com.codename1.ui.list

Class GenericListCellRenderer<T>

java.lang.Object

com.codename1.ui.list.GenericListCellRenderer<T>

All Implemented Interfaces:

CellRenderer<T>, ListCellRenderer<T>

public class GenericListCellRenderer<T>
extends Object
implements ListCellRenderer<T>, CellRenderer<T>

The generic list cell renderer can display containers or arbitrary Codename One components as items in a list, notice that we strongly discourage usage of lists.. It relies on the source data being a Map object. It extracts values from the Map using the component name as an indication to the Map key lookup.
This renderer supports label tickering, check boxes/radio buttons etc. seamlessly.

Please notice that you must use at least two distinct instances of the component when passing them to the constructor, reusing the same instance WILL NOT WORK!
Furthermore, the renderer instance cannot be reused for multiple lists, each list will need a new instance of this renderer!

Sample usage for this renderer follows:

Field Summary

Fields

Modifier and Type	Field and Description
static String	ENABLED If this flag exists in a Map of data the renderer will enable/disable the entries, the flag assumes either Boolean.TRUE or Boolean.FALSE.
static String	SELECT_ALL_FLAG Put this flag as a Map key to indicate that a checkbox entry rendered by this renderer should act as a "select all" entry and toggle all other entries.

Constructor Summary

Constructors

Constructor and Description
GenericListCellRenderer(Component selected, Component unselected) Constructs a generic renderer with the given selected/unselected components
GenericListCellRenderer(Component odd, Component oddUnselected, Component even, Component evenUnselected) Constructs a generic renderer with the given selected/unselected components for odd/even values allowing a "pinstripe" effect

Method Summary

Modifier and Type	Method and Description
Button	extractLastClickedComponent() Allows partitioning the renderer into "areas" that can be clicked.
URLImage.ImageAdapter	getAdapter() The adapter used when dealing with image URL's
Component	getCellRendererComponent(Component list, Object model, T value, int index, boolean isSelected) Returns a component instance that is already set to render "value".
static URLImage.ImageAdapter	getDefaultAdapter() The default adapter to use for image URLs
Component	getFocusComponent(Component list) Returns a component instance that is painted under the currently focused renderer and is animated to provide smooth scrolling.
Component	getListCellRendererComponent(List list, T value, int index, boolean isSelected) Returns a component instance that is already set to render "value".
Component	getListFocusComponent(List list) Returns a component instance that is painted under the currently focused renderer and is animated to provide smooth scrolling.
Component	getSelected()
Component	getSelectedEven()
Component	getUnselected()
Component	getUnselectedEven()
boolean	isFisheye() In fisheye rendering mode the renderer maintains selected component drawing
boolean	isSelectionListener()
void	setAdapter(URLImage.ImageAdapter adapter) The adapter used when dealing with image URL's
static void	setDefaultAdapter(URLImage.ImageAdapter aDefaultAdapter) The default adapter to use for image URLs
void	setFisheye(boolean fisheye) In fisheye rendering mode the renderer maintains selected component drawing
void	setSelectionListener(boolean selectionListener)
void	updateIconPlaceholders() Updates the placeholder instances, this is useful for changing the URLImage placeholder in runtime as might happen in the designer

Methods inherited from class java.lang.Object

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

Field Detail

ENABLED

public static final String ENABLED

If this flag exists in a Map of data the renderer will enable/disable the entries, the flag assumes either Boolean.TRUE or Boolean.FALSE. Notice that just setting it to false when necessary will not work, when its used it must be applied to all entries otherwise the reuse of the renderer component will break this feature.

See Also:

Constant Field Values

SELECT_ALL_FLAG

public static final String SELECT_ALL_FLAG

Put this flag as a Map key to indicate that a checkbox entry rendered by this renderer should act as a "select all" entry and toggle all other entries. The value for this entry is ignored

See Also:

Constant Field Values

Constructor Detail

GenericListCellRenderer

public GenericListCellRenderer(Component selected,
                               Component unselected)

Constructs a generic renderer with the given selected/unselected components

Parameters:

selected - indicates the selected value for the renderer

unselected - indicates the unselected value for the renderer

GenericListCellRenderer

public GenericListCellRenderer(Component odd,
                               Component oddUnselected,
                               Component even,
                               Component evenUnselected)

Constructs a generic renderer with the given selected/unselected components for odd/even values allowing a "pinstripe" effect

Parameters:

odd - indicates the selected value for the renderer

oddUnselected - indicates the unselected value for the renderer

even - indicates the selected value for the renderer

evenUnselected - indicates the unselected value for the renderer

Method Detail

getDefaultAdapter

public static URLImage.ImageAdapter getDefaultAdapter()

The default adapter to use for image URLs

Returns:

the defaultAdapter

setDefaultAdapter

public static void setDefaultAdapter(URLImage.ImageAdapter aDefaultAdapter)

The default adapter to use for image URLs

Parameters:

aDefaultAdapter - the defaultAdapter to set

updateIconPlaceholders

public void updateIconPlaceholders()

Updates the placeholder instances, this is useful for changing the URLImage placeholder in runtime as might happen in the designer

extractLastClickedComponent

public Button extractLastClickedComponent()

Allows partitioning the renderer into "areas" that can be clicked. When receiving an action event in the list this method allows a developer to query the renderer to "see" whether a button within the component was "touched" by the user on a touch screen device. This method will reset the value to null after returning a none-null value!

Returns:

a button or null

getCellRendererComponent

public Component getCellRendererComponent(Component list,
                                          Object model,
                                          T value,
                                          int index,
                                          boolean isSelected)

Returns a component instance that is already set to render "value". While it is not a requirement many renderes often derive from a component (such as a label) and return "this". Notice that a null value for the value argument might be sent when refreshing the theme of the list.

Specified by:

getCellRendererComponent in interface CellRenderer<T>

Parameters:

list - the list component

model - the model behind the render

value - the value to render

index - the index in the list

isSelected - whether the entry is selected

Returns:

a component to paint within the list

getListCellRendererComponent

public Component getListCellRendererComponent(List list,
                                              T value,
                                              int index,
                                              boolean isSelected)

Returns a component instance that is already set to render "value". While it is not a requirement many renderes often derive from a component (such as a label) and return "this". Notice that a null value for the value argument might be sent when refreshing the theme of the list.

Specified by:

getListCellRendererComponent in interface ListCellRenderer<T>

Parameters:

list - the list component

value - the value to render

index - the index in the list

isSelected - whether the entry is selected

Returns:

a component to paint within the list

getListFocusComponent

public Component getListFocusComponent(List list)

Returns a component instance that is painted under the currently focused renderer and is animated to provide smooth scrolling. When the selection moves, this component is drawn above/below the list items - it is recommended to give this component some level of transparency (see above code example). This method is optional an implementation can choose to return null.

Specified by:

getListFocusComponent in interface ListCellRenderer<T>

Parameters:

list - the parent list

Returns:

a component to use as focus

See Also:

Component.setSmoothScrolling(boolean)

getFocusComponent

public Component getFocusComponent(Component list)

Returns a component instance that is painted under the currently focused renderer and is animated to provide smooth scrolling. When the selection moves, this component is drawn above/below the list items - it is recommended to give this component some level of transparency (see above code example). This method is optional an implementation can choose to return null.

Specified by:

getFocusComponent in interface CellRenderer<T>

Parameters:

list - the parent list

Returns:

a component to use as focus

See Also:

Component.setSmoothScrolling(boolean)

isSelectionListener

public boolean isSelectionListener()

Returns:

the selectionListener

setSelectionListener

public void setSelectionListener(boolean selectionListener)

Parameters:

selectionListener - the selectionListener to set

getSelected

public Component getSelected()

Returns:

the selected

getUnselected

public Component getUnselected()

Returns:

the unselected

getSelectedEven

public Component getSelectedEven()

Returns:

the selectedEven

getUnselectedEven

public Component getUnselectedEven()

Returns:

the unselectedEven

isFisheye

public boolean isFisheye()

In fisheye rendering mode the renderer maintains selected component drawing

Returns:

the fisheye

setFisheye

public void setFisheye(boolean fisheye)

In fisheye rendering mode the renderer maintains selected component drawing

Parameters:

fisheye - the fisheye to set

getAdapter

public URLImage.ImageAdapter getAdapter()

The adapter used when dealing with image URL's

Returns:

the adapter

setAdapter

public void setAdapter(URLImage.ImageAdapter adapter)

The adapter used when dealing with image URL's

Parameters:

adapter - the adapter to set