public class ComponentView extends View
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.
BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS
BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST
Constructor and Description |
---|
ComponentView(Element elem)
Creates a new ComponentView object.
|
Modifier and Type | Method and Description |
---|---|
protected Component |
createComponent()
Create the component that is associated with
this view.
|
float |
getAlignment(int axis)
Determines the desired alignment for this view along an
axis.
|
Component |
getComponent()
Fetch the component associated with the view.
|
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.
|
Shape |
modelToView(int pos,
Shape a,
Position.Bias b)
Provides a mapping from the coordinate space of the model to
that of the view.
|
void |
paint(Graphics g,
Shape a)
The real paint behavior occurs naturally from the association
that the component has with its parent container (the same
container hosting this view).
|
void |
setParent(View p)
Sets the parent for a child 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.
|
append, breakView, changedUpdate, createFragment, forwardUpdate, forwardUpdateToView, getAttributes, getBreakWeight, getChildAllocation, getContainer, getDocument, getElement, getEndOffset, getGraphics, getNextVisualPositionFrom, getParent, getResizeWeight, getStartOffset, getToolTipText, getView, getViewCount, getViewFactory, getViewIndex, getViewIndex, insert, insertUpdate, isVisible, modelToView, modelToView, preferenceChanged, remove, removeAll, removeUpdate, replace, setSize, updateChildren, updateLayout, viewToModel
public ComponentView(Element elem)
elem
- the element to decorateprotected Component createComponent()
public final Component getComponent()
public void paint(Graphics g, Shape a)
paint
in class View
g
- the graphics contexta
- the shapeView.paint(java.awt.Graphics, java.awt.Shape)
public float getPreferredSpan(int axis)
getPreferredSpan
in class View
axis
- may be either View.X_AXIS or View.Y_AXISIllegalArgumentException
- for an invalid axisView.getPreferredSpan(int)
public float getMinimumSpan(int axis)
getMinimumSpan
in class View
axis
- may be either View.X_AXIS or View.Y_AXISIllegalArgumentException
- for an invalid axisView.getPreferredSpan(int)
public float getMaximumSpan(int axis)
getMaximumSpan
in class View
axis
- may be either View.X_AXIS or View.Y_AXISIllegalArgumentException
- for an invalid axisView.getPreferredSpan(int)
public float getAlignment(int axis)
getAlignment
in class View
axis
- may be either View.X_AXIS or View.Y_AXISpublic void setParent(View p)
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).
public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException
modelToView
in class View
pos
- the position to convert >=0a
- the allocated region to render intob
- 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:
Position.Bias.Forward
Position.Bias.Backward
BadLocationException
- if the given position does not
represent a valid location in the associated documentView.modelToView(int, java.awt.Shape, javax.swing.text.Position.Bias)
public int viewToModel(float x, float y, Shape a, Position.Bias[] bias)
viewToModel
in class View
x
- the X coordinate >=0y
- the Y coordinate >=0a
- the allocated region to render intoView.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])
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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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