public
abstract
class
OrientationHelper
extends Object
| java.lang.Object | |
| ↳ | android.support.v7.widget.OrientationHelper |
Helper class for LayoutManagers to abstract measurements depending on the View's orientation.
It is developed to easily support vertical and horizontal orientations in a LayoutManager but can also be used to abstract calls around view bounds and child measurements with margins and decorations.
See also:
Constants | |
|---|---|
int |
HORIZONTAL
|
int |
VERTICAL
|
Fields | |
|---|---|
protected
final
RecyclerView.LayoutManager |
mLayoutManager
|
Public methods | |
|---|---|
static
OrientationHelper
|
createHorizontalHelper(RecyclerView.LayoutManager layoutManager)
Creates a horizontal OrientationHelper for the given LayoutManager. |
static
OrientationHelper
|
createOrientationHelper(RecyclerView.LayoutManager layoutManager, int orientation)
Creates an OrientationHelper for the given LayoutManager and orientation. |
static
OrientationHelper
|
createVerticalHelper(RecyclerView.LayoutManager layoutManager)
Creates a vertical OrientationHelper for the given LayoutManager. |
abstract
int
|
getDecoratedEnd(View view)
Returns the end of the view including its decoration and margin. |
abstract
int
|
getDecoratedMeasurement(View view)
Returns the space occupied by this View in the current orientation including decorations and margins. |
abstract
int
|
getDecoratedMeasurementInOther(View view)
Returns the space occupied by this View in the perpendicular orientation including decorations and margins. |
abstract
int
|
getDecoratedStart(View view)
Returns the start of the view including its decoration and margin. |
abstract
int
|
getEnd()
Returns the end position of the layout without taking padding into account. |
abstract
int
|
getEndAfterPadding()
Returns the end position of the layout after the end padding is removed. |
abstract
int
|
getEndPadding()
Returns the padding at the end of the layout. |
abstract
int
|
getMode()
Returns the MeasureSpec mode for the current orientation from the LayoutManager. |
abstract
int
|
getModeInOther()
Returns the MeasureSpec mode for the perpendicular orientation from the LayoutManager. |
abstract
int
|
getStartAfterPadding()
Returns the start position of the layout after the start padding is added. |
abstract
int
|
getTotalSpace()
Returns the total space to layout. |
int
|
getTotalSpaceChange()
Returns the layout space change between the previous layout pass and current layout pass. |
abstract
int
|
getTransformedEndWithDecoration(View view)
Returns the end of the View after its matrix transformations are applied to its layout position. |
abstract
int
|
getTransformedStartWithDecoration(View view)
Returns the start of the View after its matrix transformations are applied to its layout position. |
abstract
void
|
offsetChild(View view, int offset)
Offsets the child in this orientation. |
abstract
void
|
offsetChildren(int amount)
Offsets all children's positions by the given amount. |
void
|
onLayoutComplete()
Call this method after onLayout method is complete if state is NOT pre-layout. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
int HORIZONTAL
Constant Value: 0 (0x00000000)
int VERTICAL
Constant Value: 1 (0x00000001)
OrientationHelper createHorizontalHelper (RecyclerView.LayoutManager layoutManager)
Creates a horizontal OrientationHelper for the given LayoutManager.
| Parameters | |
|---|---|
layoutManager |
RecyclerView.LayoutManager:
The LayoutManager to attach to. |
| Returns | |
|---|---|
OrientationHelper |
A new OrientationHelper |
OrientationHelper createOrientationHelper (RecyclerView.LayoutManager layoutManager, int orientation)
Creates an OrientationHelper for the given LayoutManager and orientation.
| Parameters | |
|---|---|
layoutManager |
RecyclerView.LayoutManager:
LayoutManager to attach to |
orientation |
int:
Desired orientation. Should be HORIZONTAL or VERTICAL |
| Returns | |
|---|---|
OrientationHelper |
A new OrientationHelper |
OrientationHelper createVerticalHelper (RecyclerView.LayoutManager layoutManager)
Creates a vertical OrientationHelper for the given LayoutManager.
| Parameters | |
|---|---|
layoutManager |
RecyclerView.LayoutManager:
The LayoutManager to attach to. |
| Returns | |
|---|---|
OrientationHelper |
A new OrientationHelper |
int getDecoratedEnd (View view)
Returns the end of the view including its decoration and margin.
For example, for the horizontal helper, if a View's right is at pixel 200, has 2px right decoration and 3px right margin, returned value will be 205.
| Parameters | |
|---|---|
view |
View:
The view element to check |
| Returns | |
|---|---|
int |
The last pixel of the element |
See also:
int getDecoratedMeasurement (View view)
Returns the space occupied by this View in the current orientation including decorations and margins.
| Parameters | |
|---|---|
view |
View:
The view element to check |
| Returns | |
|---|---|
int |
Total space occupied by this view |
See also:
int getDecoratedMeasurementInOther (View view)
Returns the space occupied by this View in the perpendicular orientation including decorations and margins.
| Parameters | |
|---|---|
view |
View:
The view element to check |
| Returns | |
|---|---|
int |
Total space occupied by this view in the perpendicular orientation to current one |
See also:
int getDecoratedStart (View view)
Returns the start of the view including its decoration and margin.
For example, for the horizontal helper, if a View's left is at pixel 20, has 2px left decoration and 3px left margin, returned value will be 15px.
| Parameters | |
|---|---|
view |
View:
The view element to check |
| Returns | |
|---|---|
int |
The first pixel of the element |
See also:
int getEnd ()
Returns the end position of the layout without taking padding into account.
| Returns | |
|---|---|
int |
The end boundary for this layout without considering padding. |
int getEndAfterPadding ()
Returns the end position of the layout after the end padding is removed.
| Returns | |
|---|---|
int |
The end boundary for this layout. |
int getEndPadding ()
Returns the padding at the end of the layout. For horizontal helper, this is the right padding and for vertical helper, this is the bottom padding. This method does not check whether the layout is RTL or not.
| Returns | |
|---|---|
int |
The padding at the end of the layout. |
int getMode ()
Returns the MeasureSpec mode for the current orientation from the LayoutManager.
| Returns | |
|---|---|
int |
The current measure spec mode. |
int getModeInOther ()
Returns the MeasureSpec mode for the perpendicular orientation from the LayoutManager.
| Returns | |
|---|---|
int |
The current measure spec mode. |
int getStartAfterPadding ()
Returns the start position of the layout after the start padding is added.
| Returns | |
|---|---|
int |
The very first pixel we can draw. |
int getTotalSpace ()
Returns the total space to layout. This number is the difference between
getEndAfterPadding() and getStartAfterPadding().
| Returns | |
|---|---|
int |
Total space to layout children |
int getTotalSpaceChange ()
Returns the layout space change between the previous layout pass and current layout pass.
Make sure you call onLayoutComplete() at the end of your LayoutManager's
onLayoutChildren(RecyclerView.Recycler, RecyclerView.State) method.
| Returns | |
|---|---|
int |
The difference between the current total space and previous layout's total space. |
See also:
int getTransformedEndWithDecoration (View view)
Returns the end of the View after its matrix transformations are applied to its layout position.
This method is useful when trying to detect the visible edge of a View.
It includes the decorations but does not include the margins.
| Parameters | |
|---|---|
view |
View:
The view whose transformed end will be returned |
| Returns | |
|---|---|
int |
The end of the View after its decor insets and transformation matrix is applied to its position |
int getTransformedStartWithDecoration (View view)
Returns the start of the View after its matrix transformations are applied to its layout position.
This method is useful when trying to detect the visible edge of a View.
It includes the decorations but does not include the margins.
| Parameters | |
|---|---|
view |
View:
The view whose transformed start will be returned |
| Returns | |
|---|---|
int |
The start of the View after its decor insets and transformation matrix is applied to its position |
void offsetChild (View view, int offset)
Offsets the child in this orientation.
| Parameters | |
|---|---|
view |
View:
View to offset |
offset |
int:
offset amount
|
void offsetChildren (int amount)
Offsets all children's positions by the given amount.
| Parameters | |
|---|---|
amount |
int:
Value to add to each child's layout parameters
|
void onLayoutComplete ()
Call this method after onLayout method is complete if state is NOT pre-layout. This method records information like layout bounds that might be useful in the next layout calculations.
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