BlackBerry: My Custom ListField

One of the problems we can find when we create our first BlackBerry app is to create a Custom ListField, where we can decide which colors to use for selecter or unselected elements in our list.

Here i will show you how to create a simple ListField, you can change it's color as you like.

I'm creating a new class on my project which i extend from MainScreen, so i can push it, and it will implement the ListFieldCallback.

public class MyCustomListField extends MainScreen implements ListFieldCallback{

private int selectedColor = 0x8f52a8;

private int defaultColor =  0xf2f2f2;

private int rowHeight = 50;

private Vector elements;

private ListField customList;

public MyCustomListField(){

setTitle("My Custom List Field!");

elements = new Vector();

for(int i=0; i<30; i++){

elements.addElement("My #"+i+" element");

}

customList = new ListField(elements.size());

customList.setCallback(this);

customList.setRowHeight(70);

add(customList);

}

public void drawListRow(ListField list, Graphics g, int index, int y, int w) {

String text = (String)elements.elementAt(index);

if(g.isDrawingStyleSet(Graphics.DRAWSTYLE_FOCUS)){

g.setColor(selectedColor);

g.fillRect(0,y,Display.getWidth(),list.getRowHeight());

}else{

g.setColor(defaultColor);

g.fillRect(0,y,Display.getWidth(),list.getRowHeight());

}

g.setColor(0x000000);

g.drawLine(0, y, Display.getWidth(), y);

g.drawText(text, 0, y, 0, w);

}

public Object get(ListField listField, int index) {

return elements.elementAt(index);

}

public int getPreferredWidth(ListField listField) {

return Display.getWidth();

}

public int indexOfList(ListField listField, String prefix, int start) {

return elements.indexOf(prefix, start);

}

}

Here you can download the full project example: MyCustomListField Example