Module java.desktop

Package javax.swing.text.html

Class ImageView

java.lang.Object

javax.swing.text.View

javax.swing.text.html.ImageView

All Implemented Interfaces:

SwingConstants

public class ImageView
extends View

View of an Image, intended to support the HTML <IMG> tag. Supports scaling via the HEIGHT and WIDTH attributes of the tag. If the image is unable to be loaded any text specified via the ALT attribute will be rendered.

While this class has been part of swing for a while now, it is public as of 1.4.

Since:

1.4

See Also:

• IconView

Field Summary

Fields declared in class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Fields declared in 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	Description
ImageView(Element elem)	Creates a new view that represents an IMG element.

Method Summary

Modifier and Type	Method	Description
void	changedUpdate(DocumentEvent e, Shape a, ViewFactory f)	Invoked when the Elements attributes have changed.
float	getAlignment(int axis)	Determines the desired alignment for this view along an axis.
String	getAltText()	Returns the text to display if the image cannot be loaded.
AttributeSet	getAttributes()	Fetches the attributes to use when rendering.
Image	getImage()	Returns the image to render.
URL	getImageURL()	Return a URL for the image source, or null if it could not be determined.
Icon	getLoadingImageIcon()	Returns the icon to use while in the process of loading the image.
boolean	getLoadsSynchronously()	Returns true if the image should be loaded when first asked for.
Icon	getNoImageIcon()	Returns the icon to use if the image could not be found.
float	getPreferredSpan(int axis)	Determines the preferred span for this view along an axis.
protected StyleSheet	getStyleSheet()	Convenient method to get the StyleSheet.
String	getToolTipText(float x, float y, Shape allocation)	For images the tooltip text comes from text specified with the ALT attribute.
Shape	modelToView(int pos, Shape a, Position.Bias b)	Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
void	paint(Graphics g, Shape a)	Paints the View.
void	setLoadsSynchronously(boolean newValue)	Sets how the image is loaded.
void	setParent(View parent)	Establishes the parent view for this view.
protected void	setPropertiesFromAttributes()	Update any cached values that come from attributes.
void	setSize(float width, float height)	Sets the size of the 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.

Methods declared in class javax.swing.text.View

append, breakView, createFragment, forwardUpdate, forwardUpdateToView, getBreakWeight, getChildAllocation, getContainer, getDocument, getElement, getEndOffset, getGraphics, getMaximumSpan, getMinimumSpan, getNextVisualPositionFrom, getParent, getResizeWeight, getStartOffset, getView, getViewCount, getViewFactory, getViewIndex, getViewIndex, insert, insertUpdate, isVisible, modelToView, modelToView, preferenceChanged, remove, removeAll, removeUpdate, replace, updateChildren, updateLayout, viewToModel

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ImageView

public ImageView(Element elem)

Creates a new view that represents an IMG element.

Parameters:

elem - the element to create a view for

Method Details

getAltText

public String getAltText()

Returns the text to display if the image cannot be loaded. This is obtained from the Elements attribute set with the attribute name HTML.Attribute.ALT.

Returns:

the test to display if the image cannot be loaded.

getImageURL

public URL getImageURL()

Return a URL for the image source, or null if it could not be determined.

Returns:

the URL for the image source, or null if it could not be determined.

getNoImageIcon

public Icon getNoImageIcon()

Returns the icon to use if the image could not be found.

Returns:

the icon to use if the image could not be found.

getLoadingImageIcon

public Icon getLoadingImageIcon()

Returns the icon to use while in the process of loading the image.

Returns:

the icon to use while in the process of loading the image.

getImage

public Image getImage()

Returns the image to render.

Returns:

the image to render.

setLoadsSynchronously

public void setLoadsSynchronously(boolean newValue)

Sets how the image is loaded. If newValue is true, the image will be loaded when first asked for, otherwise it will be loaded asynchronously. The default is to not load synchronously, that is to load the image asynchronously.

Parameters:

newValue - if true the image will be loaded when first asked for, otherwise it will be asynchronously.

getLoadsSynchronously

public boolean getLoadsSynchronously()

Returns true if the image should be loaded when first asked for.

Returns:

true if the image should be loaded when first asked for.

getStyleSheet

protected StyleSheet getStyleSheet()

Convenient method to get the StyleSheet.

Returns:

the StyleSheet

getAttributes

public AttributeSet getAttributes()

Fetches the attributes to use when rendering. This is implemented to multiplex the attributes specified in the model with a StyleSheet.

Overrides:

getAttributes in class View

Returns:

the attributes to use when rendering

getToolTipText

public String getToolTipText(float x,
 float y,
 Shape allocation)

For images the tooltip text comes from text specified with the ALT attribute. This is overridden to return getAltText.

Overrides:

getToolTipText in class View

Parameters:

x - the x coordinate

y - the y coordinate

allocation - current allocation of the View.

Returns:

the tooltip text at the specified location

See Also:

• JTextComponent.getToolTipText(java.awt.event.MouseEvent)

setPropertiesFromAttributes

protected void setPropertiesFromAttributes()

Update any cached values that come from attributes.

setParent

public void setParent(View parent)

Establishes the parent view for this view. Seize this moment to cache the AWT Container I'm in.

Overrides:

setParent in class View

Parameters:

parent - the new parent, or null if the view is being removed from a parent

changedUpdate

public void changedUpdate(DocumentEvent e,
 Shape a,
 ViewFactory f)

Invoked when the Elements attributes have changed. Recreates the image.

Overrides:

changedUpdate in class View

Parameters:

e - the change information from the associated document

a - the current allocation of the view

f - 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)
• View.removeUpdate(javax.swing.event.DocumentEvent, java.awt.Shape, javax.swing.text.ViewFactory)

paint

public void paint(Graphics g,
 Shape a)

Paints the View.

Specified by:

paint in class View

Parameters:

g - the rendering surface to use

a - the allocated region to render into

See Also:

• View.paint(java.awt.Graphics, java.awt.Shape)

getPreferredSpan

public float getPreferredSpan(int axis)

Determines the preferred span for this view along an axis.

Specified by:

getPreferredSpan in class View

Parameters:

axis - may be either X_AXIS or Y_AXIS

Returns:

the span the view would like to be rendered into; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view

getAlignment

public float getAlignment(int axis)

Determines the desired alignment for this view along an axis. This is implemented to give the alignment to the bottom of the icon along the y axis, and the default along the x axis.

Overrides:

getAlignment in class View

Parameters:

axis - may be either X_AXIS or Y_AXIS

Returns:

the desired alignment; this should be a value between 0.0 and 1.0 where 0 indicates alignment at the origin and 1.0 indicates alignment to the full span away from the origin; an alignment of 0.5 would be the center of the view

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 class View

Parameters:

pos - the position to convert

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:

• Position.Bias.Forward
• Position.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)

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 class View

Parameters:

x - the X coordinate

y - the Y coordinate

a - the allocated region to render into

bias - the returned bias

Returns:

the location within the model that best represents the given point of view

See Also:

• View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])

setSize

public void setSize(float width,
 float height)

Sets the size of the view. This should cause layout of the view if it has any layout duties.

Overrides:

setSize in class View

Parameters:

width - the width >= 0

height - the height >= 0