/* TablePanel.java */ package ciips.animation; import java.awt.*; import java.applet.*; import java.io.*; import java.util.*; /** * This class creates a panel with a table canvas and a vertical scrollbar * to the east of the canvas. * Most of its methods are simply directing the method calls to the table * canvas (instance of class TableCanvas) with methods of the * same name (polymorphism). *

* Since this class is of type java.awt.Panel and the drawing * panel is also of the same type, the layout manager of the drawing panel * (DrawingPanel) has to be disabled prior to adding this * table panel. *

* The way of adding the table panel to a drawing panel is similar to adding * a histogram (they are of similar nature - both inheriting from * java.awt.Panel). *

* The following line of codes can be used as an example to add a table panel * to a drawing panel:

 *	TablePanel table = new TablePanel(max_table_size);
 *	drawingPanel.setLayout(null);
 *	drawingPanel.add(table);
 *	table.setDrawingPanel(drawingPanel);
 *	table.reshape(x, y, width, height);
 * 
* drawingPanel is an instance of class DrawingPanel * which is normally obtained by calling the getDrawingPanel() * method from an instance of the AlgAnimFrame class:
 * 	drawingPanel = frame.getDrawingPanel();
 * 
* where frame is the instance of the AlgAnimFrame * class. * @see TableCanvas * @see Histogram */ public class TablePanel extends Panel implements DrawingObj { Scrollbar vScrollbar; TableCanvas draw; DrawingPanel drawingPanel; /** * Create a panel with a table canvas and a scrollbar to the east of the * table canvas. The maximum size of the table is initialized according * to the parameter of this constructor. * @param max_elem The maximum size of the table. */ public TablePanel(int max_elem) { setLayout(new BorderLayout()); int i; this.setBackground(Color.white); draw = new TableCanvas(this); vScrollbar = new Scrollbar(Scrollbar.VERTICAL); vScrollbar.setValues(0, 1, 0, 0); vScrollbar.setPageIncrement(1); add("Center", draw); add("East", vScrollbar); draw.setTableSize(max_elem); } /** * Set the size of the table and rescale the scrollbar governing the table. * This method calls the method with the same name in * TableCanvas. * @param max_size The maximum size of the table. */ public void init(int max_size) { draw.setTableSize(max_size); } /** * Simply call the repaint() method of the table panel. */ public void draw(Graphics g) { repaint(); } /** * Get the left most position of the table panel. * @return The left most position of the table panel. */ public int getX() { return location().x; } /** * Get the top most position of the table panel. * @return The top most position of the table panel. */ public int getY() { return location().y; } /** * Pass the method call to the corresponding TableCanvas, * which checks if the table has been fully filled up. * @return TRUE if all entries in the corresponding table canvas * is non-null object; FALSE otherwise. * @see TableCanvas#full */ public boolean full() { return draw.full(); } /** * Pass the method call to the corresponding TableCanvas, * which gets the number of rows in the table where the contents are * non-null objects. * @return The number of non-null object in the table. * @see TableCanvas#numOccupied */ public int numOccupied() { return draw.numOccupied(); } /** * Pass the method call to the corresponding TableCanvas, * which checks if a particular row in the table has a non-null object. * @param i The row number of the table to be checked. * @return TRUE if the row specified by the parameter is occupied. * @see TableCanvas#occupied */ public boolean occupied(int i) { return draw.occupied(i); } /** * Pass the method call to the corresponding TableCanvas. * Display a status summary of the table regarding the percentage * of the table being occupied, the number of clusters in the table, * and a rough idea of the location of the table being occupied. *

* This method should be called from the draw method * of one of the drawing object, which has been added to the drawing * panel. For example, if an object class Eg has been * defined to * implement the DrawingObj interface, such that:

     *  class Eg implements DrawingObj {
     *      TablePanel table;
     *      ....
     *
     *      public Eg(TablePanel table, ... ) {
     *          ....
     *          this.table = table;
     *      }
     *
     *      ....
     *
     *      public void draw(Graphics g) {
     *          ....
     *          if (table != null)
     *              table.drawClusters(g, x, y);
     *      }
     *  }
     * 
* Adding an instance of this Eg class into the drawing * panel (by using addDrawingObj) should result in * drawing of the table status summary in the drawing panel with its * top left corner at position (x, y). * @param g Graphical context of the drawing panel where the status * information is going to be shown. * @param x The left most position of the status information display. * @param y The top most position of the status information display. * @see TableCanvas#drawClusters */ public void drawClusters(Graphics g, int x, int y) { draw.drawClusters(g, x, y); } /** * Pass the method call to the corresponding TableCanvas, * which checks if the table contains a certain object specified by * the parameter. * @param obj The object that is going to be checked for existence. * @return TRUE if the object exists; FALSE otherwise. * @see TableCanvas#contains */ public boolean contains(Object obj) { return draw.contains(obj); } /** * Pass the method call to the corresponding TableCanvas, * which gets the location of an object in the table. * @param obj The object which location is being checked. * @return The row number of the object passed in as the parameter. * This method will return a -1 if the object does not exist. * @see TableCanvas#indexOf */ public int indexOf(Object obj) { return draw.indexOf(obj); } /** * Pass the method call to the corresponding TableCanvas, * which add an entry to the table and push the existing entries after * this newly added object one position down. * @param obj The new object to be added to the table. * @param posn The position in the table (row) where the new object is to * be added. * @see TableCanvas#addTableEntry */ public void addTableEntry(Object obj, int posn) { draw.addTableEntry(obj, posn); } /** * Scroll the display window of the table to shown the row specified by * the parameter. If the parameter indicates a row that has already * been in the current view window, nothing will happen. * @param posn The row number of the table that will be displayed. */ public void scroll2posn(int posn) { int val = vScrollbar.getValue(); if (posn < val || posn > val + 6) { val = posn - 2; if (val < 0) val = 0; else if (val > vScrollbar.getMaximum()) val = vScrollbar.getMaximum() - 4; vScrollbar.setValue(val); draw.setStart(val); draw.repaint(); delay(); } } /** * Pass the method call to the corresponding TableCanvas, * which obtains the object placed at the table row specified by the * parameter. * @param posn Table row where the object is to be obtained. * @return The table object at the row specified by the parameter. * @see TableCanvas#getTableEntryAt */ public Object getTableEntryAt(int posn) { return draw.getTableEntryAt(posn); } /** * Pass the method call to the corresponding TableCanvas, * which sets the object specified by the first parameter to the table * row defined by the second parameter. The display window will scroll * to include the row that has been newly added. * @param obj The object to be added to the table. * @param posn The row number where the object is going to be added. * @see TableCanvas#setTableEntry */ public void setTableEntry(Object obj, int posn) { draw.setTableEntry(obj, posn); scroll2posn(posn); draw.repaint(); delay(); } /** * Pass the method call to the corresponding TableCanvas, * which sets the size of the table and hence rescale the scrollbar. * @param size The new size of this table. * @see TableCanvas#setTableSize */ public void setTableSize(int i) { draw.setTableSize(i); draw.repaint(); drawingPanel.init(); } /** * Pass the method call to the corresponding TableCanvas, * which gets the maximum size of the table. * @return The maximum size of the table. * @see TableCanvas#tableSize */ public int tableSize() { return draw.tableSize(); } /** * Pass the method call to the corresponding TableCanvas, * which highlights the table entry with the row specified by the * parameter. There can only be one row highlighted at any one time. * @param i The row to be highlighted. * @see TableCanvas#highlightRow */ public void highlightRow(int i) { draw.highlightRow(i); } /** * Pass the method call to the corresponding TableCanvas, * which restores any highlighted row. * @see TableCanvas#restoreRow */ public void restoreRow() { draw.restoreRow(); } /** * Set the parent panel where this table panel is going to reside. * @param dpanel The parent drawing panel which this table panel resides. */ public void setDrawingPanel(DrawingPanel dpanel) { this.drawingPanel = dpanel; } /** * The main purpose of this method is to handle the scrollbar event. * The position of the scrollbar is obtained and used to position the * view window of the table canvas. * @param event The event captured. */ public boolean handleEvent(Event event) { if (event.target == vScrollbar) { switch (event.id) { case Event.SCROLL_LINE_UP: case Event.SCROLL_LINE_DOWN: case Event.SCROLL_PAGE_UP: case Event.SCROLL_PAGE_DOWN: case Event.SCROLL_ABSOLUTE: int val = ((Scrollbar)(event.target)).getValue(); draw.setStart(val); draw.repaint(); } } return super.handleEvent(event); } /** * This method causes a delay of 200msec. */ public void delay() { try { Thread.sleep(200); } catch (InterruptedException e) {} } }