basicscrollbarui.java

java jdk 1.4的源码

		
        public void mouseReleased(MouseEvent e)
        {
	    if (SwingUtilities.isRightMouseButton(e) ||
		(!getSupportsAbsolutePositioning() &&
		 SwingUtilities.isMiddleMouseButton(e)))
		return;
	    if(!scrollbar.isEnabled())
		return;

	    Rectangle r = getTrackBounds();
	    scrollbar.repaint(r.x, r.y, r.width, r.height);

	    trackHighlight = NO_HIGHLIGHT;
	    isDragging = false;
	    offset = 0;
	    scrollTimer.stop();
	    scrollbar.setValueIsAdjusting(false);
	}
		

        /**
	 * If the mouse is pressed above the "thumb" component
	 * then reduce the scrollbars value by one page ("page up"), 
	 * otherwise increase it by one page.  If there is no 
	 * thumb then page up if the mouse is in the upper half
	 * of the track.
	 */
        public void mousePressed(MouseEvent e) 
	{
	    if (SwingUtilities.isRightMouseButton(e) ||
		(!getSupportsAbsolutePositioning() &&
		 SwingUtilities.isMiddleMouseButton(e)))
		return;
	    if(!scrollbar.isEnabled())
		return;

	    if (!scrollbar.hasFocus() && scrollbar.isRequestFocusEnabled()) {
		scrollbar.requestFocus();
	    }

	    scrollbar.setValueIsAdjusting(true);

            currentMouseX = e.getX();
            currentMouseY = e.getY();
	
	    // Clicked in the Thumb area?
	    if(getThumbBounds().contains(currentMouseX, currentMouseY))	{
                switch (scrollbar.getOrientation()) {
                case JScrollBar.VERTICAL:
		    offset = currentMouseY - getThumbBounds().y;
                    break;
                case JScrollBar.HORIZONTAL:
		    offset = currentMouseX - getThumbBounds().x;
                    break;
                }
		isDragging = true;
		return;
	    }
	    else if (getSupportsAbsolutePositioning() &&
		     SwingUtilities.isMiddleMouseButton(e)) {
                switch (scrollbar.getOrientation()) {
                case JScrollBar.VERTICAL:
		    offset = getThumbBounds().height / 2;
                    break;
                case JScrollBar.HORIZONTAL:
		    offset = getThumbBounds().width / 2;
                    break;
                }
		isDragging = true;
		setValueFrom(e);
		return;
	    }
	    isDragging = false;
							
            Dimension sbSize = scrollbar.getSize();
            direction = +1;

            switch (scrollbar.getOrientation()) {
            case JScrollBar.VERTICAL:
                if (getThumbBounds().isEmpty()) {
                    int scrollbarCenter = sbSize.height / 2;
		    direction = (currentMouseY < scrollbarCenter) ? -1 : +1;
                } else {
                    int thumbY = getThumbBounds().y;
		    direction = (currentMouseY < thumbY) ? -1 : +1;
                }
                break;                    
            case JScrollBar.HORIZONTAL:
                if (getThumbBounds().isEmpty()) {
                    int scrollbarCenter = sbSize.width / 2;
                    direction = (currentMouseX < scrollbarCenter) ? -1 : +1;
                } else {
                    int thumbX = getThumbBounds().x;
                    direction = (currentMouseX < thumbX) ? -1 : +1;
                }
		if (!scrollbar.getComponentOrientation().isLeftToRight()) {
		    direction = -direction;
		}
                break;
            }
	    scrollByBlock(direction);

	    scrollTimer.stop();
	    scrollListener.setDirection(direction);
	    scrollListener.setScrollByBlock(true);
	    startScrollTimerIfNecessary();
        }
		

        /** 
	 * Set the models value to the position of the thumb's top of Vertical
	 * scrollbar, or the left/right of Horizontal scrollbar in
	 * left-to-right/right-to-left scrollbar relative to the origin of the
	 * track.
	 */
	public void mouseDragged(MouseEvent e) {
	    if (SwingUtilities.isRightMouseButton(e) ||
		(!getSupportsAbsolutePositioning() &&
		 SwingUtilities.isMiddleMouseButton(e)))
		return;
	    if(!scrollbar.isEnabled() || getThumbBounds().isEmpty()) {
		return;
	    }
	    if (isDragging) {
		setValueFrom(e);
	    } else {
		currentMouseX = e.getX();
		currentMouseY = e.getY();
		startScrollTimerIfNecessary();
	    }
	}

	private void setValueFrom(MouseEvent e) {
	    BoundedRangeModel model = scrollbar.getModel();
	    Rectangle thumbR = getThumbBounds();
	    float trackLength;
	    int thumbMin, thumbMax, thumbPos;
	    
	    if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
		thumbMin = decrButton.getY() + decrButton.getHeight();
		thumbMax = incrButton.getY() - thumbR.height;
		thumbPos = Math.min(thumbMax, Math.max(thumbMin, (e.getY() - offset)));
		setThumbBounds(thumbR.x, thumbPos, thumbR.width, thumbR.height);
		trackLength = getTrackBounds().height;
	    }
	    else {
		if (scrollbar.getComponentOrientation().isLeftToRight()) {
		    thumbMin = decrButton.getX() + decrButton.getWidth();
		    thumbMax = incrButton.getX() - thumbR.width;
		} else {
		    thumbMin = incrButton.getX() + incrButton.getWidth();
		    thumbMax = decrButton.getX() - thumbR.width;
		}
		thumbPos = Math.min(thumbMax, Math.max(thumbMin, (e.getX() - offset)));
		setThumbBounds(thumbPos, thumbR.y, thumbR.width, thumbR.height);
		trackLength = getTrackBounds().width;
	    }
	    
	    /* Set the scrollbars value.  If the thumb has reached the end of
	     * the scrollbar, then just set the value to its maximum.  Otherwise
	     * compute the value as accurately as possible.
	     */
	    if (thumbPos == thumbMax) {
		if (scrollbar.getOrientation() == JScrollBar.VERTICAL || 
		    scrollbar.getComponentOrientation().isLeftToRight()) {
		    scrollbar.setValue(model.getMaximum() - model.getExtent());
		} else {
		    scrollbar.setValue(model.getMinimum());
		}
	    }
	    else {
		float valueMax = model.getMaximum() - model.getExtent();
		float valueRange = valueMax - model.getMinimum();
		float thumbValue = thumbPos - thumbMin;
		float thumbRange = thumbMax - thumbMin;
		int value;
		if (scrollbar.getOrientation() == JScrollBar.VERTICAL || 
		    scrollbar.getComponentOrientation().isLeftToRight()) {
		    value = (int)(0.5 + ((thumbValue / thumbRange) * valueRange));
		} else {
		    value = (int)(0.5 + (((thumbMax - thumbPos) / thumbRange) * valueRange));
		}
		scrollbar.setValue(value + model.getMinimum());
	    }
	}

	private void startScrollTimerIfNecessary() {
	    if (scrollTimer.isRunning()) {
		return;
	    }
	    switch (scrollbar.getOrientation()) {
	    case JScrollBar.VERTICAL:
		if (direction >0) {
		    if (getThumbBounds().y + getThumbBounds().height <
			trackListener.currentMouseY) {
			scrollTimer.start();
		    }
		} else if (getThumbBounds().y >
			   trackListener.currentMouseY) {
		    scrollTimer.start();
		}
		break;
	    case JScrollBar.HORIZONTAL:
		if (direction >0) {
		    if (getThumbBounds().x + getThumbBounds().width <
			trackListener.currentMouseX) {
			scrollTimer.start();
		    }
		} else if (getThumbBounds().x >
			   trackListener.currentMouseX) {
		    scrollTimer.start();
		}
		break;
	    }
	}
		
	public void mouseMoved(MouseEvent e) {
	}
    }
        

    /**
     * Listener for cursor keys.
     */
    protected class ArrowButtonListener extends MouseAdapter
    {		
	// Because we are handling both mousePressed and Actions
	// we need to make sure we don't fire under both conditions.
	// (keyfocus on scrollbars causes action without mousePress
	boolean handledEvent;
	
	public void mousePressed(MouseEvent e)		{
	    if(!scrollbar.isEnabled()) { return; }
	    // not an unmodified left mouse button
	    //if(e.getModifiers() != InputEvent.BUTTON1_MASK) {return; }
	    if( ! SwingUtilities.isLeftMouseButton(e)) { return; }

	    int direction = (e.getSource() == incrButton) ? 1 : -1;
		
	    scrollByUnit(direction);
	    scrollTimer.stop();
	    scrollListener.setDirection(direction);
	    scrollListener.setScrollByBlock(false);
	    scrollTimer.start();

	    handledEvent = true;	
	    if (!scrollbar.hasFocus() && scrollbar.isRequestFocusEnabled()) {
		scrollbar.requestFocus();
	    }
	}

	public void mouseReleased(MouseEvent e)		{
	    scrollTimer.stop();
	    handledEvent = false;
	    scrollbar.setValueIsAdjusting(false);
	}
    }


    /**
     * Listener for scrolling events initiated in the
     * <code>ScrollPane</code>.
     */
    protected class ScrollListener implements ActionListener
    {
	int direction = +1;
	boolean useBlockIncrement;

	public ScrollListener()	{
	    direction = +1;
	    useBlockIncrement = false;
	}

        public ScrollListener(int dir, boolean block)	{
	    direction = dir;
	    useBlockIncrement = block;
	}
	
	public void setDirection(int direction) { this.direction = direction; }
	public void setScrollByBlock(boolean block) { this.useBlockIncrement = block; }
					
	public void actionPerformed(ActionEvent e) {
	    if(useBlockIncrement)	{
		scrollByBlock(direction);		
		// Stop scrolling if the thumb catches up with the mouse
		if(scrollbar.getOrientation() == JScrollBar.VERTICAL)	{
		    if(direction > 0)	{
			if(getThumbBounds().y + getThumbBounds().height 
				>= trackListener.currentMouseY)
				    ((Timer)e.getSource()).stop();
		    } else if(getThumbBounds().y <= trackListener.currentMouseY)	{
			((Timer)e.getSource()).stop();
		    }
		} else {
		    if(direction > 0)	{
			if(getThumbBounds().x + getThumbBounds().width 
				>= trackListener.currentMouseX)
				    ((Timer)e.getSource()).stop();
		    } else if(getThumbBounds().x <= trackListener.currentMouseX)	{
		        ((Timer)e.getSource()).stop();
		    }
	        }
	    } else {
		scrollByUnit(direction);
	    }

	    if(direction > 0 
		&& scrollbar.getValue()+scrollbar.getVisibleAmount() 
			>= scrollbar.getMaximum())
		((Timer)e.getSource()).stop();
	    else if(direction < 0 
		&& scrollbar.getValue() <= scrollbar.getMinimum())
	        ((Timer)e.getSource()).stop();
	}
    }


    public class PropertyChangeHandler implements PropertyChangeListener 
    {
        public void propertyChange(PropertyChangeEvent e) {
	    String propertyName = e.getPropertyName();

	    if ("model".equals(propertyName)) {
	        BoundedRangeModel oldModel = (BoundedRangeModel)e.getOldValue();
	        BoundedRangeModel newModel = (BoundedRangeModel)e.getNewValue();
		oldModel.removeChangeListener(modelListener);
		newModel.addChangeListener(modelListener);
		scrollbar.repaint();
		scrollbar.revalidate();
	    } else if ("orientation".equals(propertyName)) {
                Integer orient = (Integer)e.getNewValue();

                if (scrollbar.getComponentOrientation().isLeftToRight()) { 
                    if (incrButton instanceof BasicArrowButton) {
                        ((BasicArrowButton)incrButton).setDirection(orient.intValue() == HORIZONTAL?
                                                                EAST : SOUTH);
                    }
                    if (decrButton instanceof BasicArrowButton) {
                        ((BasicArrowButton)decrButton).setDirection(orient.intValue() == HORIZONTAL?
                                                                WEST : NORTH);
                    }
                } else {
                    if (incrButton instanceof BasicArrowButton) {
                        ((BasicArrowButton)incrButton).setDirection(orient.intValue() == HORIZONTAL?
                                                                WEST : SOUTH);
                    }
                    if (decrButton instanceof BasicArrowButton) {
                        ((BasicArrowButton)decrButton).setDirection(orient.intValue() == HORIZONTAL?
                                                                EAST : NORTH);
                    }
                }
            } else if ("componentOrientation".equals(propertyName)) {
                ComponentOrientation co = scrollbar.getComponentOrientation();
                incrButton.setComponentOrientation(co);
                decrButton.setComponentOrientation(co);

                if (scrollbar.getOrientation() == JScrollBar.HORIZONTAL) {
                    if (co.isLeftToRight()) {
                        if (incrButton instanceof BasicArrowButton) {
                            ((BasicArrowButton)incrButton).setDirection(EAST);
                        }
                        if (decrButton instanceof BasicArrowButton) {
                            ((BasicArrowButton)decrButton).setDirection(WEST);
                        }
                    } else {
                        if (incrButton instanceof BasicArrowButton) {
                            ((BasicArrowButton)incrButton).setDirection(WEST);
                        }
                        if (decrButton instanceof BasicArrowButton) {
                            ((BasicArrowButton)decrButton).setDirection(EAST);
                        }
                    }
                }

                InputMap inputMap = getInputMap(JComponent.WHEN_FOCUSED);
                SwingUtilities.replaceUIInputMap(scrollbar, JComponent.WHEN_FOCUSED, inputMap);
            }
	}
    }


    /**
     * Used for scrolling the scrollbar.
     */
    private static class SharedActionScroller extends AbstractAction {
        private int dir;
        private boolean block;

        SharedActionScroller(int dir, boolean block) {
            this.dir = dir;
            this.block = block;
        }

        public void actionPerformed(ActionEvent e) {
	    JScrollBar scrollBar = (JScrollBar)e.getSource();
	    if (dir == NEGATIVE_SCROLL || dir == POSITIVE_SCROLL) {
		int amount;
		// Don't use the BasicScrollBarUI.scrollByXXX methods as we
		// don't want to use an invokeLater to reset the trackHighlight
		// via an invokeLater
		if (block) {
		    if (dir == NEGATIVE_SCROLL) {
			amount = -1 * scrollBar.getBlockIncrement(-1);
		    }
		    else {
			amount = scrollBar.getBlockIncrement(1);
		    }
		}
		else {
		    if (dir == NEGATIVE_SCROLL) {
			amount = -1 * scrollBar.getUnitIncrement(-1);
		    }
		    else {
			amount = scrollBar.getUnitIncrement(1);
		    }
		}
		scrollBar.setValue(scrollBar.getValue() + amount);
	    }
	    else if (dir == MIN_SCROLL) {
		scrollBar.setValue(scrollBar.getMinimum());
	    }
	    else if (dir == MAX_SCROLL) {
		scrollBar.setValue(scrollBar.getMaximum());
	    }
	}
    }
}