jwo.utils.gui.html
Class ImprovedImageView

java.lang.Object
  javax.swing.text.View
      jwo.utils.gui.html.ImprovedImageView

All Implemented Interfaces:

MouseListener, MouseMotionListener, ImageObserver, EventListener, SwingConstants

public class ImprovedImageView
extends View
implements ImageObserver, MouseListener, MouseMotionListener

Customised image viewer for use by an HTML editor kit. This one handles the display of relative image URLs more flexibly than the default. Based on the JavaWorld Tip 109 by Rob Kenworthy.

Version:

2.3, 18th July, 2003.

Author:

Rob Kenworthy, modified by Jo Wood.

Field Summary

static String	ABSMIDDLE Indicates absolute centre alignment of image.
static String	BOTTOM Indicates bottom alignment of image.
static String	CENTER Indicates centre alignment of image.
static String	MIDDLE Indicates centre alignment of image.
static String	TEXTTOP Indicates top alignment of image text.
static String	TOP Indicates top alignment of image.

Fields inherited from class javax.swing.text.View

BadBreakWeight, ExcellentBreakWeight, ForcedBreakWeight, GoodBreakWeight, X_AXIS, Y_AXIS

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Fields inherited from interface javax.swing.SwingConstants

EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TRAILING, VERTICAL, WEST

Constructor Summary

ImprovedImageView(Element elem)
Creates a new view that represents an IMG element.

Method Summary

void	changedUpdate(DocumentEvent e, Shape a, ViewFactory f) Responds to a change in the document.
float	getAlignment(int axis) Determines the desired alignment for this view along an axis.
AttributeSet	getAttributes() Fetches the attributes to use when rendering.
protected Color	getHighlightColor() Reports the text editor's highlight colour.
float	getPreferredSpan(int axis) Determines the preferred span for this view along an axis.
protected int	getSelectionState() Determines whether the image is selected, and if it's the only thing selected.
protected StyleSheet	getStyleSheet() Reports the style sheet used by the component for HTML viewing.
boolean	imageUpdate(Image img, int flags, int x, int y, int width, int height) Allows progressive display of images.
protected boolean	isEditable() Reports whether the view is editable.
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	mouseClicked(MouseEvent e) On double-click, open image properties dialogue.
void	mouseDragged(MouseEvent e) Resize image if initial click was in grow-box: Mouse event logging mouse drag.
void	mouseEntered(MouseEvent e) Ignores mouse entry events.
void	mouseExited(MouseEvent e) Ignores mouse exit events.
void	mouseMoved(MouseEvent e) Ignores mouse movement events.
void	mousePressed(MouseEvent e) Select or grow image when clicked.
void	mouseReleased(MouseEvent e) Stops image being resized when mouse released.
void	paint(Graphics g, Shape a) Draws the image.
protected void	repaint(long delay) Request that this view be repainted.
protected void	resize(int width, int height) Change the size of this image.
void	setParent(View parent) Establishes the parent view for this view.
void	setSize(float width, float height) Sets the size of the view, but ignored in this case.
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 inherited from class javax.swing.text.View

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

Methods inherited from class java.lang.Object

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

Field Detail

TOP

public static final String TOP

Indicates top alignment of image.

See Also:

Constant Field Values

TEXTTOP

public static final String TEXTTOP

Indicates top alignment of image text.

See Also:

Constant Field Values

MIDDLE

public static final String MIDDLE

Indicates centre alignment of image.

See Also:

Constant Field Values

ABSMIDDLE

public static final String ABSMIDDLE

Indicates absolute centre alignment of image.

See Also:

Constant Field Values

CENTER

public static final String CENTER

Indicates centre alignment of image.

See Also:

Constant Field Values

BOTTOM

public static final String BOTTOM

Indicates bottom alignment of image.

See Also:

Constant Field Values

Constructor Detail

ImprovedImageView

public ImprovedImageView(Element elem)

Creates a new view that represents an IMG element.

Parameters:

elem - The element to create a view for

Method Detail

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:

Set of attributes to use when rendering.

setParent

public void setParent(View parent)

Establishes the parent view for this view. Also caches the AWT container that the view is within.

Overrides:

setParent in class View

Parameters:

parent - Parent view to use.

changedUpdate

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

Responds to a change in the document.

Overrides:

changedUpdate in class View

Parameters:

e - Document event logging change.

a - Shape holding new view.

f - View factory.

paint

public void paint(Graphics g,
                  Shape a)

Draws the image.

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)

repaint

protected void repaint(long delay)

Request that this view be repainted. Assumes the view is still at its last-drawn location.

Parameters:

delay - before repainting (in milliseconds).

getSelectionState

protected int getSelectionState()

Determines whether the image is selected, and if it's the only thing selected.

Returns:

0 if not selected, 1 if selected, 2 if exclusively selected. "Exclusive" selection is only returned when editable.

isEditable

protected boolean isEditable()

Reports whether the view is editable.

Returns:

True if editable.

getHighlightColor

protected Color getHighlightColor()

Reports the text editor's highlight colour.

Returns:

Highlight colour.

imageUpdate

public boolean imageUpdate(Image img,
                           int flags,
                           int x,
                           int y,
                           int width,
                           int height)

Allows progressive display of images. This can come on any thread. If in the process of reloading the image and determining state (loading == true) preference change or repaint requests are not fired. Instead width and height are reset as necessary.

Specified by:

imageUpdate in interface ImageObserver

Parameters:

img - Image to update.

flags - Image loading flags.

x - x-location of image.

y - y-location of image.

width - Width of image.

height - Height of image.

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 centre 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

Returns:

the bounding box of the given position

Throws:

BadLocationException - If the given position does not represent a valid location in the associated document

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

Returns:

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

setSize

public void setSize(float width,
                    float height)

Sets the size of the view, but ignored in this case. Image size is determined by the tag attributes and the image itself, not the layout.

Overrides:

setSize in class View

Parameters:

width - the width

height - the height

resize

protected void resize(int width,
                      int height)

Change the size of this image. This alters the HEIGHT and WIDTH attributes of the Element and causes a re-layout.

Parameters:

width - New width of image.

height - New height of image.

mousePressed

public void mousePressed(MouseEvent e)

Select or grow image when clicked.

Specified by:

mousePressed in interface MouseListener

Parameters:

e - Mouse event logging mouse press.

mouseDragged

public void mouseDragged(MouseEvent e)

Resize image if initial click was in grow-box: Mouse event logging mouse drag.

Specified by:

mouseDragged in interface MouseMotionListener

mouseReleased

public void mouseReleased(MouseEvent e)

Stops image being resized when mouse released.

Specified by:

mouseReleased in interface MouseListener

Parameters:

e - Mouse release event.

mouseClicked

public void mouseClicked(MouseEvent e)

On double-click, open image properties dialogue. Not yet implemented.

Specified by:

mouseClicked in interface MouseListener

Parameters:

e - Mouse click event.

mouseEntered

public void mouseEntered(MouseEvent e)

Ignores mouse entry events.

Specified by:

mouseEntered in interface MouseListener

Parameters:

e - Mouse event (ignored).

mouseMoved

public void mouseMoved(MouseEvent e)

Ignores mouse movement events.

Specified by:

mouseMoved in interface MouseMotionListener

Parameters:

e - Mouse event (ignored).

mouseExited

public void mouseExited(MouseEvent e)

Ignores mouse exit events.

Specified by:

mouseExited in interface MouseListener

Parameters:

e - Mouse event (ignored).

getStyleSheet

protected StyleSheet getStyleSheet()

Reports the style sheet used by the component for HTML viewing.

Returns:

Stylesheet used by the component.