GridFieldManager will not cover the entire width of the screen

Question

Ok, I'm developing for the Blackberry Bold 9700, and I'm trying to get a 1X4 grid (1 row, 4 columns) to cover the entire width of the Blackberry screen, but it continues to be short. I mean, the grid is left-aligned by default, and that’s fine if I can make the whole grid cover the entire width (then it doesn't matter). Can any developer tell me what I'm doing wrong? I thought you just added GridFieldManager.USE_ALL_WIDTH to the constructor when declaring a new grid, but it still won’t work for me.

final class App3_MainScreen extends MainScreen { private int numColumns, size; // Constructor App3_MainScreen() { // declare a layout manager to take care of all the layout stuff numColumns = 4; size = 4; VerticalFieldManager vfm = new VerticalFieldManager(); vfm.add(new LabelField("using all width & long label...", LabelField.ELLIPSIS | Field.FIELD_HCENTER)); int borderHeight = Display.getHeight()/2;g int borderWidth = Display.getWidth()/2; Manager gridFieldManager = new GridFieldManager(1, 4, GridFieldManager.USE_ALL_WIDTH | GridFieldManager.AUTO_SIZE); // 1 row and 4 columns gridFieldManager.add(new ButtonField(""+borderHeight, Field.FIELD_HCENTER)); gridFieldManager.add(new ButtonField("222", Field.FIELD_HCENTER)); gridFieldManager.add(new ButtonField("333", Field.FIELD_HCENTER)); gridFieldManager.add(new ButtonField(""+borderWidth, Field.FIELD_RIGHT)); // set padding around each buttonField - top=0, right=5, bottom=0, left=5 gridFieldManager.setPadding(0, 5, 0, 5); int gfmHeight = 48 * (size / numColumns); gridFieldManager.setBorder(BorderFactory.createSimpleBorder( new XYEdges(borderHeight/10, 0, borderHeight/10, 0), // top, right, bottom, left Border.STYLE_DASHED)); add(gridFieldManager); }} 

Answer 1

I gave an example below that does the trick. It is based on the source code you provided, but is cleaned up and made general for clarity.

Basically, the GridFieldManager does not explicitly support USE_ALL_WIDTH. As a Manager, he inherits this constant, but its documentation does not express that it is a supported state. It is best to rely on the FIXED_SIZE state and calculate the width of each of your columns depending on the size of the display (displayWidth / numColumns). Then you can use GridFieldManager # setColumnProperty () to determine a fixed column width.

Make sure you consider the indentation applied to the columns and you are good to go.

Hope this helps.

 /** * Shows an example implementation of how to have a GridFieldManager * sized to the width of the Display. */ final class ScreenWidthGridExample extends MainScreen { /** * Number of rows in the grid. */ private static final int NUM_ROWS = 1; /** * Number of columns in the grid. */ private static final int NUM_COLUMNS = 4; /** * The grid column padding. */ private static final int COLUMN_PADDING = 5; /** * Toggle switch to show the border around the grid. */ private static final boolean SHOW_BORDER = true; /** * Allocated a new instance of the ScreenWidthGridExample. */ ScreenWidthGridExample() { // Set up the GridFieldManager GridFieldManager gfm = new GridFieldManager(NUM_ROWS, NUM_COLUMNS, GridFieldManager.FIXED_SIZE); gfm.setColumnPadding(COLUMN_PADDING); if(SHOW_BORDER) { gfm.setBorder(BorderFactory.createSimpleBorder( new XYEdges(0, 0, 0, 0), // top, right, bottom, left Border.STYLE_DASHED)); } add(gfm); // Size the columns of the GridFieldManager. Make sure to calculate // for the padding applied to the columns. int columnWidth = (Display.getWidth() / NUM_COLUMNS) - gfm.getColumnPadding(); for(int i = 0; i < NUM_COLUMNS; i++) { gfm.setColumnProperty(i, GridFieldManager.FIXED_SIZE, columnWidth); } // Populate the columns. gfm.add(new ButtonField("1", Field.FIELD_HCENTER)); gfm.add(new ButtonField("2", Field.FIELD_HCENTER)); gfm.add(new ButtonField("3", Field.FIELD_HCENTER)); gfm.add(new ButtonField("4", Field.FIELD_HCENTER)); } }