org.zaval.lw
Class LwScroll

java.lang.Object
  |
  +--org.zaval.lw.LwCanvas
        |
        +--org.zaval.lw.LwPanel
              |
              +--org.zaval.lw.LwScroll

All Implemented Interfaces:

java.util.EventListener, Layoutable, LayoutContainer, LwActionListener, LwComponent, LwComposite, LwContainer, LwLayout, LwMouseListener, LwMouseMotionListener, PosInfo, PosListener, Validationable

public class LwScroll

extends LwPanel

implements LwActionListener, LwMouseListener, LwMouseMotionListener, PosInfo, PosListener, LwLayout, LwComposite

This is scrollbar component. The component is used as the vertical and horizontal scrolls by the scroll bar panel (LwScrollPan). The component reads the following resources:

• "scroll.hbg" - this is a background view of the horizontal scrollbar
• "scroll.vbg" - this is a background view of the vertical scrollbar
• "sb.b.out", "sb.b.over", "sb.b.disabled", "sb.b.pressed" - these are the lower button face views of the vertical scrollbar
• "sb.t.out", "sb.t.over", "sb.t.disabled", "sb.t.pressed" - these are the upper button face views of the vertical scrollbar
• "sb.l.out", "sb.l.over", "sb.l.disabled", "sb.l.pressed" - these are the left button face views of the horizontal scrollbar
• "sb.r.out", "sb.r.over", "sb.r.disabled", "sb.r.pressed" - these are the right button face views of the horizontal scrollbar

The scrollbar component defines a value that should be less than certain maximal value and cannot be less zero. The maximal possible value and the current value are defined by a pos controller of the component. Use the getMaxOffset, setMaxOffset methods of the component and the getOffset, setOffset methods of the pos controller to control the scrollbar properties. The sample below illustrates the scrollbar properties usage:

   ...
   LwScroll scroll = new LwScroll(LwToolkit.VERTICAL);
   scroll.setMaxOffset(100); // Setting the maximal posiible value of the scrollbar
   scroll.getPosController().getOffset();    // Getting the current value of the scrollbar
   scroll.getPosController().setOffset(10);  // Setting the current value of the scrollbar
   ...
 

A user can interact with the component using following actions:

• By pressing the scrollbar buttons. In this case, the component uses "unitIncrement" value to increase or decrease the value property.
• By pressing a mouse button inside the scrollbar area. In this case "pageIncrement" value is used to increase or decrease the scrollbar value property.
• By dragging the scrollbar bundle element. In this case the scrollbar value will be calculated basing on the current bundle location.

The component is a container that implements own layout manager. Use the defined by the component constraints to customize the container elements.

Field Summary
static java.lang.Integer	BUNDLE_EL           The bundle element constraint.
static java.lang.Integer	DECBUTTON_EL           The decrement button element constraint.
static java.lang.Integer	INCBUTTON_EL           The increment button element constraint.

 

Fields inherited from class org.zaval.lw.LwPanel

children

 

Fields inherited from class org.zaval.lw.LwCanvas

bits, bottom, height, isValidValue, left, parent, psHeight, psWidth, right, skins, temporary, top, width, x, y

 

Constructor Summary

LwScroll(int t)           Constructs a scrollbar component with the specified orientation.

 

Method Summary
void	actionPerformed(java.lang.Object src, java.lang.Object data)           Invoked when an action event occurred.
java.awt.Dimension	calcPreferredSize(LayoutContainer target)           Calculates the preferred size dimension for the layout container.
boolean	catchInput(LwComponent child)           Checks if the input event for the specified child component should be caught by the parent.
void	componentAdded(java.lang.Object id, Layoutable lw, int index)           Invoked when the specified layoutable component was added to the layout container (that uses the layout manager).
void	componentRemoved(Layoutable lw, int index)           Invoked when the specified layoutable component was removed from the layout container, that uses the layout manager.
void	endDragged(LwMouseEvent e)           Invoked when the mouse ends dragged.
protected  LwLayout	getDefaultLayout()           Gets the default layout manager that is set with the container during initialization.
LwComponent	getElement(java.lang.Object key)           Gets the element of the scroll bar by the given constraint.
int	getExtraSize()           Get the extra size.
int	getLines()           Gets the number of lines.
int	getLineSize(int line)           Gets the line size for the specified line number.
int	getMaxOffset()           Gets the maximal offset.
int	getPageIncrement()           Gets the page increment value.
PosController	getPosController()           Gets the position controller.
int	getUnitIncrement()           Gets the unit increment value.
void	layout(LayoutContainer target)           Lays out the child layoutable components inside the layout container.
void	mouseClicked(LwMouseEvent e)           Invoked when the mouse button has been clicked on a light weight component.
void	mouseDragged(LwMouseEvent e)           Invoked when a mouse button is pressed on a component and then dragged.
void	mouseEntered(LwMouseEvent e)           Invoked when the mouse enters a light weight component.
void	mouseExited(LwMouseEvent e)           Invoked when the mouse exits a light weight component.
void	mouseMoved(LwMouseEvent e)           Invoked when the mouse pointer has been moved on a light weight component (with no buttons no down).
void	mousePressed(LwMouseEvent e)           Invoked when the mouse button has been pressed on a light weight component.
void	mouseReleased(LwMouseEvent e)           Invoked when the mouse button has been released on a light weight component.
void	posChanged(java.lang.Object target, int po, int pl, int pc)           Invoked when a virtual position has been changed.
void	setExtraSize(int e)           Sets the extra size.
void	setMaximum(int m)           Sets the specified maximal value for the scrollbar component.
void	setPageIncrement(int pi)           Sets the page increment value.
void	setPosController(PosController p)           Sets the specified position controller.
void	setUnitIncrement(int li)           Sets the unit increment value.
void	startDragged(LwMouseEvent e)           Invoked when the mouse starts dragged.

 

Methods inherited from class org.zaval.lw.LwPanel

add, add, calcPreferredSize, count, get, getLayoutOffset, getLwComponentAt, getLwLayout, getPreferredSize, indexOf, insert, insert, invalidate, isInvalidatedByChild, laidout, paintOnTop, remove, remove, removeAll, setBackground, setLwLayout, setOpaque, setSize, toFront, updateCashedPs, validate

 

Methods inherited from class org.zaval.lw.LwCanvas

calcInsets, canHaveFocus, customize, cvp, getBackground, getBottom, getBounds, getHeight, getInsets, getLeft, getLocation, getLwParent, getOrigin, getPSImpl, getRight, getSize, getTop, getViewMan, getVisiblePart, getWidth, getX, getY, hasFocus, isEnabled, isOpaque, isValid, isVisible, paint, recalc, repaint, repaint, repaint, requestFocus, setEnabled, setInsets, setLocation, setLwParent, setPSSize, setViewMan, setVisible, update, viewManChanged, vrp

 

Methods inherited from class java.lang.Object

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

 

Methods inherited from interface org.zaval.lw.LwContainer

add, add, getLwLayout, indexOf, insert, isInvalidatedByChild, paintOnTop, remove, removeAll, setLwLayout

 

Methods inherited from interface org.zaval.lw.LwComponent

canHaveFocus, getBackground, getLwComponentAt, getLwParent, getOrigin, getViewMan, getVisiblePart, isEnabled, isOpaque, paint, repaint, repaint, repaint, setBackground, setEnabled, setInsets, setLwParent, setOpaque, setViewMan, setVisible, update

 

Methods inherited from interface org.zaval.lw.Layoutable

getBounds, getHeight, getInsets, getLocation, getPreferredSize, getSize, getWidth, getX, getY, isVisible, setLocation, setSize

 

Methods inherited from interface org.zaval.util.Validationable

invalidate, isValid, validate

 

Methods inherited from interface org.zaval.lw.LayoutContainer

count, get, getLayoutOffset

 

Field Detail

BUNDLE_EL

public static final java.lang.Integer BUNDLE_EL

The bundle element constraint.

INCBUTTON_EL

public static final java.lang.Integer INCBUTTON_EL

The increment button element constraint.

DECBUTTON_EL

public static final java.lang.Integer DECBUTTON_EL

The decrement button element constraint.

LwScroll

public LwScroll(int t)

Constructs a scrollbar component with the specified orientation. The orientation value can be LwToolkit.VERTICAL or LwToolkit.HORIZONTAL, otherwise the IllegalArgumentException will be thrown.

Parameters:

t - the specified orientation.

setMaximum

public void setMaximum(int m)

Sets the specified maximal value for the scrollbar component. The scrollbar value cannot be more than the maximal value, so the method sets the current value to maximal value if the current value is more than the new maximal value.

Parameters:

m - the specified maximal value.

setPageIncrement

public void setPageIncrement(int pi)

Sets the page increment value. The value is used to decrease or increase the scrollbar value whenever a mouse button has been pressed inside the component area.

Parameters:

pi - the specified page increment.

getPageIncrement

public int getPageIncrement()

Gets the page increment value.

Returns:

a page increment value.

setUnitIncrement

public void setUnitIncrement(int li)

Sets the unit increment value. The value is used to decrease or increase the scrollbar value whenever one of the scrollbar button has been pressed.

Parameters:

li - the specified unit increment.

getUnitIncrement

public int getUnitIncrement()

Gets the unit increment value.

Returns:

a unit increment value.

setPosController

public void setPosController(PosController p)

Sets the specified position controller. The controller is used to control the scrollbar value.

Parameters:

p - the specified position controller.

getPosController

public PosController getPosController()

Gets the position controller.

Returns:

a position controller.

actionPerformed

public void actionPerformed(java.lang.Object src,
                            java.lang.Object data)

Description copied from interface: LwActionListener

Invoked when an action event occurred.

Specified by:

actionPerformed in interface LwActionListener

Following copied from interface: org.zaval.lw.event.LwActionListener

Parameters:

src - the specified source where the event has been originated.

data - the event data.

mouseClicked

public void mouseClicked(LwMouseEvent e)

Description copied from interface: LwMouseListener

Invoked when the mouse button has been clicked on a light weight component.

Specified by:

mouseClicked in interface LwMouseListener

Following copied from interface: org.zaval.lw.event.LwMouseListener

Parameters:

e - the specified mouse event.

mouseEntered

public void mouseEntered(LwMouseEvent e)

Description copied from interface: LwMouseListener

Invoked when the mouse enters a light weight component.

Specified by:

mouseEntered in interface LwMouseListener

Following copied from interface: org.zaval.lw.event.LwMouseListener

Parameters:

e - the specified mouse event.

mouseExited

public void mouseExited(LwMouseEvent e)

Description copied from interface: LwMouseListener

Invoked when the mouse exits a light weight component.

Specified by:

mouseExited in interface LwMouseListener

Following copied from interface: org.zaval.lw.event.LwMouseListener

Parameters:

e - the specified mouse event.

mouseReleased

public void mouseReleased(LwMouseEvent e)

Description copied from interface: LwMouseListener

Invoked when the mouse button has been released on a light weight component.

Specified by:

mouseReleased in interface LwMouseListener

Following copied from interface: org.zaval.lw.event.LwMouseListener

Parameters:

e - the specified mouse event.

mouseMoved

public void mouseMoved(LwMouseEvent e)

Description copied from interface: LwMouseMotionListener

Invoked when the mouse pointer has been moved on a light weight component (with no buttons no down).

Specified by:

mouseMoved in interface LwMouseMotionListener

Following copied from interface: org.zaval.lw.event.LwMouseMotionListener

Parameters:

e - the specified mouse event.

startDragged

public void startDragged(LwMouseEvent e)

Description copied from interface: LwMouseMotionListener

Invoked when the mouse starts dragged.

Specified by:

startDragged in interface LwMouseMotionListener

Following copied from interface: org.zaval.lw.event.LwMouseMotionListener

Parameters:

e - the specified mouse event.

endDragged

public void endDragged(LwMouseEvent e)

Description copied from interface: LwMouseMotionListener

Invoked when the mouse ends dragged.

Specified by:

endDragged in interface LwMouseMotionListener

Following copied from interface: org.zaval.lw.event.LwMouseMotionListener

Parameters:

e - the specified mouse event.

mouseDragged

public void mouseDragged(LwMouseEvent e)

Description copied from interface: LwMouseMotionListener

Invoked when a mouse button is pressed on a component and then dragged. Mouse drag events will continue to be delivered to the component where the first originated until the mouse button is released (regardless of whether the mouse position is within the bounds of the component).

Specified by:

mouseDragged in interface LwMouseMotionListener

Following copied from interface: org.zaval.lw.event.LwMouseMotionListener

Parameters:

e - the specified mouse event.

mousePressed

public void mousePressed(LwMouseEvent e)

Description copied from interface: LwMouseListener

Invoked when the mouse button has been pressed on a light weight component.

Specified by:

mousePressed in interface LwMouseListener

Following copied from interface: org.zaval.lw.event.LwMouseListener

Parameters:

e - the specified mouse event.

posChanged

public void posChanged(java.lang.Object target,
                       int po,
                       int pl,
                       int pc)

Description copied from interface: PosListener

Invoked when a virtual position has been changed.

Specified by:

posChanged in interface PosListener

Following copied from interface: org.zaval.misc.event.PosListener

Parameters:

target - the specified pos controller.

prevOffset - the previous offset.

prevLine - the previous line.

prevColumn - the previous column.

getLines

public int getLines()

Description copied from interface: PosInfo

Gets the number of lines.

Specified by:

getLines in interface PosInfo

Following copied from interface: org.zaval.misc.PosInfo

Returns:

a number of lines.

getLineSize

public int getLineSize(int line)

Description copied from interface: PosInfo

Gets the line size for the specified line number.

Specified by:

getLineSize in interface PosInfo

Following copied from interface: org.zaval.misc.PosInfo

Parameters:

line - the specified line number.

Returns:

a size of the line.

getMaxOffset

public int getMaxOffset()

Description copied from interface: PosInfo

Gets the maximal offset. The method can return -1 as the result, in this case the pos controller that uses the pos info will try to calculate the maximal offset itself basing on the line number and the lines sizes.

Specified by:

getMaxOffset in interface PosInfo

Following copied from interface: org.zaval.misc.PosInfo

Returns:

a maximal offset.

getExtraSize

public int getExtraSize()

Get the extra size.

Returns:

an extra size.

setExtraSize

public void setExtraSize(int e)

Sets the extra size. By the size it is possible to control bundle size depending on the maximal possible size.

Parameters:

e - the given extra size.

componentAdded

public void componentAdded(java.lang.Object id,
                           Layoutable lw,
                           int index)

Description copied from interface: LwLayout

Invoked when the specified layoutable component was added to the layout container (that uses the layout manager). The specified constraints, layoutable component and child index are passed as arguments into the method.

Specified by:

componentAdded in interface LwLayout

Following copied from interface: org.zaval.lw.LwLayout

Parameters:

id - the layoutable component constraints.

lw - the layoutable component that has been added.

index - the child index.

componentRemoved

public void componentRemoved(Layoutable lw,
                             int index)

Description copied from interface: LwLayout

Invoked when the specified layoutable component was removed from the layout container, that uses the layout manager.

Specified by:

componentRemoved in interface LwLayout

Following copied from interface: org.zaval.lw.LwLayout

Parameters:

lw - the layoutable component that has been removed.

index - the child component index.

calcPreferredSize

public java.awt.Dimension calcPreferredSize(LayoutContainer target)

Description copied from interface: LwLayout

Calculates the preferred size dimension for the layout container. The method has to calculate "pure" preferred size, it means that container insets should not be taken into account.

Specified by:

calcPreferredSize in interface LwLayout

Following copied from interface: org.zaval.lw.LwLayout

Parameters:

target - the layout container.

Returns:

a "pure" preferred size.

layout

public void layout(LayoutContainer target)

Description copied from interface: LwLayout

Lays out the child layoutable components inside the layout container.

Specified by:

layout in interface LwLayout

Following copied from interface: org.zaval.lw.LwLayout

Parameters:

target - the layout container.

catchInput

public boolean catchInput(LwComponent child)

Description copied from interface: LwComposite

Checks if the input event for the specified child component should be caught by the parent.

Specified by:

catchInput in interface LwComposite

Following copied from interface: org.zaval.lw.LwComposite

Parameters:

child - the specified child component.

Returns:

true if input events for the child component should be caught by this component; false otherwise.

getElement

public LwComponent getElement(java.lang.Object key)

Gets the element of the scroll bar by the given constraint. Using the method it is possible to get bundle, increment or decrement buttons components.

Parameters:

key - the specified constraint. Use the BUNDLE_EL, INCBUTTON_EL, DECBUTTON_EL constants as the argument value.

Returns:

an element.

getDefaultLayout

protected LwLayout getDefaultLayout()

Description copied from class: LwPanel

Gets the default layout manager that is set with the container during initialization. This implementation of the method returns LwRastLayout as the default layout manager, the layout manager is got as a static object by "def.lay" key.

Overrides:

getDefaultLayout in class LwPanel

Following copied from class: org.zaval.lw.LwPanel

Returns:

a layout manager.