basicsliderui.java

java1.6众多例子参考

     * @return true if all the labels from the label table have the
     *         same baseline
     * @since 1.6
     */
    protected boolean labelsHaveSameBaselines() {
        if (!checkedLabelBaselines) {
            checkedLabelBaselines = true;
            Dictionary dictionary = slider.getLabelTable();
            if (dictionary != null) {
                sameLabelBaselines = true;
                Enumeration elements = dictionary.elements();
                int baseline = -1;
                while (elements.hasMoreElements()) {
                    Component label = (Component)elements.nextElement();
                    Dimension pref = label.getPreferredSize();
                    int labelBaseline = label.getBaseline(pref.width,
                                                          pref.height);
                    if (labelBaseline >= 0) {
                        if (baseline == -1) {
                            baseline = labelBaseline;
                        }
                        else if (baseline != labelBaseline) {
                            sameLabelBaselines = false;
                            break;
                        }
                    }
                    else {
                        sameLabelBaselines = false;
                        break;
                    }
                }
            }
            else {
                sameLabelBaselines = false;
            }
        }
        return sameLabelBaselines;
    }

    public Dimension getPreferredHorizontalSize() {
        Dimension horizDim = (Dimension)DefaultLookup.get(slider,
                this, "Slider.horizontalSize");
        if (horizDim == null) {
            horizDim = new Dimension(200, 21);
        }
        return horizDim;
    }

    public Dimension getPreferredVerticalSize() {
        Dimension vertDim = (Dimension)DefaultLookup.get(slider,
                this, "Slider.verticalSize");
        if (vertDim == null) {
            vertDim = new Dimension(21, 200);
        }
        return vertDim;
    }

    public Dimension getMinimumHorizontalSize() {
        Dimension minHorizDim = (Dimension)DefaultLookup.get(slider,
                this, "Slider.minimumHorizontalSize");
        if (minHorizDim == null) {
            minHorizDim = new Dimension(36, 21);
        }
        return minHorizDim;
    }

    public Dimension getMinimumVerticalSize() {
        Dimension minVertDim = (Dimension)DefaultLookup.get(slider,
                this, "Slider.minimumVerticalSize");
        if (minVertDim == null) {
            minVertDim = new Dimension(21, 36);
        }
        return minVertDim;
    }

    public Dimension getPreferredSize(JComponent c)    {
        recalculateIfInsetsChanged();
        Dimension d;
        if ( slider.getOrientation() == JSlider.VERTICAL ) {
            d = new Dimension(getPreferredVerticalSize());
	    d.width = insetCache.left + insetCache.right;
	    d.width += focusInsets.left + focusInsets.right;
	    d.width += trackRect.width + tickRect.width + labelRect.width;
        }
        else {
            d = new Dimension(getPreferredHorizontalSize());
	    d.height = insetCache.top + insetCache.bottom;
	    d.height += focusInsets.top + focusInsets.bottom;
	    d.height += trackRect.height + tickRect.height + labelRect.height;
        }

        return d;
    }

    public Dimension getMinimumSize(JComponent c)  {
        recalculateIfInsetsChanged();
        Dimension d;

        if ( slider.getOrientation() == JSlider.VERTICAL ) {
            d = new Dimension(getMinimumVerticalSize());
	    d.width = insetCache.left + insetCache.right;
	    d.width += focusInsets.left + focusInsets.right;
	    d.width += trackRect.width + tickRect.width + labelRect.width;
        }
        else {
            d = new Dimension(getMinimumHorizontalSize());
	    d.height = insetCache.top + insetCache.bottom;
	    d.height += focusInsets.top + focusInsets.bottom;
	    d.height += trackRect.height + tickRect.height + labelRect.height;
        }

        return d;
    }

    public Dimension getMaximumSize(JComponent c) {
        Dimension d = getPreferredSize(c);
        if ( slider.getOrientation() == JSlider.VERTICAL ) {
            d.height = Short.MAX_VALUE;
        }
        else {
            d.width = Short.MAX_VALUE;
        }

        return d;
    }

    protected void calculateGeometry() {
        calculateFocusRect();
        calculateContentRect(); 
	calculateThumbSize();
	calculateTrackBuffer();
	calculateTrackRect();
	calculateTickRect();
	calculateLabelRect();
	calculateThumbLocation();
    }
  
    protected void calculateFocusRect() {
        focusRect.x = insetCache.left;
	focusRect.y = insetCache.top;
	focusRect.width = slider.getWidth() - (insetCache.left + insetCache.right);
	focusRect.height = slider.getHeight() - (insetCache.top + insetCache.bottom);
    }
  
    protected void calculateThumbSize() {
	Dimension size = getThumbSize();
	thumbRect.setSize( size.width, size.height );
    }
  
    protected void calculateContentRect() {
        contentRect.x = focusRect.x + focusInsets.left;
        contentRect.y = focusRect.y + focusInsets.top;
        contentRect.width = focusRect.width - (focusInsets.left + focusInsets.right);
        contentRect.height = focusRect.height - (focusInsets.top + focusInsets.bottom);
    }

    protected void calculateThumbLocation() {
        if ( slider.getSnapToTicks() ) {
	    int sliderValue = slider.getValue();
	    int snappedValue = sliderValue; 
	    int majorTickSpacing = slider.getMajorTickSpacing();
	    int minorTickSpacing = slider.getMinorTickSpacing();
	    int tickSpacing = 0;
	    
	    if ( minorTickSpacing > 0 ) {
	        tickSpacing = minorTickSpacing;
	    }
	    else if ( majorTickSpacing > 0 ) {
	        tickSpacing = majorTickSpacing;
	    }

	    if ( tickSpacing != 0 ) {
	        // If it's not on a tick, change the value
	        if ( (sliderValue - slider.getMinimum()) % tickSpacing != 0 ) {
		    float temp = (float)(sliderValue - slider.getMinimum()) / (float)tickSpacing;
		    int whichTick = Math.round( temp );
		    snappedValue = slider.getMinimum() + (whichTick * tickSpacing);
		}
		
		if( snappedValue != sliderValue ) { 
		    slider.setValue( snappedValue );
		}
	    }
	}
	
        if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
            int valuePosition = xPositionForValue(slider.getValue());

	    thumbRect.x = valuePosition - (thumbRect.width / 2);
	    thumbRect.y = trackRect.y;
        }
        else {
            int valuePosition = yPositionForValue(slider.getValue());
	    
	    thumbRect.x = trackRect.x;
	    thumbRect.y = valuePosition - (thumbRect.height / 2);
        }
    }

    protected void calculateTrackBuffer() {
        if ( slider.getPaintLabels() && slider.getLabelTable()  != null ) {
            Component highLabel = getHighestValueLabel();
            Component lowLabel = getLowestValueLabel();

            if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
                trackBuffer = Math.max( highLabel.getBounds().width, lowLabel.getBounds().width ) / 2;
                trackBuffer = Math.max( trackBuffer, thumbRect.width / 2 );
            }
            else {
                trackBuffer = Math.max( highLabel.getBounds().height, lowLabel.getBounds().height ) / 2;
                trackBuffer = Math.max( trackBuffer, thumbRect.height / 2 );
            }
        }
        else {
            if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
                trackBuffer = thumbRect.width / 2;
            }
            else {
                trackBuffer = thumbRect.height / 2;
            }
        }
    }

  
    protected void calculateTrackRect() {
	int centerSpacing = 0; // used to center sliders added using BorderLayout.CENTER (bug 4275631)
        if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
	    centerSpacing = thumbRect.height;
	    if ( slider.getPaintTicks() ) centerSpacing += getTickLength();
	    if ( slider.getPaintLabels() ) centerSpacing += getHeightOfTallestLabel();
	    trackRect.x = contentRect.x + trackBuffer;
	    trackRect.y = contentRect.y + (contentRect.height - centerSpacing - 1)/2;
	    trackRect.width = contentRect.width - (trackBuffer * 2);
	    trackRect.height = thumbRect.height;
	}
	else {
	    centerSpacing = thumbRect.width;
	    if (BasicGraphicsUtils.isLeftToRight(slider)) {
		if ( slider.getPaintTicks() ) centerSpacing += getTickLength();
	    	if ( slider.getPaintLabels() ) centerSpacing += getWidthOfWidestLabel();
	    } else {
	        if ( slider.getPaintTicks() ) centerSpacing -= getTickLength();
	    	if ( slider.getPaintLabels() ) centerSpacing -= getWidthOfWidestLabel();
	    }
	    trackRect.x = contentRect.x + (contentRect.width - centerSpacing - 1)/2;
	    trackRect.y = contentRect.y + trackBuffer;
	    trackRect.width = thumbRect.width;
	    trackRect.height = contentRect.height - (trackBuffer * 2);
	}

    }

    /**
     * Gets the height of the tick area for horizontal sliders and the width of the
     * tick area for vertical sliders.  BasicSliderUI uses the returned value to
     * determine the tick area rectangle.  If you want to give your ticks some room,
     * make this larger than you need and paint your ticks away from the sides in paintTicks().
     */
    protected int getTickLength() {
        return 8;
    }

    protected void calculateTickRect() {
	if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
	    tickRect.x = trackRect.x;
	    tickRect.y = trackRect.y + trackRect.height;
	    tickRect.width = trackRect.width;
	    tickRect.height = (slider.getPaintTicks()) ? getTickLength() : 0;
	}
	else {
	    tickRect.width = (slider.getPaintTicks()) ? getTickLength() : 0;
	    if(BasicGraphicsUtils.isLeftToRight(slider)) {
	        tickRect.x = trackRect.x + trackRect.width;
	    }
	    else {
	        tickRect.x = trackRect.x - tickRect.width;
	    }
	    tickRect.y = trackRect.y;
	    tickRect.height = trackRect.height;
	}
    }

    protected void calculateLabelRect() {
        if ( slider.getPaintLabels() ) {
	    if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
	        labelRect.x = tickRect.x - trackBuffer;
		labelRect.y = tickRect.y + tickRect.height;
		labelRect.width = tickRect.width + (trackBuffer * 2);
                labelRect.height = getHeightOfTallestLabel();
            }
            else {
	        if(BasicGraphicsUtils.isLeftToRight(slider)) {
		    labelRect.x = tickRect.x + tickRect.width;
		    labelRect.width = getWidthOfWidestLabel();
		}
		else {
		    labelRect.width = getWidthOfWidestLabel();
		    labelRect.x = tickRect.x - labelRect.width;
		}
		labelRect.y = tickRect.y - trackBuffer;
		labelRect.height = tickRect.height + (trackBuffer * 2);
            }
        }
        else {
            if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
	        labelRect.x = tickRect.x;
		labelRect.y = tickRect.y + tickRect.height;
		labelRect.width = tickRect.width;
		labelRect.height = 0;
            }
            else {
	        if(BasicGraphicsUtils.isLeftToRight(slider)) {
		    labelRect.x = tickRect.x + tickRect.width;
		}
		else {
		    labelRect.x = tickRect.x;
		}
		labelRect.y = tickRect.y;
		labelRect.width = 0;
		labelRect.height = tickRect.height;
            }
        }
    }

    protected Dimension getThumbSize() {
        Dimension size = new Dimension();

        if ( slider.getOrientation() == JSlider.VERTICAL ) {
	    size.width = 20;
	    size.height = 11;
	}
	else {
	    size.width = 11;
	    size.height = 20;
	}

	return size;
    }

    public class PropertyChangeHandler implements PropertyChangeListener {
        // NOTE: This class exists only for backward compatability. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this      
        // class calls into the Handler.
        public void propertyChange( PropertyChangeEvent e ) {
            getHandler().propertyChange(e);
        }
    }

    protected int getWidthOfWidestLabel() {
        Dictionary dictionary = slider.getLabelTable();
        int widest = 0;
        if ( dictionary != null ) {
            Enumeration keys = dictionary.keys();
            while ( keys.hasMoreElements() ) {
                Component label = (Component)dictionary.get( keys.nextElement() );
                widest = Math.max( label.getPreferredSize().width, widest );
            }
        }
        return widest;
    }

    protected int getHeightOfTallestLabel() {
        Dictionary dictionary = slider.getLabelTable();
        int tallest = 0;
        if ( dictionary != null ) {
            Enumeration keys = dictionary.keys();
            while ( keys.hasMoreElements() ) {
                Component label = (Component)dictionary.get( keys.nextElement() );
                tallest = Math.max( label.getPreferredSize().height, tallest );
            }
        }
        return tallest;
    }

    protected int getWidthOfHighValueLabel() {
        Component label = getHighestValueLabel();
        int width = 0;

        if ( label != null ) {
            width = label.getPreferredSize().width;
        }