org.zaval.lw
Interface LwComponent

All Superinterfaces:

Layoutable, Validationable

All Known Subinterfaces:

LwComposite, LwContainer, LwDesktop, LwLayer

All Known Implementing Classes:

LwCanvas

public interface LwComponent

extends Layoutable

This is base interface for the library components. Any GUI component of the library should implement the interface. Actually the interface is analog of the java.awt.Component class provided by the Java AWT library. The lightweight library provides an implementation of the interface - LwCanvas - that is more handy for usage. To create a lightweight component just inherit the class. The another variation of the interface is the lightweight container interface - LwContainer. The interface extends the component interface and has implementation to create own lightweight containers - LwPanel.

Method Summary
boolean	canHaveFocus()           Specifies if the component can have focus.
java.awt.Color	getBackground()           Gets the background color of this component.
LwComponent	getLwComponentAt(int x, int y)           Determines if the component or an immediate child component contains the (x, y) location in its visible part and if so, returns the component.
LwComponent	getLwParent()           Gets the lightweight parent of this component.
java.awt.Point	getOrigin()           Returns an origin of the component.
LwViewMan	getViewMan(boolean autoCreate)           Returns a view manager of the component.
java.awt.Rectangle	getVisiblePart()           Returns the bounding rectangle of the visible part for the component.
boolean	isEnabled()           Determines whether this component is enabled.
boolean	isOpaque()           Gets the opaque of this component.
void	paint(java.awt.Graphics g)           Paints this component.
void	repaint()           Performs repainting process of this component.
void	repaint(boolean b)           Invoked whenever the component got or lost the focus.
void	repaint(int x, int y, int w, int h)           Performs repainting process of the specified rectangular area of this component.
void	setBackground(java.awt.Color c)           Sets the background color of this component.
void	setEnabled(boolean b)           Enables or disables this component.
void	setInsets(int top, int left, int bottom, int right)           Sets the specified insets for the component.
void	setLwParent(LwComponent p)           Sets the lightweight parent of this component.
void	setOpaque(boolean b)           Sets the opaque of this component.
void	setViewMan(LwViewMan man)           Sets the specified view manager for the component.
void	setVisible(boolean b)           Shows or hides this lightweight component depending on the value of parameter b.
void	update(java.awt.Graphics g)           Updates this component.

 

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

 

Method Detail

getVisiblePart

public java.awt.Rectangle getVisiblePart()

Returns the bounding rectangle of the visible part for the component.

Returns:

a visible part bounding rectangle.

getLwComponentAt

public LwComponent getLwComponentAt(int x,
                                    int y)

Determines if the component or an immediate child component contains the (x, y) location in its visible part and if so, returns the component.

Parameters:

x - the x coordinate.

y - the y coordinate.

Returns:

the component or subcomponent that contains the (x, y) location; null if the location is outside this component.

getLwParent

public LwComponent getLwParent()

Gets the lightweight parent of this component. It is supposed that the parent implements LwContainer interface.

Returns:

the parent container of this component.

setLwParent

public void setLwParent(LwComponent p)

Sets the lightweight parent of this component. It is supposed that the parent implements LwContainer interface. The method is provided for lightweight core usage to support components hierarchy, not for applications that base on the library. Don't touch the method.

Parameters:

p - the specified parent container.

setEnabled

public void setEnabled(boolean b)

Enables or disables this component. An enabled component can participate in events handling and performing processes. Component is enabled by default.

Parameters:

b - if the value is true - enables the component; otherwise disables this component.

setVisible

public void setVisible(boolean b)

Shows or hides this lightweight component depending on the value of parameter b.

Parameters:

b - if it is true, shows this component; otherwise, hides this component.

setBackground

public void setBackground(java.awt.Color c)

Sets the background color of this component. The color is going to be used to fill the component background.

Parameters:

c - the color to become this component background color.

getViewMan

public LwViewMan getViewMan(boolean autoCreate)

Returns a view manager of the component. The view manager can be null. The input argument autoCreate defines if the view manager has to be created automatically in a case if it has not been determined before. It means, if the argument is true and the view manager is null, than the component will try to create and initialize its view manager by a default view manager. If the argument is false than the method returns the component view manager as is.

Parameters:

autoCreate - the flag defines if the view manager should be created automatically.

Returns:

a view manager for the component.

setViewMan

public void setViewMan(LwViewMan man)

Sets the specified view manager for the component. The view manager defines set of views that are used as a part of the component face.

Parameters:

man - the view manager to set for the component.

canHaveFocus

public boolean canHaveFocus()

Specifies if the component can have focus.

Returns:

true if the component can have the focus.

paint

public void paint(java.awt.Graphics g)

Paints this component.

Parameters:

g - the graphics context to be used for painting.

update

public void update(java.awt.Graphics g)

Updates this component. The calling of the method precedes the calling of paint method and it is performed with repaint method. The method can be used to fill the component with the background color if the component is opaque.

Parameters:

g - the specified context to be used for updating.

repaint

public void repaint()

Performs repainting process of this component. The method causes calling of update and than paint methods.

repaint

public void repaint(int x,
                    int y,
                    int w,
                    int h)

Performs repainting process of the specified rectangular area of this component. The method causes calling of update and than paint methods.

Parameters:

x - the x coordinate.

y - the y coordinate.

w - the width.

h - the height.

isOpaque

public boolean isOpaque()

Gets the opaque of this component. If the method returns false than the component is transparent, in this case update method is not be called during painting process.

Returns:

true if the component is opaque; otherwise false.

setOpaque

public void setOpaque(boolean b)

Sets the opaque of this component. Use false argument value to make a transparent component from this component.

Parameters:

b - the opaque flag.

getOrigin

public java.awt.Point getOrigin()

Returns an origin of the component. The origin defines an offset of the component view relatively the component point of origin. The method can be implemented to organize scrolling of the component view.

Returns:

an origin of the component.

getBackground

public java.awt.Color getBackground()

Gets the background color of this component.

Returns:

a component background color.

isEnabled

public boolean isEnabled()

Determines whether this component is enabled. If the method returns true than the component is enabled and can participate in event handling and performing processes. Components are enabled initially by default.

Returns:

true if the component is enabled; false otherwise.

setInsets

public void setInsets(int top,
                      int left,
                      int bottom,
                      int right)

Sets the specified insets for the component.

Parameters:

top - the top indent.

left - the left indent.

bottom - the bottom indent.

right - the right indent.

repaint

public void repaint(boolean b)

Invoked whenever the component got or lost the focus. The method is supposed to optimize the performance of the focus marker, since in most cases it is not necessary to repaint all component area. By default the method repaint all component area.

Parameters:

b - true if the component has got the focus, and false if the component lost the focus.