A better Alert

Alert is a good screen for short messages like: "Settings saved", "Restored default values", "Network error", etc. A TextBox can only be used for user input. If you want to show a help text, with multiple lines, there is another way. On a previous post I showed a way to use Font.stringWidth, now we will see one more.

Assume you have the following attributes:

String [] message;

int messageFirstLineShown;

Command nextCommand;

First you will have to break your message in lines that fit the screen.

char[] chars = ("My long text that will not fit the screen with just one line.\n"

    + "Second line.\nThird line").toCharArray();

StringBuffer buffer = new StringBuffer();

Vector vLines = new Vector();

for (int i = 0; i < chars.length; i++) {

  if (chars[i] == ' ' || chars[i] == '.') {

  String s = buffer.toString();

  // filled a line

  if (Font.getDefaultFont().stringWidth(s) > getWidth()) {

  vLines.addElement(s.substring(0, s.lastIndexOf(' ')));

  buffer.setLength(0);

  buffer.append(s.substring(s.lastIndexOf(' ') + 1));

  }

  buffer.append(chars[i]);

  } else if (chars[i] == '\n') {

  vLines.addElement(buffer.toString());

  buffer.setLength(0);

  } else {

  buffer.append(chars[i]);

  }

}

vLines.addElement(buffer.toString());

this.message = new String[vLines.size()];

vLines.copyInto(this.message);

this.messageFirstLineShown = 0;

When the time comes when you need to paint the message, use the following code:

int y = 0;

for (int i = this.messageFirstLineShown; i < message.length; i++) {

    g.drawString(this.message[i], 0, y, Graphics.LEFT | Graphics.TOP);

    y += g.getFont().getHeight();

}

If you have more lines in message than the screen can show, you will need to add a nextCommand = Command("Next", Command.OK, 1)  to increase the value of messageFirstLineShown.

To know if this is the case check if ((getHeight() / Font.getDefaultFont().getHeight()) > message.length) and at commandAction add the following treatment:

int maxLines = this.getHeight() / Font.getDefaultFont().getHeight();

int remainingLines = this.message.length - this.messageFirstLineShown;

this.messageFirstLineShown += maxLines;

if (remainingLines < maxLines) {

    this.removeCommand(nextCommand);

}