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:

public void showForm() {
    com.codename1.ui.List list = new com.codename1.ui.List(createGenericListCellRendererModelData());
    list.setRenderer(new GenericListCellRenderer(createGenericRendererContainer(), createGenericRendererContainer()));
    Form hi = new Form("GenericListCellRenderer", new BorderLayout());
    hi.add(BorderLayout.CENTER, list);
    hi.show();
}

private Container createGenericRendererContainer() {
    Label name = new Label();
    name.setFocusable(true);
    name.setName("Name");
    Label surname = new Label();
    surname.setFocusable(true);
    surname.setName("Surname");
    CheckBox selected = new CheckBox();
    selected.setName("Selected");
    selected.setFocusable(true);
    Container c = BorderLayout.center(name).
            add(BorderLayout.SOUTH, surname).
            add(BorderLayout.WEST, selected);
    c.setUIID("ListRenderer");
    return c;
}

private Object[] createGenericListCellRendererModelData() {
    Map[] data = new HashMap[5];
    data[0] = new HashMap<>();
    data[0].put("Name", "Shai");
    data[0].put("Surname", "Almog");
    data[0].put("Selected", Boolean.TRUE);
    data[1] = new HashMap<>();
    data[1].put("Name", "Chen");
    data[1].put("Surname", "Fishbein");
    data[1].put("Selected", Boolean.TRUE);
    data[2] = new HashMap<>();
    data[2].put("Name", "Ofir");
    data[2].put("Surname", "Leitner");
    data[3] = new HashMap<>();
    data[3].put("Name", "Yaniv");
    data[3].put("Surname", "Vakarat");
    data[4] = new HashMap<>();
    data[4].put("Name", "Meirav");
    data[4].put("Surname", "Nachmanovitch");
    return data;
}

public void showForm() {
    com.codename1.ui.List list = new com.codename1.ui.List(createGenericListCellRendererModelData());
    list.setRenderer(new GenericListCellRenderer(createGenericRendererContainer(), createGenericRendererContainer()));
    Form hi = new Form("GenericListCellRenderer", new BorderLayout());
    hi.add(BorderLayout.CENTER, list);
    hi.show();
}

private Container createGenericRendererContainer() {
    Label name = new Label();
    name.setFocusable(true);
    name.setName("Name");
    Label surname = new Label();
    surname.setFocusable(true);
    surname.setName("Surname");
    CheckBox selected = new CheckBox();
    selected.setName("Selected");
    selected.setFocusable(true);
    Container c = BorderLayout.center(name).
            add(BorderLayout.SOUTH, surname).
            add(BorderLayout.WEST, selected);
    c.setUIID("ListRenderer");
    return c;
}

private Object[] createGenericListCellRendererModelData() {
    Map[] data = new HashMap[5];
    data[0] = new HashMap<>();
    data[0].put("Name", "Shai");
    data[0].put("Surname", "Almog");
    data[0].put("Selected", Boolean.TRUE);
    data[1] = new HashMap<>();
    data[1].put("Name", "Chen");
    data[1].put("Surname", "Fishbein");
    data[1].put("Selected", Boolean.TRUE);
    data[2] = new HashMap<>();
    data[2].put("Name", "Ofir");
    data[2].put("Surname", "Leitner");
    data[3] = new HashMap<>();
    data[3].put("Name", "Yaniv");
    data[3].put("Surname", "Vakarat");
    data[4] = new HashMap<>();
    data[4].put("Name", "Meirav");
    data[4].put("Surname", "Nachmanovitch");
    return data;
}

Field Summary

Fields

Modifier and Type	Field	Description
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.
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.

Constructor Summary

Constructors

Constructor	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	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()	Returns
Component	getSelectedEven()	Returns
Component	getUnselected()	Returns
Component	getUnselectedEven()	Returns
boolean	isFisheye()	In fisheye rendering mode the renderer maintains selected component drawing
boolean	isSelectionListener()	Returns
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)	Parameters
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 Object

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

Field Details

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 Details

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 Details

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.

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

Specified by:

getCellRendererComponent in interface CellRenderer<T>

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.

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

Specified by:

getListCellRendererComponent in interface ListCellRenderer<T>

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.

Parameters

• list: the parent list

Returns

a component to use as focus

See also

• List#setSmoothScrolling

Specified by:

getListFocusComponent in interface ListCellRenderer<T>

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.

Parameters

• list: the parent list

Returns

a component to use as focus

See also

• List#setSmoothScrolling

Specified by:

getFocusComponent in interface CellRenderer<T>

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