synthstyle.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

    }

    /**
     * Returns the default value for the specified property, or null if there
     * is no default for the specified value.
     */
    private static Object getDefaultValue(Object key) {
        synchronized(SynthStyle.class) {
            if (DEFAULT_VALUES == null) {
                DEFAULT_VALUES = new HashMap();
                populateDefaultValues();
            }
            Object value = DEFAULT_VALUES.get(key);
            if (value instanceof UIDefaults.LazyValue) {
                value = ((UIDefaults.LazyValue)value).createValue(null);
                DEFAULT_VALUES.put(key, value);
            }
            return value;
        }
    }

    /**
     * Constructs a SynthStyle.
     */
    public SynthStyle() {
    }

    /**
     * Returns the <code>SynthGraphicUtils</code> for the specified context.
     *
     * @param context SynthContext identifying requester
     * @return SynthGraphicsUtils
     */
    public SynthGraphicsUtils getGraphicsUtils(SynthContext context) {
        return SYNTH_GRAPHICS;
    }

    /**
     * Returns the color for the specified state. This gives precedence to
     * foreground and background of the <code>JComponent</code>. If the
     * <code>Color</code> from the <code>JComponent</code> is not appropriate,
     * or not used, this will invoke <code>getColorForState</code>. Subclasses
     * should generally not have to override this, instead override
     * {@link #getColorForState}.
     *
     * @param context SynthContext identifying requester
     * @param type Type of color being requested.
     * @return Color
     */
    public Color getColor(SynthContext context, ColorType type) {
        JComponent c = context.getComponent();
        Region id = context.getRegion();

        if ((context.getComponentState() & SynthConstants.DISABLED) != 0) {
            //This component is disabled, so return the disabled color.
            //In some cases this means ignoring the color specified by the
            //developer on the component. In other cases it means using a
            //specified disabledTextColor, such as on JTextComponents.
            //For example, JLabel doesn't specify a disabled color that the
            //developer can set, yet it should have a disabled color to the
            //text when the label is disabled. This code allows for that.
            if (c instanceof JTextComponent) {
                JTextComponent txt = (JTextComponent)c;
                Color disabledColor = txt.getDisabledTextColor();
                if (disabledColor == null || disabledColor instanceof UIResource) {
                    return getColorForState(context, type);
                }
            } else if (c instanceof JLabel 
                    && (type == ColorType.FOREGROUND || type == ColorType.TEXT_FOREGROUND)){
                return getColorForState(context, type);
            }
        }
        
        // If the developer has specified a color, prefer it. Otherwise, get
        // the color for the state.
        Color color = null;
        if (!id.isSubregion()) {
            if (type == ColorType.BACKGROUND) {
                color = c.getBackground();
            }
            else if (type == ColorType.FOREGROUND) {
                color = c.getForeground();
            }
            else if (type == ColorType.TEXT_FOREGROUND) {
                color = c.getForeground();
            }
        }
        
        if (color == null || color instanceof UIResource) {
            // Then use what we've locally defined
            color = getColorForState(context, type);
        }
        
        if (color == null) {
            // No color, fallback to that of the widget.
            if (type == ColorType.BACKGROUND ||
                        type == ColorType.TEXT_BACKGROUND) {
                return c.getBackground();
            }
            else if (type == ColorType.FOREGROUND ||
                     type == ColorType.TEXT_FOREGROUND) {
                return c.getForeground();
            }
        }
        return color;
    }

    /**
     * Returns the color for the specified state. This should NOT call any
     * methods on the <code>JComponent</code>.
     *
     * @param context SynthContext identifying requester
     * @param type Type of color being requested.
     * @return Color to render with
     */
    protected abstract Color getColorForState(SynthContext context,
                                              ColorType type);

    /**
     * Returns the Font for the specified state. This redirects to the
     * <code>JComponent</code> from the <code>context</code> as necessary.
     * If this does not redirect
     * to the JComponent {@link #getFontForState} is invoked.
     *
     * @param context SynthContext identifying requester
     * @return Font to render with
     */
    public Font getFont(SynthContext context) {
        JComponent c = context.getComponent();
        if (context.getComponentState() == SynthConstants.ENABLED) {
            return c.getFont();
        }
        Font cFont = c.getFont();
        if (cFont != null && !(cFont instanceof UIResource)) {
            return cFont;
        }
        return getFontForState(context);
    }

    /**
     * Returns the font for the specified state. This should NOT call any
     * method on the <code>JComponent</code>.
     *
     * @param context SynthContext identifying requester
     * @return Font to render with
     */
    protected abstract Font getFontForState(SynthContext context);

    /**
     * Returns the Insets that are used to calculate sizing information.
     *
     * @param context SynthContext identifying requester
     * @param insets Insets to place return value in.
     * @return Sizing Insets.
     */
    public Insets getInsets(SynthContext context, Insets insets) {
        if (insets == null) {
            insets = new Insets(0, 0, 0, 0);
        }
        insets.top = insets.bottom = insets.left = insets.right = 0;
        return insets;
    }

    /**
     * Returns the <code>SynthPainter</code> that will be used for painting.
     * This may return null.
     *
     * @param context SynthContext identifying requester
     * @return SynthPainter to use 
     */
    public SynthPainter getPainter(SynthContext context) {
        return null;
    }

    /**
     * Returns true if the region is opaque.
     *
     * @param context SynthContext identifying requester
     * @return true if region is opaque.
     */
    public boolean isOpaque(SynthContext context) {
        return true;
    }

    /**
     * Getter for a region specific style property.
     *
     * @param context SynthContext identifying requester
     * @param key Property being requested.
     * @return Value of the named property
     */
    public Object get(SynthContext context, Object key) {
        return getDefaultValue(key);
    }

    void installDefaults(SynthContext context, SynthUI ui) {
        // Special case the Border as this will likely change when the LAF
        // can have more control over this.
        if (!context.isSubregion()) {
            JComponent c = context.getComponent();
            Border border = c.getBorder();

            if (border == null || border instanceof UIResource) {
                c.setBorder(new SynthBorder(ui, getInsets(context, null)));
            }
        }
        installDefaults(context);
    }

    /**
     * Installs the necessary state from this Style on the
     * <code>JComponent</code> from <code>context</code>.
     *
     * @param context SynthContext identifying component to install properties
     *        to.
     */
    public void installDefaults(SynthContext context) {
        if (!context.isSubregion()) {
            JComponent c = context.getComponent();
            Region region = context.getRegion();
            Font font = c.getFont();

            if (font == null || (font instanceof UIResource)) {
                c.setFont(getFontForState(context));
            }
            Color background = c.getBackground();
            if (background == null || (background instanceof UIResource)) {
                c.setBackground(getColorForState(context,
                                                 ColorType.BACKGROUND));
            }
            Color foreground = c.getForeground();
            if (foreground == null || (foreground instanceof UIResource)) {
                c.setForeground(getColorForState(context, 
                         ColorType.FOREGROUND));
            }
            LookAndFeel.installProperty(c, "opaque", Boolean.valueOf(isOpaque(context)));
        }
    }

    /**
     * Uninstalls any state that this style installed on
     * the <code>JComponent</code> from <code>context</code>.
     * <p>
     * Styles should NOT depend upon this being called, in certain cases
     * it may never be called.
     *
     * @param context SynthContext identifying component to install properties
     *        to.
     */
    public void uninstallDefaults(SynthContext context) {
        if (!context.isSubregion()) {
            // NOTE: because getForeground, getBackground and getFont will look
            // at the parent Container, if we set them to null it may
            // mean we they return a non-null and non-UIResource value
            // preventing install from correctly settings its colors/font. For
            // this reason we do not uninstall the fg/bg/font.

            JComponent c = context.getComponent();
            Border border = c.getBorder();

            if (border instanceof UIResource) {
                c.setBorder(null);
            }
        }
    }

    /**
     * Convenience method to get a specific style property whose value is
     * a <code>Number</code>. If the value is a <code>Number</code>,
     * <code>intValue</code> is returned, otherwise <code>defaultValue</code>
     * is returned.
     *
     * @param context SynthContext identifying requester
     * @param key Property being requested.
     * @param defaultValue Value to return if the property has not been
     *        specified, or is not a Number
     * @return Value of the named property
     */
    public int getInt(SynthContext context, Object key, int defaultValue) {
        Object value = get(context, key);

        if (value instanceof Number) {
            return ((Number)value).intValue();
        }
        return defaultValue;
    }

    /**
     * Convenience method to get a specific style property whose value is
     * an Boolean.
     *
     * @param context SynthContext identifying requester
     * @param key Property being requested.
     * @param defaultValue Value to return if the property has not been
     *        specified, or is not a Boolean
     * @return Value of the named property
     */
    public boolean getBoolean(SynthContext context, Object key,
                              boolean defaultValue) {
        Object value = get(context, key);

        if (value instanceof Boolean) {
            return ((Boolean)value).booleanValue();
        }
        return defaultValue;
    }

    /**
     * Convenience method to get a specific style property whose value is
     * an Icon.
     *
     * @param context SynthContext identifying requester
     * @param key Property being requested.
     * @return Value of the named property, or null if not specified
     */
    public Icon getIcon(SynthContext context, Object key) {
        Object value = get(context, key);

        if (value instanceof Icon) {
            return (Icon)value;
        }
        return null;
    }

    /**
     * Convenience method to get a specific style property whose value is
     * a String.
     *
     * @param context SynthContext identifying requester
     * @param key Property being requested.
     * @param defaultValue Value to return if the property has not been
     *        specified, or is not a String
     * @return Value of the named property
     */
    public String getString(SynthContext context, Object key,
                              String defaultValue) {
        Object value = get(context, key);

        if (value instanceof String) {
            return (String)value;
        }
        return defaultValue;
    }
}