source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/focusabletip/TipUtil.java@ 25584

/*
 * 08/13/2009
 *
 * TipUtil.java - Utility methods for homemade tool tips.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rsyntaxtextarea.focusabletip;

import java.awt.Color;
import java.awt.Font;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Rectangle;
import java.awt.SystemColor;
import javax.swing.BorderFactory;
import javax.swing.JEditorPane;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.plaf.ColorUIResource;
import javax.swing.text.html.HTMLDocument;


/**
 * Static utility methods for focusable tips.
 *
 * @author Robert Futrell
 * @version 1.0
 */
public class TipUtil {


    private TipUtil() {
    }


    /**
     * Returns a hex string for the specified color, suitable for HTML.
     *
     * @param c The color.
     * @return The string representation, in the form "<code>#rrggbb</code>",
     *         or <code>null</code> if <code>c</code> is <code>null</code>.
     */
    private static final String getHexString(Color c) {

        if (c==null) {
            return null;
        }

        StringBuffer sb = new StringBuffer("#");
        int r = c.getRed();
        if (r<16) {
            sb.append('0');
        }
        sb.append(Integer.toHexString(r));
        int g = c.getGreen();
        if (g<16) {
            sb.append('0');
        }
        sb.append(Integer.toHexString(g));
        int b = c.getBlue();
        if (b<16) {
            sb.append('0');
        }
        sb.append(Integer.toHexString(b));

        return sb.toString();

    }


    /**
     * Returns the screen coordinates for the monitor that contains the
     * specified point.  This is useful for setups with multiple monitors,
     * to ensure that popup windows are positioned properly.
     *
     * @param x The x-coordinate, in screen coordinates.
     * @param y The y-coordinate, in screen coordinates.
     * @return The bounds of the monitor that contains the specified point.
     */
    public static Rectangle getScreenBoundsForPoint(int x, int y) {
        GraphicsEnvironment env = GraphicsEnvironment.
                                        getLocalGraphicsEnvironment();
        GraphicsDevice[] devices = env.getScreenDevices();
        for (int i=0; i<devices.length; i++) {
            GraphicsConfiguration[] configs = devices[i].getConfigurations();
            for (int j=0; j<configs.length; j++) {
                Rectangle gcBounds = configs[j].getBounds();
                if (gcBounds.contains(x, y)) {
                    return gcBounds;
                }
            }
        }
        // If point is outside all monitors, default to default monitor (?)
        return env.getMaximumWindowBounds();
    }


    /**
     * Returns the default background color to use for tool tip windows.
     *
     * @return The default background color.
     */
    public static Color getToolTipBackground() {

        Color c = UIManager.getColor("ToolTip.background");

        // Tooltip.background is wrong color on Nimbus (!)
        if (c==null || isNimbusLookAndFeel()) {
            c = UIManager.getColor("info"); // Used by Nimbus (and others)
            if (c==null) {
                c = SystemColor.info; // System default
            }
        }

        // Workaround for a bug (?) with Nimbus - calling JLabel.setBackground()
        // with a ColorUIResource does nothing, must be a normal Color
        if (c instanceof ColorUIResource) {
            c = new Color(c.getRGB());
        }

        return c;

    }


    /**
     * Returns the border used by tool tips in this look and feel.
     *
     * @return The border.
     */
    public static Border getToolTipBorder() {

        Border border = UIManager.getBorder("ToolTip.border");

        if (border==null || isNimbusLookAndFeel()) {
            border = UIManager.getBorder("nimbusBorder");
            if (border==null) {
                border = BorderFactory.createLineBorder(SystemColor.controlDkShadow);
            }
        }

        return border;

    }


    /**
     * Returns whether a color is a Nimbus DerivedColor, which is troublesome
     * in that it doesn't use its RGB values (uses HSB instead?) and so
     * querying them is useless.
     *
     * @param c The color to check.
     * @return Whether it is a DerivedColor
     */
    private static final boolean isDerivedColor(Color c) {
        return c!=null && c.getClass().getName().endsWith(".DerivedColor");
    }


    /**
     * Returns whether the Nimbus Look and Feel is installed.
     *
     * @return Whether the current LAF is Nimbus.
     */
    private static final boolean isNimbusLookAndFeel() {
        return UIManager.getLookAndFeel().getName().equals("Nimbus");
    }


    /**
     * Tweaks a <code>JEditorPane</code> so it can be used to render the
     * content in a focusable pseudo-tool tip.  It is assumed that the editor
     * pane is using an <code>HTMLDocument</code>.
     *
     * @param textArea The editor pane to tweak.
     */
    public static void tweakTipEditorPane(JEditorPane textArea) {

        // Jump through a few hoops to get things looking nice in Nimbus
        boolean isNimbus = isNimbusLookAndFeel();
        if (isNimbus) {
            Color selBG = textArea.getSelectionColor();
            Color selFG = textArea.getSelectedTextColor();
            textArea.setUI(new javax.swing.plaf.basic.BasicEditorPaneUI());
            textArea.setSelectedTextColor(selFG);
            textArea.setSelectionColor(selBG);
        }

        textArea.setEditable(false); // Required for links to work!
        textArea.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

        // Make selection visible even though we are not (initially) focusable.
        textArea.getCaret().setSelectionVisible(true);

        // Set the foreground color.  Important because when rendering HTML,
        // default foreground becomes black, which may not match all LAF's
        // (e.g. Substance).
        Color fg = UIManager.getColor("Label.foreground");
        if (fg==null || (isNimbus && isDerivedColor(fg))) {
            fg = SystemColor.textText;
        }
        textArea.setForeground(fg);

        // Make it use the "tool tip" background color.
        textArea.setBackground(TipUtil.getToolTipBackground());

        // Force JEditorPane to use a certain font even in HTML.
        // All standard LookAndFeels, even Nimbus (!), define Label.font.
        Font font = UIManager.getFont("Label.font");
        if (font == null) { // Try to make a sensible default
            font = new Font("SansSerif", Font.PLAIN, 12);
        }
        HTMLDocument doc = (HTMLDocument) textArea.getDocument();
        doc.getStyleSheet().addRule(
                "body { font-family: " + font.getFamily() +
                        "; font-size: " + font.getSize() + "pt" +
                        "; color: " + getHexString(fg) + "; }");

    }


}