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LinearLayoutCompat

public class LinearLayoutCompat
extends ViewGroup

java.lang.Object
   ↳ android.view.View
     ↳ android.view.ViewGroup
       ↳ android.support.v7.widget.LinearLayoutCompat
Known Direct Subclasses


A Layout that arranges its children in a single column or a single row. The direction of the row can be set by calling setOrientation(). You can also specify gravity, which specifies the alignment of all the child elements by calling setGravity() or specify that specific children grow to fill up any remaining space in the layout by setting the weight member of LinearLayoutCompat.LayoutParams. The default orientation is horizontal.

See the Linear Layout guide.

Also see LinearLayoutCompat.LayoutParams for layout attributes

Summary

Nested classes

class LinearLayoutCompat.LayoutParams

Per-child layout information associated with ViewLinearLayout. 

Inherited XML attributes

From class android.view.ViewGroup
From class android.view.View

Constants

int HORIZONTAL

int SHOW_DIVIDER_BEGINNING

Show a divider at the beginning of the group.

int SHOW_DIVIDER_END

Show a divider at the end of the group.

int SHOW_DIVIDER_MIDDLE

Show dividers between each item in the group.

int SHOW_DIVIDER_NONE

Don't show any dividers.

int VERTICAL

Inherited constants

From class android.view.ViewGroup
From class android.view.View

Inherited fields

From class android.view.View

Public constructors

LinearLayoutCompat(Context context)
LinearLayoutCompat(Context context, AttributeSet attrs)
LinearLayoutCompat(Context context, AttributeSet attrs, int defStyleAttr)

Public methods

LinearLayoutCompat.LayoutParams generateLayoutParams(AttributeSet attrs)

Returns a new set of layout parameters based on the supplied attributes set.

int getBaseline()

Return the offset of the widget's text baseline from the widget's top boundary.

int getBaselineAlignedChildIndex()
Drawable getDividerDrawable()
int getDividerPadding()

Get the padding size used to inset dividers in pixels

int getOrientation()

Returns the current orientation.

int getShowDividers()
float getWeightSum()

Returns the desired weights sum.

boolean isBaselineAligned()

Indicates whether widgets contained within this layout are aligned on their baseline or not.

boolean isMeasureWithLargestChildEnabled()

When true, all children with a weight will be considered having the minimum size of the largest child.

void onInitializeAccessibilityEvent(AccessibilityEvent event)

Initializes an AccessibilityEvent with information about this View which is the event source.

void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info)

Initializes an AccessibilityNodeInfo with information about this view.

void setBaselineAligned(boolean baselineAligned)

Defines whether widgets contained in this layout are baseline-aligned or not.

void setBaselineAlignedChildIndex(int i)
void setDividerDrawable(Drawable divider)

Set a drawable to be used as a divider between items.

void setDividerPadding(int padding)

Set padding displayed on both ends of dividers.

void setGravity(int gravity)

Describes how the child views are positioned.

void setHorizontalGravity(int horizontalGravity)
void setMeasureWithLargestChildEnabled(boolean enabled)

When set to true, all children with a weight will be considered having the minimum size of the largest child.

void setOrientation(int orientation)

Should the layout be a column or a row.

void setShowDividers(int showDividers)

Set how dividers should be shown between items in this layout

void setVerticalGravity(int verticalGravity)
void setWeightSum(float weightSum)

Defines the desired weights sum.

boolean shouldDelayChildPressedState()

Return true if the pressed state should be delayed for children or descendants of this ViewGroup.

Protected methods

boolean checkLayoutParams(ViewGroup.LayoutParams p)
LinearLayoutCompat.LayoutParams generateDefaultLayoutParams()

Returns a set of layout parameters with a width of MATCH_PARENT and a height of WRAP_CONTENT when the layout's orientation is VERTICAL.

LinearLayoutCompat.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p)

Returns a safe set of layout parameters based on the supplied layout params.

void onDraw(Canvas canvas)

Implement this to do your drawing.

void onLayout(boolean changed, int l, int t, int r, int b)

Called from layout when this view should assign a size and position to each of its children.

void onMeasure(int widthMeasureSpec, int heightMeasureSpec)

Measure the view and its content to determine the measured width and the measured height.

Inherited methods

From class android.view.ViewGroup
From class android.view.View
From class java.lang.Object
From interface android.view.ViewParent
From interface android.view.ViewManager
From interface android.graphics.drawable.Drawable.Callback
From interface android.view.KeyEvent.Callback
From interface android.view.accessibility.AccessibilityEventSource

Constants

HORIZONTAL

int HORIZONTAL

Constant Value: 0 (0x00000000)

SHOW_DIVIDER_BEGINNING

int SHOW_DIVIDER_BEGINNING

Show a divider at the beginning of the group.

Constant Value: 1 (0x00000001)

SHOW_DIVIDER_END

int SHOW_DIVIDER_END

Show a divider at the end of the group.

Constant Value: 4 (0x00000004)

SHOW_DIVIDER_MIDDLE

int SHOW_DIVIDER_MIDDLE

Show dividers between each item in the group.

Constant Value: 2 (0x00000002)

SHOW_DIVIDER_NONE

int SHOW_DIVIDER_NONE

Don't show any dividers.

Constant Value: 0 (0x00000000)

VERTICAL

int VERTICAL

Constant Value: 1 (0x00000001)

Public constructors

LinearLayoutCompat

LinearLayoutCompat (Context context)

Parameters
context Context

LinearLayoutCompat

LinearLayoutCompat (Context context, 
                AttributeSet attrs)

Parameters
context Context
attrs AttributeSet

LinearLayoutCompat

LinearLayoutCompat (Context context, 
                AttributeSet attrs, 
                int defStyleAttr)

Parameters
context Context
attrs AttributeSet
defStyleAttr int

Public methods

generateLayoutParams

LinearLayoutCompat.LayoutParams generateLayoutParams (AttributeSet attrs)

Returns a new set of layout parameters based on the supplied attributes set.

Parameters
attrs AttributeSet: the attributes to build the layout parameters from
Returns
LinearLayoutCompat.LayoutParams an instance of ViewGroup.LayoutParams or one of its descendants

getBaseline

int getBaseline ()

Return the offset of the widget's text baseline from the widget's top boundary. If this widget does not support baseline alignment, this method returns -1.

Returns
int the offset of the baseline within the widget's bounds or -1 if baseline alignment is not supported

getBaselineAlignedChildIndex

int getBaselineAlignedChildIndex ()

Returns
int The index of the child that will be used if this layout is part of a larger layout that is baseline aligned, or -1 if none has been set.

getDividerDrawable

Drawable getDividerDrawable ()

Returns
Drawable the divider Drawable that will divide each item.

See also:

getDividerPadding

int getDividerPadding ()

Get the padding size used to inset dividers in pixels

Returns
int

See also:

getOrientation

int getOrientation ()

Returns the current orientation.

Returns
int either HORIZONTAL or VERTICAL

getShowDividers

int getShowDividers ()

Returns
int A flag set indicating how dividers should be shown around items.

See also:

getWeightSum

float getWeightSum ()

Returns the desired weights sum.

Returns
float A number greater than 0.0f if the weight sum is defined, or a number lower than or equals to 0.0f if not weight sum is to be used.

isBaselineAligned

boolean isBaselineAligned ()

Indicates whether widgets contained within this layout are aligned on their baseline or not.

Returns
boolean true when widgets are baseline-aligned, false otherwise

isMeasureWithLargestChildEnabled

boolean isMeasureWithLargestChildEnabled ()

When true, all children with a weight will be considered having the minimum size of the largest child. If false, all children are measured normally.

Returns
boolean True to measure children with a weight using the minimum size of the largest child, false otherwise.

onInitializeAccessibilityEvent

void onInitializeAccessibilityEvent (AccessibilityEvent event)

Initializes an AccessibilityEvent with information about this View which is the event source. In other words, the source of an accessibility event is the view whose state change triggered firing the event.

Example: Setting the password property of an event in addition to properties set by the super implementation:

 public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
     super.onInitializeAccessibilityEvent(event);
     event.setPassword(true);
 }

If an View.AccessibilityDelegate has been specified via calling setAccessibilityDelegate(AccessibilityDelegate) its onInitializeAccessibilityEvent(View, AccessibilityEvent) is responsible for handling this call.

Note: Always call the super implementation before adding information to the event, in case the default implementation has basic information to add.

Parameters
event AccessibilityEvent: The event to initialize.

onInitializeAccessibilityNodeInfo

void onInitializeAccessibilityNodeInfo (AccessibilityNodeInfo info)

Initializes an AccessibilityNodeInfo with information about this view. The base implementation sets:

Subclasses should override this method, call the super implementation, and set additional attributes.

If an View.AccessibilityDelegate has been specified via calling setAccessibilityDelegate(AccessibilityDelegate) its onInitializeAccessibilityNodeInfo(View, AccessibilityNodeInfo) is responsible for handling this call.

Parameters
info AccessibilityNodeInfo: The instance to initialize.

setBaselineAligned

void setBaselineAligned (boolean baselineAligned)

Defines whether widgets contained in this layout are baseline-aligned or not.

Parameters
baselineAligned boolean: true to align widgets on their baseline, false otherwise

setBaselineAlignedChildIndex

void setBaselineAlignedChildIndex (int i)

Parameters
i int: The index of the child that will be used if this layout is part of a larger layout that is baseline aligned.

setDividerDrawable

void setDividerDrawable (Drawable divider)

Set a drawable to be used as a divider between items.

Parameters
divider Drawable: Drawable that will divide each item.

See also:

setDividerPadding

void setDividerPadding (int padding)

Set padding displayed on both ends of dividers.

Parameters
padding int: Padding value in pixels that will be applied to each end

See also:

setGravity

void setGravity (int gravity)

Describes how the child views are positioned. Defaults to GRAVITY_TOP. If this layout has a VERTICAL orientation, this controls where all the child views are placed if there is extra vertical space. If this layout has a HORIZONTAL orientation, this controls the alignment of the children.

Parameters
gravity int: See Gravity

setHorizontalGravity

void setHorizontalGravity (int horizontalGravity)

Parameters
horizontalGravity int

setMeasureWithLargestChildEnabled

void setMeasureWithLargestChildEnabled (boolean enabled)

When set to true, all children with a weight will be considered having the minimum size of the largest child. If false, all children are measured normally. Disabled by default.

Parameters
enabled boolean: True to measure children with a weight using the minimum size of the largest child, false otherwise.

setOrientation

void setOrientation (int orientation)

Should the layout be a column or a row.

Parameters
orientation int: Pass HORIZONTAL or VERTICAL. Default value is HORIZONTAL.

setShowDividers

void setShowDividers (int showDividers)

Set how dividers should be shown between items in this layout

Parameters
showDividers int: One or more of SHOW_DIVIDER_BEGINNING, SHOW_DIVIDER_MIDDLE, or SHOW_DIVIDER_END, or SHOW_DIVIDER_NONE to show no dividers.

setVerticalGravity

void setVerticalGravity (int verticalGravity)

Parameters
verticalGravity int

setWeightSum

void setWeightSum (float weightSum)

Defines the desired weights sum. If unspecified the weights sum is computed at layout time by adding the layout_weight of each child. This can be used for instance to give a single child 50% of the total available space by giving it a layout_weight of 0.5 and setting the weightSum to 1.0.

Parameters
weightSum float: a number greater than 0.0f, or a number lower than or equals to 0.0f if the weight sum should be computed from the children's layout_weight

shouldDelayChildPressedState

boolean shouldDelayChildPressedState ()

Return true if the pressed state should be delayed for children or descendants of this ViewGroup. Generally, this should be done for containers that can scroll, such as a List. This prevents the pressed state from appearing when the user is actually trying to scroll the content. The default implementation returns true for compatibility reasons. Subclasses that do not scroll should generally override this method and return false.

Returns
boolean

Protected methods

checkLayoutParams

boolean checkLayoutParams (ViewGroup.LayoutParams p)

Parameters
p ViewGroup.LayoutParams
Returns
boolean

generateDefaultLayoutParams

LinearLayoutCompat.LayoutParams generateDefaultLayoutParams ()

Returns a set of layout parameters with a width of MATCH_PARENT and a height of WRAP_CONTENT when the layout's orientation is VERTICAL. When the orientation is HORIZONTAL, the width is set to WRAP_CONTENT and the height to WRAP_CONTENT.

Returns
LinearLayoutCompat.LayoutParams a set of default layout parameters or null

generateLayoutParams

LinearLayoutCompat.LayoutParams generateLayoutParams (ViewGroup.LayoutParams p)

Returns a safe set of layout parameters based on the supplied layout params. When a ViewGroup is passed a View whose layout params do not pass the test of checkLayoutParams(android.view.ViewGroup.LayoutParams), this method is invoked. This method should return a new set of layout params suitable for this ViewGroup, possibly by copying the appropriate attributes from the specified set of layout params.

Parameters
p ViewGroup.LayoutParams: The layout parameters to convert into a suitable set of layout parameters for this ViewGroup.
Returns
LinearLayoutCompat.LayoutParams an instance of ViewGroup.LayoutParams or one of its descendants

onDraw

void onDraw (Canvas canvas)

Implement this to do your drawing.

Parameters
canvas Canvas: the canvas on which the background will be drawn

onLayout

void onLayout (boolean changed, 
                int l, 
                int t, 
                int r, 
                int b)

Called from layout when this view should assign a size and position to each of its children. Derived classes with children should override this method and call layout on each of their children.

Parameters
changed boolean: This is a new size or position for this view
l int: Left position, relative to parent
t int: Top position, relative to parent
r int: Right position, relative to parent
b int: Bottom position, relative to parent

onMeasure

void onMeasure (int widthMeasureSpec, 
                int heightMeasureSpec)

Measure the view and its content to determine the measured width and the measured height. This method is invoked by measure(int, int) and should be overridden by subclasses to provide accurate and efficient measurement of their contents.

CONTRACT: When overriding this method, you must call setMeasuredDimension(int, int) to store the measured width and height of this view. Failure to do so will trigger an IllegalStateException, thrown by measure(int, int). Calling the superclass' onMeasure(int, int) is a valid use.

The base class implementation of measure defaults to the background size, unless a larger size is allowed by the MeasureSpec. Subclasses should override onMeasure(int, int) to provide better measurements of their content.

If this method is overridden, it is the subclass's responsibility to make sure the measured height and width are at least the view's minimum height and width (getSuggestedMinimumHeight() and getSuggestedMinimumWidth()).

Parameters
widthMeasureSpec int: horizontal space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.
heightMeasureSpec int: vertical space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.

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