source: main/trunk/greenstone3/src/java/org/greenstone/applet/phind/JResultCanvas.java@ 38799

/**********************************************************************
 *
 * ResultCanvas.java -- a Canvas onto which a phrase list is drawn
 *
 * Copyright 1997-2000 Gordon W. Paynter
 * Copyright 2000 The New Zealand Digital Library Project
 *
 * A component of the Greenstone digital library software
 * from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *********************************************************************/

/*********************************************************************

This class is used in the Phind java applet (Phind.java).

The results of a query are displayed on a ResultCanvas object.  Each 
entry in the result list is stored in a ResultItem, and the ResultCanvas 
contains a Vector of ResultItems.

Each ResultCanvas is embedded in a ResultBox alongside a Scrollbar.  
When the ResultCanvas is drawn, it looks at the scrollbar, calculates 
which ResultItems are visible, then draws them on the screen.

**********************************************************************/

package org.greenstone.applet.phind;

import javax.swing.JScrollBar;
import javax.swing.JComponent;

import java.awt.Graphics;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Dimension;
import java.awt.Color;
import java.util.Vector;
import java.awt.Image;
//import java.awt.Event;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import java.net.URL;
import java.util.Date;

public class JResultCanvas extends JComponent {    

    // Other objects associated with this 
    JPhind phind;
    JResultBox parent;
    JScrollBar scrollbar;
    
    // fonts and font spacings to use
    Font areaPlain, areaBold;
    int lineSpacing;
    
    // The items to display on this canvas
    int numberOfItems;
    int firstItemDisplayed;
    int itemSelected;
    Vector<ResultItem> items;
    
    // the background image
    public static Image backgroundImage;
    
    
    // Create a ResultCanvas from the ResultBox which is its parent.
    JResultCanvas(JResultBox p) {
    
    parent = p;
    phind = p.phind;
    scrollbar = p.s;
    parent.disableScrollbar();

    areaPlain = phind.plainFont;
    areaBold  = phind.boldFont;

    lineSpacing = phind.fontSize + 2;

    items = new Vector<ResultItem>();
    numberOfItems = 0;
    firstItemDisplayed = 0;
    itemSelected = -1;
    
    if (backgroundImage == null) {
        backgroundImage = p.phind.backgroundImage;
    }

    // add a mouse listener for the mouse clicks. we only want to override
    // one method, so we use the adaptor class
    addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent evt) {
            JResultCanvas.this.mouseClicked(evt); // custom method called mouseClicked
        }
        });
    

    }

    void resetCanvas( ) {
    items.removeAllElements();
    numberOfItems = 0;
    repaint();
    }


    // Add a new search result.
    // Return true if successful, otherwise false.
    boolean addResultItem( ResultItem item ) {
 
    // Add a new result, in sorted order.
    // First sort key is item kind (lowest first),
    // second is frequency (highest first).
    // This is not efficient, but I don't care right now.
    int index = 0;
    while ((index < numberOfItems) &&
           ((item.sort < items.elementAt(index).sort) ||
        ((item.sort == items.elementAt(index).sort) &&
         (item.frequency <= items.elementAt(index).frequency)))) {
        index++;
    }
    items.insertElementAt(item,index);
    numberOfItems++;
    return true;
    }


    // Update more phrases/documents/links markers
    void updateMarkers() {
    updateMorePhrasesMarker();
    updateMoreDocumentsMarker();
    updateMoreLinksMarker();
    }

    // Make sure the more Phrases item only appears in the list
    // if it is meant to.
    void updateMorePhrasesMarker() {
    
     System.out.println("updateMorePhrasesMarker() ");
     System.out.println("expansions retrieved = "+parent.expansionsRetrieved +" num expansions = "+parent.numberOfExpansions);
    // look for a marker
    boolean found = false;
    int index = 0;
    while (!found && (index < numberOfItems)) {
        if (items.elementAt(index).isMorePhrases()) {
        found = true;
        } else {
        index++;
        }
    }

    if (parent.expansionsRetrieved == parent.numberOfExpansions) {
        // there should be no marker
        if (found) {
        items.removeElementAt(index);
        numberOfItems--;
        }

    } else if (parent.expansionsRetrieved < parent.numberOfExpansions) {
        if (!found) {
        ResultItem ri = new ResultItem(ResultItem.morePhrases);
        addResultItem(ri);
        }
    }
    }


    // Make sure the more documents marker appears when required
    void updateMoreDocumentsMarker() {
    
    // System.out.println("updateMoreDocumentsMarker() ");

    // look for a marker
    boolean found = false;
    int index = 0;
    while (!found && (index < numberOfItems)) {
        if (items.elementAt(index).isMoreDocuments()) {
        found = true;
        } else {
        index++;
        }
    }

    if (parent.documentsRetrieved == parent.numberOfDocuments) {
        // there should be no marker
        if (found) {
        items.removeElementAt(index);
        numberOfItems--;
        }

    } else if (parent.documentsRetrieved < parent.numberOfDocuments) {
        // there should be a marker
        if (!found) {
        ResultItem ri = new ResultItem(ResultItem.moreDocuments);
        addResultItem(ri);
        }
    }
    }

      
    // Make sure the more links marker appears when required
    void updateMoreLinksMarker() {
    
    // System.out.println("updateMoreLinksMarker() ");

    // look for a marker
    boolean found = false;
    int index = 0;
    while (!found && (index < numberOfItems)) {
        if (items.elementAt(index).isMoreLinks()) {
        found = true;
        } else {
        index++;
        }
    }

    if (parent.thesaurusLinksRetrieved == parent.numberOfThesaurusLinks) {
        // there should be no marker
        if (found) {
        items.removeElementAt(index);
        numberOfItems--;
        }

    } else if (parent.thesaurusLinksRetrieved < parent.numberOfThesaurusLinks) {
        // there should be a marker
        if (!found) {
        ResultItem ri = new ResultItem(ResultItem.moreLinks);
        addResultItem(ri);
        }
    }
    }

    public void paintComponent(Graphics g) {
    super.paintComponent(g);

    // calculate the canvas size, margins, and spacing
    
    // Note: the size() method is deprecated, but getSize fails in NetScape 4
    Dimension canvasSize = getSize();
    
    g.setFont(areaPlain);
    int space = g.getFontMetrics().stringWidth(" ");
    int nought = g.getFontMetrics().stringWidth("0");

    int firstColumnWidth = phind.column_1_width * nought;
    int secondColumnWidth = phind.column_2_width * nought;
    int columnWidth = firstColumnWidth + secondColumnWidth;

    int firstColumnLeft = canvasSize.width - columnWidth;
    int secondColumnLeft = firstColumnLeft + firstColumnWidth;

    int mainLeftMargin = 0;
    int mainRightMargin = firstColumnLeft;

    // the number of items that will fit on the canvas
    int visible = canvasSize.height / lineSpacing;

    // calculate the first item to output
    int scrollValue = scrollbar.getValue();
    if (numberOfItems <= visible) {
        scrollValue = 0;
    } else if (scrollValue > (numberOfItems - visible)) {
        scrollValue = numberOfItems - visible;
    } 
    firstItemDisplayed = scrollValue;

    // Draw the phrase area
    Color fore = phind.panel_fg;
    Color back = phind.panel_bg;


    // draw the background
    if (phind.showImage) {
        try {
        g.drawImage(backgroundImage, 
                mainLeftMargin, 0, mainRightMargin, canvasSize.height, 
                back, null);
        } catch (Exception e) {
        phind.showImage = false;
        System.err.println("JResultCanvas paint error: " + e); 
        g.setColor(back);
        g.fillRect(0, 0, canvasSize.width, canvasSize.height);
        }
    } else {
        g.setColor(back);
        g.fillRect(0, 0, canvasSize.width, canvasSize.height);
    }
    
    // If there are no phrases, output a brief explanation.
    if (numberOfItems == 0) {
        g.drawString("No phrases match this query.", mainLeftMargin + 10, lineSpacing);
    }

    // Output each of the visible ResultItems
    ResultItem result;
    int tab, i, y = 0;
    int center = mainLeftMargin 
        + ((mainRightMargin - mainLeftMargin 
        - g.getFontMetrics().stringWidth(parent.searchPhrase)) / 2);
    int thesColumn = mainLeftMargin + firstColumnWidth 
        + g.getFontMetrics().stringWidth("Narrower term");

    String body, prefix, suffix;
    
    for (i = scrollValue; 
         (i < numberOfItems) && (y + lineSpacing < canvasSize.height); i++) {

        // Get the resultItem to output
        result = items.elementAt(i);
        
        // Graphics settings for drawing this line
        y += lineSpacing;
        g.setFont(areaPlain);

        // Highlight the selected phrase.
        if (i == itemSelected) {
        g.setColor(phind.highlight_bg);
        g.fillRect(mainLeftMargin, y-lineSpacing+2, mainRightMargin, lineSpacing);
        }

        // Draw the item

        // Draw a phrase item
        if (result.isPhrase()) {
        prefix = result.prefixText();
        body = result.mainText();
        suffix = result.suffixText();
        
        g.setColor(phind.expansion_fg);
        g.setFont(areaPlain);
        tab = center - g.getFontMetrics().stringWidth(prefix) - space;
        g.drawString(prefix, tab, y);
        
        g.setFont(areaBold);
        g.drawString(body, center, y);
        
        tab = center + space + g.getFontMetrics().stringWidth(body);
        g.setFont(areaPlain);
        g.drawString(suffix, tab, y);
    
        } 

        // Draw a document item
        else if (result.isDocument()){
        body = result.mainText();

        g.setColor(phind.document_fg);
        g.setFont(areaPlain);
        tab = (mainRightMargin - g.getFontMetrics().stringWidth(body)) / 2;
        g.drawString(body, tab, y);
      
        } 
    
        // Draw a thesaurus link item
        else if (result.isLink()){
        prefix = result.prefixText() + ":";
        body = result.mainText();
        tab = thesColumn - g.getFontMetrics().stringWidth(prefix) - space;

        g.setColor(phind.thesaurus_fg);
        g.setFont(areaPlain);
        g.drawString(prefix, tab, y);
        g.setFont(areaBold);
        g.drawString(body, thesColumn, y);
        } 
        
        // Draw a "more phrases/documents/links" marker
        else if (result.isMorePhrases() 
             || result.isMoreDocuments() 
             || result.isMoreLinks()){
        body = result.mainText();
        
        if (result.isMorePhrases()) {
            g.setColor(phind.expansion_bar_bg);
        } else if (result.isMoreDocuments()) {
            g.setColor(phind.document_bar_bg);
        } else {
            g.setColor(phind.thesaurus_bar_bg);         
        }
        g.fillRect(mainLeftMargin, y-lineSpacing+2, mainRightMargin, lineSpacing);

        if (result.isMorePhrases()) {
            g.setColor(phind.expansion_bar_fg);
        } else if (result.isMoreDocuments()) {
            g.setColor(phind.document_bar_fg);
        } else {
            g.setColor(phind.thesaurus_bar_fg);         
        }
        g.setFont(areaPlain);
        tab = (mainRightMargin - g.getFontMetrics().stringWidth(body)) / 2;
        g.drawString(body, tab, y);
        } 
    }

    // Draw the frequecy columns

    // column backgrounds
    g.setColor(phind.column_1_bg);
    g.fillRect(firstColumnLeft, 0, firstColumnWidth, canvasSize.height);
    g.setColor(phind.column_2_bg);
    g.fillRect(secondColumnLeft, 0, secondColumnWidth, canvasSize.height);

    // fill in the numbers
    g.setColor(phind.column_1_fg);
    g.setFont(areaPlain);
    y = 0;
    String docsText, freqText;

    for (i = scrollValue; 
         (i < numberOfItems) && (y + lineSpacing < canvasSize.height); i++) {
        
        // Get the resultItem to output
        result = items.elementAt(i);
        docsText = result.docsText();
        freqText = result.freqText();
        
        // Graphics settings for drawing this line
        y += lineSpacing;

        // Write the document frequency
        if (docsText.length() > 0) {
        tab = secondColumnLeft - space - g.getFontMetrics().stringWidth(docsText);
        g.drawString(docsText, tab, y);
        }

        // Write the term frequency
        if (freqText.length() > 0) {
        tab = secondColumnLeft + secondColumnWidth 
            - space - g.getFontMetrics().stringWidth(freqText);
        g.drawString(freqText, tab, y);
        }
    }

    // Adjust the scrollbar
    if (visible >= numberOfItems) {
        parent.disableScrollbar();
    } else {
        scrollbar.setValues(scrollValue, visible, 0, numberOfItems);
        // Deprecated - setPageIncrement() has been replaced by
        // setBlockIncrement(), but the latter doesn't work on some
        // browsers.  Damn.
        scrollbar.setBlockIncrement(visible - 1);
        //scrollbar.setPageIncrement(visible - 1);
        // Deprecated - more nonsense: enable() has been replaced by
        // setEnabled(true), but this doesn't work on some browsers.
        scrollbar.setEnabled(true);
        //scrollbar.enable();
    }

    
    // draw the border
    if (phind.showBorder) {
        g.setColor(phind.panel_fg);
        g.drawRect(0,0, canvasSize.width - 1, canvasSize.height - 1);
    }
    }

    // handle mouse clicks in the new way. just copy gordons thing for now
    public void mouseClicked(MouseEvent event) {

    // ignore actions that occur within 1 second of the last
    Date now = new Date();
    // System.out.println("Click time: " + now.toString());
    if (now.getTime() < (phind.lastQueryEndTime.getTime() + 1000)) {
        System.out.println("Ignoring click - too close to last query.");
        return;
    }

    // which Item is selected?
    int rowSelected = event.getY() / lineSpacing;
    itemSelected = rowSelected + firstItemDisplayed;
    ResultItem item = items.elementAt(itemSelected);

    if (itemSelected <= numberOfItems) {
        
        //User clicks on a phrase
        if (item.isPhrase()) {
        itemSelected = itemSelected;
        update(getGraphics());
        parent.lookupPhrase(item.hiddenText(), item.toString(), 2);
        
        // If meta key is held down, send query to search engine
        /*if (event.metaDown() && !phind.library_address.equals("")) {
            String address = phind.library_address  
            + "a=q&sa=text&c=" + phind.collection
            + "&q=%22" + item.toString().replace(' ', '+') + "%22";
            phind.displayWebPage(address, phind.searchWindowName);
            }*/
        } 
        
        // Click on a thesaurus link
        else if (item.isLink()) {
        itemSelected = itemSelected;
        update(getGraphics());
        parent.lookupPhrase(item.hiddenText(), item.toString(), 2);
        
        // If meta key is held down, send query to search engine
        /*if (event.metaDown() && !phind.library_address.equals("")) {
            String address = phind.library_address  
            + "a=q&sa=text&c=" + phind.collection
            + "&q=%22" + item.toString().replace(' ', '+') + "%22";
            phind.displayWebPage(address, phind.searchWindowName);
            }*/
        } 
        
        // The user clicks on a URL; display it.
        else if (item.isDocument()) {
        itemSelected = itemSelected;
        update(getGraphics());
        
        String address = phind.library_address 
            + "a=d&c=" + phind.collection 
            + "&d=" + item.hiddenText()
            + "&q=" + parent.searchPhrase.replace(' ', '+');
        
        phind.displayWebPage(address, phind.documentWindowName);
        }
        
        // When the user clicks on "get more phrases" or other marker,
        // we have to send a new query to the host
        else if (item.isMorePhrases()){
        parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 3);
        } else if (item.isMoreDocuments()){
        parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 4);
        } else if (item.isMoreLinks()){
        parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 5);
        
        
        }
        repaint();
    }
    }
    
    // If uncommenting this, it may need porting from awt to swing
    
    // User interaction
    //
    // All interaction with the ResultCanvas is through mouse clicks, and
    // is handles in this method.  Note we ignore clicks that follow
    // another too closely to avoid problems with slow connections.
    /*  public boolean processEvent(Event event) {
    
    if (event.id == Event.MOUSE_UP) {

        // ignore actions that occur within 1 second of the last
        Date now = new Date();
        // System.out.println("Click time: " + now.toString());
        if (now.getTime() < (phind.lastQueryEndTime.getTime() + 1000)) {
        System.out.println("Ignoring click - too close to last query.");
        return true;
        }

        // which Item is selected?
        int rowSelected = event.y / lineSpacing;
        itemSelected = rowSelected + firstItemDisplayed;
        ResultItem item = (ResultItem) items.elementAt(itemSelected);

        if (itemSelected <= numberOfItems) {
    
        //User clicks on a phrase
        if (item.isPhrase()) {
            itemSelected = itemSelected;
            update(getGraphics());
            parent.lookupPhrase(item.hiddenText(), item.toString(), 2);

            // If meta key is held down, send query to search engine
            if (event.metaDown() && !phind.library_address.equals("")) {
            String address = phind.library_address  
                + "a=q&sa=text&c=" + phind.collection
                + "&q=%22" + item.toString().replace(' ', '+') + "%22";
            phind.displayWebPage(address, phind.searchWindowName);
            }
        } 

        // Click on a thesaurus link
        else if (item.isLink()) {
            itemSelected = itemSelected;
            update(getGraphics());
            parent.lookupPhrase(item.hiddenText(), item.toString(), 2);

            // If meta key is held down, send query to search engine
            if (event.metaDown() && !phind.library_address.equals("")) {
            String address = phind.library_address  
                + "a=q&sa=text&c=" + phind.collection
                + "&q=%22" + item.toString().replace(' ', '+') + "%22";
            phind.displayWebPage(address, phind.searchWindowName);
            }
        } 

        // The user clicks on a URL; display it.
        else if (item.isDocument()) {
            itemSelected = itemSelected;
            update(getGraphics());

            String address = phind.library_address 
            + "a=r&c=" + phind.collection 
            + "&r=" + item.hiddenText()
            + "&q=" + parent.searchPhrase.replace(' ', '+');

            phind.displayWebPage(address, phind.documentWindowName);
        }
         
        // When the user clicks on "get more phrases" or other marker,
        // we have to send a new query to the host
        else if (item.isMorePhrases()){
            parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 3);
        } else if (item.isMoreDocuments()){
            parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 4);
        } else if (item.isMoreLinks()){
            parent.lookupPhrase(parent.searchKey, parent.searchPhrase, 5);


        }
        repaint();
        }
    }
    return true;
    } */   
  
}