- java.lang.Object
-
- javax.swing.text.View
-
- javax.swing.text.CompositeView
-
- javax.swing.text.BoxView
-
- javax.swing.text.FlowView
-
- All Implemented Interfaces:
- SwingConstants
- Direct Known Subclasses:
- ParagraphView
public abstract class FlowView extends BoxView
A View that tries to flow it's children into some partially constrained space. This can be used to build things like paragraphs, pages, etc. The flow is made up of the following pieces of functionality.- A logical set of child views, which as used as a layout pool from which a physical view is formed.
- A strategy for translating the logical view to a physical (flowed) view.
- Constraints for the strategy to work against.
- A physical structure, that represents the flow. The children of this view are where the pieces of of the logical views are placed to create the flow.
- Since:
- 1.3
- See Also:
View
-
-
Nested Class Summary
Nested Classes Modifier and Type Class and Description static class
FlowView.FlowStrategy
Strategy for maintaining the physical form of the flow.
-
Field Summary
Fields Modifier and Type Field and Description protected View
layoutPool
These are the views that represent the child elements of the element this view represents (The logical view to translate to a physical view).protected int
layoutSpan
Default constraint against which the flow is created against.protected FlowView.FlowStrategy
strategy
The behavior for keeping the flow updated.-
Fields inherited from class javax.swing.text.View
BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS
-
Fields inherited from interface javax.swing.SwingConstants
BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST
-
-
Constructor Summary
Constructors Constructor and Description FlowView(Element elem, int axis)
Constructs a FlowView for the given element.
-
Method Summary
Methods Modifier and Type Method and Description protected SizeRequirements
calculateMinorAxisRequirements(int axis, SizeRequirements r)
Calculate equirements along the minor axis.void
changedUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification from the document that attributes were changed in a location that this view is responsible for.protected abstract View
createRow()
Create a View that should be used to hold a a rows worth of children in a flow.int
getFlowAxis()
Fetches the axis along which views should be flowed.int
getFlowSpan(int index)
Fetch the constraining span to flow against for the given child index.int
getFlowStart(int index)
Fetch the location along the flow axis that the flow span will start at.protected int
getViewIndexAtPosition(int pos)
Fetches the child view index representing the given position in the model.void
insertUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification that something was inserted into the document in a location that this view is responsible for.protected void
layout(int width, int height)
Lays out the children.protected void
loadChildren(ViewFactory f)
Loads all of the children to initialize the view.void
removeUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification that something was removed from the document in a location that this view is responsible for.void
setParent(View parent)
Sets the parent of the view.-
Methods inherited from class javax.swing.text.BoxView
baselineLayout, baselineRequirements, calculateMajorAxisRequirements, childAllocation, flipEastAndWestAtEnds, forwardUpdate, getAlignment, getAxis, getChildAllocation, getHeight, getMaximumSpan, getMinimumSpan, getOffset, getPreferredSpan, getResizeWeight, getSpan, getViewAtPoint, getWidth, isAfter, isAllocationValid, isBefore, isLayoutValid, layoutChanged, layoutMajorAxis, layoutMinorAxis, modelToView, paint, paintChild, preferenceChanged, replace, setAxis, setSize, viewToModel
-
Methods inherited from class javax.swing.text.CompositeView
getBottomInset, getInsideAllocation, getLeftInset, getNextEastWestVisualPositionFrom, getNextNorthSouthVisualPositionFrom, getNextVisualPositionFrom, getRightInset, getTopInset, getView, getViewAtPosition, getViewCount, getViewIndex, modelToView, setInsets, setParagraphInsets
-
Methods inherited from class javax.swing.text.View
append, breakView, createFragment, forwardUpdateToView, getAttributes, getBreakWeight, getContainer, getDocument, getElement, getEndOffset, getGraphics, getParent, getStartOffset, getToolTipText, getViewFactory, getViewIndex, insert, isVisible, modelToView, remove, removeAll, updateChildren, updateLayout, viewToModel
-
-
-
-
Field Detail
-
layoutSpan
protected int layoutSpan
Default constraint against which the flow is created against.
-
layoutPool
protected View layoutPool
These are the views that represent the child elements of the element this view represents (The logical view to translate to a physical view). These are not directly children of this view. These are either placed into the rows directly or used for the purpose of breaking into smaller chunks, to form the physical view.
-
strategy
protected FlowView.FlowStrategy strategy
The behavior for keeping the flow updated. By default this is a singleton shared by all instances of FlowView (FlowStrategy is stateless). Subclasses can create an alternative strategy, which might keep state.
-
-
Constructor Detail
-
FlowView
public FlowView(Element elem, int axis)
Constructs a FlowView for the given element.- Parameters:
elem
- the element that this view is responsible foraxis
- may be either View.X_AXIS or View.Y_AXIS
-
-
Method Detail
-
getFlowAxis
public int getFlowAxis()
Fetches the axis along which views should be flowed. By default, this will be the axis orthogonal to the axis along which the flow rows are tiled (the axis of the default flow rows themselves). This is typically used by theFlowStrategy
.
-
getFlowSpan
public int getFlowSpan(int index)
Fetch the constraining span to flow against for the given child index. This is called by the FlowStrategy while it is updating the flow. A flow can be shaped by providing different values for the row constraints. By default, the entire span inside of the insets along the flow axis is returned.- Parameters:
index
- the index of the row being updated. This should be a value >= 0 and < getViewCount().- See Also:
getFlowStart(int)
-
getFlowStart
public int getFlowStart(int index)
Fetch the location along the flow axis that the flow span will start at. This is called by the FlowStrategy while it is updating the flow. A flow can be shaped by providing different values for the row constraints.- Parameters:
index
- the index of the row being updated. This should be a value >= 0 and < getViewCount().- See Also:
getFlowSpan(int)
-
createRow
protected abstract View createRow()
Create a View that should be used to hold a a rows worth of children in a flow. This is called by the FlowStrategy when new children are added or removed (i.e. rows are added or removed) in the process of updating the flow.
-
loadChildren
protected void loadChildren(ViewFactory f)
Loads all of the children to initialize the view. This is called by thesetParent
method. This is reimplemented to not load any children directly (as they are created in the process of formatting). If the layoutPool variable is null, an instance of LogicalView is created to represent the logical view that is used in the process of formatting.- Overrides:
loadChildren
in classCompositeView
- Parameters:
f
- the view factory- See Also:
CompositeView.setParent(javax.swing.text.View)
-
getViewIndexAtPosition
protected int getViewIndexAtPosition(int pos)
Fetches the child view index representing the given position in the model.- Overrides:
getViewIndexAtPosition
in classCompositeView
- Parameters:
pos
- the position >= 0- Returns:
- index of the view representing the given position, or -1 if no view represents that position
-
layout
protected void layout(int width, int height)
Lays out the children. If the span along the flow axis has changed, layout is marked as invalid which which will cause the superclass behavior to recalculate the layout along the box axis. The FlowStrategy.layout method will be called to rebuild the flow rows as appropriate. If the height of this view changes (determined by the perferred size along the box axis), a preferenceChanged is called. Following all of that, the normal box layout of the superclass is performed.
-
calculateMinorAxisRequirements
protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r)
Calculate equirements along the minor axis. This is implemented to forward the request to the logical view by calling getMinimumSpan, getPreferredSpan, and getMaximumSpan on it.- Overrides:
calculateMinorAxisRequirements
in classBoxView
- Parameters:
axis
- the axis being studiedr
- theSizeRequirements
object; ifnull
one will be created- Returns:
- the newly initialized
SizeRequirements
object - See Also:
SizeRequirements
-
insertUpdate
public void insertUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification that something was inserted into the document in a location that this view is responsible for.- Overrides:
insertUpdate
in classView
- Parameters:
changes
- the change information from the associated documenta
- the current allocation of the viewf
- the factory to use to rebuild if the view has children- See Also:
View.insertUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)
-
removeUpdate
public void removeUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification that something was removed from the document in a location that this view is responsible for.- Overrides:
removeUpdate
in classView
- Parameters:
changes
- the change information from the associated documenta
- the current allocation of the viewf
- the factory to use to rebuild if the view has children- See Also:
View.removeUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)
-
changedUpdate
public void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f)
Gives notification from the document that attributes were changed in a location that this view is responsible for.- Overrides:
changedUpdate
in classView
- Parameters:
changes
- the change information from the associated documenta
- the current allocation of the viewf
- the factory to use to rebuild if the view has children- See Also:
View.changedUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)
-
setParent
public void setParent(View parent)
Sets the parent of the view. This is reimplemented to provide the superclass behavior as well as calling theloadChildren
method if this view does not already have children. The children should not be loaded in the constructor because the act of setting the parent may cause them to try to search up the hierarchy (to get the hostingContainer
for example). If this view has children (the view is being moved from one place in the view hierarchy to another), theloadChildren
method will not be called.- Overrides:
setParent
in classCompositeView
- Parameters:
parent
- the parent of the view,null
if none
-
-
Document created the 11/06/2005, last modified the 04/03/2020
Source of the printed document:https://www.gaudry.be/en/java-api-rf-javax/swing/text/FlowView.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.