org.htmlparser.lexerapplications.thumbelina

Class PicturePanel

public class PicturePanel extends JPanel implements MouseListener, Scrollable, ComponentListener, HierarchyListener

Hold and display a group of pictures.

Author: derrick

Field Summary
protected static intBLOCK_INCREMENT
Scrolling block increment (both directions).
protected TileSetmMosaic
The display mosaic.
protected DimensionmPreferredSize
The preferred size of this component.
protected ThumbelinamThumbelina
The thumbelina object in use.
protected static intUNIT_INCREMENT
Scrolling unit increment (both directions).
Constructor Summary
PicturePanel(Thumbelina thumbelina)
Creates a new instance of PicturePanel
Method Summary
voidadjustClipForInsets(Graphics graphics)
Adjust the graphics clip region to account for insets.
voidbringToTop(Picture picture)
Move the given picture to the top of the Z order.
protected DimensioncalculatePreferredSize()
Compute the preferred size of the component.
voidcomponentHidden(ComponentEvent event)
Invoked when the component has been made invisible.
voidcomponentMoved(ComponentEvent event)
Invoked when the component's position changes.
voidcomponentResized(ComponentEvent event)
Invoked when the container's size changes.
voidcomponentShown(ComponentEvent event)
Invoked when the component has been made visible.
protected voiddraw(Picture picture, boolean add)
Draw an image on screen.
Picturefind(String url)
Find a picture with the given URL in the panel.
DimensiongetPreferredScrollableViewportSize()
Returns the preferred size of the viewport for a view component.
DimensiongetPreferredSize()
Get the preferred size of the component.
intgetScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)
Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.
booleangetScrollableTracksViewportHeight()
Return true if a viewport should always force the height of this Scrollable to match the height of the viewport.
booleangetScrollableTracksViewportWidth()
Return true if a viewport should always force the width of this Scrollable to match the width of the viewport.
intgetScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)
Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation.
voidhierarchyChanged(HierarchyEvent event)
Handles this components ancestor being added to a container.
voidmouseClicked(MouseEvent event)
Invoked when the mouse button has been clicked (pressed and released) on a component.
voidmouseEntered(MouseEvent event)
Invoked when the mouse enters a component.
voidmouseExited(MouseEvent event)
Invoked when the mouse exits a component.
voidmousePressed(MouseEvent event)
Handle left click on a picture by bringing it to the top.
voidmouseReleased(MouseEvent event)
Invoked when a mouse button has been released on a component.
voidpaint(Graphics graphics)
Paints this component.
voidreset()
Clears the panel, discarding any existing images.
voidsetPreferredSize(Dimension dimension)
Sets the preferred size of this component.
voidupdate(Graphics graphics)
Updates this component.

Field Detail

BLOCK_INCREMENT

protected static final int BLOCK_INCREMENT
Scrolling block increment (both directions).

mMosaic

protected TileSet mMosaic
The display mosaic.

mPreferredSize

protected Dimension mPreferredSize
The preferred size of this component. null initially, caches the results of calculatePreferredSize ().

mThumbelina

protected Thumbelina mThumbelina
The thumbelina object in use.

UNIT_INCREMENT

protected static final int UNIT_INCREMENT
Scrolling unit increment (both directions).

Constructor Detail

PicturePanel

public PicturePanel(Thumbelina thumbelina)
Creates a new instance of PicturePanel

Parameters: thumbelina The Thumeblina this panel is associated with.

Method Detail

adjustClipForInsets

public void adjustClipForInsets(Graphics graphics)
Adjust the graphics clip region to account for insets.

Parameters: graphics The graphics object to set the clip region for.

bringToTop

public void bringToTop(Picture picture)
Move the given picture to the top of the Z order. Adds it, even it if it doesn't exist. Also puts the URL in the url text of the status bar.

Parameters: picture The picture being brought forward.

calculatePreferredSize

protected Dimension calculatePreferredSize()
Compute the preferred size of the component. Computes the minimum bounding rectangle covering all the pictures in the panel. It then does some funky stuff to handle embedding in the view port of a scroll pane, basically asking up the ancestor heirarchy what size is available, and filling it.

Returns: The optimal dimension for this component.

componentHidden

public void componentHidden(ComponentEvent event)
Invoked when the component has been made invisible. Not used.

Parameters: event The component event.

componentMoved

public void componentMoved(ComponentEvent event)
Invoked when the component's position changes. Not used.

Parameters: event The component event.

componentResized

public void componentResized(ComponentEvent event)
Invoked when the container's size changes. Un-caches the preferred size.

Parameters: event The resize event.

componentShown

public void componentShown(ComponentEvent event)
Invoked when the component has been made visible. Not used.

Parameters: event The component event.

draw

protected void draw(Picture picture, boolean add)
Draw an image on screen.

Parameters: picture The picture to draw. add If true, the picture is added to the history.

find

public Picture find(String url)
Find a picture with the given URL in the panel. This should really only be used to discover if the picture is still visible. There could be more than one picture with the given URL because it may be partially obscured by another picture, in which case the pieces are each given their own picture object, but all point at the same URL and Image.

Parameters: url The url to locate.

Returns: The first picture encountered in the panel, or null if the picture was not found.

getPreferredScrollableViewportSize

public Dimension getPreferredScrollableViewportSize()
Returns the preferred size of the viewport for a view component. For example the preferredSize of a JList component is the size required to accommodate all of the cells in its list however the value of preferredScrollableViewportSize is the size required for JList.getVisibleRowCount() rows. A component without any properties that would effect the viewport size should just return getPreferredSize() here.

Returns: The preferredSize of a JViewport whose view is this Scrollable.

See Also: JViewport#getPreferredSize

getPreferredSize

public Dimension getPreferredSize()
Get the preferred size of the component.

Returns: The dimension of this component.

getScrollableBlockIncrement

public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)
Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.

Scrolling containers, like JScrollPane, will use this method each time the user requests a block scroll.

Parameters: visibleRect The view area visible within the viewport orientation Either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL. direction Less than zero to scroll up/left, greater than zero for down/right.

Returns: The "block" increment for scrolling in the specified direction. This value should always be positive.

getScrollableTracksViewportHeight

public boolean getScrollableTracksViewportHeight()
Return true if a viewport should always force the height of this Scrollable to match the height of the viewport. For example a columnar text view that flowed text in left to right columns could effectively disable vertical scrolling by returning true here.

Scrolling containers, like JViewport, will use this method each time they are validated.

Returns: true if a viewport should force the Scrollables height to match its own.

getScrollableTracksViewportWidth

public boolean getScrollableTracksViewportWidth()
Return true if a viewport should always force the width of this Scrollable to match the width of the viewport. For example a normal text view that supported line wrapping would return true here, since it would be undesirable for wrapped lines to disappear beyond the right edge of the viewport. Note that returning true for a Scrollable whose ancestor is a JScrollPane effectively disables horizontal scrolling.

Scrolling containers, like JViewport, will use this method each time they are validated.

Returns: true if a viewport should force the Scrollables width to match its own.

getScrollableUnitIncrement

public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)
Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation. Ideally, components should handle a partially exposed row or column by returning the distance required to completely expose the item.

Scrolling containers, like JScrollPane, will use this method each time the user requests a unit scroll.

Parameters: visibleRect The view area visible within the viewport orientation Either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL. direction Less than zero to scroll up/left, greater than zero for down/right.

Returns: The "unit" increment for scrolling in the specified direction. This value should always be positive.

hierarchyChanged

public void hierarchyChanged(HierarchyEvent event)
Handles this components ancestor being added to a container. Registers this component as a listener for size changes on the ancestor so that we may un-cache the prefereed size and force a recalculation.

Parameters: event The heirarchy event.

mouseClicked

public void mouseClicked(MouseEvent event)
Invoked when the mouse button has been clicked (pressed and released) on a component. Not used.

Parameters: event The object providing details of the mouse event.

mouseEntered

public void mouseEntered(MouseEvent event)
Invoked when the mouse enters a component. Not used.

Parameters: event The object providing details of the mouse event.

mouseExited

public void mouseExited(MouseEvent event)
Invoked when the mouse exits a component. Not used.

Parameters: event The object providing details of the mouse event.

mousePressed

public void mousePressed(MouseEvent event)
Handle left click on a picture by bringing it to the top.

Parameters: event The object providing details of the mouse event.

mouseReleased

public void mouseReleased(MouseEvent event)
Invoked when a mouse button has been released on a component. Not used.

Parameters: event The object providing details of the mouse event.

paint

public void paint(Graphics graphics)
Paints this component. Runs through the list of tiles and for every one that intersects the clip region performs a drawImage().

Parameters: graphics The graphics context used to paint with.

reset

public void reset()
Clears the panel, discarding any existing images.

setPreferredSize

public void setPreferredSize(Dimension dimension)
Sets the preferred size of this component.

Parameters: dimension The new value to use for getPreferredSize() until recalculated.

update

public void update(Graphics graphics)
Updates this component.

Parameters: graphics The graphics context in which to update the component.

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