jpl_rolo.jpl

UNIX下perl实现代码

import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.util.*;

public class JPL_Rolo extends Frame {

    // The primary key of the row that is current onscreen.
    //
    int current_row = 0;

    // TextField objects for each column.
    //
    TextField fld_name, fld_address, fld_city, fld_state, fld_zip, fld_id;

    // Add or Edit mode.
    //
    String edit_status; 

    // a layout manager for the Frame
    //
    GridBagLayout gb = new GridBagLayout();

    // Action buttons.
    //
    Button next, previous, quit, save, newrow, edit, cancel, delete;

    // A Panel for the action buttons.
    //
    Panel actionbuttons;

    /**
     * Construct a new instance of JPL_Rolo.
     */
    public JPL_Rolo(String[] argv) {
        CreateForm();
        addWindowListener(new WinEventHandler() );
    }

    public void CreateForm() {

        // set the layout for the frame
        //
        this.setLayout(gb);

        // this is the offset within the GridBagLayout. If
        // I want the next object on a different line, I 
        // postincrement. If not, I don't.
        //
        int i = 0;

        // Add a text field for the name.
        // 
        AddToFrame(new Label("Name:"), 0, i);
        fld_name = new TextField(20);
        fld_name.setEditable(false);
        AddToFrame(fld_name, 1, i++);

        // The address.
        //
        AddToFrame(new Label("Address:"), 0, i);
        fld_address = new TextField(35);
        fld_address.setEditable(false);
        AddToFrame(fld_address, 1, i++);

        // The City. I'm not going to increment i, so the
        // next field will show up on the same line.
        //
        AddToFrame(new Label("City:"), 0, i);
        fld_city = new TextField(20);
        fld_city.setEditable(false);
        AddToFrame(fld_city, 1, i);

        // The State.
        //
        AddToFrame(new Label("State:"), 2, i);
        fld_state = new TextField(2);
        fld_state.setEditable(false);
        AddToFrame(fld_state, 3, i++);

        // The Zip Code.
        //
        AddToFrame(new Label("Zip:"), 0, i);
        fld_zip = new TextField(11);
        fld_zip.setEditable(false);
        AddToFrame(fld_zip, 1, i++);

        // The id - this is always read-only.
        //
        AddToFrame(new Label("Id:"), 0, i);
        fld_id = new TextField(4);
        fld_id.setEditable(false);
        AddToFrame(fld_id, 1, i++);

        // create the button panel and give it a FlowLayout
        //
        actionbuttons = new Panel();
        actionbuttons.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
    
        // Add the button panel to the Frame. The AddToFrame
        // method isn't really set up to handle this sort of
        // panel, so we will go through the tedious process
        // of managing the GridBagConstraints...
        //
        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = 3; c.gridheight = 1;
        c.fill = GridBagConstraints.NONE;
        c.anchor = GridBagConstraints.CENTER;
        c.weightx = 0.0; c.weighty = 0.0;   
        c.gridx = 0; c.gridy = i;
        ((GridBagLayout)this.getLayout()).setConstraints(actionbuttons, c);   
        this.add(actionbuttons);

        // instantiate and add each of the buttons
        //
        previous = new Button("Previous");
        actionbuttons.add(previous);
        previous.addActionListener( new PrevRowHandler() );

        next = new Button("Next");
        actionbuttons.add(next);
        next.addActionListener( new NextRowHandler() );

        quit = new Button("Quit");
        actionbuttons.add(quit);
        quit.addActionListener( new QuitHandler() );

        newrow = new Button("New");
        actionbuttons.add(newrow);
        newrow.addActionListener( new NewRowHandler() );

        edit = new Button("Edit");
        actionbuttons.add(edit);
        edit.addActionListener( new EditRowHandler() );

        delete = new Button("Delete");
        actionbuttons.add(delete);
        delete.addActionListener( new DeleteRowHandler() );

        // save and cancel are disabled until the user
        // is adding or editing.
        //
        save = new Button("Save");
        actionbuttons.add(save);
        save.setEnabled(false);
        save.addActionListener( new SaveHandler() );

        cancel = new Button("Cancel");
        actionbuttons.add(cancel);
        cancel.setEnabled(false);
        cancel.addActionListener( new CancelHandler() );

        // Invoke getRow() to display the first row in the table.
        //
        getRow(0);

    }

    /**
     * Return the id of the current row.
     */
    public int getCurrentRowVal() {
        return current_row;
    }

    public void setCols(String name, String address, String city, String state, String zip, String id) {

        clearForm();

        fld_name.setText(name);
        fld_address.setText(address);
        fld_city.setText(city);
        fld_state.setText(state);
        fld_zip.setText(zip);
        fld_id.setText(id);
        current_row = Integer.parseInt(id);
          
    }


    public void setCurrentRow(int r) {
        current_row = r;
    }

    public String getName()    { return fld_name.getText(); }
    public String getAddress() { return fld_address.getText(); }
    public String getCity()    { return fld_city.getText(); }
    public String getState()   { return fld_state.getText(); }
    public String getZip()     { return fld_zip.getText(); }
    public String getId()      { return fld_id.getText(); }

    /**
     * This eventhandler will move to the previous row.
     */
    class PrevRowHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            getRow(-1);
        }
    }

    /**
     * This eventhandler will move to the next row.
     */
    class NextRowHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            getRow(1);
        }
    }

    /**
     * This eventhandler will terminate the application.
     */
    class QuitHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            System.exit(0);
        }
    }

    /**
     * This eventhandler will display a blank record and put
     * this application in new record mode.
     */
    class NewRowHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
                clearForm();
                edit_status = "new";
                setEdit();
        }
    }

    /**
     * This eventhandler will put the application in edit
     * mode (for the current row).
     */
    class EditRowHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            edit_status = "edit";
            setEdit();
        }
    }
    /**
     * This eventhandler will delete the current row.
     */
    class DeleteRowHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            delRow();
        }
    }

    /**
     * This eventhandler will save (update or insert) the
     * current record.
     */
    class SaveHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {

            if (edit_status.equals("new")) {
                saveIt();
            }
            if (edit_status.equals("edit")) {
                updateRow();
            }

            // set the edit_status to "browse", and call setBrowse()
            //
            edit_status = "browse";
            setBrowse();
        }
    }

    /**
     * This eventhandler cancels any pending edit.
     */
    class CancelHandler implements ActionListener {
        public void actionPerformed( ActionEvent e) {
            // if it was new, make sure that they can't edit the
            // id field...

            if (edit_status.equals("new")) {
                fld_id.setEditable(false);
            } 

            // return the edit_status to browse, call getRow()
            // to retrieve the row they were looking at
            // before editing or adding, and call setBrowse()
            //
            edit_status = "browse";
            getRow(0);
            setBrowse();
        }
    }

    // This is the event handler to deal with cases where
    // the user closes the window with a window control.
    //  
    class WinEventHandler extends WindowAdapter {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    }       

    /**
     * clearForm()
     */
    protected void clearForm () {
        fld_name.setText("");
        fld_address.setText("");
        fld_city.setText("");
        fld_state.setText("");
        fld_zip.setText("");
        fld_id.setText("");
    }

    /**
     * AddToFrame()
     * A convenience method to wrap the living hell
     * that is GridBagConstraints()
     */
    protected void AddToFrame (Component item, int x, int y) {

        // some sane layout defaults.
        //
        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = 1; c.gridheight = 1;
        c.fill = GridBagConstraints.NONE;
        c.anchor = GridBagConstraints.NORTHWEST;
        c.weightx = 0.0; c.weighty = 0.0;        

        // set the grid coordinates
        //
        c.gridx = x; c.gridy = y;

        // set the constraints, and add the item to the layout
        //

        ((GridBagLayout)this.getLayout()).setConstraints(item, c);    
        this.add(item);
    }

    /**
     * setEdit()
     *
     * prepare the form for editing/adding
     */
    protected void setEdit () {
    
        // disable all these buttons
        //
        next.setEnabled(false);
        previous.setEnabled(false);
        newrow.setEnabled(false);
        edit.setEnabled(false);
        delete.setEnabled(false);

        // set everything except the id to be editable
        //
        fld_name.setEditable(true);
        fld_address.setEditable(true);
        fld_city.setEditable(true);
        fld_state.setEditable(true);
        fld_zip.setEditable(true);

        // enable these two buttons
        //
        save.setEnabled(true);
        cancel.setEnabled(true);
    }

    /**
     * setBrowse()
     *
     * prepare the form for viewing
     *
     */
    protected void setBrowse() {

        // enable all these buttons
        //
        next.setEnabled(true);
        previous.setEnabled(true);
        newrow.setEnabled(true);
        edit.setEnabled(true);
        delete.setEnabled(true);

        // disable the fields
        //
        fld_name.setEditable(false);
        fld_address.setEditable(false);
        fld_city.setEditable(false);
        fld_state.setEditable(false);
        fld_zip.setEditable(false);
        fld_id.setEditable(false);
   
        // disable these two buttons
        //
        save.setEnabled(false);
        cancel.setEnabled(false);
    }

    perl void delRow() {{

        my $id      = $self->getId____s();

        $sql = qq[delete from cardfile ] .
               qq[where (id = $id)];
        
        use Sprite;
        my $rdb = new Sprite();
        my @data = $rdb->sql($sql);
        $rdb->close("cardfile");
        my $status = shift @data;
        if (!$status) {
            print STDERR "Bummer - couldn't execute query!\n";
            die;
        }
        $self->setCurrentRow__I(0);
        $self->getRow__I(0);

    }}

    perl void updateRow() {{

        my $name    = $self->getName____s();
        my $address = $self->getAddress____s();
        my $city    = $self->getCity____s();
        my $state   = $self->getState____s();
        my $zip     = $self->getZip____s();
        my $id      = $self->getId____s();

        $sql = qq[update cardfile ] .
               qq[set name    = ('$name'), ] .
               qq[set address = ('$address'), ] .
               qq[set city    = ('$city'), ] .
               qq[set state   = ('$state'), ] .
               qq[set zip     = ('$zip') ] .
               qq[where (id = $id)];
        
        use Sprite;
        my $rdb = new Sprite();
        my @data = $rdb->sql($sql);
        $rdb->close("cardfile");
        my $status = shift @data;
        if (!$status) {
            print STDERR "Bummer - couldn't execute query!\n";
            die;
        }

    }}


    /**
     * getRow()
     *
     * This method is used to either fetch this current row,
     * in which case it is given an argument of zero, or it
     * can be used to move relative to the current row, in
     * which case it must be given an argument of 1 or -1.
     *
     */


    perl void getRow(int direction) {{

        use Sprite;
        my $rdb = new Sprite();

        my $nextid = $self->getCurrentRowVal____I() + $direction;
        my $op;
        if ($direction == -1) {
            $op = "<=";
        } else {
            $op = ">=";
        }
        my $sql = "select name, address, city, "  .
                  "state, zip, id from cardfile " .
                  "where id $op $nextid";
	
        my @data = $rdb->sql($sql);
        $rdb->close("cardfile");

        my $status = shift @data;
        if (!$status) {
            print STDERR "Bummer - couldn't execute query!\n";
            die;
        }

        my $numrows = scalar(@data);

        if (!$numrows) {
            print STDERR "End of file reached.\n";
            return;
        }

        my $index;
        if ($direction == -1) {
            $index = $#data;
        } else {
            $index = 0;
        }
        my($name, $address, $city, $state, $zip, $id) = @{$data[$index]};
        $self->setCols__ssssss($name, $address, $city, $state, $zip, $id);

    }}

    perl void saveIt() {{

        use Sprite;
        my $rdb = new Sprite();

        my @data = $rdb->sql("select id, name from cardfile");

        my $status = shift @data;
        if (!$status) {
            print STDERR "Bummer - couldn't execute query!\n";
            die;
        }

        my @ids;
        foreach $record (@data) {
            my ($id, $name) = split (/\0/, $record, 2);
            push @ids, $id;
        }
        @ids = sort @ids;
        my $newid = $ids[$#ids] + 1;

        my $name    = $self->getName____s();
        my $address = $self->getAddress____s();
        my $city    = $self->getCity____s();
        my $state   = $self->getState____s();
        my $zip     = $self->getZip____s();

        my $sql = "insert into cardfile (name, address, city, state, zip, id) values ('$name', '$address', '$city', '$state', '$zip', $newid)";
        @data = $rdb->sql($sql);
        $rdb->close("cardfile");

        $status = shift @data;
        if (!$status) {
            print STDERR "Bummer - couldn't execute insert!\n";
            die;
        }

        $self->setCurrentRow__I($newid);

    }}

    public static void main(String[] args) {

        // make a new JPL_Rolo, pack() it and show() it.
        JPL_Rolo cardfile = new JPL_Rolo(args);
        cardfile.pack();
        cardfile.show();

    }

}