParent (int16_t offset=0)

void 

Lays out the view on the left of the parent view.

LayoutRightOfParent (int16_t offset=0)

void 

Lays out the view on the right of the parent view.

LayoutTopOfParent (int16_t offset=0)

void 

Lays out the view on the top of the parent view.

LayoutBottomOfParent (int16_t offset=0)

void 

Lays out the view on the bottom of the parent view.

AlignLeftToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the left of a sibling view.

AlignRightToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the right of a sibling view.

AlignTopToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the top of a sibling view.

AlignBottomToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the bottom of a sibling view.

AlignHorCenterToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the center of a sibling view in the x-axis.

AlignVerCenterToSibling (const char *id, int16_t offset=0)

void 

Aligns the view with the center of a sibling view in the y-axis.

LayoutLeftToSibling (const char *id, int16_t offset=0)

void 

Lays out the view on the left of a sibling view.

LayoutRightToSibling (const char *id, int16_t offset=0)

void 

Lays out the view on the right of a sibling view.

LayoutTopToSibling (const char *id, int16_t offset=0)

void 

Lays out the view on the above of a sibling view.

LayoutBottomToSibling (const char *id, int16_t offset=0)

void 

Lays out the view on the below of a sibling view.

SetStyle (Style &style)

virtual void 

Sets the view style.

SetStyle (uint8_t key, int64_t value)

virtual void 

Sets a style.

GetStyle (uint8_t key) const

virtual int64_t 

Obtains the value of a style.

GetStyleConst () const

const Style & 

Obtains the view style. This function applies to scenarios where the style does not need to be modified, which saves memory.

operator new (size_t size)

void * 

Overrides the new function.

operator delete (void *p)

void 

Overrides the delete function.

## Additional Inherited Members

Additional Inherited Member Name

Description

GetAllChildRelativeRect () const

Obtains the rectangle area of a new view group after being adaptive to the size of all child views.

OnChildChanged ()

Performs operations needed after a child view is added or removed.

childrenHead_

Indicates the pointer to the first child view of this view group.

childrenTail_

Indicates the pointer to the last child view of this view group.

childrenNum_

Represents the number of child views.

isDragging_

Specifies the sliding state of this view group.

disallowIntercept_

Specifies whether this view group is intercepted upon touch events.

isAutoSize_

Specifies whether the size of this view group is adaptive to that of all child views.