eu.webtoolkit.jwt
Class WItemDelegate

java.lang.Object
  eu.webtoolkit.jwt.WObject
      eu.webtoolkit.jwt.WAbstractItemDelegate
          eu.webtoolkit.jwt.WItemDelegate

public class WItemDelegate
extends WAbstractItemDelegate

Standard delegate class for rendering a view item.

This class provides the standard implementation for rendering an item (as in a WAbstractItemView), and renders data provided by the standard data roles (see ItemDataRole). It also provides default editing support using a line edit.

You may provide special editing support for an item by specializing the widget and reimplement createEditor(), setModelData(), getEditState(), and setEditState().

Constructor Summary

WItemDelegate()
Create an item delegate.

WItemDelegate(WObject parent)
Create an item delegate.

Method Summary

protected WWidget	createEditor(WModelIndex index, java.util.EnumSet<ViewItemRenderFlag> flags) Creates an editor for a data item.
protected WWidget	createEditor(WModelIndex index, ViewItemRenderFlag flag, ViewItemRenderFlag... flags) Creates an editor for a data item.
java.lang.Object	getEditState(WWidget editor) Returns the current edit state.
java.lang.String	getTextFormat() Returns the text format string.
void	setEditState(WWidget editor, java.lang.Object value) Sets the editor data from the editor state.
void	setModelData(java.lang.Object editState, WAbstractItemModel model, WModelIndex index) Saves the edited data to the model.
void	setTextFormat(java.lang.String format) Sets the text format string.
WWidget	update(WWidget widget, WModelIndex index, java.util.EnumSet<ViewItemRenderFlag> flags) Creates or updates a widget that renders an item.
void	updateModelIndex(WWidget widget, WModelIndex index) Updates the model index of a widget.

Methods inherited from class eu.webtoolkit.jwt.WAbstractItemDelegate

closeEditor, update, validate

Methods inherited from class eu.webtoolkit.jwt.WObject

getId, getObjectName, remove, setObjectName, tr

Methods inherited from class java.lang.Object

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

Constructor Detail

WItemDelegate

public WItemDelegate(WObject parent)

Create an item delegate.

WItemDelegate

public WItemDelegate()

Create an item delegate.

Calls this((WObject)null)

Method Detail

update

public WWidget update(WWidget widget,
                      WModelIndex index,
                      java.util.EnumSet<ViewItemRenderFlag> flags)

Creates or updates a widget that renders an item.

The following properties of an item are rendered:

• text using the ItemDataRole.DisplayRole data, with the format specified by setTextFormat()
• a check box depending on the ItemFlag.ItemIsUserCheckable flag and ItemDataRole.CheckStateRole data
• an anchor depending on Wt::InternalPathRole or Wt::UrlRole values
• an icon depending on the value of ItemDataRole.DecorationRole
• a tooltip depending on the value of ItemDataRole.ToolTipRole
• a custom style class depending on the value of ItemDataRole.StyleClassRole

When the flags indicates ViewItemRenderFlag.RenderEditing, then createEditor() is called to create a suitable editor for editing the item.

Specified by:

update in class WAbstractItemDelegate

updateModelIndex

public void updateModelIndex(WWidget widget,
                             WModelIndex index)

Description copied from class: WAbstractItemDelegate

Updates the model index of a widget.

This method is invoked by the view when due to row/column insertions or removals, the index has shifted.

You should reimplement this method only if you are storing the model index in the widget, to update the stored model index.

The default implementation does nothing.

Overrides:

updateModelIndex in class WAbstractItemDelegate

setTextFormat

public void setTextFormat(java.lang.String format)

Sets the text format string.

The DisplayRole data is converted to a string using StringUtils.asString(Object), passing the given format. If the format is an empty string, this corresponds to Object.toString().

The default value is "".

getTextFormat

public java.lang.String getTextFormat()

Returns the text format string.

See Also:

setTextFormat(String format)

setModelData

public void setModelData(java.lang.Object editState,
                         WAbstractItemModel model,
                         WModelIndex index)

Saves the edited data to the model.

The default implementation saves the current edit value to the model. You will need to reimplement this method for a custom editor.

As an example of how to deal with a specialized editor, consider the default implementation:

 public void setModelData(Object editState, WAbstractItemModel model,
                WModelIndex index) {
        model.setData(index, editState, ItemDataRole.EditRole);
 }
 

Overrides:

setModelData in class WAbstractItemDelegate

See Also:

createEditor(WModelIndex index, EnumSet flags), getEditState(WWidget editor)

getEditState

public java.lang.Object getEditState(WWidget editor)

Returns the current edit state.

The default implementation returns the current text in the line edit. You will need to reimplement this method for a custom editor.

As an example of how to deal with a specialized editor, consider the default implementation:

 public Object getEditState(WWidget editor) {
        WContainerWidget w = (WContainerWidget) editor;
        WLineEdit lineEdit = (WLineEdit) w.getWidget(0);
        return lineEdit.getText();
 }
 

Overrides:

getEditState in class WAbstractItemDelegate

See Also:

createEditor(WModelIndex index, EnumSet flags), setEditState(WWidget editor, Object value), setModelData(Object editState, WAbstractItemModel model, WModelIndex index)

setEditState

public void setEditState(WWidget editor,
                         java.lang.Object value)

Sets the editor data from the editor state.

The default implementation resets the text in the line edit. You will need to reimplement this method if for a custom editor.

As an example of how to deal with a specialized editor, consider the default implementation:

 public void setEditState(WWidget editor, Object value) {
        WContainerWidget w = (WContainerWidget) editor;
        WLineEdit lineEdit = (WLineEdit) w.getWidget(0);
        lineEdit.setText((String) value);
 }
 

Overrides:

setEditState in class WAbstractItemDelegate

See Also:

createEditor(WModelIndex index, EnumSet flags)

createEditor

protected WWidget createEditor(WModelIndex index,
                               java.util.EnumSet<ViewItemRenderFlag> flags)

Creates an editor for a data item.

The default implementation returns a WLineEdit which edits the item's ItemDataRole.EditRole value.

You may reimplement this method to provide a suitable editor, or to attach a custom validator. In that case, you will probably also want to reimplement getEditState(), setEditState(), and setModelData().

The editor should not keep a reference to the model index (it does not need to since setModelData() will provide the proper model index to save the data to the model). Otherwise, because model indexes may shift because of row or column insertions, you should reimplement updateModelIndex().

As an example of how to provide a specialized editor, consider the default implementation, which returns a WLineEdit:

 protected WWidget createEditor(WModelIndex index,
                EnumSet<ViewItemRenderFlag> flags) {
        final WContainerWidget result = new WContainerWidget();
        result.setSelectable(true);
        WLineEdit lineEdit = new WLineEdit();
        lineEdit.setText(StringUtils.asString(index.getData(ItemDataRole.EditRole),
                        this.textFormat_).toString());
        lineEdit.enterPressed().addListener(this, new Signal.Listener() {
                public void trigger() {
                        WItemDelegate.this.closeEditor().trigger(result, true);
                }
        });
        lineEdit.escapePressed().addListener(this, new Signal.Listener() {
                public void trigger() {
                        WItemDelegate.this.closeEditor().trigger(result, false);
                }
        });
 
        if (flags.contains(ViewItemRenderFlag.RenderFocused))
                lineEdit.setFocus();
 
        result.setLayout(new WHBoxLayout());
        result.getLayout().setContentsMargins(1, 1, 1, 1);
        result.getLayout().addWidget(lineEdit);
        return result;
 }
 

createEditor

protected final WWidget createEditor(WModelIndex index,
                                     ViewItemRenderFlag flag,
                                     ViewItemRenderFlag... flags)

Creates an editor for a data item.

Returns createEditor(index, EnumSet.of(flag, flags))