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
Views. Subclasses that wish to manage the
collection of child
Views should use the
replace(int,int,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
Views,
it does allow for inseting the child
Views
it will contain. The insets can be set by either
setInsets(short,short,short,short) or
setParagraphInsets(AttributeSet).
In addition to the abstract methods of
View,
subclasses of
CompositeView will need to
override:
childAllocation
protected abstract void childAllocation(int index,
Rectangle a) Returns the allocation for a given child.
index - the index of the child, >= 0 && <32getViewCount()a - the allocation to the interior of the box on entry,
and the allocation of the child view at the index on exit.
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
Views 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
Views are layed out in descending order.
This unconditionally returns false, subclasses should override this
method if there is the possibility for laying
Views in
descending order.
position - position into the modelbias - either Position.Bias.Forward or
Position.Bias.Backward
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.
- getChildAllocation in interface View
index - the index of the child, >= 0 && <32getViewCount()a - the allocation to this view
- the allocation to the child
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.
a - the allocation given to the view
- 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 is null
getLeftInset
protected short getLeftInset()
Gets the left inset.
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.
pos - the position to convert >= 0b - a bias value of either Position.Bias.Forward
or Position.Bias.Backwarda - the allocated region to render intodirection - 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
- the location within the model that best represents the next
west or east location
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.
pos - the position to convert >= 0b - a bias value of either Position.Bias.Forward
or Position.Bias.Backwarda - the allocated region to render intodirection - 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
- the location within the model that best represents the next
north or south location
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,Position.Bias,Shape,int,Position.Bias[])
and
getNextEastWestVisualPositionFrom(int,Position.Bias,Shape,int,Position.Bias[]).
- getNextVisualPositionFrom in interface View
pos - the position to convert >= 0b - a bias value of either Position.Bias.Forward
or Position.Bias.Backwarda - the allocated region to render intodirection - 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
- the location within the model that best represents the next
location visual position
getRightInset
protected short getRightInset()
Gets the right inset.
getTopInset
protected short getTopInset()
Gets the top inset.
getView
public View getView(int n)
Returns the n-th view in this container.
- getView in interface View
n - the number of the desired view, >= 0 && <32getViewCount()
getViewAtPoint
protected abstract View getViewAtPoint(int x,
int y,
Rectangle alloc) Fetches the child view at the given coordinates.
x - the X coordinate >= 0y - the Y coordinate >= 0alloc - the parent's allocation on entry, which should
be changed to the child's allocation 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.
pos - the position >= 0a - the allocation to the interior of the box on entry,
and the allocation of the view containing the position on exit
- the view representing the given position, or
null if there isn't one
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.
- getViewIndex in interface View
- index of the view representing the given position, or
-1 if no view represents that position
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.
- index of the view representing the given position, or
-1 if no view represents that position
isAfter
protected abstract boolean isAfter(int x,
int y,
Rectangle alloc) Tests whether a point lies after the rectangle range.
x - the X coordinate >= 0y - the Y coordinate >= 0alloc - the rectangle
- true if the point is after the specified range
isBefore
protected abstract boolean isBefore(int x,
int y,
Rectangle alloc) Tests whether a point lies before the rectangle range.
x - the X coordinate >= 0y - the Y coordinate >= 0alloc - the rectangle
- true if the point is before the specified range
loadChildren
protected void loadChildren(ViewFactory f)
Loads all of the children to initialize the view.
This is called by the
setParent(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.
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.
- modelToView in interface View
pos - the position to convert >= 0a - the allocated region to render intob - a bias value of either Position.Bias.Forward
or Position.Bias.Backward
- the bounding box of the given position
BadLocationException - if the given position does
not represent a valid location in the associated document
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.
- modelToView in interface View
p0 - the position to convert >= 0b0 - the bias toward the previous character or the
next character represented by p0, in case the
position is a boundary of two views; either
Position.Bias.Forward or
Position.Bias.Backwardp1 - the position to convert >= 0b1 - the bias toward the previous character or the
next character represented by p1, in case the
position is a boundary of two viewsa - the allocated region to render into
- the bounding box of the given position is returned
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.
- replace in interface View
offset - the starting index into the child views to insert
the new views; >= 0 and <= getViewCountlength - 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 be
null
to indicate no children are being added (useful to remove)
setInsets
protected void setInsets(short top,
short left,
short bottom,
short right) Sets the insets for the view.
top - the top inset >= 0left - the left inset >= 0bottom - the bottom inset >= 0right - the right inset >= 0
setParagraphInsets
protected void setParagraphInsets(AttributeSet attr)
Sets the insets from the paragraph attributes specified in
the given attributes.
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.
- setParent in interface View
parent - the parent of the view, null if none
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.
- viewToModel in interface View
x - x coordinate of the view location to convert >= 0y - y coordinate of the view location to convert >= 0a - the allocated region to render intobias - either Position.Bias.Forward or
Position.Bias.Backward
- the location within the model that best represents the
given point in the view >= 0