CompositeView
Class CompositeView
- java.lang.Object
-
- javax-swing-text-View
-
- javax.swing.text.CompositeView
- All Implemented Interfaces:
- SwingConstants
- Direct Known Subclasses:
- BoxView
public abstract class CompositeView extends View
CompositeView
is an abstract View
implementation which manages one or more child views. (Note that CompositeView
is intended for managing relatively small numbers of child views.) CompositeView
is intended to be used as a starting point for View
implementations, such as BoxView
, that will contain child View
s. Subclasses that wish to manage the collection of child View
s should use the replace(int, int, javax.swing.text.View[])
method. As View
invokes replace
during DocumentListener
notification, you normally won't need to directly invoke replace
.
While CompositeView
does not impose a layout policy on its child View
s, it does allow for inseting the child View
s it will contain. The insets can be set by either setInsets(short, short, short, short)
or setParagraphInsets(javax.swing.text.AttributeSet)
.
In addition to the abstract methods of View
, subclasses of CompositeView
will need to override:
-
isBefore(int, int, java.awt.Rectangle)
- Used to test if a givenView
location is before the visual space of theCompositeView
. -
isAfter(int, int, java.awt.Rectangle)
- Used to test if a givenView
location is after the visual space of theCompositeView
. -
getViewAtPoint(int, int, java.awt.Rectangle)
- Returns the view at a given visual location. -
childAllocation(int, java.awt.Rectangle)
- Returns the bounds of a particular childView
.getChildAllocation
will invokechildAllocation
after offseting the bounds by theInset
s of theCompositeView
.
Fields
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
Constructors
CompositeView
public CompositeView(Element elem)
Constructs a CompositeView
for the given element.
- Parameters:
-
elem
- the element this view is responsible for
Methods
loadChildren
protected void loadChildren(ViewFactory f)
Loads all of the children to initialize the view. This is called by the setParent(javax.swing.text.View)
method. Subclasses can reimplement this to initialize their child views in a different manner. The default implementation creates a child view for each child element.
- Parameters:
-
f
- the view factory - See Also:
setParent(javax.swing.text.View)
setParent
public void setParent(View parent)
Sets the parent of the view. This is reimplemented to provide the superclass behavior as well as calling the loadChildren
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 hosting Container
for example). If this view has children (the view is being moved from one place in the view hierarchy to another), the loadChildren
method will not be called.
getViewCount
public int getViewCount()
Returns the number of child views of this view.
- Overrides:
-
getViewCount
in classView
- Returns:
- the number of views >= 0
- See Also:
getView(int)
getView
public View getView(int n)
Returns the n-th view in this container.
- Overrides:
-
getView
in classView
- Parameters:
-
n
- the number of the desired view, >= 0 && < getViewCount() - Returns:
- the view at index
n
replace
public void replace(int offset, int length, View[] views)
Replaces child views. If there are no views to remove this acts as an insert. If there are no views to add this acts as a remove. Views being removed will have the parent set to null
, and the internal reference to them removed so that they may be garbage collected.
- Overrides:
-
replace
in classView
- Parameters:
-
offset
- the starting index into the child views to insert the new views; >= 0 and <= getViewCount -
length
- the number of existing child views to remove; this should be a value >= 0 and <= (getViewCount() - offset) -
views
- the child views to add; this value can benull
to indicate no children are being added (useful to remove)
getChildAllocation
public Shape getChildAllocation(int index, Shape a)
Fetches the allocation for the given child view to render into. This enables finding out where various views are located.
- Overrides:
-
getChildAllocation
in classView
- Parameters:
-
index
- the index of the child, >= 0 && < getViewCount() -
a
- the allocation to this view - Returns:
- the allocation to the child
modelToView
public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException
Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
- Specified by:
-
modelToView
in classView
- Parameters:
-
pos
- the position to convert >= 0 -
a
- the allocated region to render into -
b
- a bias value of eitherPosition-Bias-Forward
orPosition-Bias-Backward
- Returns:
- the bounding box of the given position
- Throws:
-
BadLocationException
- if the given position does not represent a valid location in the associated document - See Also:
View.modelToView(int, java.awt.Shape, javax.swing.text.Position.Bias)
modelToView
public Shape modelToView(int p0, Position.Bias b0, int p1, Position.Bias b1, Shape a) throws BadLocationException
Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
- Overrides:
-
modelToView
in classView
- Parameters:
-
p0
- the position to convert >= 0 -
b0
- the bias toward the previous character or the next character represented by p0, in case the position is a boundary of two views; eitherPosition-Bias-Forward
orPosition-Bias-Backward
-
p1
- the position to convert >= 0 -
b1
- the bias toward the previous character or the next character represented by p1, in case the position is a boundary of two views -
a
- the allocated region to render into - Returns:
- the bounding box of the given position is returned
- Throws:
-
BadLocationException
- if the given position does not represent a valid location in the associated document -
IllegalArgumentException
- for an invalid bias argument - See Also:
View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])
viewToModel
public 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.
- Specified by:
-
viewToModel
in classView
- Parameters:
-
x
- x coordinate of the view location to convert >= 0 -
y
- y coordinate of the view location to convert >= 0 -
a
- the allocated region to render into -
bias
- eitherPosition-Bias-Forward
orPosition-Bias-Backward
- Returns:
- the location within the model that best represents the given point in the view >= 0
- See Also:
View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])
getNextVisualPositionFrom
public int getNextVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) throws BadLocationException
Provides a way to determine the next visually represented model location that one might place a caret. Some views may not be visible, they might not be in the same order found in the model, or they just might not allow access to some of the locations in the model. This is a convenience method for getNextNorthSouthVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])
and getNextEastWestVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])
. This method enables specifying a position to convert within the range of >=0. If the value is -1, a position will be calculated automatically. If the value < -1, the BadLocationException
will be thrown.
- Overrides:
-
getNextVisualPositionFrom
in classView
- Parameters:
-
pos
- the position to convert -
b
- a bias value of eitherPosition-Bias-Forward
orPosition-Bias-Backward
-
a
- the allocated region to render into -
direction
- the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:-
SwingConstants-WEST
-
SwingConstants-EAST
-
SwingConstants-NORTH
-
SwingConstants-SOUTH
-
-
biasRet
- an array containing the bias that was checked - Returns:
- the location within the model that best represents the next location visual position
- Throws:
-
BadLocationException
- the given position is not a valid position within the document -
IllegalArgumentException
- ifdirection
is invalid
getViewIndex
public int getViewIndex(int pos, Position.Bias b)
Returns the child view index representing the given position in the model. This is implemented to call the getViewIndexByPosition
method for backward compatibility.
- Overrides:
-
getViewIndex
in classView
- Parameters:
-
pos
- the position >= 0 - Returns:
- index of the view representing the given position, or -1 if no view represents that position
- Since:
- 1-3
isBefore
protected abstract boolean isBefore(int x, int y, Rectangle alloc)
Tests whether a point lies before the rectangle range.
- Parameters:
-
x
- the X coordinate >= 0 -
y
- the Y coordinate >= 0 -
alloc
- the rectangle - Returns:
- true if the point is before the specified range
isAfter
protected abstract boolean isAfter(int x, int y, Rectangle alloc)
Tests whether a point lies after the rectangle range.
- Parameters:
-
x
- the X coordinate >= 0 -
y
- the Y coordinate >= 0 -
alloc
- the rectangle - Returns:
- true if the point is after the specified range
getViewAtPoint
protected abstract View getViewAtPoint(int x, int y, Rectangle alloc)
Fetches the child view at the given coordinates.
- Parameters:
-
x
- the X coordinate >= 0 -
y
- the Y coordinate >= 0 -
alloc
- the parent's allocation on entry, which should be changed to the child's allocation on exit - Returns:
- the child view
childAllocation
protected abstract void childAllocation(int index, Rectangle a)
Returns the allocation for a given child.
- Parameters:
-
index
- the index of the child, >= 0 && < getViewCount() -
a
- the allocation to the interior of the box on entry, and the allocation of the child view at the index on exit.
getViewAtPosition
protected View getViewAtPosition(int pos, Rectangle a)
Fetches the child view that represents the given position in the model. This is implemented to fetch the view in the case where there is a child view for each child element.
- Parameters:
-
pos
- the position >= 0 -
a
- the allocation to the interior of the box on entry, and the allocation of the view containing the position on exit - Returns:
- the view representing the given position, or
null
if there isn't one
getViewIndexAtPosition
protected int getViewIndexAtPosition(int pos)
Fetches the child view index representing the given position in the model. This is implemented to fetch the view in the case where there is a child view for each child element.
- Parameters:
-
pos
- the position >= 0 - Returns:
- index of the view representing the given position, or -1 if no view represents that position
getInsideAllocation
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. It is expected that the returned value would be further mutated to represent an allocation to a child view. This is implemented to reuse an instance variable so it avoids creating excessive Rectangles. Typically the result of calling this method would be fed to the childAllocation
method.
- Parameters:
-
a
- the allocation given to the view - Returns:
- the allocation that represents the inside of the view after the margins have all been removed; if the given allocation was
null
, the return value isnull
setParagraphInsets
protected void setParagraphInsets(AttributeSet attr)
Sets the insets from the paragraph attributes specified in the given attributes.
- Parameters:
-
attr
- the attributes
setInsets
protected void setInsets(short top, short left, short bottom, short right)
Sets the insets for the view.
- Parameters:
-
top
- the top inset >= 0 -
left
- the left inset >= 0 -
bottom
- the bottom inset >= 0 -
right
- the right inset >= 0
getLeftInset
protected short getLeftInset()
Gets the left inset.
- Returns:
- the inset >= 0
getRightInset
protected short getRightInset()
Gets the right inset.
- Returns:
- the inset >= 0
getTopInset
protected short getTopInset()
Gets the top inset.
- Returns:
- the inset >= 0
getBottomInset
protected short getBottomInset()
Gets the bottom inset.
- Returns:
- the inset >= 0
getNextNorthSouthVisualPositionFrom
protected int getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) throws BadLocationException
Returns the next visual position for the cursor, in either the north or south direction.
- Parameters:
-
pos
- the position to convert >= 0 -
b
- a bias value of eitherPosition.Bias.Forward
orPosition.Bias.Backward
-
a
- the allocated region to render into -
direction
- the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:-
SwingConstants.NORTH
-
SwingConstants.SOUTH
-
-
biasRet
- an array containing the bias that was checked - Returns:
- the location within the model that best represents the next north or south location
- Throws:
BadLocationException
-
IllegalArgumentException
- ifdirection
is invalid - See Also:
getNextVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])
getNextEastWestVisualPositionFrom
protected int getNextEastWestVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) throws BadLocationException
Returns the next visual position for the cursor, in either the east or west direction.
- Parameters:
-
pos
- the position to convert >= 0 -
b
- a bias value of eitherPosition.Bias.Forward
orPosition.Bias.Backward
-
a
- the allocated region to render into -
direction
- the direction from the current position that can be thought of as the arrow keys typically found on a keyboard; this may be one of the following:-
SwingConstants.WEST
-
SwingConstants.EAST
-
-
biasRet
- an array containing the bias that was checked - Returns:
- the location within the model that best represents the next west or east location
- Throws:
BadLocationException
-
IllegalArgumentException
- ifdirection
is invalid - See Also:
getNextVisualPositionFrom(int, javax.swing.text.Position.Bias, java.awt.Shape, int, javax.swing.text.Position.Bias[])
flipEastAndWestAtEnds
protected boolean flipEastAndWestAtEnds(int position, Position.Bias bias)
Determines in which direction the next view lays. Consider the View
at index n. Typically the View
s are layed out from left to right, so that the View
to the EAST will be at index n + 1, and the View
to the WEST will be at index n - 1. In certain situations, such as with bidirectional text, it is possible that the View
to EAST is not at index n + 1, but rather at index n - 1, or that the View
to the WEST is not at index n - 1, but index n + 1. In this case this method would return true, indicating the View
s are layed out in descending order.
This unconditionally returns false, subclasses should override this method if there is the possibility for laying View
s in descending order.
- Parameters:
-
position
- position into the model -
bias
- eitherPosition.Bias.Forward
orPosition.Bias.Backward
- Returns:
- false
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