Class BlockView

javax.swing.text.html.BlockView

All Implemented Interfaces:: SwingConstants

Direct Known Subclasses:: ListView

public class BlockView extends BoxView

A view implementation to display a block (as a box) with CSS specifications.

Field Summary

Fields declared in class View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Modifier and Type	Field	Description
`static final int`	`BadBreakWeight`	The weight to indicate a view is a bad break opportunity for the purpose of formatting.
`static final int`	`ExcellentBreakWeight`	The weight to indicate a view supports breaking, and this represents a very attractive place to break.
`static final int`	`ForcedBreakWeight`	The weight to indicate a view supports breaking, and must be broken to be represented properly when placed in a view that formats its children by breaking them.
`static final int`	`GoodBreakWeight`	The weight to indicate a view supports breaking, but better opportunities probably exist.
`static final int`	`X_AXIS`	Axis for format/break operations.
`static final int`	`Y_AXIS`	Axis for format/break operations.

Fields declared in interface SwingConstants

BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST

Modifier and Type	Field	Description
`static final int`	`BOTTOM`	Box-orientation constant used to specify the bottom of a box.
`static final int`	`CENTER`	The central position in an area.
`static final int`	`EAST`	Compass-direction east (right).
`static final int`	`HORIZONTAL`	Horizontal orientation.
`static final int`	`LEADING`	Identifies the leading edge of text for use with left-to-right and right-to-left languages.
`static final int`	`LEFT`	Box-orientation constant used to specify the left side of a box.
`static final int`	`NEXT`	Identifies the next direction in a sequence.
`static final int`	`NORTH`	Compass-direction North (up).
`static final int`	`NORTH_EAST`	Compass-direction north-east (upper right).
`static final int`	`NORTH_WEST`	Compass-direction north west (upper left).
`static final int`	`PREVIOUS`	Identifies the previous direction in a sequence.
`static final int`	`RIGHT`	Box-orientation constant used to specify the right side of a box.
`static final int`	`SOUTH`	Compass-direction south (down).
`static final int`	`SOUTH_EAST`	Compass-direction south-east (lower right).
`static final int`	`SOUTH_WEST`	Compass-direction south-west (lower left).
`static final int`	`TOP`	Box-orientation constant used to specify the top of a box.
`static final int`	`TRAILING`	Identifies the trailing edge of text for use with left-to-right and right-to-left languages.
`static final int`	`VERTICAL`	Vertical orientation.
`static final int`	`WEST`	Compass-direction west (left).

Constructor Summary

Constructor	Description
`BlockView(Element elem, int axis)`	Creates a new view that represents an html box.

Method Summary

Modifier and Type	Method	Description
`protected SizeRequirements`	`calculateMajorAxisRequirements(int axis, SizeRequirements r)`	Calculate the requirements of the block along the major axis (i.e. the axis along with it tiles).
`protected SizeRequirements`	`calculateMinorAxisRequirements(int axis, SizeRequirements r)`	Calculate the requirements of the block along the minor axis (i.e. the axis orthogonal to the axis along with it tiles).
`float`	`getAlignment(int axis)`	Gets the alignment.
`AttributeSet`	`getAttributes()`	Fetches the attributes to use when rendering.
`float`	`getMaximumSpan(int axis)`	Determines the maximum span for this view along an axis.
`float`	`getMinimumSpan(int axis)`	Determines the minimum span for this view along an axis.
`float`	`getPreferredSpan(int axis)`	Determines the preferred span for this view along an axis.
`int`	`getResizeWeight(int axis)`	Gets the resize weight.
`protected StyleSheet`	`getStyleSheet()`	Convenient method to get the StyleSheet.
`protected void`	`layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans)`	Performs layout for the minor axis of the box (i.e. the axis orthogonal to the axis that it represents).
`void`	`paint(Graphics g, Shape allocation)`	Renders using the given rendering surface and area on that surface.
`void`	`setParent(View parent)`	Establishes the parent view for this view.
`protected void`	`setPropertiesFromAttributes()`	Update any cached values that come from attributes.

Methods declared in class BoxView

baselineLayout, baselineRequirements, childAllocation, flipEastAndWestAtEnds, forwardUpdate, getAxis, getChildAllocation, getHeight, getOffset, getSpan, getViewAtPoint, getWidth, isAfter, isAllocationValid, isBefore, isLayoutValid, layout, layoutChanged, layoutMajorAxis, modelToView, paintChild, preferenceChanged, replace, setAxis, setSize, viewToModel

Modifier and Type	Method	Description
`protected void`	`baselineLayout(int targetSpan, int axis, int[] offsets, int[] spans)`	Computes the location and extent of each child view in this `BoxView` given the `targetSpan`, which is the width (or height) of the region we have to work with.
`protected SizeRequirements`	`baselineRequirements(int axis, SizeRequirements r)`	Calculates the size requirements for this `BoxView` by examining the size of each child view.
`protected void`	`childAllocation(int index, Rectangle alloc)`	Allocates a region for a child view.
`protected boolean`	`flipEastAndWestAtEnds(int position, Position.Bias bias)`	Determines in which direction the next view lays.
`protected void`	`forwardUpdate(DocumentEvent.ElementChange ec, DocumentEvent e, Shape a, ViewFactory f)`	Forwards the given `DocumentEvent` to the child views that need to be notified of the change to the model.
`int`	`getAxis()`	Fetches the tile axis property.
`Shape`	`getChildAllocation(int index, Shape a)`	Fetches the allocation for the given child view.
`int`	`getHeight()`	Returns the current height of the box.
`protected int`	`getOffset(int axis, int childIndex)`	Fetches the offset of a particular child's current layout.
`protected int`	`getSpan(int axis, int childIndex)`	Fetches the span of a particular child's current layout.
`protected View`	`getViewAtPoint(int x, int y, Rectangle alloc)`	Fetches the child view at the given coordinates.
`int`	`getWidth()`	Returns the current width of the box.
`protected boolean`	`isAfter(int x, int y, Rectangle innerAlloc)`	Determines if a point falls after an allocated region.
`protected boolean`	`isAllocationValid()`	Are the allocations for the children still valid?
`protected boolean`	`isBefore(int x, int y, Rectangle innerAlloc)`	Determines if a point falls before an allocated region.
`protected boolean`	`isLayoutValid(int axis)`	Determines if the layout is valid along the given axis.
`protected void`	`layout(int width, int height)`	Perform layout on the box
`void`	`layoutChanged(int axis)`	Invalidates the layout along an axis.
`protected void`	`layoutMajorAxis(int targetSpan, int axis, int[] offsets, int[] spans)`	Performs layout for the major axis of the box (i.e. the axis that it represents).
`Shape`	`modelToView(int pos, Shape a, Position.Bias b)`	Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
`protected void`	`paintChild(Graphics g, Rectangle alloc, int index)`	Paints a child.
`void`	`preferenceChanged(View child, boolean width, boolean height)`	This is called by a child to indicate its preferred span has changed.
`void`	`replace(int index, int length, View[] elems)`	Invalidates the layout and resizes the cache of requests/allocations.
`void`	`setAxis(int axis)`	Sets the tile axis property.
`void`	`setSize(float width, float height)`	Sets the size of the view.
`int`	`viewToModel(float x, float y, Shape a, Position.Bias[] bias)`	Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Methods declared in class CompositeView

getBottomInset, getInsideAllocation, getLeftInset, getNextEastWestVisualPositionFrom, getNextNorthSouthVisualPositionFrom, getNextVisualPositionFrom, getRightInset, getTopInset, getView, getViewAtPosition, getViewCount, getViewIndex, getViewIndexAtPosition, loadChildren, modelToView, setInsets, setParagraphInsets

Modifier and Type	Method	Description
`protected short`	`getBottomInset()`	Gets the bottom inset.
`protected Rectangle`	`getInsideAllocation(Shape a)`	Translates the immutable allocation given to the view to a mutable allocation that represents the interior allocation (i.e. the bounds of the given allocation with the top, left, bottom, and right insets removed.
`protected short`	`getLeftInset()`	Gets the left inset.
`protected int`	`getNextEastWestVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet)`	Returns the next visual position for the cursor, in either the east or west direction.
`protected int`	`getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet)`	Returns the next visual position for the cursor, in either the north or south direction.
`int`	`getNextVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet)`	Provides a way to determine the next visually represented model location that one might place a caret.
`protected short`	`getRightInset()`	Gets the right inset.
`protected short`	`getTopInset()`	Gets the top inset.
`View`	`getView(int n)`	Returns the n-th view in this container.
`protected View`	`getViewAtPosition(int pos, Rectangle a)`	Fetches the child view that represents the given position in the model.
`int`	`getViewCount()`	Returns the number of child views of this view.
`int`	`getViewIndex(int pos, Position.Bias b)`	Returns the child view index representing the given position in the model.
`protected int`	`getViewIndexAtPosition(int pos)`	Fetches the child view index representing the given position in the model.
`protected void`	`loadChildren(ViewFactory f)`	Loads all of the children to initialize the view.
`Shape`	`modelToView(int p0, Position.Bias b0, int p1, Position.Bias b1, Shape a)`	Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
`protected void`	`setInsets(short top, short left, short bottom, short right)`	Sets the insets for the view.
`protected void`	`setParagraphInsets(AttributeSet attr)`	Sets the insets from the paragraph attributes specified in the given attributes.

Methods declared in class View

append, breakView, changedUpdate, createFragment, forwardUpdateToView, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getGraphics, getParent, getStartOffset, getToolTipText, getViewFactory, getViewIndex, insert, insertUpdate, isVisible, modelToView, remove, removeAll, removeUpdate, updateChildren, updateLayout, viewToModel

Modifier and Type	Method	Description
`void`	`append(View v)`	Appends a single child view.
`View`	`breakView(int axis, int offset, float pos, float len)`	Tries to break this view on the given axis.
`void`	`changedUpdate(DocumentEvent e, Shape a, ViewFactory f)`	Gives notification from the document that attributes were changed in a location that this view is responsible for.
`View`	`createFragment(int p0, int p1)`	Creates a view that represents a portion of the element.
`protected void`	`forwardUpdateToView(View v, DocumentEvent e, Shape a, ViewFactory f)`	Forwards the `DocumentEvent` to the give child view.
`int`	`getBreakWeight(int axis, float pos, float len)`	Determines how attractive a break opportunity in this view is.
`Container`	`getContainer()`	Fetches the container hosting the view.
`Document`	`getDocument()`	Fetches the model associated with the view.
`Element`	`getElement()`	Fetches the structural portion of the subject that this view is mapped to.
`int`	`getEndOffset()`	Fetches the portion of the model for which this view is responsible.
`Graphics`	`getGraphics()`	Fetch a `Graphics` for rendering.
`View`	`getParent()`	Returns the parent of the view.
`int`	`getStartOffset()`	Fetches the portion of the model for which this view is responsible.
`String`	`getToolTipText(float x, float y, Shape allocation)`	Returns the tooltip text at the specified location.
`ViewFactory`	`getViewFactory()`	Fetches the `ViewFactory` implementation that is feeding the view hierarchy.
`int`	`getViewIndex(float x, float y, Shape allocation)`	Returns the child view index representing the given position in the view.
`void`	`insert(int offs, View v)`	Inserts a single child view.
`void`	`insertUpdate(DocumentEvent e, Shape a, ViewFactory f)`	Gives notification that something was inserted into the document in a location that this view is responsible for.
`boolean`	`isVisible()`	Returns a boolean that indicates whether the view is visible or not.
`Shape`	`modelToView(int pos, Shape a)`	Deprecated.
`void`	`remove(int i)`	Removes one of the children at the given position.
`void`	`removeAll()`	Removes all of the children.
`void`	`removeUpdate(DocumentEvent e, Shape a, ViewFactory f)`	Gives notification that something was removed from the document in a location that this view is responsible for.
`protected boolean`	`updateChildren(DocumentEvent.ElementChange ec, DocumentEvent e, ViewFactory f)`	Updates the child views in response to receiving notification that the model changed, and there is change record for the element this view is responsible for.
`protected void`	`updateLayout(DocumentEvent.ElementChange ec, DocumentEvent e, Shape a)`	Updates the layout in response to receiving notification of change from the model.
`int`	`viewToModel(float x, float y, Shape a)`	Deprecated.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

BlockView

public BlockView(Element elem, int axis)

Creates a new view that represents an html box. This can be used for a number of elements.

Parameters:: elem - the element to create a view for; axis - either View.X_AXIS or View.Y_AXIS

Method Details

setParent

public void setParent(View parent)

Establishes the parent view for this view. This is guaranteed to be called before any other methods if the parent view is functioning properly.

This is implemented to forward to the superclass as well as call the setPropertiesFromAttributes() method to set the paragraph properties from the css attributes. The call is made at this time to ensure the ability to resolve upward through the parents view attributes.

Overrides:: setParent in class CompositeView
Parameters:: parent - the new parent, or null if the view is being removed from a parent it was previously added to

calculateMajorAxisRequirements

protected SizeRequirements calculateMajorAxisRequirements(int axis, SizeRequirements r)

Calculate the requirements of the block along the major axis (i.e. the axis along with it tiles). This is implemented to provide the superclass behavior and then adjust it if the CSS width or height attribute is specified and applicable to the axis.

Overrides:

calculateMajorAxisRequirements in class BoxView

Parameters:

axis - the axis being studied

r - the SizeRequirements object; if null one will be created

Returns:

the newly initialized SizeRequirements object

See Also:

calculateMinorAxisRequirements

protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r)

Calculate the requirements of the block along the minor axis (i.e. the axis orthogonal to the axis along with it tiles). This is implemented to provide the superclass behavior and then adjust it if the CSS width or height attribute is specified and applicable to the axis.

Overrides:

calculateMinorAxisRequirements in class BoxView

Parameters:

axis - the axis being studied

r - the SizeRequirements object; if null one will be created

Returns:

the newly initialized SizeRequirements object

See Also:

layoutMinorAxis

protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans)

Performs layout for the minor axis of the box (i.e. the axis orthogonal to the axis that it represents). The results of the layout (the offset and span for each children) are placed in the given arrays which represent the allocations to the children along the minor axis.

Overrides:: layoutMinorAxis in class BoxView
Parameters:: targetSpan - the total span given to the view, which would be used to layout the children.; axis - the axis being laid out; offsets - the offsets from the origin of the view for each of the child views; this is a return value and is filled in by the implementation of this method; spans - the span of each child view; this is a return value and is filled in by the implementation of this method

paint

public void paint(Graphics g, Shape allocation)

Renders using the given rendering surface and area on that surface. This is implemented to delegate to the css box painter to paint the border and background prior to the interior.

Overrides:

paint in class BoxView

Parameters:

g - the rendering surface to use

allocation - the allocated region to render into

See Also:

getAttributes

public AttributeSet getAttributes()

Fetches the attributes to use when rendering. This is implemented to multiplex the attributes specified in the model with a StyleSheet.

Overrides:: getAttributes in class View
Returns:: the attributes to use when rendering

getResizeWeight

public int getResizeWeight(int axis)

Gets the resize weight.

Overrides:: getResizeWeight in class BoxView
Parameters:: axis - may be either X_AXIS or Y_AXIS
Returns:: the weight
Throws:: IllegalArgumentException - for an invalid axis

getAlignment

public float getAlignment(int axis)

Gets the alignment.

Overrides:: getAlignment in class BoxView
Parameters:: axis - may be either X_AXIS or Y_AXIS
Returns:: the alignment

getPreferredSpan

public float getPreferredSpan(int axis)

Determines the preferred span for this view along an axis.

Overrides:: getPreferredSpan in class BoxView
Parameters:: axis - may be either View.X_AXIS or View.Y_AXIS
Returns:: the span the view would like to be rendered into >= 0; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view
Throws:: IllegalArgumentException - for an invalid axis type

getMinimumSpan

public float getMinimumSpan(int axis)

Determines the minimum span for this view along an axis.

Overrides:

getMinimumSpan in class BoxView

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Returns:

the span the view would like to be rendered into >= 0; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view

Throws:

IllegalArgumentException - for an invalid axis type

See Also:

getMaximumSpan

public float getMaximumSpan(int axis)

Determines the maximum span for this view along an axis.

Overrides:

getMaximumSpan in class BoxView

Parameters:

axis - may be either View.X_AXIS or View.Y_AXIS

Returns:

Throws:

IllegalArgumentException - for an invalid axis type

See Also:

setPropertiesFromAttributes

protected void setPropertiesFromAttributes()

Update any cached values that come from attributes.

getStyleSheet

protected StyleSheet getStyleSheet()

Convenient method to get the StyleSheet.

Returns:: the StyleSheet

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.