CD Ware Multimedia 1999 February/CDW0299.iso/Demos/Cafe/Source.bin/LabelButton.java

Java Source | 1998-03-18 | 22.4 KB | 692 lines

package symantec.itools.awt;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Font;
import java.awt.Graphics;
import java.beans.PropertyVetoException;
import java.beans.PropertyChangeListener;
import java.beans.VetoableChangeListener;
import java.beans.PropertyChangeEvent;
import java.lang.IllegalArgumentException;
import symantec.itools.awt.util.ColorUtils;
import java.util.ResourceBundle;

//     01/29/97    TWB    Integrated changes from Macintosh
//     02/27/97    RKM    Merged in Scott's changes
//     05/31/97    LAB Updated to Java 1.1
//     07/09/97    LAB Changed the way the button is drawn.  Now it uses the offscreen
//                    Image.  Cleaned up the drawing code to be more universal.
//                    Added pressed and disabled colors for the text durring those states.
//                    Added a VerticalAlignStyle property to align the text vertically.
//                    Added a preferedSize() method that works.
//                    Removed BevelStyle, Show/HideLabel, and BorderIndent.
//                    No longer overrides setFont(), minimumSize(), or paint().
//    07/13/97    RKM    Fixed misspelling of prefered
//     07/20/97    LAB    Fixed a logic problem when testing for null strings.
//  07/23/97    CAR changed getPreferredSize
//  07/23/97    CAR marked field transient as needed, inner classes implement java.io.Serializable
//     08/05/97    LAB    Added a call to clipRect in the updateButtonImage method to clip subsequent
//                    drawings to the internal button area (sans border and bevel). This should be
//                    removed when the VM interprets the base class' call to clipRect correctly.
//     08/06/97    LAB    Removed the call to clipRect; now uses the base classes buttonImageGraphics
//                    Graphics to draw with, which inherits the clipping.
//  08/19/97    CAR commented out duplicate call to setVerticalAlignStyle in constructor

/**
 * LabelButton is a 3D looking button that displays a string on it's face.
 * Use an LabelButton to:
 * <UL>
 * <DT>╖ Display text in a 3D looking button.</DT>
 * <DT>╖ Generate a train of action events while the user presses the button.</DT>
 * </UL>
 * <p>
 * @version 1.1, July 8, 1997
 * @author  Symantec
 */
public class LabelButton extends ButtonBase implements AlignStyle
{
    /**
     * Defines the "top" label text alignment style.
     */
    public static final int ALIGN_TOP = 0;

    /**
     * Defines the "bottom" label text alignment style.
     */
    public static final int ALIGN_BOTTOM = 2;

    /**
     * Constructs an empty LabelButton with center aligned black text.
     */
    public LabelButton()
    {
        this("", ALIGN_CENTERED, ALIGN_CENTERED, Color.black);
    }

    /**
     * Constructs a LabelButton with the specified centered, black text.
     * @param sText the label text
     */
    public LabelButton(String sText)
    {
        this(sText, ALIGN_CENTERED, ALIGN_CENTERED, Color.black);
    }

    /**
     * Constructs a LabelButton with the specified centered text,
     * with the specified color.
     * @param sText the label text
     */
    public LabelButton(String sText, Color color)
    {
        this(sText, ALIGN_CENTERED, ALIGN_CENTERED, color);
    }

    /**
     * Constructs a LabelButton with the specified vertically centered black text, and the
     * specified horizontal text alignment style.
     * @param sText the label text
     * @param alignStyle the text alignment style: ALIGN_LEFT, ALIGN_CENTERED, or ALIGN_RIGHT
     * @see AlignStyle#ALIGN_LEFT
     * @see AlignStyle#ALIGN_CENTERED
     * @see AlignStyle#ALIGN_RIGHT
     */
    public LabelButton(String sText, int alignStyle)
    {
        this(sText, alignStyle, ALIGN_CENTERED, Color.black);
    }

    /**
     * Constructs a LabelButton with the specified attributes.
     * @param sText the label text
     * @param hAlignStyle the text horizontal alignment style: ALIGN_LEFT, ALIGN_CENTERED, or ALIGN_RIGHT
     * @param vAlignStyle the text vertical alignment style: ALIGN_TOP, ALIGN_CENTERED, or ALIGN_BOTTOM
     * @param color the label text color
     * @see AlignStyle#ALIGN_LEFT
     * @see AlignStyle#ALIGN_CENTERED
     * @see AlignStyle#ALIGN_RIGHT
     * @see #ALIGN_TOP
     * @see #ALIGN_BOTTOM
     */
    public LabelButton(String sText, int hAlignStyle, int vAlignStyle, Color color)
    {
        try
        {
            setText(sText);
            setTextColor(color);
            setAlignStyle(hAlignStyle);
            setVerticalAlignStyle(vAlignStyle);
            //setVerticalAlignStyle(ALIGN_CENTERED);
        }
        catch(PropertyVetoException e){}
    }

    /**
     * Sets the text horizontal alignment style.
     * Causes the component to redraw.
     * @param style the text alignment style: ALIGN_LEFT, ALIGN_CENTERED, or ALIGN_RIGHT
     * @see #getAlignStyle
     * @see AlignStyle#ALIGN_LEFT
     * @see AlignStyle#ALIGN_CENTERED
     * @see AlignStyle#ALIGN_RIGHT
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setAlignStyle(int style) throws PropertyVetoException
    {
        if(hAlignStyle != style)
        {
            Integer oldValue = new Integer(hAlignStyle);
            Integer newValue = new Integer(style);

            vetos.fireVetoableChange("AlignStyle", oldValue, newValue);

            hAlignStyle = style;
            repaint();

            changes.firePropertyChange("AlignStyle", oldValue, newValue);
        }
    }

    /**
     * Gets the current text alignment style.
     * @return the text alignment style: ALIGN_LEFT, ALIGN_CENTERED, or ALIGN_RIGHT
     * @see #setAlignStyle
     * @see AlignStyle#ALIGN_LEFT
     * @see AlignStyle#ALIGN_CENTERED
     * @see AlignStyle#ALIGN_RIGHT
     */
    public int getAlignStyle()
    {
        return hAlignStyle;
    }

    /**
     * Sets the text vertical alignment style.
     * Causes the component to redraw.
     * @param style the text alignment style: ALIGN_TOP, ALIGN_CENTERED, or ALIGN_BOTTOM
     * @see #getVerticalAlignStyle
     * @see #ALIGN_TOP
     * @see AlignStyle#ALIGN_CENTERED
     * @see #ALIGN_BOTTOM
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setVerticalAlignStyle(int style) throws PropertyVetoException
    {
        if(vAlignStyle != style)
        {
            Integer oldValue = new Integer(vAlignStyle);
            Integer newValue = new Integer(style);

            vetos.fireVetoableChange("VerticalAlignStyle", oldValue, newValue);

            vAlignStyle = style;
            repaint();

            changes.firePropertyChange("VerticalAlignStyle", oldValue, newValue);
        }
    }

    /**
     * Gets the current text alignment style.
     * @return the text alignment style: ALIGN_TOP, ALIGN_CENTERED, or ALIGN_BOTTOM
     * @see #setVerticalAlignStyle
     * @see #ALIGN_TOP
     * @see AlignStyle#ALIGN_CENTERED
     * @see #ALIGN_BOTTOM
     */
    public int getVerticalAlignStyle()
    {
        return vAlignStyle;
    }

    /**
     * Sets the label text.
     * Causes the component to redraw.
     * @param sText the new label text
     * @see #getText
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setText(String sText) throws PropertyVetoException
    {
        if(sLabelButton == null || !sLabelButton.equals(sText))
        {
            String oldValue = sLabelButton == null ? null : new String(sLabelButton);

            vetos.fireVetoableChange("Text", oldValue, sText);

            sLabelButton = sText;
            repaint();

            changes.firePropertyChange("Text", oldValue, sText);
        }
    }

    /**
     * Gets the current label text.
     * @return the current label text
     * @see #setText
     */
    public String getText()
    {
        return sLabelButton;
    }

    /**
     * Sets the label text color.
     * Causes the component to redraw.
     * @param color the new color for the label text
     * @see #getTextColor
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setTextColor(Color color) throws PropertyVetoException
    {
        if(! symantec.itools.util.GeneralUtils.objectsEqual(textColor, color))
        {
            Color oldValue = textColor;

            vetos.fireVetoableChange("TextColor", oldValue, color);

            textColor = color;
            try
            {
                disabledTextColor    = ColorUtils.lighten(textColor,    0.333);
                pressedTextColor    = ColorUtils.darken(textColor,    0.250);
            }
            catch (IllegalArgumentException exc) {}
            repaint();

            changes.firePropertyChange("TextColor", oldValue, color);
        }
    }

    /**
     * Gets the current label text color.
     * @return the current color of the label text
     * @see #setTextColor
     */
    public Color getTextColor()
    {
        return textColor;
    }

    /**
     * Returns the recommended dimensions to properly display this component.
     * This is a standard Java AWT method which gets called to determine
     * the recommended size of this component.
     *
     * The Dimension returned is large enough for the label and a one pixel
     * space between the label and the button's bevel.
     */
    public Dimension getPreferredSize()
    {
        if(isAdded)
        {
            Dimension s        = size();
            Graphics g        = getGraphics();
            FontMetrics fm    = g.getFontMetrics();
            int labelWidth    = 0;

            //Make sure we don't cause a NullPointerException when accessing the string width.
            if(!(sLabelButton == null || sLabelButton.equals("")))
                labelWidth = fm.stringWidth(sLabelButton);

            if (g != null)
                g.dispose();

            return new Dimension(labelWidth + bevel + bevel + 4, fm.getAscent() + fm.getDescent() + bevel + bevel + 4);
        }
        return super.getPreferredSize();
    }

    /**
     * Tells this component that it has been added to a container.
     * This is a standard Java AWT method which gets called by the AWT when
     * this component is added to a container. Typically, it is used to
     * create this component's peer.
     *
     * It has been overridden here to hook-up event listeners.
     *
     * @see #removeNotify
     */
    public synchronized void addNotify()
    {
        super.addNotify();
        errors = ResourceBundle.getBundle("symantec.itools.resources.ErrorsBundle");

        //Hook up listeners
        if (horizontalVeto == null)
        {
            horizontalVeto = new HAVeto();
            addAlignStyleListener(horizontalVeto);
        }
        if (verticalVeto == null)
        {
            verticalVeto = new VAVeto();
            addVerticalAlignStyleListener(verticalVeto);
        }
    }

    /**
     * Tells this component that it is being removed from a container.
     * This is a standard Java AWT method which gets called by the AWT when
     * this component is removed from a container. Typically, it is used to
     * destroy the peers of this component and all its subcomponents.
     *
     * It has been overridden here to unhook event listeners.
     *
     * @see #addNotify
     */
    public synchronized void removeNotify()
    {
        //Unhook listeners
        if (horizontalVeto != null)
        {
            removeAlignStyleListener(horizontalVeto);
            horizontalVeto = null;
        }
        if (verticalVeto != null)
        {
            removeVerticalAlignStyleListener(verticalVeto);
            verticalVeto = null;
        }

        super.removeNotify();
    }

    /**
     * Adds a listener for all event changes.
     * @param listener the listener to add.
     * @see #removePropertyChangeListener
     */
    public synchronized void addPropertyChangeListener(PropertyChangeListener listener)
    {
        super.addPropertyChangeListener(listener);
        changes.addPropertyChangeListener(listener);
    }

    /**
     * Removes a listener for all event changes.
     * @param listener the listener to remove.
     * @see #addPropertyChangeListener
     */
    public synchronized void removePropertyChangeListener(PropertyChangeListener listener)
    {
        super.removePropertyChangeListener(listener);
        changes.removePropertyChangeListener(listener);
    }

    /**
     * Adds a vetoable listener for all event changes.
     * @param listener the listener to add.
     * @see #removeVetoableChangeListener(java.beans.VetoableChangeListener)
     */
    public synchronized void addVetoableChangeListener(VetoableChangeListener listener)
    {
        super.addVetoableChangeListener(listener);
        vetos.addVetoableChangeListener(listener);
    }

    /**
     * Removes a vetoable listener for all event changes.
     * @param listener the listener to remove.
     * @see #addVetoableChangeListener(java.beans.VetoableChangeListener)
     */
    public synchronized void removeVetoableChangeListener(VetoableChangeListener listener)
    {
        super.removeVetoableChangeListener(listener);
        vetos.removeVetoableChangeListener(listener);
    }

    /**
     * Adds a listener for the AlignStyle property changes.
     * @param listener the listener to add.
     * @see #removeAlignStyleListener(java.beans.PropertyChangeListener)
     */
    public synchronized void addAlignStyleListener(PropertyChangeListener listener)
    {
        changes.addPropertyChangeListener("AlignStyle", listener);
    }

    /**
     * Removes a listener for the AlignStyle property changes.
     * @param listener the listener to remove.
     * @see #addAlignStyleListener(java.beans.PropertyChangeListener)
     */
    public synchronized void removeAlignStyleListener(PropertyChangeListener listener)
    {
        changes.removePropertyChangeListener("AlignStyle", listener);
    }

    /**
     * Adds a vetoable listener for the AlignStyle property changes.
     * @param listener the listener to add.
     * @see #removeAlignStyleListener(java.beans.VetoableChangeListener)
     */
    public synchronized void addAlignStyleListener(VetoableChangeListener listener)
    {
        vetos.addVetoableChangeListener("AlignStyle", listener);
    }

    /**
     * Removes a vetoable listener for the AlignStyle property changes.
     * @param listener the listener to remove.
     * @see #addAlignStyleListener(java.beans.VetoableChangeListener)
     */
    public synchronized void removeAlignStyleListener(VetoableChangeListener listener)
    {
        vetos.removeVetoableChangeListener("AlignStyle", listener);
    }

    /**
     * Adds a listener for the VerticalAlignStyle property changes.
     * @param listener the listener to add.
     * @see #removeVerticalAlignStyleListener(java.beans.PropertyChangeListener)
     */
    public synchronized void addVerticalAlignStyleListener(PropertyChangeListener listener)
    {
        changes.addPropertyChangeListener("VerticalAlignStyle", listener);
    }

    /**
     * Removes a listener for the VerticalAlignStyle property changes.
     * @param listener the listener to remove.
     * @see #addVerticalAlignStyleListener(java.beans.PropertyChangeListener)
     */
    public synchronized void removeVerticalAlignStyleListener(PropertyChangeListener listener)
    {
        changes.removePropertyChangeListener("VerticalAlignStyle", listener);
    }

    /**
     * Adds a vetoable listener for the VerticalAlignStyle property changes.
     * @param listener the listener to add.
     * @see #removeVerticalAlignStyleListener(java.beans.VetoableChangeListener)
     */
    public synchronized void addVerticalAlignStyleListener(VetoableChangeListener listener)
    {
        vetos.addVetoableChangeListener("VerticalAlignStyle", listener);
    }

    /**
     * Removes a vetoable listener for the VerticalAlignStyle property changes.
     * @param listener the listener to remove.
     * @see #addVerticalAlignStyleListener(java.beans.VetoableChangeListener)
     */
    public synchronized void removeVerticalAlignStyleListener(VetoableChangeListener listener)
    {
        vetos.removeVetoableChangeListener("VerticalAlignStyle", listener);
    }

    /**
     * This is the PropertyChangeEvent handling inner class for the constrained AlignStyle property.
     * Handles vetoing AlignStyles that are not valid.
     */
    class HAVeto implements java.beans.VetoableChangeListener, java.io.Serializable
    {
        /**
         * This method gets called when an attempt to change the constrained AlignStyle property is made.
         * Ensures the given AlignStyle is valid.
         *
         * @param     e a <code>PropertyChangeEvent</code> object describing the
         *             event source and the property that has changed.
         * @exception PropertyVetoException if the recipient wishes the property
         *              change to be rolled back.
         */
        public void vetoableChange(PropertyChangeEvent e) throws PropertyVetoException
        {
            int i = ((Integer)e.getNewValue()).intValue();
            if (!isValidHorizontalAlignStyle(i))
            {
                throw new PropertyVetoException(errors.getString("InvalidAlignStyle") + i, e);
            }
        }
    }

    /**
     * This is the PropertyChangeEvent handling inner class for the constrained VerticalAlignStyle property.
     * Handles vetoing VerticalAlignStyles that are not valid.
     */
    class VAVeto implements java.beans.VetoableChangeListener, java.io.Serializable
    {
        /**
         * This method gets called when an attempt to change the constrained VerticalAlignStyle property is made.
         * Ensures the given AlignStyle is valid.
         *
         * @param     e a <code>PropertyChangeEvent</code> object describing the
         *             event source and the property that has changed.
         * @exception PropertyVetoException if the recipient wishes the property
         *              change to be rolled back.
         */
        public void vetoableChange(PropertyChangeEvent e) throws PropertyVetoException
        {
            int i = ((Integer)e.getNewValue()).intValue();
            if (!isValidVerticalAlignStyle(i))
            {
                throw new PropertyVetoException(errors.getString("InvalidVerticalAlignStyle") + i, e);
            }
        }
    }

    /**
     * Is the given Horizontal AlignStyle valid for this button.
     * @param i the given Horizontal AlignStyle
     * @return true if the given Horizontal AlignStyle is acceptable, false if not.
     */
    protected boolean isValidHorizontalAlignStyle(int i)
    {
        switch(i)
        {
            case ALIGN_LEFT:
            case ALIGN_CENTERED:
            case ALIGN_RIGHT:
                return true;
            default:
                return false;
        }
    }

    /**
     * Is the given Vertical AlignStyle valid for this button.
     * @param i the given Vertical AlignStyle
     * @return true if the given Vertical AlignStyle is acceptable, false if not.
     */
    protected boolean isValidVerticalAlignStyle(int i)
    {
        switch(i)
        {
            case ALIGN_TOP:
            case ALIGN_CENTERED:
            case ALIGN_BOTTOM:
                return true;
            default:
                return false;
        }
    }

    /**
     * Draws the button in the buttonImage offscreen image.
     * This should only be called after the component is added to a container,
     * to avoid a NullPointerException when accessing FontMetrics.
     * @see symantec.itools.awt.ButtonBase#updateButtonImage
     */
    protected void updateButtonImage()
    {
        super.updateButtonImage();

        FontMetrics fm = buttonImageGraphics.getFontMetrics();
        Color tempColor;
        int xPos = 0;
        int yPos = 0;
        int labelWidth = 0;
        Dimension s = size();

        //Make sure we don't cause a NullPointerException when accessing the string width.
        if(!(sLabelButton == null || sLabelButton.equals("")))
            labelWidth = fm.stringWidth(sLabelButton);

        if(isEnabled())
        {
            if(pressed)
                tempColor = pressedTextColor;
            else
                tempColor = textColor;
        }
        else
        {
            tempColor = disabledTextColor;
        }


        switch(hAlignStyle)
        {
            case ALIGN_LEFT:
                //Align with the left edge and add a one pixel margin.
                xPos = bevel + 2;
                break;
            case ALIGN_RIGHT:
                //Align with the right edge and add a one pixel margin.
                xPos = s.width - 3 - bevel - labelWidth;
               break;
            case ALIGN_CENTERED:
                xPos = (s.width - labelWidth) >> 1;
                break;
        }

        switch(vAlignStyle)
        {
            case ALIGN_TOP:
                //Align with the top edge and add a one pixel margin.
                yPos = bevel + 2 + fm.getAscent();
                break;
            case ALIGN_BOTTOM:
                //Align with the bottom edge and add a one pixel margin.
                yPos = s.height - 3 - bevel - fm.getDescent();
                break;
            case ALIGN_CENTERED:
                yPos = (s.height + fm.getAscent()) >> 1;
                break;
        }

        buttonImageGraphics.setColor(tempColor);
        buttonImageGraphics.drawString(sLabelButton, xPos + pressedAdjustment, yPos + pressedAdjustment);
    }

    /**
     * The button label text.
     */
    protected String sLabelButton;
    /**
     * The text vertical alignment style.
     * The value is one of: ALIGN_TOP, ALIGN_CENTERED, or ALIGN_BOTTOM
     * @see #getVerticalAlignStyle
     * @see #setVerticalAlignStyle
     * @see #ALIGN_TOP
     * @see AlignStyle#ALIGN_CENTERED
     * @see #ALIGN_BOTTOM
     */
    protected int vAlignStyle;
    /**
     * The text horizontal alignment style.
     * The value is one of: ALIGN_LEFT, ALIGN_CENTERED, or ALIGN_RIGHT
     * @see #getAlignStyle
     * @see #setAlignStyle
     * @see AlignStyle#ALIGN_LEFT
     * @see AlignStyle#ALIGN_CENTERED
     * @see AlignStyle#ALIGN_RIGHT
     */
    protected int hAlignStyle;
    /**
     * The color used for text when this component is enabled.
     * @see #getTextColor
     * @see #setTextColor
     */
    protected Color textColor            = null;
    /**
     * The color used for text when this component is pressed.
     * This color is automatically determined.
     */
    protected Color pressedTextColor    = null;
    /**
     * The color used for text when this component is disabled.
     * This color is automatically determined.
     */
    protected Color disabledTextColor    = null;

    /**
     * Error strings.
     */
    transient protected ResourceBundle errors;

    private HAVeto    horizontalVeto    = null;
    private VAVeto    verticalVeto    = null;
    private symantec.itools.beans.VetoableChangeSupport vetos = new symantec.itools.beans.VetoableChangeSupport(this);
    private symantec.itools.beans.PropertyChangeSupport changes = new symantec.itools.beans.PropertyChangeSupport(this);
}