Module java.desktop
Package javax.swing

Class SwingUtilities

java.lang.Object
javax.swing.SwingUtilities
All Implemented Interfaces:
SwingConstants
public class SwingUtilities
extends Object
implements SwingConstants
A collection of utility methods for Swing.
Since:
1.2

  • Method Details

    • isRectangleContainingRectangle

      public static final boolean isRectangleContainingRectangle​(Rectangle a, Rectangle b)
      Return true if @{code a} contains b
      Parameters:
      a - the first rectangle
      b - the second rectangle
      Returns:
      true if @{code a} contains b

    • getLocalBounds

      public static Rectangle getLocalBounds​(Component aComponent)
      Return the rectangle (0,0,bounds.width,bounds.height) for the component aComponent
      Parameters:
      aComponent - a component
      Returns:
      the local bounds for the component aComponent

    • getWindowAncestor

      public static Window getWindowAncestor​(Component c)
      Returns the first Window ancestor of c, or null if c is not contained inside a Window.
      Parameters:
      c - Component to get Window ancestor of.
      Returns:
      the first Window ancestor of c, or null if c is not contained inside a Window.
      Since:
      1.3

    • convertPoint

      public static Point convertPoint​(Component source, Point aPoint, Component destination)
      Convert a aPoint in source coordinate system to destination coordinate system. If source is null, aPoint is assumed to be in destination's root component coordinate system. If destination is null, aPoint will be converted to source's root component coordinate system. If both source and destination are null, return aPoint without any conversion.
      Parameters:
      source - the source component
      aPoint - the point
      destination - the destination component
      Returns:
      the converted coordinate

    • convertPoint

      public static Point convertPoint​(Component source, int x, int y, Component destination)
      Convert the point (x,y) in source coordinate system to destination coordinate system. If source is null, (x,y) is assumed to be in destination's root component coordinate system. If destination is null, (x,y) will be converted to source's root component coordinate system. If both source and destination are null, return (x,y) without any conversion.
      Parameters:
      source - the source component
      x - the x-coordinate of the point
      y - the y-coordinate of the point
      destination - the destination component
      Returns:
      the converted coordinate

    • convertRectangle

      public static Rectangle convertRectangle​(Component source, Rectangle aRectangle, Component destination)
      Convert the rectangle aRectangle in source coordinate system to destination coordinate system. If source is null, aRectangle is assumed to be in destination's root component coordinate system. If destination is null, aRectangle will be converted to source's root component coordinate system. If both source and destination are null, return aRectangle without any conversion.
      Parameters:
      source - the source component
      aRectangle - a rectangle
      destination - the destination component
      Returns:
      the converted rectangle

    • getAncestorOfClass

      public static Container getAncestorOfClass​(Class<?> c, Component comp)
      Convenience method for searching above comp in the component hierarchy and returns the first object of class c it finds. Can return null, if a class c cannot be found.
      Parameters:
      c - the class of a component
      comp - the component
      Returns:
      the ancestor of the comp, or null if c cannot be found.

    • getAncestorNamed

      public static Container getAncestorNamed​(String name, Component comp)
      Convenience method for searching above comp in the component hierarchy and returns the first object of name it finds. Can return null, if name cannot be found.
      Parameters:
      name - the name of a component
      comp - the component
      Returns:
      the ancestor of the comp, or null if name cannot be found.

    • getDeepestComponentAt

      public static Component getDeepestComponentAt​(Component parent, int x, int y)
      Returns the deepest visible descendent Component of parent that contains the location x, y. If parent does not contain the specified location, then null is returned. If parent is not a container, or none of parent's visible descendents contain the specified location, parent is returned.
      Parameters:
      parent - the root component to begin the search
      x - the x target location
      y - the y target location
      Returns:
      the deepest component

    • convertMouseEvent

      public static MouseEvent convertMouseEvent​(Component source, MouseEvent sourceEvent, Component destination)
      Returns a MouseEvent similar to sourceEvent except that its x and y members have been converted to destination's coordinate system. If source is null, sourceEvent x and y members are assumed to be into destination's root component coordinate system. If destination is null, the returned MouseEvent will be in source's coordinate system. sourceEvent will not be changed. A new event is returned. the source field of the returned event will be set to destination if destination is non-null use the translateMouseEvent() method to translate a mouse event from one component to another without changing the source.
      Parameters:
      source - the source component
      sourceEvent - the source mouse event
      destination - the destination component
      Returns:
      the new mouse event

    • convertPointToScreen

      public static void convertPointToScreen​(Point p, Component c)
      Convert a point from a component's coordinate system to screen coordinates.
      Parameters:
      p - a Point object (converted to the new coordinate system)
      c - a Component object

    • convertPointFromScreen

      public static void convertPointFromScreen​(Point p, Component c)
      Convert a point from a screen coordinates to a component's coordinate system
      Parameters:
      p - a Point object (converted to the new coordinate system)
      c - a Component object

    • windowForComponent

      public static Window windowForComponent​(Component c)
      Returns the first Window ancestor of c, or null if c is not contained inside a Window.

      Note: This method provides the same functionality as getWindowAncestor.

      Parameters:
      c - Component to get Window ancestor of.
      Returns:
      the first Window ancestor of c, or null if c is not contained inside a Window.

    • isDescendingFrom

      public static boolean isDescendingFrom​(Component a, Component b)
      Return true if a component a descends from a component b
      Parameters:
      a - the first component
      b - the second component
      Returns:
      true if a component a descends from a component b

    • computeIntersection

      public static Rectangle computeIntersection​(int x, int y, int width, int height, Rectangle dest)
      Convenience to calculate the intersection of two rectangles without allocating a new rectangle. If the two rectangles don't intersect, then the returned rectangle begins at (0,0) and has zero width and height.
      Parameters:
      x - the X coordinate of the first rectangle's top-left point
      y - the Y coordinate of the first rectangle's top-left point
      width - the width of the first rectangle
      height - the height of the first rectangle
      dest - the second rectangle
      Returns:
      dest, modified to specify the intersection

    • computeUnion

      public static Rectangle computeUnion​(int x, int y, int width, int height, Rectangle dest)
      Convenience method that calculates the union of two rectangles without allocating a new rectangle.
      Parameters:
      x - the x-coordinate of the first rectangle
      y - the y-coordinate of the first rectangle
      width - the width of the first rectangle
      height - the height of the first rectangle
      dest - the coordinates of the second rectangle; the union of the two rectangles is returned in this rectangle
      Returns:
      the dest Rectangle

    • computeDifference

      public static Rectangle[] computeDifference​(Rectangle rectA, Rectangle rectB)
      Convenience returning an array of rect representing the regions within rectA that do not overlap with rectB. If the two Rects do not overlap, returns an empty array
      Parameters:
      rectA - the first rectangle
      rectB - the second rectangle
      Returns:
      an array of rectangles representing the regions within rectA that do not overlap with rectB.

    • isLeftMouseButton

      public static boolean isLeftMouseButton​(MouseEvent anEvent)
      Returns true if the mouse event specifies the left mouse button.
      Parameters:
      anEvent - a MouseEvent object
      Returns:
      true if the left mouse button was active

    • isMiddleMouseButton

      public static boolean isMiddleMouseButton​(MouseEvent anEvent)
      Returns true if the mouse event specifies the middle mouse button.
      Parameters:
      anEvent - a MouseEvent object
      Returns:
      true if the middle mouse button was active

    • isRightMouseButton

      public static boolean isRightMouseButton​(MouseEvent anEvent)
      Returns true if the mouse event specifies the right mouse button.
      Parameters:
      anEvent - a MouseEvent object
      Returns:
      true if the right mouse button was active

    • computeStringWidth

      public static int computeStringWidth​(FontMetrics fm, String str)
      Compute the width of the string using a font with the specified "metrics" (sizes).
      Parameters:
      fm - a FontMetrics object to compute with
      str - the String to compute
      Returns:
      an int containing the string width

    • layoutCompoundLabel

      public static String layoutCompoundLabel​(JComponent c, FontMetrics fm, String text, Icon icon, int verticalAlignment, int horizontalAlignment, int verticalTextPosition, int horizontalTextPosition, Rectangle viewR, Rectangle iconR, Rectangle textR, int textIconGap)
      Compute and return the location of the icons origin, the location of origin of the text baseline, and a possibly clipped version of the compound labels string. Locations are computed relative to the viewR rectangle. The JComponents orientation (LEADING/TRAILING) will also be taken into account and translated into LEFT/RIGHT values accordingly.
      Parameters:
      c - the component
      fm - the instance of FontMetrics
      text - the text
      icon - the icon
      verticalAlignment - the vertical alignment
      horizontalAlignment - the horizontal alignment
      verticalTextPosition - the vertical text position
      horizontalTextPosition - the horizontal text position
      viewR - the available rectangle
      iconR - the rectangle for the icon
      textR - the rectangle for the text
      textIconGap - the gap between text and icon
      Returns:
      the possibly clipped version of the compound labels string

    • layoutCompoundLabel

      public static String layoutCompoundLabel​(FontMetrics fm, String text, Icon icon, int verticalAlignment, int horizontalAlignment, int verticalTextPosition, int horizontalTextPosition, Rectangle viewR, Rectangle iconR, Rectangle textR, int textIconGap)
      Compute and return the location of the icons origin, the location of origin of the text baseline, and a possibly clipped version of the compound labels string. Locations are computed relative to the viewR rectangle. This layoutCompoundLabel() does not know how to handle LEADING/TRAILING values in horizontalTextPosition (they will default to RIGHT) and in horizontalAlignment (they will default to CENTER). Use the other version of layoutCompoundLabel() instead.
      Parameters:
      fm - the instance of FontMetrics
      text - the text
      icon - the icon
      verticalAlignment - the vertical alignment
      horizontalAlignment - the horizontal alignment
      verticalTextPosition - the vertical text position
      horizontalTextPosition - the horizontal text position
      viewR - the available rectangle
      iconR - the rectangle for the icon
      textR - the rectangle for the text
      textIconGap - the gap between text and icon
      Returns:
      the possibly clipped version of the compound labels string

    • paintComponent

      public static void paintComponent​(Graphics g, Component c, Container p, int x, int y, int w, int h)
      Paints a component to the specified Graphics. This method is primarily useful to render Components that don't exist as part of the visible containment hierarchy, but are used for rendering. For example, if you are doing your own rendering and want to render some text (or even HTML), you could make use of JLabel's text rendering support and have it paint directly by way of this method, without adding the label to the visible containment hierarchy.

      This method makes use of CellRendererPane to handle the actual painting, and is only recommended if you use one component for rendering. If you make use of multiple components to handle the rendering, as JTable does, use CellRendererPane directly. Otherwise, as described below, you could end up with a CellRendererPane per Component.

      If c's parent is not a CellRendererPane, a new CellRendererPane is created, c is added to it, and the CellRendererPane is added to p. If c's parent is a CellRendererPane and the CellRendererPanes parent is not p, it is added to p.

      The component should either descend from JComponent or be another kind of lightweight component. A lightweight component is one whose "lightweight" property (returned by the Component isLightweight method) is true. If the Component is not lightweight, bad things map happen: crashes, exceptions, painting problems...

      Parameters:
      g - the Graphics object to draw on
      c - the Component to draw
      p - the intermediate Container
      x - an int specifying the left side of the area draw in, in pixels, measured from the left edge of the graphics context
      y - an int specifying the top of the area to draw in, in pixels measured down from the top edge of the graphics context
      w - an int specifying the width of the area draw in, in pixels
      h - an int specifying the height of the area draw in, in pixels
      See Also:
      CellRendererPane, Component.isLightweight()

    • paintComponent

      public static void paintComponent​(Graphics g, Component c, Container p, Rectangle r)
      Paints a component to the specified Graphics. This is a cover method for paintComponent(Graphics,Component,Container,int,int,int,int). Refer to it for more information.
      Parameters:
      g - the Graphics object to draw on
      c - the Component to draw
      p - the intermediate Container
      r - the Rectangle to draw in
      See Also:
      paintComponent(Graphics,Component,Container,int,int,int,int), CellRendererPane

    • updateComponentTreeUI

      public static void updateComponentTreeUI​(Component c)
      A simple minded look and feel change: ask each node in the tree to updateUI() -- that is, to initialize its UI property with the current look and feel.
      Parameters:
      c - the component

    • invokeLater

      public static void invokeLater​(Runnable doRun)
      Causes doRun.run() to be executed asynchronously on the AWT event dispatching thread. This will happen after all pending AWT events have been processed. This method should be used when an application thread needs to update the GUI. In the following example the invokeLater call queues the Runnable object doHelloWorld on the event dispatching thread and then prints a message. 
       Runnable doHelloWorld = new Runnable() {
     public void run() {
         System.out.println("Hello World on " + Thread.currentThread());
     }
 };

 SwingUtilities.invokeLater(doHelloWorld);
 System.out.println("This might well be displayed before the other message.");
      If invokeLater is called from the event dispatching thread -- for example, from a JButton's ActionListener -- the doRun.run() will still be deferred until all pending events have been processed. Note that if the doRun.run() throws an uncaught exception the event dispatching thread will unwind (not the current thread).

      Additional documentation and examples for this method can be found in Concurrency in Swing.

      As of 1.3 this method is just a cover for java.awt.EventQueue.invokeLater().

      Unlike the rest of Swing, this method can be invoked from any thread.

      Parameters:
      doRun - the instance of Runnable
      See Also:
      invokeAndWait(java.lang.Runnable)

    • invokeAndWait

      public static void invokeAndWait​(Runnable doRun) throws InterruptedException, InvocationTargetException
      Causes doRun.run() to be executed synchronously on the AWT event dispatching thread. This call blocks until all pending AWT events have been processed and (then) doRun.run() returns. This method should be used when an application thread needs to update the GUI. It shouldn't be called from the event dispatching thread. Here's an example that creates a new application thread that uses invokeAndWait to print a string from the event dispatching thread and then, when that's finished, print a string from the application thread. 
       final Runnable doHelloWorld = new Runnable() {
     public void run() {
         System.out.println("Hello World on " + Thread.currentThread());
     }
 };

 Thread appThread = new Thread() {
     public void run() {
         try {
             SwingUtilities.invokeAndWait(doHelloWorld);
         }
         catch (Exception e) {
             e.printStackTrace();
         }
         System.out.println("Finished on " + Thread.currentThread());
     }
 };
 appThread.start();
      Note that if the Runnable.run method throws an uncaught exception (on the event dispatching thread) it's caught and rethrown, as an InvocationTargetException, on the caller's thread.

      Additional documentation and examples for this method can be found in Concurrency in Swing.

      As of 1.3 this method is just a cover for java.awt.EventQueue.invokeAndWait().

      Parameters:
      doRun - the instance of Runnable
      Throws:
      InterruptedException - if we're interrupted while waiting for the event dispatching thread to finish executing doRun.run()
      InvocationTargetException - if an exception is thrown while running doRun
      See Also:
      invokeLater(java.lang.Runnable)

    • isEventDispatchThread

      public static boolean isEventDispatchThread()
      Returns true if the current thread is an AWT event dispatching thread.

      As of 1.3 this method is just a cover for java.awt.EventQueue.isDispatchThread().

      Returns:
      true if the current thread is an AWT event dispatching thread

    • getAccessibleIndexInParent

      public static int getAccessibleIndexInParent​(Component c)
      Get the index of this object in its accessible parent.

      Note: as of the Java 2 platform v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleIndexInParent() instead of using this method.

      Parameters:
      c - the component
      Returns:
      -1 of this object does not have an accessible parent. Otherwise, the index of the child in its accessible parent.

    • getAccessibleAt

      public static Accessible getAccessibleAt​(Component c, Point p)
      Returns the Accessible child contained at the local coordinate Point, if one exists. Otherwise returns null.
      Parameters:
      c - the component
      p - the local coordinate
      Returns:
      the Accessible at the specified location, if it exists; otherwise null

    • getAccessibleStateSet

      public static AccessibleStateSet getAccessibleStateSet​(Component c)
      Get the state of this object.

      Note: as of the Java 2 platform v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleIndexInParent() instead of using this method.

      Parameters:
      c - the component
      Returns:
      an instance of AccessibleStateSet containing the current state set of the object
      See Also:
      AccessibleState

    • getAccessibleChildrenCount

      public static int getAccessibleChildrenCount​(Component c)
      Returns the number of accessible children in the object. If all of the children of this object implement Accessible, than this method should return the number of children of this object.

      Note: as of the Java 2 platform v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleIndexInParent() instead of using this method.

      Parameters:
      c - the component
      Returns:
      the number of accessible children in the object.

    • getAccessibleChild

      public static Accessible getAccessibleChild​(Component c, int i)
      Return the nth Accessible child of the object.

      Note: as of the Java 2 platform v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleIndexInParent() instead of using this method.

      Parameters:
      c - the component
      i - zero-based index of child
      Returns:
      the nth Accessible child of the object

    • findFocusOwner

      @Deprecated public static Component findFocusOwner​(Component c)
      Deprecated.
      As of 1.4, replaced by KeyboardFocusManager.getFocusOwner().
      Return the child Component of the specified Component that is the focus owner, if any.
      Parameters:
      c - the root of the Component hierarchy to search for the focus owner
      Returns:
      the focus owner, or null if there is no focus owner, or if the focus owner is not comp, or a descendant of comp
      See Also:
      KeyboardFocusManager.getFocusOwner()

    • getRootPane

      public static JRootPane getRootPane​(Component c)
      If c is a JRootPane descendant return its JRootPane ancestor. If c is a RootPaneContainer then return its JRootPane.
      Parameters:
      c - the component
      Returns:
      the JRootPane for Component c or null.

    • getRoot

      public static Component getRoot​(Component c)
      Returns the root component for the current component tree.
      Parameters:
      c - the component
      Returns:
      the first ancestor of c that's a Window or the last Applet ancestor

    • processKeyBindings

      public static boolean processKeyBindings​(KeyEvent event)
      Process the key bindings for the Component associated with event. This method is only useful if event.getComponent() does not descend from JComponent, or your are not invoking super.processKeyEvent from within your JComponent subclass. JComponent automatically processes bindings from within its processKeyEvent method, hence you rarely need to directly invoke this method.
      Parameters:
      event - KeyEvent used to identify which bindings to process, as well as which Component has focus.
      Returns:
      true if a binding has found and processed
      Since:
      1.4

    • notifyAction

      public static boolean notifyAction​(Action action, KeyStroke ks, KeyEvent event, Object sender, int modifiers)
      Invokes actionPerformed on action if action is non-null and accepts the sender object. The command for the ActionEvent is determined by:
      1. If the action was registered via registerKeyboardAction, then the command string passed in (null will be used if null was passed in).
      2. Action value with name Action.ACTION_COMMAND_KEY, unless null.
      3. String value of the KeyEvent, unless getKeyChar returns KeyEvent.CHAR_UNDEFINED..
      This will return true if action is non-null and actionPerformed is invoked on it.
      Parameters:
      action - an action
      ks - a key stroke
      event - a key event
      sender - a sender
      modifiers - action modifiers
      Returns:
      true if action is non-null and actionPerformed is invoked on it.
      Since:
      1.3
      See Also:
      Action.accept(java.lang.Object)

    • replaceUIInputMap

      public static void replaceUIInputMap​(JComponent component, int type, InputMap uiInputMap)
      Convenience method to change the UI InputMap for component to uiInputMap. If uiInputMap is null, this removes any previously installed UI InputMap.
      Parameters:
      component - a component
      type - a type
      uiInputMap - an InputMap
      Since:
      1.3

    • replaceUIActionMap

      public static void replaceUIActionMap​(JComponent component, ActionMap uiActionMap)
      Convenience method to change the UI ActionMap for component to uiActionMap. If uiActionMap is null, this removes any previously installed UI ActionMap.
      Parameters:
      component - a component
      uiActionMap - an ActionMap
      Since:
      1.3

    • getUIInputMap

      public static InputMap getUIInputMap​(JComponent component, int condition)
      Returns the InputMap provided by the UI for condition condition in component component.

      This will return null if the UI has not installed an InputMap of the specified type.

      Parameters:
      component - a component
      condition - a condition
      Returns:
      the ActionMap provided by the UI for condition in the component, or null if the UI has not installed an InputMap of the specified type.
      Since:
      1.3

    • getUIActionMap

      public static ActionMap getUIActionMap​(JComponent component)
      Returns the ActionMap provided by the UI in component component.

      This will return null if the UI has not installed an ActionMap.

      Parameters:
      component - a component
      Returns:
      the ActionMap provided by the UI in the component, or null if the UI has not installed an ActionMap.
      Since:
      1.3

    • calculateInnerArea

      public static Rectangle calculateInnerArea​(JComponent c, Rectangle r)
      Stores the position and size of the inner painting area of the specified component in r and returns r. The position and size specify the bounds of the component, adjusted so as not to include the border area (the insets). This method is useful for classes that implement painting code.
      Parameters:
      c - the JComponent in question; if null, this method returns null
      r - the Rectangle instance to be modified; may be null
      Returns:
      null if the Component is null; otherwise, returns the passed-in rectangle (if non-null) or a new rectangle specifying position and size information
      Since:
      1.4

    • getUnwrappedParent

      public static Container getUnwrappedParent​(Component component)
      Returns the first ancestor of the component which is not an instance of JLayer.
      Parameters:
      component - Component to get the first ancestor of, which is not a JLayer instance.
      Returns:
      the first ancestor of the component which is not an instance of JLayer. If such an ancestor can not be found, null is returned.
      Throws:
      NullPointerException - if component is null
      Since:
      1.7
      See Also:
      JLayer

    • getUnwrappedView

      public static Component getUnwrappedView​(JViewport viewport)
      Returns the first JViewport's descendant which is not an instance of JLayer. If such a descendant can not be found, null is returned. If the viewport's view component is not a JLayer, this method is equivalent to JViewport.getView() otherwise JLayer.getView() will be recursively called on all descending JLayers.
      Parameters:
      viewport - JViewport to get the first descendant of, which in not a JLayer instance.
      Returns:
      the first JViewport's descendant which is not an instance of JLayer. If such a descendant can not be found, null is returned.
      Throws:
      NullPointerException - if viewport is null
      Since:
      1.7
      See Also:
      JViewport.getView(), JLayer