Module java.desktop
Package javax.swing.plaf.basic

Class BasicScrollBarUI

java.lang.Object
javax.swing.plaf.ComponentUI
javax.swing.plaf.ScrollBarUI
javax.swing.plaf.basic.BasicScrollBarUI
All Implemented Interfaces:
LayoutManager, SwingConstants
Direct Known Subclasses:
MetalScrollBarUI, SynthScrollBarUI
public class BasicScrollBarUI extends ScrollBarUI implements LayoutManager, SwingConstants
Implementation of ScrollBarUI for the Basic Look and Feel

  • Field Details

    • minimumThumbSize

      protected Dimension minimumThumbSize
      Minimum thumb size

    • maximumThumbSize

      protected Dimension maximumThumbSize
      Maximum thumb size

    • thumbHighlightColor

      protected Color thumbHighlightColor
      Thumb highlight color

    • thumbLightShadowColor

      protected Color thumbLightShadowColor
      Thumb light shadow color

    • thumbDarkShadowColor

      protected Color thumbDarkShadowColor
      Thumb dark shadow color

    • thumbColor

      protected Color thumbColor
      Thumb color

    • trackColor

      protected Color trackColor
      Track color

    • trackHighlightColor

      protected Color trackHighlightColor
      Track highlight color

    • scrollbar

      protected JScrollBar scrollbar
      Scrollbar

    • incrButton

      protected JButton incrButton
      Increment button

    • decrButton

      protected JButton decrButton
      Decrement button

    • isDragging

      protected boolean isDragging
      Dragging

    • trackListener

      protected BasicScrollBarUI.TrackListener trackListener
      Track listener

    • buttonListener

      protected BasicScrollBarUI.ArrowButtonListener buttonListener
      Button listener

    • modelListener

      protected BasicScrollBarUI.ModelListener modelListener
      Model listener

    • thumbRect

      protected Rectangle thumbRect
      Thumb rectangle

    • trackRect

      protected Rectangle trackRect
      Track rectangle

    • trackHighlight

      protected int trackHighlight
      Track highlight

    • NO_HIGHLIGHT

      protected static final int NO_HIGHLIGHT
      No highlight
      See Also:

    • DECREASE_HIGHLIGHT

      protected static final int DECREASE_HIGHLIGHT
      Decrease highlight
      See Also:

    • INCREASE_HIGHLIGHT

      protected static final int INCREASE_HIGHLIGHT
      Increase highlight
      See Also:

    • scrollListener

      protected BasicScrollBarUI.ScrollListener scrollListener
      Scroll listener

    • propertyChangeListener

      protected PropertyChangeListener propertyChangeListener
      Property change listener

    • scrollTimer

      protected Timer scrollTimer
      Scroll timer

    • scrollBarWidth

      protected int scrollBarWidth
      Hint as to what width (when vertical) or height (when horizontal) should be.
      Since:
      1.7

    • incrGap

      protected int incrGap
      Distance between the increment button and the track. This may be a negative number. If negative, then an overlap between the button and track will occur, which is useful for shaped buttons.
      Since:
      1.7

    • decrGap

      protected int decrGap
      Distance between the decrement button and the track. This may be a negative number. If negative, then an overlap between the button and track will occur, which is useful for shaped buttons.
      Since:
      1.7

  • Constructor Details

    • BasicScrollBarUI

      public BasicScrollBarUI()
      Constructs a BasicScrollBarUI.

  • Method Details

    • createUI

      public static ComponentUI createUI(JComponent c)
      Creates the UI.
      Parameters:
      c - the component
      Returns:
      the UI

    • configureScrollBarColors

      protected void configureScrollBarColors()
      Configures the scroll bar colors.

    • installUI

      public void installUI(JComponent c)
      Installs the UI.
      Overrides:
      installUI in class ComponentUI
      Parameters:
      c - the component
      See Also:

    • uninstallUI

      public void uninstallUI(JComponent c)
      Uninstalls the UI.
      Overrides:
      uninstallUI in class ComponentUI
      Parameters:
      c - the component
      See Also:

    • installDefaults

      protected void installDefaults()
      Installs the defaults.

    • installComponents

      protected void installComponents()
      Installs the components.

    • uninstallComponents

      protected void uninstallComponents()
      Uninstalls the components.

    • installListeners

      protected void installListeners()
      Installs the listeners.

    • installKeyboardActions

      protected void installKeyboardActions()
      Installs the keyboard actions.

    • uninstallKeyboardActions

      protected void uninstallKeyboardActions()
      Uninstalls the keyboard actions.

    • uninstallListeners

      protected void uninstallListeners()
      Uninstall the listeners.

    • uninstallDefaults

      protected void uninstallDefaults()
      Uninstalls the defaults.

    • createTrackListener

      protected BasicScrollBarUI.TrackListener createTrackListener()
      Creates a track listener.
      Returns:
      a track listener

    • createArrowButtonListener

      protected BasicScrollBarUI.ArrowButtonListener createArrowButtonListener()
      Creates an arrow button listener.
      Returns:
      an arrow button listener

    • createModelListener

      protected BasicScrollBarUI.ModelListener createModelListener()
      Creates a model listener.
      Returns:
      a model listener

    • createScrollListener

      protected BasicScrollBarUI.ScrollListener createScrollListener()
      Creates a scroll listener.
      Returns:
      a scroll listener

    • createPropertyChangeListener

      protected PropertyChangeListener createPropertyChangeListener()
      Creates a property change listener.
      Returns:
      a property change listener

    • setThumbRollover

      protected void setThumbRollover(boolean active)
      Sets whether or not the mouse is currently over the thumb.
      Parameters:
      active - True indicates the thumb is currently active.
      Since:
      1.5

    • isThumbRollover

      public boolean isThumbRollover()
      Returns true if the mouse is currently over the thumb.
      Returns:
      true if the thumb is currently active
      Since:
      1.5

    • getPreferredSize

      public Dimension getPreferredSize(JComponent c)
      A vertical scrollbar's preferred width is the maximum of preferred widths of the (non null) increment/decrement buttons, and the minimum width of the thumb. The preferred height is the sum of the preferred heights of the same parts. The basis for the preferred size of a horizontal scrollbar is similar.

      The preferredSize is only computed once, subsequent calls to this method just return a cached size.

      Overrides:
      getPreferredSize in class ComponentUI
      Parameters:
      c - the JScrollBar that's delegating this method to us
      Returns:
      the preferred size of a Basic JScrollBar
      See Also:

    • getMaximumSize

      public Dimension getMaximumSize(JComponent c)
      Description copied from class: ComponentUI
      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.
      Overrides:
      getMaximumSize in class ComponentUI
      Parameters:
      c - The JScrollBar that's delegating this method to us.
      Returns:
      new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
      See Also:

    • createDecreaseButton

      protected JButton createDecreaseButton(int orientation)
      Creates a decrease button.
      Parameters:
      orientation - the orientation
      Returns:
      a decrease button

    • createIncreaseButton

      protected JButton createIncreaseButton(int orientation)
      Creates an increase button.
      Parameters:
      orientation - the orientation
      Returns:
      an increase button

    • paintDecreaseHighlight

      protected void paintDecreaseHighlight(Graphics g)
      Paints the decrease highlight.
      Parameters:
      g - the graphics

    • paintIncreaseHighlight

      protected void paintIncreaseHighlight(Graphics g)
      Paints the increase highlight.
      Parameters:
      g - the graphics

    • paintTrack

      protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds)
      Paints the track.
      Parameters:
      g - the graphics
      c - the component
      trackBounds - the track bounds

    • paintThumb

      protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds)
      Paints the thumb.
      Parameters:
      g - the graphics
      c - the component
      thumbBounds - the thumb bounds

    • getMinimumThumbSize

      protected Dimension getMinimumThumbSize()
      Returns the smallest acceptable size for the thumb. If the scrollbar becomes so small that this size isn't available, the thumb will be hidden.

      Warning : the value returned by this method should not be be modified, it's a shared static constant.

      Returns:
      The smallest acceptable size for the thumb.
      See Also:

    • getMaximumThumbSize

      protected Dimension getMaximumThumbSize()
      Returns the largest acceptable size for the thumb. To create a fixed size thumb one make this method and getMinimumThumbSize return the same value.

      Warning : the value returned by this method should not be be modified, it's a shared static constant.

      Returns:
      The largest acceptable size for the thumb.
      See Also:

    • addLayoutComponent

      public void addLayoutComponent(String name, Component child)
      Description copied from interface: LayoutManager
      If the layout manager uses a per-component string, adds the component comp to the layout, associating it with the string specified by name.
      Specified by:
      addLayoutComponent in interface LayoutManager
      Parameters:
      name - the string to be associated with the component
      child - the component to be added

    • removeLayoutComponent

      public void removeLayoutComponent(Component child)
      Description copied from interface: LayoutManager
      Removes the specified component from the layout.
      Specified by:
      removeLayoutComponent in interface LayoutManager
      Parameters:
      child - the component to be removed

    • preferredLayoutSize

      public Dimension preferredLayoutSize(Container scrollbarContainer)
      Description copied from interface: LayoutManager
      Calculates the preferred size dimensions for the specified container, given the components it contains.
      Specified by:
      preferredLayoutSize in interface LayoutManager
      Parameters:
      scrollbarContainer - the container to be laid out
      Returns:
      the preferred dimension for the container
      See Also:

    • minimumLayoutSize

      public Dimension minimumLayoutSize(Container scrollbarContainer)
      Description copied from interface: LayoutManager
      Calculates the minimum size dimensions for the specified container, given the components it contains.
      Specified by:
      minimumLayoutSize in interface LayoutManager
      Parameters:
      scrollbarContainer - the component to be laid out
      Returns:
      the minimum dimension for the container
      See Also:

    • layoutVScrollbar

      protected void layoutVScrollbar(JScrollBar sb)
      Lays out a vertical scroll bar.
      Parameters:
      sb - the scroll bar

    • layoutHScrollbar

      protected void layoutHScrollbar(JScrollBar sb)
      Lays out a horizontal scroll bar.
      Parameters:
      sb - the scroll bar

    • layoutContainer

      public void layoutContainer(Container scrollbarContainer)
      Description copied from interface: LayoutManager
      Lays out the specified container.
      Specified by:
      layoutContainer in interface LayoutManager
      Parameters:
      scrollbarContainer - the container to be laid out

    • setThumbBounds

      protected void setThumbBounds(int x, int y, int width, int height)
      Set the bounds of the thumb and force a repaint that includes the old thumbBounds and the new one.
      Parameters:
      x - set the x location of the thumb
      y - set the y location of the thumb
      width - set the width of the thumb
      height - set the height of the thumb
      See Also:

    • getThumbBounds

      protected Rectangle getThumbBounds()
      Return the current size/location of the thumb.

      Warning : the value returned by this method should not be be modified, it's a reference to the actual rectangle, not a copy.

      Returns:
      The current size/location of the thumb.
      See Also:

    • getTrackBounds

      protected Rectangle getTrackBounds()
      Returns the current bounds of the track, i.e. the space in between the increment and decrement buttons, less the insets. The value returned by this method is updated each time the scrollbar is laid out (validated).

      Warning : the value returned by this method should not be be modified, it's a reference to the actual rectangle, not a copy.

      Returns:
      the current bounds of the scrollbar track
      See Also:

    • scrollByBlock

      protected void scrollByBlock(int direction)
      Scrolls by block.
      Parameters:
      direction - the direction to scroll

    • scrollByUnit

      protected void scrollByUnit(int direction)
      Scrolls by unit.
      Parameters:
      direction - the direction to scroll

    • getSupportsAbsolutePositioning

      public boolean getSupportsAbsolutePositioning()
      Indicates whether the user can absolutely position the thumb with a mouse gesture (usually the middle mouse button).
      Returns:
      true if a mouse gesture can absolutely position the thumb
      Since:
      1.5