Package | spark.layouts |
Class | public class ConstraintLayout |
Inheritance | ConstraintLayout ![]() ![]() ![]() |
Subclasses | FormItemLayout |
Language Version: | ActionScript 3.0 |
Product Version: | Flex 4.5 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Note: The Spark list-based controls (the Spark List control and its subclasses such as ButtonBar, ComboBox, DropDownList, and TabBar) do not support the ConstraintLayout class. Do not use ConstraintLayout with the Spark list-based controls.
Per-element supported constraints are left
, right
,
top
, bottom
, baseline
,
percentWidth
, and percentHeight
.
Element's minimum and maximum sizes will always be respected.
Columns and rows may have an explicit size or content size (no explicit size). Explicit size regions will be fixed at their specified size, while content size regions will stretch to fit only the elements constrained to them. If multiple content size regions are spanned by an element, the space will be divided equally among the content size regions.
The measured size of the container is calculated from the elements, their constraints, their preferred sizes, and the sizes of the rows and columns. The size of each row and column is just big enough to hold all of the elements constrained to it at their preferred sizes with constraints satisfied. The measured size of the container is big enough to hold all of the columns and rows as well as any other elements left at their preferred sizes with constraints satisfied.
During a call to the updateDisplayList()
method,
the element's size is determined according to
the rules in the following order of precedence (the element's minimum and
maximum sizes are always respected):
- If the element has
percentWidth
orpercentHeight
set, then its size is calculated as a percentage of the available size, where the available size is the region or container size minus anyleft
,right
,top
, orbottom
constraints. - If the element has both left and right constraints, it's width is
set to be the region's or container's width minus the
left
andright
constraints. - If the element has both
top
andbottom
constraints, it's height is set to be the container's height minus thetop
andbottom
constraints. - The element is set to its preferred width and/or height.
The element's position is determined according to the rules in the following order of precedence:
- If element's baseline is specified, then the element is positioned in
the vertical direction such that its
baselinePosition
(usually the base line of its first line of text) is aligned withbaseline
constraint. - If element's
top
orleft
constraints are specified, then the element is positioned such that the top-left corner of the element's layout bounds is offset from the top-left corner of the container by the specified values. - If element's
bottom
orright
constraints are specified, then the element is positioned such that the bottom-right corner of the element's layout bounds is offset from the bottom-right corner of the container by the specified values. - When no constraints determine the position in the horizontal or vertical direction, the element is positioned according to its x and y coordinates.
The content size of the container is calculated as the maximum of the coordinates of the bottom-right corner of all the layout elements and constraint regions.
Property | Defined By | ||
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![]() | constructor : Object
A reference to the class object or constructor function for a given object instance. | Object |
Method | Defined By | ||
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Indicates whether an object has a specified property defined. | Object | |
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Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
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Indicates whether the specified property exists and is enumerable. | Object | |
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Sets the availability of a dynamic property for loop operations. | Object | |
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Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
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Returns the string representation of the specified object. | Object | |
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Returns the primitive value of the specified object. | Object |
Method | Defined By |
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Wed Nov 21 2018, 06:34 AM -08:00