java.lang.Object | ||
↳ | javax.swing.text.View | |
↳ | javax.swing.text.ComponentView |
Known Direct Subclasses |
Component decorator that implements the view interface. The entire element is used to represent the component. This acts as a gateway from the display-only View implementations to interactive lightweight components (ie it allows components to be embedded into the View hierarchy).
The component is placed relative to the text baseline
according to the value returned by
Component.getAlignmentY
. For Swing components
this value can be conveniently set using the method
JComponent.setAlignmentY
. For example, setting
a value of 0.75
will cause 75 percent of the
component to be above the baseline, and 25 percent of the
component to be below the baseline.
This class is implemented to do the extra work necessary to work properly in the presence of multiple threads (i.e. from asynchronous notification of model changes for example) by ensuring that all component access is done on the event thread.
The component used is determined by the return value of the createComponent method. The default implementation of this method is to return the component held as an attribute of the element (by calling StyleConstants.getComponent). A limitation of this behavior is that the component cannot be used by more than one text component (i.e. with a shared model). Subclasses can remove this constraint by implementing the createComponent to actually create a component based upon some kind of specification contained in the attributes. The ObjectView class in the html package is an example of a ComponentView implementation that supports multiple component views of a shared model.
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Inherited Constants | |||||||||||
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From class
javax.swing.text.View
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From interface
javax.swing.SwingConstants
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Public Constructors | |||||||||||
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Creates a new ComponentView object.
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Public Methods | |||||||||||
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Determines the desired alignment for this view along an
axis.
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Fetch the component associated with the view.
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Determines the maximum span for this view along an
axis.
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Determines the minimum span for this view along an
axis.
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Determines the preferred span for this view along an
axis.
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Provides a mapping from the coordinate space of the model to
that of the view.
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The real paint behavior occurs naturally from the association
that the component has with its parent container (the same
container hosting this view).
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Sets the parent for a child view.
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Provides a mapping from the view coordinate space to the logical
coordinate space of the model.
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Protected Methods | |||||||||||
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Create the component that is associated with
this view.
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Inherited Methods | |||||||||||
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From class
javax.swing.text.View
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From class
java.lang.Object
|
Creates a new ComponentView object.
elem | the element to decorate |
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Determines the desired alignment for this view along an axis. This is implemented to give the alignment of the embedded component.
axis | may be either View.X_AXIS or View.Y_AXIS |
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Determines the maximum span for this view along an axis. This is implemented to return the value returned by Component.getMaximumSize along the axis of interest.
axis | may be either View.X_AXIS or View.Y_AXIS |
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IllegalArgumentException | for an invalid axis |
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Determines the minimum span for this view along an axis. This is implemented to return the value returned by Component.getMinimumSize along the axis of interest.
axis | may be either View.X_AXIS or View.Y_AXIS |
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IllegalArgumentException | for an invalid axis |
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Determines the preferred span for this view along an axis. This is implemented to return the value returned by Component.getPreferredSize along the axis of interest.
axis | may be either View.X_AXIS or View.Y_AXIS |
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IllegalArgumentException | for an invalid axis |
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Provides a mapping from the coordinate space of the model to that of the view.
pos | the position to convert >= 0 |
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a | the allocated region to render into |
b | the bias toward the previous character or the
next character represented by the offset, in case the
position is a boundary of two views; b will have one
of these values:
|
BadLocationException | if the given position does not represent a valid location in the associated document |
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The real paint behavior occurs naturally from the association that the component has with its parent container (the same container hosting this view). This is implemented to do nothing.
g | the graphics context |
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a | the shape |
Sets the parent for a child view.
The parent calls this on the child to tell it who its
parent is, giving the view access to things like
the hosting Container. The superclass behavior is
executed, followed by a call to createComponent if
the parent view parameter is non-null and a component
has not yet been created. The embedded components parent
is then set to the value returned by getContainer
.
If the parent view parameter is null, this view is being
cleaned up, thus the component is removed from its parent.
The changing of the component hierarchy will touch the component lock, which is the one thing that is not safe from the View hierarchy. Therefore, this functionality is executed immediately if on the event thread, or is queued on the event queue if called from another thread (notification of change from an asynchronous update).
p | the parent |
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Provides a mapping from the view coordinate space to the logical coordinate space of the model.
x | the X coordinate >= 0 |
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y | the Y coordinate >= 0 |
a | the allocated region to render into |
Create the component that is associated with this view. This will be called when it has been determined that a new component is needed. This would result from a call to setParent or as a result of being notified that attributes have changed.