File	Doc	Category	Size	Date	Package
ComponentUI.java	API Doc	Java SE 5 API	11937	Fri Aug 26 14:58:02 BST 2005	javax.swing.plaf

ComponentUI

• java.lang.Object

Fields Summary

Constructors Summary
public ComponentUI() Sole constructor. (For invocation by subclass constructors, typically implicit.)

Methods Summary
public boolean	contains(javax.swing.JComponent c, int x, int y) Returns true if the specified x,y location is contained within the look and feel's defined shape of the specified component. x and y are defined to be relative to the coordinate system of the specified component. Although a component's bounds is constrained to a rectangle, this method provides the means for defining a non-rectangular shape within those bounds for the purpose of hit detection. param c the component where the x,y location is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components param x the x coordinate of the point param y the y coordinate of the point see javax.swing.JComponent#contains see java.awt.Component#contains return c.inside(x, y);
public static javax.swing.plaf.ComponentUI	createUI(javax.swing.JComponent c) Returns an instance of the UI delegate for the specified component. Each subclass must provide its own static createUI method that returns an instance of that UI delegate subclass. If the UI delegate subclass is stateless, it may return an instance that is shared by multiple components. If the UI delegate is stateful, then it should return a new instance per component. The default implementation of this method throws an error, as it should never be invoked. throw new Error("ComponentUI.createUI not implemented.");
public javax.accessibility.Accessible	getAccessibleChild(javax.swing.JComponent c, int i) Returns the ith Accessible child of the object. UIs might need to override this if they present areas on the screen that can be viewed as components, but actual components are not used for presenting those areas. Note: As of v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleChild() instead of this method. see #getAccessibleChildrenCount param i zero-based index of child return the ith Accessible child of the object return SwingUtilities.getAccessibleChild(c, i);
public int	getAccessibleChildrenCount(javax.swing.JComponent c) Returns the number of accessible children in the object. If all of the children of this object implement Accessible, this method should return the number of children of this object. UIs might wish to override this if they present areas on the screen that can be viewed as components, but actual components are not used for presenting those areas. Note: As of v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleChildrenCount() instead of this method. see #getAccessibleChild return the number of accessible children in the object return SwingUtilities.getAccessibleChildrenCount(c);
public java.awt.Dimension	getMaximumSize(javax.swing.JComponent c) Returns the specified component's maximum size appropriate for the look and feel. If null is returned, the maximum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value. param c the component whose maximum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components return a Dimension object or null see javax.swing.JComponent#getMaximumSize see java.awt.LayoutManager2#maximumLayoutSize return getPreferredSize(c);
public java.awt.Dimension	getMinimumSize(javax.swing.JComponent c) Returns the specified component's minimum size appropriate for the look and feel. If null is returned, the minimum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value. param c the component whose minimum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components return a Dimension object or null see javax.swing.JComponent#getMinimumSize see java.awt.LayoutManager#minimumLayoutSize see #getPreferredSize return getPreferredSize(c);
public java.awt.Dimension	getPreferredSize(javax.swing.JComponent c) Returns the specified component's preferred size appropriate for the look and feel. If null is returned, the preferred size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method returns null. param c the component whose preferred size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components see javax.swing.JComponent#getPreferredSize see java.awt.LayoutManager#preferredLayoutSize return null;
public void	installUI(javax.swing.JComponent c) Configures the specified component appropriate for the look and feel. This method is invoked when the ComponentUI instance is being installed as the UI delegate on the specified component. This method should completely configure the component for the look and feel, including the following: Install any default property values for color, fonts, borders, icons, opacity, etc. on the component. Whenever possible, property values initialized by the client program should not be overridden. Install a LayoutManager on the component if necessary. Create/add any required sub-components to the component. Create/install event listeners on the component. Create/install a PropertyChangeListener on the component in order to detect and respond to component property changes appropriately. Install keyboard UI (mnemonics, traversal, etc.) on the component. Initialize any appropriate instance data. param c the component where this UI delegate is being installed see #uninstallUI see javax.swing.JComponent#setUI see javax.swing.JComponent#updateUI
public void	paint(java.awt.Graphics g, javax.swing.JComponent c) Paints the specified component appropriate for the look and feel. This method is invoked from the ComponentUI.update method when the specified component is being painted. Subclasses should override this method and use the specified Graphics object to render the content of the component. param g the Graphics context in which to paint param c the component being painted; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components see #update
public void	uninstallUI(javax.swing.JComponent c) Reverses configuration which was done on the specified component during installUI. This method is invoked when this UIComponent instance is being removed as the UI delegate for the specified component. This method should undo the configuration performed in installUI, being careful to leave the JComponent instance in a clean state (no extraneous listeners, look-and-feel-specific property objects, etc.). This should include the following: Remove any UI-set borders from the component. Remove any UI-set layout managers on the component. Remove any UI-added sub-components from the component. Remove any UI-added event/property listeners from the component. Remove any UI-installed keyboard UI from the component. Nullify any allocated instance data objects to allow for GC. param 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 components see #installUI see javax.swing.JComponent#updateUI
public void	update(java.awt.Graphics g, javax.swing.JComponent c) Notifies this UI delegate that it's time to paint the specified component. This method is invoked by JComponent when the specified component is being painted. By default this method will fill the specified component with its background color (if its opaque property is true) and then immediately call paint. In general this method need not be overridden by subclasses; all look-and-feel rendering code should reside in the paint method. param g the Graphics context in which to paint param c the component being painted; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components see #paint see javax.swing.JComponent#paintComponent if (c.isOpaque()) { g.setColor(c.getBackground()); g.fillRect(0, 0, c.getWidth(),c.getHeight()); } paint(g, c);