hades.gui
Class CanvasScroller

java.lang.Object
  java.awt.Component
      java.awt.Container
          java.awt.Panel
              hades.gui.CanvasScroller

All Implemented Interfaces:

javax.accessibility.Accessible, java.awt.event.AdjustmentListener, java.awt.event.ComponentListener, java.util.EventListener, java.awt.image.ImageObserver, java.awt.MenuContainer, java.awt.event.MouseMotionListener, java.io.Serializable, ZoomListener

public class CanvasScroller

extends java.awt.Panel

implements java.awt.event.AdjustmentListener, java.awt.event.ComponentListener, java.awt.event.MouseMotionListener, ZoomListener

CanvasScroller - an AWT component to manage a JavaFIG/HADES editor canvas with rulers at the top and left sides, and additional standard right and bottom scrollbars. Also, a simple Label field is provided to display the current mouse coordinates and zoom factor.

This class needs to be provided with the (real or approximate) bounding box of all visible objects, in order to calculate and set the size and position of the scrollbar thumbs. The thumbs are sized to match the ratio of the visible region to the union of the visible region plus the bounding box of all displayed objects.
Remember to call 'setObjectBoundingBox( xl, yt, xr, yb )' after any editing operation in your application which changes this bounding box - otherwise the visible objects will not match the user expectations built from the scrollbar sizes.
Usually, you may want to initialize the bounding box with a suitable default value. For example, call setObjectBoundingBox( 0, 0, 28000, 18600 ) to initialize the CanvasScroller to (approximate) "A4 paper size" in landscape orientation. This is also the default object bounding box used. See class jfig.canvas.FigTrafo2D for documentation about the coordinate system used in JavaFIG/HADES (2400 dpi world coords, origin at top left).

Usually, the default behaviour of scrollbars is to clip all scrolling to the limit of the underlying data model: Once you arrive at the end of your document, you cannot scroll further. This is the default behaviour of CanvasScroller, where the limit of the 'allowed' region is set by calling setObjectBoundingBox.

However, in order to get the xfig/JavaFIG/HADES behaviour of enlarging the current object region as needed, CanvasScroller also implements a variant of the above strategy, where the scrollbars are not clipped to the visible region or any other predefined values. Instead, the scrollbar thumbs are clipped after each event, to allow one more click in the respective direction. For simplicity, scrollbar values are used in the range 0 ... 99. Therefore, we clip the scrollbar thumb position to the range 1 .. 98. Call setClipToBoudingBox( boolean ) to switch the scrollbar clipping on or off.

See Also:

Serialized Form

Nested Class Summary

(package private) class	CanvasScroller.DummyObjectEnumerator
(package private) class	CanvasScroller.Filler inner class Filler: used to fill the bottom right corner in a BorderLayout with two Scrollbars
(package private) class	CanvasScroller.InfoLabel

Nested classes inherited from class java.awt.Panel

java.awt.Panel.AccessibleAWTPanel

Nested classes inherited from class java.awt.Container

java.awt.Container.AccessibleAWTContainer

Nested classes inherited from class java.awt.Component

java.awt.Component.AccessibleAWTComponent, java.awt.Component.BltBufferStrategy, java.awt.Component.FlipBufferStrategy

Field Summary

protected java.awt.Panel	bottomPanel
protected boolean	clipToObjectBoundingBox
protected java.awt.Label	coordLabel
protected FigCanvas	editorCanvas
protected CanvasScroller.Filler	filler
protected CanvasScroller.InfoLabel	infoLabel
protected java.awt.Panel	labelPanel
protected FigBbox	objectBBox
protected java.awt.Scrollbar	scrollbarX
protected java.awt.Scrollbar	scrollbarY
protected FigBbox	totalBBox
protected FigBbox	visibleRegionBBox
protected java.awt.Label	zoomLabel

Fields inherited from class java.awt.Container

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

CanvasScroller(FigCanvas _canvas)

Method Summary

void	adjustmentValueChanged(java.awt.event.AdjustmentEvent evt)
(package private) void	buildGUI()
int	clip(int value, int min_value, int max_value)
void	componentHidden(java.awt.event.ComponentEvent evt)
void	componentMoved(java.awt.event.ComponentEvent evt)
void	componentResized(java.awt.event.ComponentEvent evt)
void	componentShown(java.awt.event.ComponentEvent evt)
void	doLayout()
int	getScrollbarWidth()
static void	main(java.lang.String[] argv)
void	mouseDragged(java.awt.event.MouseEvent evt)
void	mouseMoved(java.awt.event.MouseEvent evt)
static void	msg(java.lang.String s)
void	rebuildBoundingBoxes()
void	rebuildScrollbars() rebuild the scrollbar thumbs, assuming that the visible region and object bounding boxes are set correctly (by a previous call to rebuildBoundingBoxes).
void	setCanvas(FigCanvas _canvas)
void	setClipToObjectBoundingBox(boolean b)
void	setObjectBoundingBox(int xl, int yt, int xr, int yb)
void	trackScrollbarX()
void	trackScrollbarY()
void	zoomChanged(java.lang.Object arg)

Methods inherited from class java.awt.Panel

addNotify, getAccessibleContext

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getInsets, getLayout, getListeners, getMaximumSize, getMinimumSize, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paint, paintComponents, paramString, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setFont, setLayout, transferFocusBackward, transferFocusDownCycle, update, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isOpaque, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

editorCanvas

protected FigCanvas editorCanvas

bottomPanel

protected java.awt.Panel bottomPanel

labelPanel

protected java.awt.Panel labelPanel

scrollbarX

protected java.awt.Scrollbar scrollbarX

scrollbarY

protected java.awt.Scrollbar scrollbarY

coordLabel

protected java.awt.Label coordLabel

zoomLabel

protected java.awt.Label zoomLabel

filler

protected CanvasScroller.Filler filler

infoLabel

protected CanvasScroller.InfoLabel infoLabel

objectBBox

protected FigBbox objectBBox

visibleRegionBBox

protected FigBbox visibleRegionBBox

totalBBox

protected FigBbox totalBBox

clipToObjectBoundingBox

protected boolean clipToObjectBoundingBox

Constructor Detail

CanvasScroller

public CanvasScroller(FigCanvas _canvas)

Method Detail

setCanvas

public void setCanvas(FigCanvas _canvas)

buildGUI

void buildGUI()

getScrollbarWidth

public int getScrollbarWidth()

doLayout

public void doLayout()

rebuildBoundingBoxes

public void rebuildBoundingBoxes()

setObjectBoundingBox

public void setObjectBoundingBox(int xl,
                                 int yt,
                                 int xr,
                                 int yb)

setClipToObjectBoundingBox

public void setClipToObjectBoundingBox(boolean b)

rebuildScrollbars

public void rebuildScrollbars()

rebuild the scrollbar thumbs, assuming that the visible region and object bounding boxes are set correctly (by a previous call to rebuildBoundingBoxes).

clip

public int clip(int value,
                int min_value,
                int max_value)

componentHidden

public void componentHidden(java.awt.event.ComponentEvent evt)

Specified by:

componentHidden in interface java.awt.event.ComponentListener

componentMoved

public void componentMoved(java.awt.event.ComponentEvent evt)

Specified by:

componentMoved in interface java.awt.event.ComponentListener

componentShown

public void componentShown(java.awt.event.ComponentEvent evt)

Specified by:

componentShown in interface java.awt.event.ComponentListener

componentResized

public void componentResized(java.awt.event.ComponentEvent evt)

Specified by:

componentResized in interface java.awt.event.ComponentListener

adjustmentValueChanged

public void adjustmentValueChanged(java.awt.event.AdjustmentEvent evt)

Specified by:

adjustmentValueChanged in interface java.awt.event.AdjustmentListener

trackScrollbarX

public void trackScrollbarX()

trackScrollbarY

public void trackScrollbarY()

mouseMoved

public void mouseMoved(java.awt.event.MouseEvent evt)

Specified by:

mouseMoved in interface java.awt.event.MouseMotionListener

mouseDragged

public void mouseDragged(java.awt.event.MouseEvent evt)

Specified by:

mouseDragged in interface java.awt.event.MouseMotionListener

zoomChanged

public void zoomChanged(java.lang.Object arg)

Specified by:

zoomChanged in interface ZoomListener

msg

public static void msg(java.lang.String s)

main

public static void main(java.lang.String[] argv)