RenderNode
class RenderNode
kotlin.Any | |
↳ | android.graphics.RenderNode |
RenderNode is used to build hardware accelerated rendering hierarchies. Each RenderNode contains both a display list as well as a set of properties that affect the rendering of the display list. RenderNodes are used internally for all Views by default and are not typically used directly.
RenderNodes are used to divide up the rendering content of a complex scene into smaller pieces that can then be updated individually more cheaply. Updating part of the scene only needs to update the display list or properties of a small number of RenderNode instead of redrawing everything from scratch. A RenderNode only needs its display list re-recorded when its content alone should be changed. RenderNodes can also be transformed without re-recording the display list through the transform properties.
A text editor might for instance store each paragraph into its own RenderNode. Thus when the user inserts or removes characters, only the display list of the affected paragraph needs to be recorded again.
Hardware acceleration
RenderNodes can be drawn using a RecordingCanvas
. They are not supported in software. Always make sure that the android.graphics.Canvas
you are using to render a display list is hardware accelerated using android.graphics.Canvas#isHardwareAccelerated()
.
Creating a RenderNode
RenderNode renderNode = new RenderNode("myRenderNode"); renderNode.setPosition(0, 0, 50, 50); // Set the size to 50x50 RecordingCanvas canvas = renderNode.beginRecording(); try { // Draw with the canvas canvas.drawRect(...); } finally { renderNode.endRecording(); }
Drawing a RenderNode in a View
protected void onDraw(Canvas canvas) { if (canvas.isHardwareAccelerated()) { // Check that the RenderNode has a display list, re-recording it if it does not. if (!myRenderNode.hasDisplayList()) { updateDisplayList(myRenderNode); } // Draw the RenderNode into this canvas. canvas.drawRenderNode(myRenderNode); } }
Releasing resources
This step is not mandatory but recommended if you want to release resources held by a display list as soon as possible. Most significantly any bitmaps it may contain.
// Discards the display list content allowing for any held resources to be released. // After calling this renderNode.discardDisplayList();
Properties
In addition, a RenderNode offers several properties, such as setScaleX(float)
or setTranslationX(float)
, that can be used to affect all the drawing commands recorded within. For instance, these properties can be used to move around a large number of images without re-issuing all the individual canvas.drawBitmap()
calls.
private void createDisplayList() { mRenderNode = new RenderNode("MyRenderNode"); mRenderNode.setPosition(0, 0, width, height); RecordingCanvas canvas = mRenderNode.beginRecording(); try { for (Bitmap b : mBitmaps) { canvas.drawBitmap(b, 0.0f, 0.0f, null); canvas.translate(0.0f, b.getHeight()); } } finally { mRenderNode.endRecording(); } } protected void onDraw(Canvas canvas) { if (canvas.isHardwareAccelerated()) canvas.drawRenderNode(mRenderNode); } } private void moveContentBy(int x) { // This will move all the bitmaps recorded inside the display list // by x pixels to the right and redraw this view. All the commands // recorded in createDisplayList() won't be re-issued, only onDraw() // will be invoked and will execute very quickly mRenderNode.offsetLeftAndRight(x); invalidate(); }
A few of the properties may at first appear redundant, such as setElevation(float)
and setTranslationZ(float)
. The reason for these duplicates are to allow for a separation between static & transient usages. For example consider a button that raises from 2dp to 8dp when pressed. To achieve that an application may decide to setElevation(2dip), and then on press to animate setTranslationZ to 6dip. Combined this achieves the final desired 8dip value, but the animation need only concern itself with animating the lift from press without needing to know the initial starting value. setTranslationX(float)
and setTranslationY(float)
are similarly provided for animation uses despite the functional overlap with setPosition(android.graphics.Rect)
.
The RenderNode's transform matrix is computed at render time as follows:
Matrix transform = new Matrix(); transform.setTranslate(renderNode.getTranslationX(), renderNode.getTranslationY()); transform.preRotate(renderNode.getRotationZ(), renderNode.getPivotX(), renderNode.getPivotY()); transform.preScale(renderNode.getScaleX(), renderNode.getScaleY(), renderNode.getPivotX(), renderNode.getPivotY());
renderNode.setTranslationX(100); renderNode.setScaleX(100);
renderNode.setScaleX(100); renderNode.setTranslationX(100);
Threading
RenderNode may be created and used on any thread but they are not thread-safe. Only a single thread may interact with a RenderNode at any given time. It is critical that the RenderNode is only used on the same thread it is drawn with. For example when using RenderNode with a custom View, then that RenderNode must only be used from the UI thread.
When to re-render
Many of the RenderNode mutation methods, such as setTranslationX(float)
, return a boolean indicating if the value actually changed or not. This is useful in detecting if a new frame should be rendered or not. A typical usage would look like:
public void translateTo(int x, int y) { boolean needsUpdate = myRenderNode.setTranslationX(x); needsUpdate |= myRenderNode.setTranslationY(y); if (needsUpdate) { myOwningView.invalidate(); } }
getTranslationX()
as it minimizes JNI transitions. The actual mechanism of requesting a new frame to be rendered will depend on how this RenderNode is being drawn. If it's drawn to a containing View, as in the above snippet, then simply invalidating that View works. If instead the RenderNode is being drawn to a Canvas directly such as with Surface#lockHardwareCanvas()
then a new frame needs to be drawn by calling Surface#lockHardwareCanvas()
, re-drawing the root RenderNode or whatever top-level content is desired, and finally calling Surface#unlockCanvasAndPost(Canvas)
.
Summary
Public constructors | |
---|---|
RenderNode(name: String?) Creates a new RenderNode that can be used to record batches of drawing operations, and store / apply render properties when drawn. |
Public methods | |
---|---|
RecordingCanvas |
beginRecording(width: Int, height: Int) Starts recording a display list for the render node. |
RecordingCanvas |
Same as |
Long |
Gets the approximate memory usage of the RenderNode for debug purposes. |
Unit |
Reset native resources. |
Unit |
` Ends the recording for this display list. |
Float |
getAlpha() Returns the translucency level of this display list. |
Int | |
Int |
Gets the bottom position for the RenderNode. |
Float |
Returns the distance in Z of the camera for this RenderNode |
Boolean |
Returns whether or not the RenderNode is clipping to its bounds. |
Boolean | |
Float | |
Int |
Gets the height of the RenderNode, which is the bottom - top. |
Unit |
getInverseMatrix(outMatrix: Matrix) Gets the current transform inverted. |
Int |
getLeft() Gets the left position for the RenderNode. |
Unit |
Gets the current transform matrix |
Float |
Returns the pivot value for this display list on the X axis, in pixels. |
Float |
Returns the pivot value for this display list on the Y axis, in pixels. |
Int |
getRight() Gets the right position for the RenderNode. |
Float |
Returns the rotation value for this display list around the X axis, in degrees. |
Float |
Returns the rotation value for this display list around the Y axis, in degrees. |
Float |
Returns the rotation value for this display list around the Z axis, in degrees. |
Float |
Returns the scale value for this display list on the X axis. |
Float |
Returns the scale value for this display list on the Y axis. |
Int | |
Int |
getTop() Gets the top position for the RenderNode. |
Float |
Returns the translation value for this display list on the X axis, in pixels. |
Float |
Returns the translation value for this display list on the Y axis, in pixels. |
Float |
Returns the translation value for this display list on the Z axis. |
Long |
Returns the unique ID that identifies this RenderNode. |
Boolean |
Gets whether or not a compositing layer is forced to be used. |
Int |
getWidth() Gets the width of the RenderNode, which is the right - left. |
Boolean |
Returns whether the RenderNode has a display list. |
Boolean |
Whether or not the RenderNode has an identity transform. |
Boolean |
Indicates whether the content of this display list overlaps. |
Boolean |
Checks if the RenderNode has a shadow. |
Boolean | |
Boolean | |
Boolean |
offsetLeftAndRight(offset: Int) Offsets the left and right positions for the RenderNode |
Boolean |
offsetTopAndBottom(offset: Int) Offsets the top and bottom values for the RenderNode |
Boolean |
Clears any pivot previously set by a call to |
Boolean |
Sets the translucency level for the display list. |
Boolean |
setAmbientShadowColor(color: Int) Sets the color of the ambient shadow that is drawn when the RenderNode has a positive Z or elevation value and is drawn inside of a |
Boolean |
setCameraDistance(distance: Float) Sets the distance along the Z axis (orthogonal to the X/Y plane on which RenderNodes are drawn) from the camera to this RenderNode. |
Boolean |
setClipRect(rect: Rect?) Sets an additional clip on the RenderNode. |
Boolean |
setClipToBounds(clipToBounds: Boolean) Set whether the Render node should clip itself to its bounds. |
Boolean |
setClipToOutline(clipToOutline: Boolean) Enables or disables clipping to the outline. |
Boolean |
setElevation(lift: Float) Sets the base elevation of this RenderNode in pixels |
Boolean |
setForceDarkAllowed(allow: Boolean) Sets whether or not to allow force dark to apply to this RenderNode. |
Boolean |
setHasOverlappingRendering(hasOverlappingRendering: Boolean) Sets whether the display list renders content which overlaps. |
Boolean |
setOutline(outline: Outline?) Sets the outline, defining the shape that casts a shadow, and the path to be clipped if setClipToOutline is set. |
Boolean |
Sets the pivot value for the display list on the X axis |
Boolean |
Sets the pivot value for the display list on the Y axis |
Boolean |
setPosition(left: Int, top: Int, right: Int, bottom: Int) Sets the position of the RenderNode. |
Boolean |
setPosition(position: Rect) Sets the position of the RenderNode. |
Boolean |
setProjectBackwards(shouldProject: Boolean) Sets whether the RenderNode should be drawn immediately after the closest ancestor RenderNode containing a projection receiver. |
Boolean |
setProjectionReceiver(shouldReceive: Boolean) Sets whether the RenderNode is a projection receiver. |
Boolean |
setRenderEffect(renderEffect: RenderEffect?) Configure the |
Boolean |
setRotationX(rotationX: Float) Sets the rotation value for the display list around the X axis. |
Boolean |
setRotationY(rotationY: Float) Sets the rotation value for the display list around the Y axis. |
Boolean |
setRotationZ(rotation: Float) Sets the rotation value for the display list around the Z axis. |
Boolean |
Sets the scale value for the display list on the X axis. |
Boolean |
Sets the scale value for the display list on the Y axis. |
Boolean |
setSpotShadowColor(color: Int) Sets the color of the spot shadow that is drawn when the RenderNode has a positive Z or elevation value and is drawn inside of a |
Boolean |
setTranslationX(translationX: Float) Sets the translation value for the display list on the X axis. |
Boolean |
setTranslationY(translationY: Float) Sets the translation value for the display list on the Y axis. |
Boolean |
setTranslationZ(translationZ: Float) Sets the translation value for the display list on the Z axis. |
Boolean |
setUseCompositingLayer(forceToLayer: Boolean, paint: Paint?) Controls whether or not to force this RenderNode to render to an intermediate buffer. |
Public constructors
RenderNode
RenderNode(name: String?)
Creates a new RenderNode that can be used to record batches of drawing operations, and store / apply render properties when drawn.
Parameters | |
---|---|
name |
String?: The name of the RenderNode, used for debugging purpose. May be null. |
Public methods
beginRecording
fun beginRecording(
width: Int,
height: Int
): RecordingCanvas
Starts recording a display list for the render node. All operations performed on the returned canvas are recorded and stored in this display list. endRecording()
must be called when the recording is finished in order to apply the updated display list. Failing to call endRecording()
will result in an IllegalStateException
if beginRecording(int,int)
is called again.
Parameters | |
---|---|
width |
Int: The width of the recording viewport. This will not alter the width of the RenderNode itself, that must be set with setPosition(android.graphics.Rect) . |
height |
Int: The height of the recording viewport. This will not alter the height of the RenderNode itself, that must be set with setPosition(android.graphics.Rect) . |
Return | |
---|---|
RecordingCanvas |
A canvas to record drawing operations. This value cannot be null . |
Exceptions | |
---|---|
java.lang.IllegalStateException |
If a recording is already in progress. That is, the previous call to beginRecording(int,int) did not call endRecording() . |
See Also
beginRecording
fun beginRecording(): RecordingCanvas
Same as beginRecording(int,int)
with the width & height set to the RenderNode's own width & height. The RenderNode's width & height may be set with setPosition(int,int,int,int)
.
Return | |
---|---|
RecordingCanvas |
A canvas to record drawing operations. This value cannot be null . |
Exceptions | |
---|---|
java.lang.IllegalStateException |
If a recording is already in progress. That is, the previous call to beginRecording(int,int) did not call endRecording() . |
See Also
computeApproximateMemoryUsage
fun computeApproximateMemoryUsage(): Long
Gets the approximate memory usage of the RenderNode for debug purposes. Does not include the memory usage of any child RenderNodes nor any bitmaps, only the memory usage of this RenderNode and any data it owns.
Value is a non-negative number of bytes.
Return | |
---|---|
Long |
Approximate memory usage in bytes. Value is a non-negative number of bytes. |
discardDisplayList
fun discardDisplayList(): Unit
Reset native resources. This is called when cleaning up the state of display lists during destruction of hardware resources, to ensure that we do not hold onto obsolete resources after related resources are gone.
endRecording
fun endRecording(): Unit
` Ends the recording for this display list. Calling this method marks the display list valid and hasDisplayList()
will return true.
getAlpha
fun getAlpha(): Float
Returns the translucency level of this display list.
Return | |
---|---|
Float |
A value between 0.0f and 1.0f |
See Also
getAmbientShadowColor
fun getAmbientShadowColor(): Int
Return | |
---|---|
Int |
The shadow color set by setAmbientShadowColor(int) , or black if nothing was set |
getBottom
fun getBottom(): Int
Gets the bottom position for the RenderNode.
Return | |
---|---|
Int |
the bottom position in pixels |
getCameraDistance
fun getCameraDistance(): Float
Returns the distance in Z of the camera for this RenderNode
Return | |
---|---|
Float |
the distance along the Z axis in pixels. Value is between 0.0f and Float.MAX_VALUE inclusive |
See Also
getClipToBounds
fun getClipToBounds(): Boolean
Returns whether or not the RenderNode is clipping to its bounds. See setClipToBounds(boolean)
and setPosition(int,int,int,int)
Return | |
---|---|
Boolean |
true if the render node clips to its bounds, false otherwise. |
getClipToOutline
fun getClipToOutline(): Boolean
Return | |
---|---|
Boolean |
True if this RenderNode clips to its outline, false otherwise |
getElevation
fun getElevation(): Float
Return | |
---|---|
Float |
The RenderNode's current elevation |
getHeight
fun getHeight(): Int
Gets the height of the RenderNode, which is the bottom - top.
Return | |
---|---|
Int |
the height of the RenderNode |
getInverseMatrix
fun getInverseMatrix(outMatrix: Matrix): Unit
Gets the current transform inverted. This is a faster way to do the otherwise equivalent getMatrix(android.graphics.Matrix)
followed by Matrix#invert(Matrix)
Parameters | |
---|---|
outMatrix |
Matrix: The matrix to store the inverse transform of the RenderNode This value cannot be null . |
getLeft
fun getLeft(): Int
Gets the left position for the RenderNode.
Return | |
---|---|
Int |
the left position in pixels |
getMatrix
fun getMatrix(outMatrix: Matrix): Unit
Gets the current transform matrix
Parameters | |
---|---|
outMatrix |
Matrix: The matrix to store the transform of the RenderNode This value cannot be null . |
getPivotX
fun getPivotX(): Float
Returns the pivot value for this display list on the X axis, in pixels.
See Also
getPivotY
fun getPivotY(): Float
Returns the pivot value for this display list on the Y axis, in pixels.
See Also
getRight
fun getRight(): Int
Gets the right position for the RenderNode.
Return | |
---|---|
Int |
the right position in pixels |
getRotationX
fun getRotationX(): Float
Returns the rotation value for this display list around the X axis, in degrees.
See Also
getRotationY
fun getRotationY(): Float
Returns the rotation value for this display list around the Y axis, in degrees.
See Also
getRotationZ
fun getRotationZ(): Float
Returns the rotation value for this display list around the Z axis, in degrees.
See Also
getScaleX
fun getScaleX(): Float
Returns the scale value for this display list on the X axis.
See Also
getScaleY
fun getScaleY(): Float
Returns the scale value for this display list on the Y axis.
See Also
getSpotShadowColor
fun getSpotShadowColor(): Int
Return | |
---|---|
Int |
The shadow color set by setSpotShadowColor(int) , or black if nothing was set |
getTop
fun getTop(): Int
Gets the top position for the RenderNode.
Return | |
---|---|
Int |
the top position in pixels |
getTranslationX
fun getTranslationX(): Float
Returns the translation value for this display list on the X axis, in pixels.
See Also
getTranslationY
fun getTranslationY(): Float
Returns the translation value for this display list on the Y axis, in pixels.
See Also
getTranslationZ
fun getTranslationZ(): Float
Returns the translation value for this display list on the Z axis.
See Also
getUniqueId
fun getUniqueId(): Long
Returns the unique ID that identifies this RenderNode. This ID is unique for the lifetime of the process. IDs are reset on process death, and are unique only within the process. This ID is intended to be used with debugging tools to associate a particular RenderNode across different debug dumping & inspection tools. For example a View layout inspector should include the unique ID for any RenderNodes that it owns to associate the drawing content with the layout content.
Return | |
---|---|
Long |
the unique ID for this RenderNode |
getUseCompositingLayer
fun getUseCompositingLayer(): Boolean
Gets whether or not a compositing layer is forced to be used. The default & recommended is false, as it is typically faster to avoid using compositing layers. See setUseCompositingLayer(boolean,android.graphics.Paint)
.
Return | |
---|---|
Boolean |
true if a compositing layer is forced, false otherwise |
getWidth
fun getWidth(): Int
Gets the width of the RenderNode, which is the right - left.
Return | |
---|---|
Int |
the width of the RenderNode |
hasDisplayList
fun hasDisplayList(): Boolean
Returns whether the RenderNode has a display list. If this returns false, the RenderNode should be re-recorded with beginRecording()
and endRecording()
. A RenderNode without a display list may still be drawn, however it will have no impact on the rendering content until its display list is updated. When a RenderNode is no longer drawn by anything the system may automatically invoke discardDisplayList()
. It is therefore important to ensure that hasDisplayList()
is true on a RenderNode prior to drawing it. See discardDisplayList()
Return | |
---|---|
Boolean |
boolean true if this RenderNode has a display list, false otherwise. |
hasIdentityMatrix
fun hasIdentityMatrix(): Boolean
Whether or not the RenderNode has an identity transform. This is a faster way to do the otherwise equivalent getMatrix(android.graphics.Matrix)
Matrix#isIdentity()
as it doesn't require copying the Matrix first, thus minimizing overhead.
Return | |
---|---|
Boolean |
true if the RenderNode has an identity transform, false otherwise |
hasOverlappingRendering
fun hasOverlappingRendering(): Boolean
Indicates whether the content of this display list overlaps.
Return | |
---|---|
Boolean |
True if this display list renders content which overlaps, false otherwise. |
See Also
hasShadow
fun hasShadow(): Boolean
Checks if the RenderNode has a shadow. That is, if the combination of getElevation()
and getTranslationZ()
is greater than zero, there is an Outline
set with a valid shadow caster path, and the provided outline has a non-zero Outline#getAlpha()
.
Return | |
---|---|
Boolean |
True if this RenderNode has a shadow, false otherwise |
isForceDarkAllowed
fun isForceDarkAllowed(): Boolean
See setForceDarkAllowed(boolean)
Return | |
---|---|
Boolean |
true if force dark is allowed (default), false if it is disabled |
isPivotExplicitlySet
fun isPivotExplicitlySet(): Boolean
Return | |
---|---|
Boolean |
Whether or not a pivot was explicitly set with setPivotX(float) or setPivotY(float) . If no pivot has been set then the pivot will be the center of the RenderNode. |
offsetLeftAndRight
fun offsetLeftAndRight(offset: Int): Boolean
Offsets the left and right positions for the RenderNode
Parameters | |
---|---|
offset |
Int: The amount that the left and right positions are offset in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
offsetTopAndBottom
fun offsetTopAndBottom(offset: Int): Boolean
Offsets the top and bottom values for the RenderNode
Parameters | |
---|---|
offset |
Int: The amount that the left and right positions are offset in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
resetPivot
fun resetPivot(): Boolean
Clears any pivot previously set by a call to setPivotX(float)
or setPivotY(float)
. After calling this isPivotExplicitlySet()
will be false and the pivot used for rotation will return to default of being centered on the view.
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setAlpha
fun setAlpha(alpha: Float): Boolean
Sets the translucency level for the display list.
Parameters | |
---|---|
alpha |
Float: The translucency of the display list, must be a value between 0.0f and 1.0f |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setAmbientShadowColor
fun setAmbientShadowColor(color: Int): Boolean
Sets the color of the ambient shadow that is drawn when the RenderNode has a positive Z or elevation value and is drawn inside of a Canvas#enableZ()
section.
By default the shadow color is black. Generally, this color will be opaque so the intensity of the shadow is consistent between different RenderNodes with different colors.
The opacity of the final ambient shadow is a function of the shadow caster height, the alpha channel of the outlineAmbientShadowColor (typically opaque), and the android.R.attr#ambientShadowAlpha
theme attribute.
Parameters | |
---|---|
color |
Int: The color this RenderNode will cast for its elevation shadow. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setCameraDistance
fun setCameraDistance(distance: Float): Boolean
Sets the distance along the Z axis (orthogonal to the X/Y plane on which RenderNodes are drawn) from the camera to this RenderNode. The camera's distance affects 3D transformations, for instance rotations around the X and Y axis. If the rotationX or rotationY properties are changed and this view is large (more than half the size of the screen), it is recommended to always use a camera distance that's greater than the height (X axis rotation) or the width (Y axis rotation) of this view.
The distance of the camera from the drawing plane can have an affect on the perspective distortion of the RenderNode when it is rotated around the x or y axis. For example, a large distance will result in a large viewing angle, and there will not be much perspective distortion of the view as it rotates. A short distance may cause much more perspective distortion upon rotation, and can also result in some drawing artifacts if the rotated view ends up partially behind the camera (which is why the recommendation is to use a distance at least as far as the size of the view, if the view is to be rotated.)
The distance is expressed in pixels and must always be positive
Parameters | |
---|---|
distance |
Float: The distance in pixels, must always be positive Value is between 0.0f and Float.MAX_VALUE inclusive |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
See Also
setClipRect
fun setClipRect(rect: Rect?): Boolean
Sets an additional clip on the RenderNode. If null, the extra clip is removed from the RenderNode. If non-null, the RenderNode will be clipped to this rect. In addition if setClipToBounds(boolean)
is true, then the RenderNode will be clipped to the intersection of this rectangle and the bounds of the render node, which is set with setPosition(android.graphics.Rect)
.
This is equivalent to do a Canvas#clipRect(Rect)
at the start of this RenderNode's display list. However, as this is a property of the RenderNode instead of part of the display list it can be more easily animated for transient additional clipping. An example usage of this would be the android.transition.ChangeBounds
transition animation with the resizeClip=true option.
Parameters | |
---|---|
rect |
Rect?: the bounds to clip to. If null, the additional clip is removed. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setClipToBounds
fun setClipToBounds(clipToBounds: Boolean): Boolean
Set whether the Render node should clip itself to its bounds. This defaults to true, and is useful to the renderer in enable quick-rejection of chunks of the tree as well as better partial invalidation support. Clipping can be further restricted or controlled through the combination of this property as well as setClipRect(android.graphics.Rect)
, which allows for a different clipping rectangle to be used in addition to or instead of the setPosition(int,int,int,int)
or the RenderNode.
Parameters | |
---|---|
clipToBounds |
Boolean: true if the display list should clip to its bounds, false otherwise. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setClipToOutline
fun setClipToOutline(clipToOutline: Boolean): Boolean
Enables or disables clipping to the outline.
Parameters | |
---|---|
clipToOutline |
Boolean: true if clipping to the outline. |
Return | |
---|---|
Boolean |
True if the clipToOutline value changed, false if previous value matched the new value. |
setElevation
fun setElevation(lift: Float): Boolean
Sets the base elevation of this RenderNode in pixels
Parameters | |
---|---|
lift |
Float: the elevation in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setForceDarkAllowed
fun setForceDarkAllowed(allow: Boolean): Boolean
Sets whether or not to allow force dark to apply to this RenderNode. Setting this to false will disable the auto-dark feature on everything this RenderNode draws, including any descendants. Setting this to true will allow this RenderNode to be automatically made dark, however a value of 'true' will not override any 'false' value in its parent chain nor will it prevent any 'false' in any of its children.
Parameters | |
---|---|
allow |
Boolean: Whether or not to allow force dark. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setHasOverlappingRendering
fun setHasOverlappingRendering(hasOverlappingRendering: Boolean): Boolean
Sets whether the display list renders content which overlaps. Non-overlapping rendering can use a fast path for alpha that avoids rendering to an offscreen buffer. By default display lists consider they do not have overlapping content.
Parameters | |
---|---|
hasOverlappingRendering |
Boolean: False if the content is guaranteed to be non-overlapping, true otherwise. |
setOutline
fun setOutline(outline: Outline?): Boolean
Sets the outline, defining the shape that casts a shadow, and the path to be clipped if setClipToOutline is set. This will make a copy of the provided Outline
, so any future modifications to the outline will need to call setOutline(android.graphics.Outline)
with the modified outline for those changes to be applied.
Parameters | |
---|---|
outline |
Outline?: The outline to use for this RenderNode. This value may be null . |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setPivotX
fun setPivotX(pivotX: Float): Boolean
Sets the pivot value for the display list on the X axis
Parameters | |
---|---|
pivotX |
Float: The pivot value of the display list on the X axis, in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setPivotY
fun setPivotY(pivotY: Float): Boolean
Sets the pivot value for the display list on the Y axis
Parameters | |
---|---|
pivotY |
Float: The pivot value of the display list on the Y axis, in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setPosition
fun setPosition(
left: Int,
top: Int,
right: Int,
bottom: Int
): Boolean
Sets the position of the RenderNode.
Parameters | |
---|---|
left |
Int: The left position of the RenderNode, in pixels |
top |
Int: The top position of the RenderNode, in pixels |
right |
Int: The right position of the RenderNode, in pixels |
bottom |
Int: The bottom position of the RenderNode, in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setPosition
fun setPosition(position: Rect): Boolean
Sets the position of the RenderNode.
Parameters | |
---|---|
position |
Rect: The position rectangle in pixels This value cannot be null . |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setProjectBackwards
fun setProjectBackwards(shouldProject: Boolean): Boolean
Sets whether the RenderNode should be drawn immediately after the closest ancestor RenderNode containing a projection receiver.
The default is false, and the rendering of this node happens in the typical draw order.
If true, then at rendering time this rendernode will not be drawn in order with the Canvas#drawRenderNode(RenderNode)
command that drew this RenderNode, but instead it will be re-positioned in the RenderNode tree to be drawn on the closet ancestor with a child rendernode that has setProjectionReceiver(boolean)
as true.
The typical usage of this is to allow a child RenderNode to draw on a parent's background, such as the platform's usage with android.graphics.drawable.RippleDrawable
. Consider the following structure, built out of which RenderNode called drawRenderNode on a different RenderNode:
+-------------+ |RenderNode: P| +-+----------++ | | v v +-------+-----+ +-+--------------+ |RenderNode: C| |RenderNode: P'BG| +-------+-----+ +----------------+ | | +--------+-------+ |RenderNode: C'BG| +----------------+
Parameters | |
---|---|
shouldProject |
Boolean: true if the display list should be projected onto a containing volume. Default is false. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setProjectionReceiver
fun setProjectionReceiver(shouldReceive: Boolean): Boolean
Sets whether the RenderNode is a projection receiver. If true then this RenderNode's parent should draw any descendant RenderNodes with ProjectBackwards=true directly on top of it. Default value is false. See setProjectBackwards(boolean)
for a description of what this entails.
Parameters | |
---|---|
shouldReceive |
Boolean: True if this RenderNode is a projection receiver, false otherwise. Default is false. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setRenderEffect
fun setRenderEffect(renderEffect: RenderEffect?): Boolean
Configure the android.graphics.RenderEffect
to apply to this RenderNode. This will apply a visual effect to the end result of the contents of this RenderNode before it is drawn into the destination. For example if RenderEffect#createBlurEffect(float, float, RenderEffect, Shader.TileMode)
is provided, the contents will be drawn in a separate layer, then this layer will be blurred when this RenderNode is drawn into the destination.
Parameters | |
---|---|
renderEffect |
RenderEffect?: to be applied to the RenderNode. Passing null clears all previously configured RenderEffects |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setRotationX
fun setRotationX(rotationX: Float): Boolean
Sets the rotation value for the display list around the X axis.
Parameters | |
---|---|
rotationX |
Float: The rotation value of the display list, in degrees |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setRotationY
fun setRotationY(rotationY: Float): Boolean
Sets the rotation value for the display list around the Y axis.
Parameters | |
---|---|
rotationY |
Float: The rotation value of the display list, in degrees |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setRotationZ
fun setRotationZ(rotation: Float): Boolean
Sets the rotation value for the display list around the Z axis.
Parameters | |
---|---|
rotation |
Float: The rotation value of the display list, in degrees |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setScaleX
fun setScaleX(scaleX: Float): Boolean
Sets the scale value for the display list on the X axis.
Parameters | |
---|---|
scaleX |
Float: The scale value of the display list |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setScaleY
fun setScaleY(scaleY: Float): Boolean
Sets the scale value for the display list on the Y axis.
Parameters | |
---|---|
scaleY |
Float: The scale value of the display list |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setSpotShadowColor
fun setSpotShadowColor(color: Int): Boolean
Sets the color of the spot shadow that is drawn when the RenderNode has a positive Z or elevation value and is drawn inside of a Canvas#enableZ()
section.
By default the shadow color is black. Generally, this color will be opaque so the intensity of the shadow is consistent between different RenderNodes with different colors.
The opacity of the final spot shadow is a function of the shadow caster height, the alpha channel of the outlineSpotShadowColor (typically opaque), and the android.R.attr#spotShadowAlpha
theme attribute
Parameters | |
---|---|
color |
Int: The color this RenderNode will cast for its elevation spot shadow. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setTranslationX
fun setTranslationX(translationX: Float): Boolean
Sets the translation value for the display list on the X axis.
Parameters | |
---|---|
translationX |
Float: The X axis translation value of the display list, in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setTranslationY
fun setTranslationY(translationY: Float): Boolean
Sets the translation value for the display list on the Y axis.
Parameters | |
---|---|
translationY |
Float: The Y axis translation value of the display list, in pixels |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setTranslationZ
fun setTranslationZ(translationZ: Float): Boolean
Sets the translation value for the display list on the Z axis.
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |
setUseCompositingLayer
fun setUseCompositingLayer(
forceToLayer: Boolean,
paint: Paint?
): Boolean
Controls whether or not to force this RenderNode to render to an intermediate buffer. Internally RenderNode will already promote itself to a composition layer if it's useful for performance or required for the current combination of setAlpha(float)
and setHasOverlappingRendering(boolean)
.
The usage of this is instead to allow for either overriding of the internal behavior if it's measured to be necessary for the particular rendering content in question or, more usefully, to add a composition effect to the RenderNode via the optional paint parameter.
Note: When a RenderNode is using a compositing layer it will also result in clipToBounds=true behavior.
Parameters | |
---|---|
forceToLayer |
Boolean: if true this forces the RenderNode to use an intermediate buffer. Default & generally recommended value is false. |
paint |
Paint?: The blend mode, alpha, and ColorFilter to apply to the compositing layer. Only applies if forceToLayer is true. The paint's alpha is multiplied with getAlpha() to resolve the final alpha of the RenderNode. If null then no additional composition effects are applied on top of the composition layer. |
Return | |
---|---|
Boolean |
True if the value changed, false if the new value was the same as the previous value. |