J2ME

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Outliner.java：源码内容
							import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.util.Vector;
import java.util.Enumeration;
/**
* A simple outlining midlet.
*/ 
public class Outliner extends MIDlet 
    implements CommandListener, ItemCommandListener
{ 
    private static Display DISPLAY;
    private static Command exitCommand, editCommand, insertCommand, 
        indentCommand, outdentCommand, expandCommand, collapseCommand,
        deleteCommand, okCommand, cancelCommand, upCommand, downCommand;
    private Form form;
    private TextBox textBox;
    private OutlineItem editedItem;
    
    // user-visible strings
    private final static String EXIT = "Exit";
    private final static String EDIT = "Edit";
    private final static String UP = "Move Up";
    private final static String DOWN = "Move Down";
    private final static String INDENT = "Indent";
    private final static String OUTDENT = "Outdent";
    private final static String EXPAND = "Expand";
    private final static String COLLAPSE = "Collapse";
    private final static String INSERT = "Insert";
    private final static String DELETE = "Delete";
    private final static String OK = "OK";
    private final static String CANCEL = "Cancel";
    // font for rendering items
    public static Font FONT = Font.getFont( Font.FONT_STATIC_TEXT );
    public static int FONT_HEIGHT = Math.max( FONT.getHeight(), 9 );
    
    public Outliner()
    {
        DISPLAY = null;
        editedItem = null;
    
        exitCommand = new Command( EXIT, Command.EXIT, 0 );
        okCommand = new Command( OK, Command.OK, 1 );
        cancelCommand = new Command( CANCEL, Command.CANCEL, 2 );
        editCommand = new Command( EDIT, Command.ITEM, 1 );
        insertCommand = new Command( INSERT, Command.ITEM, 2 );
        indentCommand = new Command( INDENT, Command.ITEM, 3 );
        outdentCommand = new Command( OUTDENT, Command.ITEM, 4 );
        upCommand = new Command( UP, Command.ITEM, 5 );
        downCommand = new Command( DOWN, Command.ITEM, 6 );
        expandCommand = new Command( EXPAND, Command.ITEM, 7 );
        collapseCommand = new Command( COLLAPSE, Command.ITEM, 8 );
        deleteCommand = new Command( DELETE, Command.ITEM, 9 );
        
        // set up outline form
        form = new Form( "CustomItem 演示" );
        form.addCommand( exitCommand );
        form.setCommandListener( this );
        
        // setup input form
        textBox = new TextBox( null, "", 255, TextField.ANY );
        textBox.addCommand( okCommand );
        textBox.addCommand( cancelCommand );
        textBox.setCommandListener( this );
        
        OutlineItem item;
        item = new OutlineItem( 0, "This is an outline" );
        item.setItemCommandListener( this );
        item.appendToForm( form );
        item = new OutlineItem( 1, "This is a nested item" );
        item.setItemCommandListener( this );
        item.appendToForm( form );
        item = new OutlineItem( 2, "This is a double-nested item" );
        item.setItemCommandListener( this );
        item.appendToForm( form );
        item = new OutlineItem( 1, "This is another nested item" );
        item.setItemCommandListener( this );
        item.appendToForm( form );
    }
    public void startApp()
    {
        if ( DISPLAY == null )
        {
            DISPLAY = Display.getDisplay( this );
            DISPLAY.setCurrent( form );
        }
    }
    public void pauseApp()
    {
    }
    
    public void destroyApp( boolean unconditional )
    {
    }
        
    public void onShowInput()
    {
        if ( editedItem != null )
        {
            textBox.setString( editedItem.getString() );
        }
        DISPLAY.setCurrent( textBox );
    }
    
    public void onDoInput()
    {
        if ( editedItem != null )
        {
            editedItem.setString( textBox.getString() );
            editedItem = null;
        }
    }   
    
    public void onHideInput()
    {
        DISPLAY.setCurrent( form );
        textBox.setString( "" ); // clear last command if any
        editedItem = null;
    }
    
    // interface CommandListener
    
    public void commandAction( Command aCommand, Displayable aDisplayable )
    {
        if ( aCommand == exitCommand )
        {
            destroyApp( true );
            notifyDestroyed();
        }
        else
        if ( aCommand == okCommand )
        {
            onDoInput();
            onHideInput();
        }
        else
        if ( aCommand == cancelCommand )
        {
            onHideInput();
        }
    }
    
    // interface ItemCommandListener
    
    public void commandAction( Command aCommand, Item anItem )
    {
        OutlineItem item = (OutlineItem) anItem;
        
        if ( aCommand == expandCommand )
        {
            item.expand();
        }
        else
        if ( aCommand == collapseCommand )
        {
            item.collapse();
        }
        else
        if ( aCommand == indentCommand )
        {
            item.indent();
        }
        else
        if ( aCommand == outdentCommand )
        {
            item.outdent();
        }
        else
        if ( aCommand == upCommand )
        {
            item.moveUp();
        }
        else
        if ( aCommand == downCommand )
        {
            item.moveDown();
        }
        else
        if ( aCommand == editCommand )
        {
            editedItem = item;
            onShowInput();
        }
        else
        if ( aCommand == insertCommand )
        {
            OutlineItem newItem = new OutlineItem( 
                item.indent, "" );
            newItem.setItemCommandListener( this );
            newItem.insertAfterItem( form, item );
        }
        else
        if ( aCommand == deleteCommand )
        {
            item.removeFromForm();
        }
    }
    
        public static class OutlineItem extends CustomItem
        {
        /**
        * The number of pixels to shift for each level of indent.
        */ 
        private static final int INDENT_MARGIN = 8;
        /**
        * The number of levels to indent.
        */ 
        private int indent;
        /**
        * The text to display when painted.
        */
        private String text;
        /**
        * The parent form of this item.  Needed to 
        * perform expand and collapse operations.
        */
        private Form parentForm;
        /**
        * A list of OutlineItems that are collapsed under this one.
        * If this item is expanded, this vector is null.
        */
        private Vector children;
        /**
        * The traversing item.
        */ 
        private static OutlineItem traversingItem;
        /**
        * Creates an OutlineItem with the specified initial indent and text.
        */
        public OutlineItem( int inIndent, String inText )
        {
            // we don't want a system-supplied label
            super( null );
            
            indent = inIndent;
            text = inText;
            children = null;
            // define layout constraitns
            setLayout( LAYOUT_2 | LAYOUT_LEFT | LAYOUT_TOP |
                LAYOUT_EXPAND | LAYOUT_NEWLINE_AFTER );
            // add the commands that always apply
            addCommand( editCommand );
            addCommand( insertCommand );
        }
        /**
        * Returns the indent for this item.
        */
        public int getIndent()
        {
            return indent;
        }
        
        /**
        * Sets the indent for this item.
        */
        public void setIndent( int inIndent )
        {
            indent = inIndent;
            updateCommands();
        }
        
        /**
        * Returns the text for this item.
        */
        public String getString()
        {
            return text;
        }
        
        /**
        * Sets the text for this item.
        */
        public void setString( String inText )
        {
            text = inText;
            invalidate();
        }
        
        /**
        * Add this item to the end of the form.
        */
        public void appendToForm( Form inForm )
        {
            insertBeforeItem( inForm, null );
        }
        
        /**
        * Add this item to the form before the specified item.
        */
        public void insertBeforeItem( Form inForm, OutlineItem inItem )
        {
            if ( parentForm != null )
            {
                removeFromForm();
            }
            parentForm = inForm;
        
            int i;
            int size = parentForm.size();
            for ( i = 0; i < size; i++ )
            {
                if ( parentForm.get( i ) == inItem )
                {
                    break;
                }
            }
            parentForm.insert( i, this );
            if ( inItem != null ) inItem.updateCommands();
            updateCommands();
        }
        
        /**
        * Add this item to the form before the specified item.
        */
        public void insertAfterItem( Form inForm, OutlineItem inItem )
        {
            if ( parentForm != null )
            {
                removeFromForm();
            }
            parentForm = inForm;
        
            int i;
            int size = parentForm.size();
            for ( i = 0; i < size; i++ )
            {
                if ( parentForm.get( i ) == inItem )
                {
                    break;
                }
            }
            parentForm.insert( i+1, this );
            if ( inItem != null ) inItem.updateCommands();
            updateCommands();
        }
        
        /**
        * Remove this item from the form.
        */
        public void removeFromForm()
        {
            int size = parentForm.size();
            for ( int i = 0; i < size; i++ )
            {
                if ( parentForm.get( i ) == this )
                {
                    parentForm.delete( i ); // delete this
                    break;
                }
            }
        }
        
        /**
        * Returns the index of this item on the form.
        * Returns -1 if the item is not on the form.
        */
        public int getIndex()
        {
            if ( parentForm != null )
            {
                int size = parentForm.size();
                for ( int i = 0; i < size; i++ )
                {
                    if ( parentForm.get( i ) == this )
                    {
                        return i;
                    }
                }
            }
            return -1;
        }
        
        /**
        * Returns whether this item can be indented further.
        */
        public boolean isIndentable()
        {
            int index = getIndex();
            // root cannot be indented
            if ( index == 0 ) return false;
            OutlineItem parent = (OutlineItem)parentForm.get( index - 1 );
            if ( this.indent < parent.indent ) return true;
            return ( !parent.isCollapsed() && this.indent <= parent.indent);
        }
        
        /**
        * Indent the specified node by one unit.
        */
        public void indent()
        {
            indentChildren();
            setIndent( indent+1 );
        }
        
        private void indentChildren()
        {
            if ( isCollapsed() )
            {
                Enumeration e = getHiddenChildren().elements();
                while ( e.hasMoreElements() )
                {
                    ((OutlineItem)e.nextElement()).indent++;
                }
            }
            else
            {   
                OutlineItem item;
                for ( int index = getIndex() + 1; index < parentForm.size(); index++ )
                {
                    item = (OutlineItem) parentForm.get( index );
                    if ( item.getIndent() > getIndent() ) // our indent hasn't changed yet
                    {
                        item.indent++;
                    }
                    else // end of children
                    {
                        break;
                    }
                }
            }
        }
        
        /**
        * Returns whether this item can be outdented further.
        */
        public boolean isOutdentable()
        {
            return ( indent > 0 );
        }
        
        /**
        * Outdent the specified node by one unit.
        */
        public void outdent()
        {
            outdentChildren();
            setIndent( indent-1 );
        }
        
        private void outdentChildren()
        {
            if ( isCollapsed() )
            {
                Enumeration e = getHiddenChildren().elements();
                while ( e.hasMoreElements() )
                {
                    ((OutlineItem)e.nextElement()).indent--;
                }
            }
            else
            {   
                OutlineItem item;
                for ( int index = getIndex() + 1; index < parentForm.size(); index++ )
                {
                    item = (OutlineItem) parentForm.get( index );
                    if ( item.getIndent() > getIndent() ) // our indent hasn't changed yet
                    {
                        item.indent--;
                    }
                    else // end of children
                    {
                        break;
                    }
                }
            }
        }
        
        /**
        * Returns whether this item can be moved up.
        */
        public boolean canMoveUp()
        {
            if ( parentForm == null ) return false;
            OutlineItem item;
            int index = getIndex();
            for ( int i = getIndex(); i > 0; i = i-1 )
            {
                item = (OutlineItem) parentForm.get( i );
                if ( item.indent == this.indent )
                {
                    return true;
                }
                if ( item.indent < this.indent )
                {
                    return false;
                }
            }
            return false;
        }
        
        /**
        * Outdent the specified node by one unit.
        */
        public void moveUp()
        {
            OutlineItem item;
            for ( int i = getIndex()-1; i > 0; i = i-1 )
            {
                item = (OutlineItem) parentForm.get( i );
                if ( item.indent == this.indent )
                {
                    // collapse children before moving node
                    Form f = this.parentForm;
                    boolean collapsed = this.isCollapsed();
                    if ( !collapsed ) this.collapse();
                    this.removeFromForm();
                    this.insertBeforeItem( f, item );
                    if ( !collapsed ) this.expand();
                    break;
                }
                if ( item.indent < this.indent )
                {
                    break;
                }
            }
            updateCommands();
        }
        
        /**
        * Returns whether this item can be moved down.
        */
        public boolean canMoveDown()
        {
            if ( parentForm == null ) return false;
            OutlineItem item;
            int size = parentForm.size();
            for ( int i = getIndex(); i < size-1; i = i+1 )
            {
                item = (OutlineItem) parentForm.get( i );
                if ( item.indent == this.indent )
                {
                    return true;
                }
                if ( item.indent < this.indent )
                {
                    return false;
                }
            }
            return false;
        }
        
        /**
        * Outdent the specified node by one unit.
        */
        public void moveDown()
        {
            OutlineItem item;
            int size = parentForm.size();
            for ( int i = getIndex(); i < size; i = i+1 )
            {
                item = (OutlineItem) parentForm.get( i );
                if ( item.indent == this.indent )
                {
                    i = i+1;
                    Form f = this.parentForm;
                    boolean collapsed = this.isCollapsed();
                    if ( !collapsed ) this.collapse();
                    if ( i > size ) 
                    {
                        this.removeFromForm();
                        this.appendToForm( f );
                    }
                    else
                    {
                        // collapse children before moving node
                        item = (OutlineItem) parentForm.get( i );
                        this.removeFromForm();
                        boolean targetCollapsed = item.isCollapsed();
                        if ( !targetCollapsed ) item.collapse();
                        this.insertAfterItem( f, item );
                        if ( !targetCollapsed ) item.expand();
                    }
                    if ( !collapsed ) this.expand();
                    break;
                }
            }
            updateCommands();
        }
        
        /**
        * Returns whether this item has hidden children.
        */
        public boolean isCollapsed()
        {
            return ( children != null );
        }
        
        /**
        * Hide all subsequent items with greater indent
        * and add them to the hidden children list.
        */
        public void collapse()
        {
            if ( children != null ) return;
            Vector hidden = new Vector();
            for ( int i = 0; i < parentForm.size(); i++ )
            {
                if ( parentForm.get( i ) == this )
                {
                    OutlineItem item;
                    i = i + 1;
                    while ( i < parentForm.size() )
                    {
                        item = (OutlineItem)parentForm.get( i );
                        if ( item.indent > this.indent )
                        {
                            parentForm.delete( i ); // delete item
                            hidden.addElement( item );
                        }
                        else
                        {
                            break;
                        }
                    }
                    break;
                }
            }
            if ( hidden.size() > 0 )
            { 
                setHiddenChildren( hidden );
                updateCommands();
            }
        }
        
        /**
        * Show this nodes hidden children, if any.
        */
        public void expand()
        {
            if ( children == null ) return;
            int i;
            int size = parentForm.size();
            for ( i = 0; i < size; i++ )
            {
                if ( parentForm.get( i ) == this )
                {
                    i = i + 1;
                    break;
                }
            }
            OutlineItem item;
            Enumeration e = children.elements();
            while ( e.hasMoreElements() )
            {
                item = (OutlineItem) e.nextElement();
                parentForm.insert( i, item ); // insert item
                i = i + 1;
            }
            setHiddenChildren( null );
            updateCommands();
        }
        
        /**
        * Returns the children that are currently collapsed
        * and are therefore not referenced by the parent form.
        */
        protected Vector getHiddenChildren()
        {
            return children;
        }
        
        /**
        * Set the children that are currently collapsed
        * so that we retain a reference to them when they
        * are removed from the form.
        */
        protected void setHiddenChildren( Vector inChildren )
        {
            children = inChildren;
        }
        
        private boolean hasPointerPress()
        {
            return ( getInteractionModes() & POINTER_PRESS ) != 0;
        }
        
        private boolean hasHorizontalTraversal()
        {
            return ( getInteractionModes() & TRAVERSE_HORIZONTAL ) != 0;
        }
        
        private void updateCommands()
        {
            removeCommand( expandCommand );
            removeCommand( collapseCommand );
            if ( !hasPointerPress() )
            {
                // fall back on commands to expand/collapse
                if ( isCollapsed() )
                    addCommand( expandCommand );
                else
                    addCommand( collapseCommand );
            }
            
            removeCommand( indentCommand );
            removeCommand( outdentCommand );
            if ( !hasHorizontalTraversal() )
            {
                // fall back on commands to indent/outdent
                if ( isIndentable() )
                    addCommand( indentCommand );
                if ( isOutdentable() )                
                    addCommand( outdentCommand );
            }
            
            removeCommand( upCommand );
            removeCommand( downCommand );
            if ( canMoveUp() )
                addCommand( upCommand );
            if ( canMoveDown() )                
                addCommand( downCommand );
            removeCommand( deleteCommand );
            if ( getIndex() > 0 )
            {
                // if not root
                addCommand( deleteCommand );
            }
            
            // force a repaint
            if ( parentForm != null )
            {
                invalidate();
                //repaint();
            }
        }
        
        // event handler overrides
        
        /**
        * Overridden to grab or drop the current item
        * when the FIRE key is pressed.
        */
        protected void keyPressed( int keyCode )
        {
            if ( getGameAction( keyCode ) == Canvas.FIRE )
            {
                if ( isCollapsed() )
                    expand();
                else
                    collapse();
            }
        }
                                       
        /**
        * Overridden to expand or collapse an item
        * if the 'expansion widget' is clicked.
        * Note that the reference implementation only
        * delivers this event if the item is "focused".
        */
        protected void pointerPressed( int x, int y )
        {
            // if in widget area
            if ( x < FONT_HEIGHT )
            {
                if ( isCollapsed() ) 
                    expand();
                else 
                    collapse();
            }
        }
        
        /**
        * Used to indent and outdent the item when possible.
        */
        protected boolean traverse( 
            int dir,
            int viewportWidth,
            int viewportHeight,
            int[] visRect_inout )
        {
            // this flag distinguishes between
            // traversing INTO this item and
            // traversing WITHIN this item:
            if ( traversingItem != this )
            {
                // traversing INTO: mark self and return true
                traversingItem = this;
                return true;
            }
            
            // handle traversing WITHIN this item
            switch ( dir )
            {
                case Canvas.RIGHT:
                    if ( isIndentable() )
                    {
                        indent();
                    }
                    return true;
                case Canvas.LEFT:
                    if ( isOutdentable() )
                    {
                        outdent();
                    }
                    return true;
                case NONE:
                    // do nothing: just a form layout reflow
                    return true;
                default:
                    // break out
            }
            return false;
        }
                                       
        // implementation of abstract methods
        
        public int getMinContentHeight()
        {
            return FONT_HEIGHT;
        }
        public int getMinContentWidth()
        {
            return indent * INDENT_MARGIN + FONT_HEIGHT;
            // we might not have text to calculate font width
        }
        public int getPrefContentWidth( int height )
        {
            return indent * INDENT_MARGIN 
                + FONT.stringWidth( text ) + FONT_HEIGHT;
        }
        public int getPrefContentHeight( int width )
        {
            return FONT_HEIGHT;
        }
        public void paint( Graphics g, int w, int h )
        {
            // clear all with background color
            g.setColor( DISPLAY.getColor( DISPLAY.COLOR_BACKGROUND ) );
            g.fillRect( 0, 0, w, h );
            
            // now use foreground color for drawing
            g.setColor( DISPLAY.getColor( DISPLAY.COLOR_FOREGROUND ) );
                        
            if ( isCollapsed() )
            {
                // draw a filled circle to represent hidden items
                g.fillArc( indent * INDENT_MARGIN + 2, 2, 
                    FONT_HEIGHT-7, FONT_HEIGHT-7, 0, 360 );
            }
            else
            {
                // no hidden items so draw an empty circle
                g.drawArc( indent * INDENT_MARGIN + 2, 2, 
                    FONT_HEIGHT-7, FONT_HEIGHT-7, 0, 360 );
            }
            
            // draw the text: word-wrap is an exercise for the reader
            g.drawString( text, 
                indent * INDENT_MARGIN + FONT_HEIGHT, 0, g.TOP | g.LEFT );
        }
    }
    
}

						