Java Development

[shreyasb]

Hi all,

I m creating a ListField with Checkboxex from  How To - Create a ListField with check boxes

But I m not getting how to wrap Text in a row in that ListField.

I referred the code http://pastie.org/282759/wrap but the Checkbox is not coming in ListField.

I think we cant mess up the code in these 2 links.

I referred the thread

Text Wrapping for text in List Field items

Here its written as

If all you are displaying is text, then I would go with the approach suggested by rab.

 I m displaying Text only in ListField which I want to wrap if it doesnt fit within device screen.

But i m not getting "approach suggested by rab"  in which How to calculate?

 String [] linesToDraw = calculate the number of lines depending on the row width

I m stucked at this so any details on this issue ?

[RexDoug]

You calculate the width of the text using Font.getAdvance(String text)

See the API docs.

[shreyasb]

I got the no. of lines properly according to row width & stored it in a Vector & i m doing

        int fontHeight = this.getFont().getHeight();

         for (int i = 0; i < linesToDraw .size(); i++)
        {           
            textToDraw = (String)linesToDraw.elementAt(i);
            graphics.drawText(textToDraw, xpos, ypos, 0 , width);
            ypos += fontHeight;
        }

now its drawing the lines but over the previous one as by default listField.setRowHeight() is taking only one row. If there r 2 rows then I write setRowHeight(getFont().getHeight()*2) in drawListRow() but then it goes in loop

If I write setRowHeight() while creating ListField then it comes properly but for all rows same row height is set.

I gets the String to draw at Runtime & the row height should be variable for different rows then how can I setRowHeight() with what parameter & in which method ?

[peter_strange]

There is no public API to have a variable height ListField.

There are a number of Threads on this forum that discuss this and the various options, search round for them. 

[bbdeveloper2009]

Hey Shreyas can you guide me to calculate number of lines required? and also to create linesToDraw collection?

Thanks in Advance

[shreyasb]

The Logic is like..

    * split text on words
    * create string array and while words array not empty do
          o create string lineStr
          o while getFont().getAdvance(lineStr+" "+words[i]) < row width move words[i] to lineStr

in the end you will get:

    * String[] lines with lines for row
    * Row height = lines.lenght * (getFont().getHeight() + topMargin + bottomMargin)

& do g.drawText() like in my previous post.

But i m confused from where to call setRowHeight()  as the Row Height is varible for different Rows.

[BBDeveloper]

setRowHeight method apply on your ListField.

http://supportforums.blackberry.com/t5/Java-Development/setRowHeight-dramaticly-slows-down-performan...

[shreyasb]

Thanks for thr reply but  list.setRowHeight(45);   is hardcoded there

& In my case the row height is variable for different rows & I gets the String to draw at Runtime.

So if I write setRowHeight(fontHeight*2) in drawListRow() like

public void drawListRow(ListField list, Graphics graphics, int index, int y, int w) 
{
  ................................
  ...............................
  for (int i = 0; i < linesToDraw.size(); i++)
  {		           
	String textToDraw = (String)linesToDraw.elementAt(i);
	list.setRowHeight(fontHeight);
	graphics.drawText(textToDraw, 0, y, 0, w);
	y += fontHeight;
  }
}

but then it goes in loop

If I write setRowHeight() while creating ListField then it comes properly but for all rows same row height is set & I have t o give a fixed value there.

So how to write setRowHeight() with variable value & where to write it?

[BBDeveloper]

The code which provided will be just for reference and you may need to change a bit which suites your requirement.

Following one thread is also about setting variable height in Listfield and it is discussed about the performace too.. you just give a look at it.

http://supportforums.blackberry.com/t5/Java-Development/Variable-height-ListField-solved/m-p/223906