| Package | spark.layouts |
| Class | public class VerticalLayout |
| Inheritance | VerticalLayout  LayoutBase OnDemandEventDispatcher Object |
| Subclasses | FormLayout |
| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The vertical position of the elements is determined by arranging them in a vertical sequence, top to bottom, taking into account the padding before the first element and the gaps between the elements.
The horizontal position of the elements is determined by the layout's
horizontalAlign property.
During the execution of the measure() method,
the default size of the container is calculated by
accumulating the preferred sizes of the elements, including gaps and padding.
When requestedRowCount is set, only the space for that many elements
is measured, starting from the first element.
During the execution of the updateDisplayList() method,
the height of each element is calculated
according to the following rules, listed in their respective order of
precedence (element's minimum height and maximum height are always respected):
- If
variableRowHeightisfalse, then set the element's height to the value of therowHeightproperty. - If the element's
percentHeightis set, then calculate the element's height by distributing the available container height between all elements with apercentHeightsetting. The available container height is equal to the container height minus the gaps, the padding and the space occupied by the rest of the elements. The element'sprecentHeightproperty is ignored when the layout is virtualized. - Set the element's height to its preferred height.
The width of each element is calculated according to the following rules, listed in their respective order of precedence (element's minimum width and maximum width are always respected):
- If
horizontalAlignis"justify", then set the element's width to the container width. - If
horizontalAlignis"contentJustify", then set the element's width to the maximum between the container's width and all elements' preferred width. - If the element's
percentWidthis set, then calculate the element's width as a percentage of the container's width. - Set the element's width to its preferred width.
Show MXML Syntax
Hide MXML SyntaxThe <s:VerticalLayout> tag inherits all of the tag
attributes of its superclass and adds the following tag attributes:
<s:VerticalLayout
Properties
gap="6"
horizontalAlign="left"
paddingBottom="0"
paddingLeft="0"
paddingRight="0"
paddingTop="0"
requestedMaxRowCount="-1"
requestedMinRowCount="-1"
requestedRowCount="-1"
rowHeight="calculated"
variableRowHeight="true"
verticalAlign="top"
/>
More examples
Set the padding and gap of a layout
Set the alignment of a layout
Set the row height or column width of a layout
Learn more
| Property | Defined By | ||
|---|---|---|---|
 | clipAndEnableScrolling : Boolean
If true, specifies to clip the children to the boundaries of the viewport. | LayoutBase | |
| constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | |
| dropIndicator : DisplayObject
The DisplayObject that this layout uses for
the drop indicator during a drag-and-drop operation. | LayoutBase | |
| firstIndexInView : int [read-only]
The index of the first layout element that is part of the
layout and within the layout target's scroll rectangle, or -1
if nothing has been displayed yet. | VerticalLayout | ||
| gap : int
The vertical space between layout elements, in pixels. | VerticalLayout | ||
| horizontalAlign : String
The horizontal alignment of layout elements. | VerticalLayout | ||
| horizontalScrollPosition : Number
The x coordinate of the origin of the viewport in the component's coordinate system,
where the default value is (0,0) corresponding to the upper-left corner of the component. | LayoutBase | |
| lastIndexInView : int [read-only]
The index of the last row that's part of the layout and within
the container's scroll rectangle, or -1 if nothing has been displayed yet. | VerticalLayout | ||
| paddingBottom : Number
Number of pixels between the container's bottom edge
and the bottom edge of the last layout element. | VerticalLayout | ||
| paddingLeft : Number
The minimum number of pixels between the container's left edge and
the left edge of the layout element. | VerticalLayout | ||
| paddingRight : Number
The minimum number of pixels between the container's right edge and
the right edge of the layout element. | VerticalLayout | ||
| paddingTop : Number
Number of pixels between the container's top edge
and the top edge of the first layout element. | VerticalLayout | ||
| prototype : Object [static]
A reference to the prototype object of a class or function object. | Object | |
| requestedMaxRowCount : int
The measured height of this layout is large enough to display
at most requestedMaxRowCount layout elements. | VerticalLayout | ||
| requestedMinRowCount : int
The measured height of this layout is large enough to display
at least requestedMinRowCount layout elements. | VerticalLayout | ||
| requestedRowCount : int
The measured size of this layout is tall enough to display
the first requestedRowCount layout elements. | VerticalLayout | ||
| rowCount : int [read-only]
The current number of visible elements. | VerticalLayout | ||
| rowHeight : Number
If variableRowHeight is false, then
this property specifies the actual height of each child, in pixels. | VerticalLayout | ||
| target : GroupBase
The GroupBase container whose elements are measured, sized and positioned
by this layout. | LayoutBase | |
| typicalLayoutElement : ILayoutElement
Used by layouts when fixed row/column sizes are requested but
a specific size isn't specified. | LayoutBase | |
| useVirtualLayout : Boolean
A container can hold any number of children. | LayoutBase | |
| variableRowHeight : Boolean
Specifies whether layout elements are allocated their
preferred height. | VerticalLayout | ||
| verticalAlign : String
The vertical alignment of the content relative to the container's height. | VerticalLayout | ||
| verticalScrollPosition : Number
The y coordinate of the origin of the viewport in the component's coordinate system,
where the default value is (0,0) corresponding to the upper-left corner of the component. | LayoutBase | |
| Method | Defined By | ||
|---|---|---|---|
Constructor. | VerticalLayout | ||
| addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener
receives notification of an event. | OnDemandEventDispatcher | |
|
Calculates the drop location in the data provider of the drop target for
the specified dragEvent. | LayoutBase | |
|
When useVirtualLayout is true,
this method can be used by the layout target
to clear cached layout information when the target changes. | LayoutBase | |
|
Dispatches an event into the event flow. | OnDemandEventDispatcher | |
|
Called by the target after a layout element
has been added and before the target's size and display list are
validated. | LayoutBase | |
|
This method must is called by the target after a layout element
has been removed and before the target's size and display list are
validated. | LayoutBase | |
Returns 1.0 if the specified index is completely in view, 0.0 if
it's not, or a value between 0.0 and 1.0 that represents the percentage
of the if the index that is partially in view. | VerticalLayout | ||
|
Returns the specified element's layout bounds as a Rectangle or null
if the index is invalid, the corresponding element is null,
includeInLayout=false,
or if this layout's target property is null. | LayoutBase | |
|
Returns the change to the horizontal scroll position to handle
different scrolling options. | LayoutBase | |
| getNavigationDestinationIndex(currentIndex:int, navigationUnit:uint, arrowKeysWrapFocus:Boolean):int
Delegation method that determines which item
to navigate to based on the current item in focus
and user input in terms of NavigationUnit. | LayoutBase | |
|
Computes the verticalScrollPosition and
horizontalScrollPosition deltas needed to
scroll the element at the specified index into view. | LayoutBase | |
|
Returns the change to the vertical scroll position to handle
different scrolling options. | LayoutBase | |
|
Checks whether the EventDispatcher object has any listeners registered for a specific type
of event. | OnDemandEventDispatcher | |
|
Indicates whether an object has a specified property defined. | Object | |
|
Hides the previously shown drop indicator,
created by the showDropIndicator() method,
removes it from the display list and also stops the drag scrolling. | LayoutBase | |
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
|
Measures the target's default size based on its content, and optionally
measures the target's default minimum size. | LayoutBase | |
|
Indicates whether the specified property exists and is enumerable. | Object | |
|
Removes a listener from the EventDispatcher object. | OnDemandEventDispatcher | |
|
Sets the availability of a dynamic property for loop operations. | Object | |
|
Sizes, positions and parents the drop indicator based on the specified
drop location. | LayoutBase | |
|
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
|
Returns the string representation of the specified object. | Object | |
|
Sizes and positions the target's elements. | LayoutBase | |
|
Called by the target at the end of its updateDisplayList
to have the layout update its scrollRect. | LayoutBase | |
|
Returns the primitive value of the specified object. | Object | |
|
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. | OnDemandEventDispatcher | |
firstIndexInView | property |
firstIndexInView:int [read-only] | Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The index of the first layout element that is part of the layout and within the layout target's scroll rectangle, or -1 if nothing has been displayed yet.
"Part of the layout" means that the element is non-null
and that its includeInLayout property is true.
Note that the layout element may only be partially in view.
This property can be used as the source for data binding. When this property is modified, it dispatches the indexInViewChanged event.
Implementation
public function get firstIndexInView():intRelated API Elements
gap | property |
gap:int| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The vertical space between layout elements, in pixels. Note that the gap is only applied between layout elements, so if there's just one element, the gap has no effect on the layout.
The default value is 6.
Implementation
public function get gap():int public function set gap(value:int):voidhorizontalAlign | property |
horizontalAlign:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The horizontal alignment of layout elements.
If the value is "left", "right", or "center" then the
layout element is aligned relative to the container's contentWidth property.
If the value is "contentJustify", then the layout element's actual
width is set to the contentWidth of the container.
The contentWidth of the container is the width of the largest layout element.
If all layout elements are smaller than the width of the container,
then set the width of all layout elements to the width of the container.
If the value is "justify" then the layout element's actual width
is set to the container's width.
This property does not affect the layout's measured size.
The default value is "left".
Implementation
public function get horizontalAlign():String public function set horizontalAlign(value:String):voidlastIndexInView | property |
lastIndexInView:int [read-only] | Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The index of the last row that's part of the layout and within the container's scroll rectangle, or -1 if nothing has been displayed yet.
"Part of the layout" means that the child is non-null
and that its includeInLayout property is true.
Note that the row may only be partially in view.
This property can be used as the source for data binding. When this property is modified, it dispatches the indexInViewChanged event.
Implementation
public function get lastIndexInView():intRelated API Elements
fractionOfElementInView
paddingBottom | property |
paddingBottom:Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
Number of pixels between the container's bottom edge and the bottom edge of the last layout element.
The default value is 0.
Implementation
public function get paddingBottom():Number public function set paddingBottom(value:Number):voidpaddingLeft | property |
paddingLeft:Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The minimum number of pixels between the container's left edge and the left edge of the layout element.
The default value is 0.
Implementation
public function get paddingLeft():Number public function set paddingLeft(value:Number):voidpaddingRight | property |
paddingRight:Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The minimum number of pixels between the container's right edge and the right edge of the layout element.
The default value is 0.
Implementation
public function get paddingRight():Number public function set paddingRight(value:Number):voidpaddingTop | property |
paddingTop:Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
Number of pixels between the container's top edge and the top edge of the first layout element.
The default value is 0.
Implementation
public function get paddingTop():Number public function set paddingTop(value:Number):voidrequestedMaxRowCount | property |
requestedMaxRowCount:int| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4.5 |
| Runtime Versions: | Flash Player 10, AIR 2.5 |
The measured height of this layout is large enough to display
at most requestedMaxRowCount layout elements.
If requestedRowCount is set, then
this property has no effect.
If the actual size of the container has been explicitly set, then this property has no effect.
The default value is -1.
Implementation
public function get requestedMaxRowCount():int public function set requestedMaxRowCount(value:int):voidRelated API Elements
requestedMinRowCount | property |
requestedMinRowCount:int| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4.5 |
| Runtime Versions: | Flash Player 10, AIR 2.5 |
The measured height of this layout is large enough to display
at least requestedMinRowCount layout elements.
If requestedRowCount is set, then
this property has no effect.
If the actual size of the container has been explicitly set, then this property has no effect.
The default value is -1.
Implementation
public function get requestedMinRowCount():int public function set requestedMinRowCount(value:int):voidRelated API Elements
requestedRowCount | property |
requestedRowCount:int| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The measured size of this layout is tall enough to display
the first requestedRowCount layout elements.
If requestedRowCount is -1, then the measured
size will be big enough for all of the layout elements.
If the actual size of the container has been explicitly set, then this property has no effect.
The default value is -1.
Implementation
public function get requestedRowCount():int public function set requestedRowCount(value:int):voidRelated API Elements
rowCount | property |
rowCount:int [read-only] | Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The current number of visible elements.
The default value is -1.
This property can be used as the source for data binding. When this property is modified, it dispatches the propertyChange event.
Implementation
public function get rowCount():introwHeight | property |
rowHeight:Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
If variableRowHeight is false, then
this property specifies the actual height of each child, in pixels.
If variableRowHeight is true,
the default, then this property has no effect.
The default value of this property is the preferred height
of the typicalLayoutElement.
Implementation
public function get rowHeight():Number public function set rowHeight(value:Number):voidvariableRowHeight | property |
variableRowHeight:Boolean| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
Specifies whether layout elements are allocated their
preferred height.
Setting this property to false specifies fixed height rows.
If false, the actual height of each layout element is
the value of rowHeight.
Setting this property to false causes the layout to ignore
the layout elements' percentHeight property.
The default value is true.
Implementation
public function get variableRowHeight():Boolean public function set variableRowHeight(value:Boolean):voidverticalAlign | property |
verticalAlign:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
The vertical alignment of the content relative to the container's height.
If the value is "bottom", "middle",
or "top" then the layout elements are aligned relative
to the container's contentHeight property.
This property has no effect when clipAndEnableScrolling is true
and the contentHeight is greater than the container's height.
This property does not affect the layout's measured size.
The default value is "top".
Implementation
public function get verticalAlign():String public function set verticalAlign(value:String):voidVerticalLayout | () | Constructor |
public function VerticalLayout()| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
Constructor.
fractionOfElementInView | () | method |
public function fractionOfElementInView(index:int):Number| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 4 |
| Runtime Versions: | Flash Player 10, AIR 1.5 |
Returns 1.0 if the specified index is completely in view, 0.0 if it's not, or a value between 0.0 and 1.0 that represents the percentage of the if the index that is partially in view.
An index is "in view" if the corresponding non-null layout element is
within the vertical limits of the container's scrollRect
and included in the layout.
If the specified index is partially within the view, the returned value is the percentage of the corresponding layout element that's visible.
Parameters
index:int — The index of the row.
|
Number — The percentage of the specified element that's in view.
Returns 0.0 if the specified index is invalid or if it corresponds to
null element, or a ILayoutElement for which
the includeInLayout property is false.
|
Mon Nov 28 2011, 06:48 AM -08:00