public class BasicListUI extends ListUI
An extensible implementation of ListUI.
BasicListUI instances cannot be shared between multiple lists.
| Modifier and Type | Class and Description |
|---|---|
class |
BasicListUI.FocusHandler This class should be treated as a "protected" inner class. |
class |
BasicListUI.ListDataHandler The ListDataListener that's added to the JLists model at installUI time, and whenever the JList.model property changes. |
class |
BasicListUI.ListSelectionHandler The ListSelectionListener that's added to the JLists selection model at installUI time, and whenever the JList.selectionModel property changes. |
class |
BasicListUI.MouseInputHandler Mouse input, and focus handling for JList. |
class |
BasicListUI.PropertyChangeHandler The PropertyChangeListener that's added to the JList at installUI time. |
protected JList list
protected CellRendererPane rendererPane
protected FocusListener focusListener
protected MouseInputListener mouseInputListener
protected ListSelectionListener listSelectionListener
protected ListDataListener listDataListener
protected PropertyChangeListener propertyChangeListener
protected int[] cellHeights
protected int cellHeight
protected int cellWidth
protected int updateLayoutStateNeeded
protected static final int modelChanged
protected static final int selectionModelChanged
protected static final int fontChanged
protected static final int fixedCellWidthChanged
protected static final int fixedCellHeightChanged
protected static final int prototypeCellValueChanged
protected static final int cellRendererChanged
public BasicListUI()
protected void paintCell(Graphics g,
int row,
Rectangle rowBounds,
ListCellRenderer cellRenderer,
ListModel dataModel,
ListSelectionModel selModel,
int leadIndex) Paint one List cell: compute the relevant state, get the "rubber stamp" cell renderer component, and then use the CellRendererPane to paint it. Subclasses may want to override this method rather than paint().
public void paint(Graphics g,
JComponent c) Paint the rows that intersect the Graphics objects clipRect. This method calls paintCell as necessary. Subclasses may want to override these methods.
paint in class ComponentUI
g - the Graphics context in which to paintc - the component being painted; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple componentspaintCell(java.awt.Graphics, int, java.awt.Rectangle, javax.swing.ListCellRenderer, javax.swing.ListModel, javax.swing.ListSelectionModel, int)public int getBaseline(JComponent c,
int width,
int height) Returns the baseline.
getBaseline in class ComponentUI
c - JComponent baseline is being requested forwidth - the width to get the baseline forheight - the height to get the baseline forNullPointerException - if c is null
IllegalArgumentException - if width or height is < 0JComponent.getBaseline(int, int)public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)
Returns an enum indicating how the baseline of the component changes as the size changes.
getBaselineResizeBehavior in class ComponentUI
c - JComponent to return baseline resize behavior forNullPointerException - if c is null
JComponent.getBaseline(int, int)public Dimension getPreferredSize(JComponent c)
| Layout Orientation | Preferred Size |
|---|---|
| JList.VERTICAL | The preferredSize of the list is total height of the rows and the maximum width of the cells. If JList.fixedCellHeight is specified then the total height of the rows is just (cellVerticalMargins + fixedCellHeight) * model.getSize() where rowVerticalMargins is the space we allocate for drawing the yellow focus outline. Similarly if fixedCellWidth is specified then we just use that. |
| JList.VERTICAL_WRAP | If the visible row count is greater than zero, the preferredHeight is the maximum cell height * visibleRowCount. If the visible row count is <= 0, the preferred height is either the current height of the list, or the maximum cell height, whichever is bigger. The preferred width is than the maximum cell width * number of columns needed. Where the number of columns needs is list.height / max cell height. Max cell height is either the fixed cell height, or is determined by iterating through all the cells to find the maximum height from the ListCellRenderer. |
| JList.HORIZONTAL_WRAP | If the visible row count is greater than zero, the preferredHeight is the maximum cell height * adjustedRowCount. Where visibleRowCount is used to determine the number of columns. Because this lays out horizontally the number of rows is then determined from the column count. For example, lets say you have a model with 10 items and the visible row count is 8. The number of columns needed to display this is 2, but you no longer need 8 rows to display this, you only need 5, thus the adjustedRowCount is 5. If the visible row count is <= 0, the preferred height is dictated by the number of columns, which will be as many as can fit in the width of the |
Insets are determined from list.getInsets().getPreferredSize in class ComponentUI
c - The JList component.JComponent.getPreferredSize(), LayoutManager.preferredLayoutSize(java.awt.Container)
protected void selectPreviousIndex()
Selected the previous row and force it to be visible.
JList.ensureIndexIsVisible(int)protected void selectNextIndex()
Selected the previous row and force it to be visible.
JList.ensureIndexIsVisible(int)protected void installKeyboardActions()
Registers the keyboard bindings on the JList that the BasicListUI is associated with. This method is called at installUI() time.
installUI(javax.swing.JComponent)protected void uninstallKeyboardActions()
Unregisters keyboard actions installed from installKeyboardActions. This method is called at uninstallUI() time - subclassess should ensure that all of the keyboard actions registered at installUI time are removed here.
installUI(javax.swing.JComponent)protected void installListeners()
Creates and installs the listeners for the JList, its model, and its selectionModel. This method is called at installUI() time.
protected void uninstallListeners()
Removes the listeners from the JList, its model, and its selectionModel. All of the listener fields, are reset to null here. This method is called at uninstallUI() time, it should be kept in sync with installListeners.
protected void installDefaults()
Initializes list properties such as font, foreground, and background, and adds the CellRendererPane. The font, foreground, and background properties are only set if their current value is either null or a UIResource, other properties are set if the current value is null.
protected void uninstallDefaults()
Sets the list properties that have not been explicitly overridden to null. A property is considered overridden if its current value is not a UIResource.
public void installUI(JComponent c)
Initializes this.list by calling installDefaults(), installListeners(), and installKeyboardActions() in order.
installUI in class ComponentUI
c - the component where this UI delegate is being installedinstallDefaults(), installListeners(), installKeyboardActions()
public void uninstallUI(JComponent c)
Uninitializes this.list by calling uninstallListeners(), uninstallKeyboardActions(), and uninstallDefaults() in order. Sets this.list to null.
uninstallUI in class ComponentUI
c - the component from which this UI delegate is being removed; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple componentsuninstallListeners(), uninstallKeyboardActions(), uninstallDefaults()
public static ComponentUI createUI(JComponent list)
Returns a new instance of BasicListUI. BasicListUI delegates are allocated one per JList.
public int locationToIndex(JList list,
Point location) Returns the cell index in the specified JList closest to the given location in the list's coordinate system. To determine if the cell actually contains the specified location, compare the point against the cell's bounds, as provided by getCellBounds. This method returns -1 if the list's model is empty.
locationToIndex in class ListUI
list - the listlocation - the coordinates of the point-1
NullPointerException - if location is nullpublic Point indexToLocation(JList list,
int index) Returns the origin in the given JList, of the specified item, in the list's coordinate system. Returns null if the index isn't valid.
indexToLocation in class ListUI
list - the listindex - the cell indexnull
public Rectangle getCellBounds(JList list,
int index1,
int index2) Returns the bounding rectangle, in the given list's coordinate system, for the range of cells specified by the two indices. The indices can be supplied in any order.
If the smaller index is outside the list's range of cells, this method returns null. If the smaller index is valid, but the larger index is outside the list's range, the bounds of just the first index is returned. Otherwise, the bounds of the valid range is returned.
getCellBounds in class ListUI
list - the listindex1 - the first index in the rangeindex2 - the second index in the rangenull
protected int getRowHeight(int row)
Returns the height of the specified row based on the current layout.
convertYToRow(int), convertRowToY(int), updateLayoutState()
protected int convertYToRow(int y0)
Convert the JList relative coordinate to the row that contains it, based on the current layout. If y0 doesn't fall within any row, return -1.
getRowHeight(int), updateLayoutState()
protected int convertRowToY(int row)
Return the JList relative Y coordinate of the origin of the specified row or -1 if row isn't valid.
getRowHeight(int), updateLayoutState()
protected void maybeUpdateLayoutState()
If updateLayoutStateNeeded is non zero, call updateLayoutState() and reset updateLayoutStateNeeded. This method should be called by methods before doing any computation based on the geometry of the list. For example it's the first call in paint() and getPreferredSize().
updateLayoutState()protected void updateLayoutState()
Recompute the value of cellHeight or cellHeights based and cellWidth, based on the current font and the current values of fixedCellWidth, fixedCellHeight, and prototypeCellValue.
maybeUpdateLayoutState()protected MouseInputListener createMouseInputListener()
Creates a delegate that implements MouseInputListener. The delegate is added to the corresponding java.awt.Component listener lists at installUI() time. Subclasses can override this method to return a custom MouseInputListener, e.g.
class MyListUI extends BasicListUI {
protected MouseInputListener createMouseInputListener() {
return new MyMouseInputHandler();
}
public class MyMouseInputHandler extends MouseInputHandler {
public void mouseMoved(MouseEvent e) {
// do some extra work when the mouse moves
super.mouseMoved(e);
}
}
} protected FocusListener createFocusListener()
protected ListSelectionListener createListSelectionListener()
Creates an instance of ListSelectionHandler that's added to the JLists by selectionModel as needed. Subclasses can override this method to return a custom ListSelectionListener, e.g.
class MyListUI extends BasicListUI {
protected ListSelectionListener createListSelectionListener() {
return new MySelectionListener();
}
public class MySelectionListener extends ListSelectionHandler {
public void valueChanged(ListSelectionEvent e) {
// do some extra work when the selection changes
super.valueChange(e);
}
}
} protected ListDataListener createListDataListener()
Creates an instance of ListDataListener that's added to the JLists by model as needed. Subclasses can override this method to return a custom ListDataListener, e.g.
class MyListUI extends BasicListUI {
protected ListDataListener createListDataListener() {
return new MyListDataListener();
}
public class MyListDataListener extends ListDataHandler {
public void contentsChanged(ListDataEvent e) {
// do some extra work when the models contents change
super.contentsChange(e);
}
}
} protected PropertyChangeListener createPropertyChangeListener()
Creates an instance of PropertyChangeHandler that's added to the JList by installUI(). Subclasses can override this method to return a custom PropertyChangeListener, e.g.
class MyListUI extends BasicListUI {
protected PropertyChangeListener createPropertyChangeListener() {
return new MyPropertyChangeListener();
}
public class MyPropertyChangeListener extends PropertyChangeHandler {
public void propertyChange(PropertyChangeEvent e) {
if (e.getPropertyName().equals("model")) {
// do some extra work when the model changes
}
super.propertyChange(e);
}
}
}
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