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

Class BasicScrollBarUI

    • Field Detail

      • 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

      • thumbRect

        protected Rectangle thumbRect
        Thumb rectangle

      • trackRect

        protected Rectangle trackRect
        Track rectangle

      • trackHighlight

        protected int trackHighlight
        Track highlight

      • DECREASE_HIGHLIGHT

        protected static final int DECREASE_HIGHLIGHT
        Decrease highlight
        See Also:
        Constant Field Values

      • INCREASE_HIGHLIGHT

        protected static final int INCREASE_HIGHLIGHT
        Increase highlight
        See Also:
        Constant Field Values

      • 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 Detail

      • BasicScrollBarUI

        public BasicScrollBarUI​()

    • Method Detail

      • 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.

      • 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.

      • 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

      • paint

        public void paint​(Graphics g,
                  JComponent c)
        Description copied from class: ComponentUI
        Paints the specified component appropriately 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.
        Overrides:
        paint in class ComponentUI
        Parameters:
        g - the Graphics context in which to paint
        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 Also:
        ComponentUI.update(java.awt.Graphics, javax.swing.JComponent)

      • 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(javax.swing.JComponent), ComponentUI.getMinimumSize(javax.swing.JComponent)

      • 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:
        ComponentUI.getMinimumSize(javax.swing.JComponent), getPreferredSize(javax.swing.JComponent)

      • 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()

      • 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:
        getMinimumThumbSize()

      • 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

      • layoutVScrollbar

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

      • layoutHScrollbar

        protected void layoutHScrollbar​(JScrollBar sb)
        Laysouts a vertical 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()

      • 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:
        setThumbBounds(int, int, int, int)

      • 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:
        layoutContainer(java.awt.Container)

      • 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