Blackberry: change sorting of a KeywordFilterField_问答_开发者

I have prepared a simple test case demonstrating my problem.

It is just 1 file (CheckMenu.java, listed below) and instantly runnable.

Once the user changes the sorting method by selecting 1 of the 2 MenuItems, how do I redraw the underlying KeywordFilterField? I've tried calling myList.updateList() and myList.invalidate() - it doesn't help - the myList items are not reorganized.

Also I wonder, what to use instead of the deprecated MenuItem.setText(String)?

Blackberry: change sorting of a KeywordFilterField

package mypackage;

import net.rim.device.api.system.*;
import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.util.Comparator;
import net.rim.device.api.util.StringUtilities;
import net.rim.device.api.collection.util.*;

public class CheckMenu extends UiApplication {
    public static void main(String[] args) {
        CheckMenu myApp = new CheckMenu();       
        myApp.enterEventDispatcher();
    }

    public CheckMenu() {        
        pushScreen(new MyScreen());
    }    
}

class MyScreen extends MainScreen {
    KeywordFilterField myList = new KeywordFilterField();
    MyItemList myItems = new MyItemList();

    public MyScreen() {
        setTitle(myList.getKeywordField());

        myItems.doAdd(new MyItem(1, "Eins"));
        myItems.doAdd(new MyItem(2, "Zwei"));
        myItems.doAdd(new MyItem(3, "Drei"));
        myItems.doAdd(new MyItem(4, "Vier"));

        myList.setSourceList(myItems, new MyItem.MyProvider());
        // XXX commenting the line below does not help
        myList.setCallback(new MyListFieldCallback());
        add(myList);
    }

    private MenuItem numMenu = new MenuItem("num sort", 0, 0) {  
        public void run() {
            MyItem.NUMERIC_SORT = true;
            Status.show("Use " + toString());
            setText("num sort \u221A");
            alphaMenu.setText("alpha sort");
            myList.updateList();
        }
    };
    private MenuItem alphaMenu = new MenuItem("alpha sort", 1, 0) {  
        public void run() {
            MyItem.NUMERIC_SORT = false;
            Status.show("Use " + toString());
            setText("alpha sort \u221A");
            numMenu.setText("num sort");
            myList.updateList();
        }
    };

    protected void makeMenu(Menu menu, int instance) {
        super.makeMenu(menu, instance);
        menu.add(numMenu);
        menu.add(alphaMenu);
    }

    private class MyListFieldCallback implements ListFieldCallback {

        public void drawListRow(ListField list, Graphics g, int index, int y, int width) {
            Object obj = ((KeywordFilterField)list).getElementAt(index);
            if(obj != null && obj instanceof MyItem) {
                MyItem item = (MyItem) obj;
                g.drawText(item.toString(), 20 * (1 + index), y);
            } else if(index == 0) {
                g.drawText(list.getEmptyString(), 0, y);
            }
        }

        public Object get(ListField list, int index) { 
            return null; 
        }

        public int getPreferredWidth(ListField list) { 
            return 0; 
        }

        public int indexOfList(ListField list, String prefix, int start) { 
            return 0; 
        }
    }
}

class MyItemList extends SortedReadableList {
    public MyItemList() {
        super(new MyItem.MyComparator());        
    } 

    protected void doAdd(Object obj) {
        super.doAdd(obj);   
    }

    protected boolean doRemove(Object obj) {
        return super.doRemove(obj);        
    }
}

class MyItem {
    public static boolean NUMERIC_SORT;

    private int _num;
    private String _name;

    public MyItem(int num, String name) {
        _num = num;
        _name = name;
    }

    public String toString() {
        return _num + ": " + _name;
    }

    static class MyComparator implements Comparator {
        public int compare(Object obj1, Object obj2) {
            if (! (obj1 instanceof MyItem && obj2 instanceof MyItem))
               开发者_StackOverflow中文版 throw new IllegalArgumentException("Cannot compare non-MyItems");

            MyItem item1 = (MyItem) obj1;
            MyItem item2 = (MyItem) obj2;

            if (MyItem.NUMERIC_SORT) {
                if (item1._num == item2._num)
                    return 0;
                return (item1._num > item2._num ? 1 : -1);
            }

            return item1._name.compareTo(item2._name);
        }
    }

    static class MyProvider implements KeywordProvider {
        public String[] getKeywords(Object obj) {
            if (obj instanceof MyItem) {
                MyItem item = (MyItem) obj;
                return new String[]{ Integer.toString(item._num), item._name };
            }
            return null;
        }
    }
}

UPDATE: I've updated the code to use makeMenu() as suggested by Arhimed. I've also posted my question at the BlackBerry forum.

Thank you! Alex

Maybe I don't understand your problem..... But as I see, this code works fine on simulator

import net.rim.device.api.system.*;
import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.util.Comparator;
import net.rim.device.api.util.StringUtilities;
import net.rim.device.api.collection.util.*;

public class CheckMenu extends UiApplication {
    public static void main(String[] args) {
        CheckMenu myApp = new CheckMenu();       
        myApp.enterEventDispatcher();
    }

    public CheckMenu() {        
        pushScreen(new MyScreen());
    }    
}

class MyScreen extends MainScreen {
    KeywordFilterField myList = new KeywordFilterField();
    MyItemList myItems = new MyItemList();

    public MyScreen() {
        setTitle(myList.getKeywordField());

        myItems.doAdd(new MyItem(1, "Eins"));
        myItems.doAdd(new MyItem(2, "Zwei"));
        myItems.doAdd(new MyItem(3, "Drei"));
        myItems.doAdd(new MyItem(4, "Vier"));

        myList.setSourceList(myItems, new MyItem.MyProvider());
        // XXX commenting the line below does not help
        myList.setCallback(new MyListFieldCallback());
        add(myList);
    }

    private MenuItem numMenu = new MenuItem("num sort", 0, 0) {  
    public void run() {
        MyItem.NUMERIC_SORT = true;
        Status.show("Use " + toString());
        setText("num sort \u221A");
        alphaMenu.setText("alpha sort");
        myItems.sort();
        myList.updateList();
    }
};
private MenuItem alphaMenu = new MenuItem("alpha sort", 1, 0) {  
    public void run() {
        MyItem.NUMERIC_SORT = false;
        Status.show("Use " + toString());
        setText("alpha sort \u221A");
        numMenu.setText("num sort");
        myItems.sort();
        myList.updateList();
    }
};

protected void makeMenu(Menu menu, int instance) {
    super.makeMenu(menu, instance);
    menu.add(numMenu);
    menu.add(alphaMenu);
}

private class MyListFieldCallback implements ListFieldCallback {

    public void drawListRow(ListField listField, Graphics g, int index, int y, int    width) {
        Object obj = ((KeywordFilterField)listField).getElementAt(index);
        if(obj != null && obj instanceof MyItem) {
            MyItem item = (MyItem) obj;
            g.drawText(item.toString(), 20 * (1 + index), y);
        } else if(index == 0) {
            g.drawText("ssssssss", 0, y);
        }
    }

    public Object get(ListField listField, int index) { 
        return null; 
    }

    public int getPreferredWidth(ListField listField) { 
        return 0; 
    }

    public int indexOfList(ListField listField, String prefix, int start) { 
        return 0; 
    }
}
}

class MyItemList extends SortedReadableList {
    public MyItemList() {
        super(new MyItem.MyComparator());        
    } 

    protected void doAdd(Object obj) {
        super.doAdd(obj);   
    }

    protected boolean doRemove(Object obj) {
        return super.doRemove(obj);        
    }
 }

class MyItem {
    public static boolean NUMERIC_SORT;

    private int _num;
    private String _name;

    public MyItem(int num, String name) {
        _num = num;
        _name = name;
    }

    public String toString() {
        return _num + ": " + _name;
    }

    static class MyComparator implements Comparator {
        public int compare(Object obj1, Object obj2) {
            if (! (obj1 instanceof MyItem && obj2 instanceof MyItem))
                throw new IllegalArgumentException("Cannot compare non-MyItems");

            MyItem item1 = (MyItem) obj1;
            MyItem item2 = (MyItem) obj2;

            if (MyItem.NUMERIC_SORT) {
                if (item1._num == item2._num)
                    return 0;
                return (item1._num > item2._num ? 1 : -1);
            }

            return item1._name.compareTo(item2._name);
        }
    }

    static class MyProvider implements KeywordProvider {
        public String[] getKeywords(Object obj) {
            if (obj instanceof MyItem) {
                MyItem item = (MyItem) obj;
                return new String[]{ Integer.toString(item._num), item._name };
            }
        return null;
    }
}
}

1). How can I modify a MenuItem text? I'd like to display/hide a check mark symbol \u221A - depending on which sorting order is currently selected by the user. The setText(String text) method is deprecated and I'm not sure how to use the setText(StringProvider text)?

Instead of using addMenuItem(myMenu1); override makeMenu(Menu menu, int instance):

protected void makeMenu(Menu menu, int instance) {
    super.makeMenu(menu, instance);

    // add menu items on-the-fly
    // generating their labels in accordance to some conditions
    menu.add(new MenuItem("any label", 1, 1) {
        public void run() {
            // do smth useful
        }
    });
}

2). Once the user changes the sorting method by selecting 1 of the 2 MenuItems, how do I redraw the underlying KeywordFilterField? I've tried calling myList.updateList() and myList.invalidate() - it doesn't help.

Try to comment out the myList.setCallback(new MyListFieldCallback()); line. I believe KeywordFilterField already implements this callback in some specific way, so by setting your custom ListFieldCallback you break the default/expected behaviour.

UPDATE about menu items:

Get rid of private MenuItem alphaMenu and private MenuItem numMenu fields completely. Generate those menu items on the fly:

protected void makeMenu(Menu menu, int instance) {
    super.makeMenu(menu, instance);

    String label = "num sort" + (MyItem.NUMERIC_SORT ? " \u221A" : "");

    menu.add(new MenuItem(label, 0, 0) {  
        public void run() {
            MyItem.NUMERIC_SORT = true;
            Status.show("Use " + toString());
            // setText("num sort \u221A");
            // alphaMenu.setText("alpha sort");
            myList.updateList();
        }
    });

    label = "alpha sort" + (MyItem.NUMERIC_SORT ? "" : " \u221A");

    menu.add(new MenuItem(label, 1, 0) {
        public void run() {
            MyItem.NUMERIC_SORT = false;
            Status.show("Use " + toString());
            // setText("alpha sort \u221A");
            // numMenu.setText("num sort");
            myList.updateList();
        }
    });
}

UPDATE on the major problem:

class MyScreen extends MainScreen {
    KeywordFilterField myList = new KeywordFilterField();
    MyItemList myItems = new MyItemList();

    public MyScreen() {
        setTitle(myList.getKeywordField());

        myItems.doAdd(new MyItem(1, "Eins"));
        myItems.doAdd(new MyItem(2, "Zwei"));
        myItems.doAdd(new MyItem(3, "Drei"));
        myItems.doAdd(new MyItem(4, "Vier"));

        myList.setSourceList(myItems, new MyItem.MyProvider());

        // XXX commenting the line below does not help
        myList.setCallback(new MyListFieldCallback());
        add(myList);
    }

    protected void makeMenu(Menu menu, int instance) {
        super.makeMenu(menu, instance);

        String label = "num sort" + (MyItem.NUMERIC_SORT ? " \u221A" : "");

        menu.add(new MenuItem(label, 0, 0) {  
            public void run() {
                MyItem.NUMERIC_SORT = true;
                Status.show("Use " + toString());
                // setText("num sort \u221A");
                // alphaMenu.setText("alpha sort");

                myItems.setComparator(new MyItem.MyComparator());
                myList.updateList();
            }
        });

        label = "alpha sort" + (MyItem.NUMERIC_SORT ? "" : " \u221A");

        menu.add(new MenuItem(label, 1, 0) {
            public void run() {
                MyItem.NUMERIC_SORT = false;
                Status.show("Use " + toString());
                // setText("alpha sort \u221A");
                // numMenu.setText("num sort");

                myItems.setComparator(new MyItem.MyComparator());
                myList.updateList();
            }
        });

    }

// .. the rest of the code is the same