source: trunk/src/org/expeditee/gio/swing/SwingTextLayoutManager.java@ 1184

package org.expeditee.gio.swing;

import java.awt.Rectangle;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextAttribute;
import java.text.AttributedString;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;

import org.expeditee.core.Font;
import org.expeditee.core.Line;
import org.expeditee.core.Point;
import org.expeditee.core.TextHitInfo;
import org.expeditee.core.TextLayout;
import org.expeditee.core.bounds.AxisAlignedBoxBounds;
import org.expeditee.gio.TextLayoutManager;

/**
 * TODO: Comment. cts16
 * 
 * @author cts16
 */
public class SwingTextLayoutManager extends TextLayoutManager
{
        /** Singleton instance. */
        private static SwingTextLayoutManager _instance = null;
        
        /** Singleton instantiator. */
        public static SwingTextLayoutManager getInstance()
        {
                if (_instance == null) {
                        _instance = new SwingTextLayoutManager();
                }
                
                return _instance;
        }
        
        /** Mapping from Expeditee text-layout objects to swing equivalents. */
        private HashMap<Long, java.awt.font.TextLayout> _layoutMap;
        
        private SwingTextLayoutManager()
        {
                _layoutMap = new HashMap<Long, java.awt.font.TextLayout>();
        }
        
        private synchronized void register(TextLayout layout, java.awt.font.TextLayout swingLayout)
        {
                if (layout == null || swingLayout == null) {
                        return;
                }
                
                _layoutMap.put(layout.getHandle(), swingLayout);
        }
        
        public synchronized java.awt.font.TextLayout getInternalLayout(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return _layoutMap.get(layout.getHandle());
        }

        public synchronized boolean isTextLayoutValid(TextLayout layout)
        {
                if (layout == null) {
                        return false;
                }
                
                return _layoutMap.containsKey(layout.getHandle());
        }

        @Override
        public float getAdvance(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return Float.NaN;
                }
                
                return getInternalLayout(layout).getAdvance();
        }

        @Override
        public int getCharacterCount(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return 0;
                }
                
                return getInternalLayout(layout).getCharacterCount();
        }

        @Override
        public TextHitInfo getNextLeftHit(TextLayout layout, int offset)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingTextHitInfo(getInternalLayout(layout).getNextLeftHit(offset));
        }

        @Override
        public TextHitInfo getNextLeftHit(TextLayout layout, TextHitInfo hit)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingTextHitInfo(getInternalLayout(layout).getNextLeftHit(SwingConversions.toSwingTextHitInfo(hit)));
        }

        @Override
        public TextHitInfo getNextRightHit(TextLayout layout, int offset)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingTextHitInfo(getInternalLayout(layout).getNextRightHit(offset));
        }

        @Override
        public TextHitInfo getNextRightHit(TextLayout layout, TextHitInfo hit)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingTextHitInfo(getInternalLayout(layout).getNextRightHit(SwingConversions.toSwingTextHitInfo(hit)));
        }

        @Override
        public float[] getCaretInfo(TextLayout layout, TextHitInfo hit)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return getInternalLayout(layout).getCaretInfo(SwingConversions.toSwingTextHitInfo(hit));
        }

        @Override
        public TextHitInfo hitTestChar(TextLayout layout, float x, float y)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingTextHitInfo(getInternalLayout(layout).hitTestChar(x, y));
        }

        @Override
        public AxisAlignedBoxBounds getPixelBounds(TextLayout layout, float x, float y)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                return SwingConversions.fromSwingRectangle(getInternalLayout(layout).getPixelBounds(null, x, y));
        }

        @Override
        public AxisAlignedBoxBounds getLogicalHighlightShape(TextLayout layout, int firstEndpoint, int secondEndpoint)
        {
                if (!isTextLayoutValid(layout)) {
                        return null;
                }
                
                Rectangle rect = getInternalLayout(layout).getLogicalHighlightShape(firstEndpoint, secondEndpoint).getBounds();
                
                return SwingConversions.fromSwingRectangle(rect);
        }

        @Override
        public float getAscent(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return Float.NaN;
                }
                
                return getInternalLayout(layout).getAscent();
        }

        @Override
        public float getDescent(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return Float.NaN;
                }
                
                return getInternalLayout(layout).getDescent();
        }

        @Override
        public float getLeading(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return Float.NaN;
                }
                
                return getInternalLayout(layout).getLeading();
        }

        @Override
        public synchronized void releaseLayout(TextLayout layout)
        {
                if (!isTextLayoutValid(layout)) {
                        return;
                }
                
                _layoutMap.remove(layout.getHandle());
        }
        
        @Override
        public List<TextLayout> layoutString(String string, Font font, Point start, Line[] lineBreakers, int widthLimit, int lineSpacing, boolean dontBreakWords, boolean fullJustify)
        {
                if (string == null || font == null || start == null) {
                        return null;
                }
                
                // Make sure we have a swing font to use
                java.awt.Font swingFont;
                SwingFontManager fontManager = SwingMiscManager.getIfUsingSwingFontManager();
                if (fontManager == null) {
                        return null;
                }
                swingFont = fontManager.getInternalFont(font);
                if (swingFont == null) {
                        return null;
                }
                
                // Temporary list to accumulate the TextLayouts in to
                List<java.awt.font.TextLayout> layouts = new LinkedList<java.awt.font.TextLayout>();
                List<Integer> offsets = new LinkedList<Integer>();
                offsets.add(0);
                List<Point> positions = new LinkedList<Point>();
                positions.add(new Point(start));
                
                // Set up a line-break measurer to layout the text
                AttributedString paragraphText = new AttributedString(string);
                paragraphText.addAttribute(TextAttribute.FONT, swingFont);
                FontRenderContext frc = new FontRenderContext(null, true, true);
                LineBreakMeasurer lineBreaker = new LineBreakMeasurer(paragraphText.getIterator(), frc);
                lineBreaker.setPosition(0);
                
                // Keep laying out text until the input string is completely laid out
                while (lineBreaker.getPosition() < string.length()) {
                        
                        int width = widthLimit;
                        if (lineBreakers != null) {
                                width = Math.min(width, (int) getLineWidth(start, lineBreakers));
                        }
                        
                        int end = string.length();
                        for (int i = lineBreaker.getPosition() + 1; i < string.length(); i++) {
                                if (string.charAt(i) == '\n') {
                                        end = i;
                                        break;
                                }
                        }
                        
                        java.awt.font.TextLayout layout = lineBreaker.nextLayout(width, end, dontBreakWords);
                        
                        // If it's impossible to layout any more text without breaking a word, just do it
                        if (layout == null && width == widthLimit) {
                                layout = lineBreaker.nextLayout(Integer.MAX_VALUE, end, false);
                                // If still impossible, give up
                                
                                if (layout == null) {
                                        break;
                                }
                        }

                        if (fullJustify && lineBreaker.getPosition() < string.length()) {
                                layout = layout.getJustifiedLayout(width);
                        }
                        
                        layouts.add(layout);
                        offsets.add(lineBreaker.getPosition());
                        int lineDrop = (int) (layout.getAscent() + layout.getDescent());
                        if (lineSpacing >= 0) {
                                lineDrop += lineSpacing; 
                        } else {
                                lineDrop += layout.getLeading();
                        }
                        start.setY(start.getY() + lineDrop);
                        positions.add(new Point(start));
                }
                
                // Convert the accumulated list into an internal-type array
                List<TextLayout> ret = new LinkedList<TextLayout>();
                for (int i = 0; i < layouts.size(); i++) {
                        java.awt.font.TextLayout swingLayout = layouts.get(i);
                        int startCharIndex = offsets.get(i);
                        int endCharIndex = offsets.get(i + 1) - 1;
                        String line = string.substring(startCharIndex, endCharIndex + 1);
                        TextLayout layout = TextLayout.get(line, font, startCharIndex, endCharIndex);
                        register(layout, swingLayout);
                        ret.add(layout);
                }
                
                return ret;
                
        }

        @Override
        public int getStringWidth(Font font, String string)
        {
                SwingGraphicsManager g = SwingMiscManager.getIfUsingSwingGraphicsManager();
                SwingFontManager f = SwingMiscManager.getIfUsingSwingFontManager();
                
                if (g == null || f == null) {
                        return -1;
                }
                
                if (font != null) {
                        return g.getFontMetrics(f.getInternalFont(font)).stringWidth(string);
                } else {
                        return g.getFontMetrics(f.getInternalFont(f.getDefaultFont())).stringWidth(string);
                }
                
        }

}