Selecting Text within Graphics / Graphics2D

Question

Selecting Text using Graphics/Graphics2D

How do I select text from a string using the mouse when it's rendering in Graphics?

Hey, I'm developing UI Controls for software I'm making in JAVA. I'm rendering everything using Graphics/Graphics2D and I need a little assistance with a problem I've come across. I have the textbox control all set up so you can type, and backspace text. The next problem I have is being able to select portions of this text. I'm not exactly sure where I should start on this matter. Be low I will post at my controls render code and it's typing code.

Render Code

@Override
public void render(Graphics g) {

    // Draw Fill
    Graphics2D g2 = (Graphics2D) g.create();
    if (isActive) {
        g2.setPaint(new GradientPaint(new Point(x, y), Colors.textboxActiveTop, new Point(x, y + h), Colors.textboxActiveBottom));
    } else {
        g2.setPaint(new GradientPaint(new Point(x, y), Colors.textboxTop, new Point(x, y + h), Colors.textboxBottom));
    }
    g2.fillRect(x, y, w, h);

    // Draw Text
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    if (isPassword) {
        int count = text.toString().length();
        for (int i = 0; i < text.toString().length(); i++) {
            g2.setColor(Colors.white50percent);
            g2.fillArc(x + (w / 2) + (i * 5) - ((count * 5) / 2), y + (h / 2), 4, 4, 0, 360);
            g2.setColor(foreColor);
            g2.fillArc(x + (w / 2) + (i * 5) - ((count * 5) / 2), y + (h / 2) - 1, 4, 4, 0, 360);
        }
    } else {
        if (isCentered) {
            g2.setColor(Colors.white50percent);
            g2.drawString(text.toString(), x + (w / 2) - (g.getFontMetrics().stringWidth(text.toString()) / 2), y + (h / 2) + (g.getFontMetrics().getMaxAscent() / 2) + 1);
            g2.setColor(foreColor);
            g2.drawString(text.toString(), x + (w / 2) - (g.getFontMetrics().stringWidth(text.toString()) / 2), y + (h / 2) + (g.getFontMetrics().getMaxAscent() / 2));
        } else {
            g2.setColor(Colors.white50percent);
            g2.drawString(text.toString(), x + 5, y + (h / 2) + (g.getFontMetrics().getMaxAscent() / 2) + 1);
            g2.setColor(foreColor);
            g2.drawString(text.toString(), x + 5, y + (h / 2) + (g.getFontMetrics().getMaxAscent() / 2));
        }
    }
    // Draw Border
    g.setColor(Colors.borderColor);
    g.drawRect(x, y, w, h);

    // Draw Hightlights
    g.setColor(Colors.white50percent);
    g.drawRect(x + 1, y + 1, w - 2, h - 2);
    g.drawRect(x - 1, y - 1, w + 2, h + 2);
}

Typing Code

@Override
public void keyTyped(KeyEvent e) {
    int code = (int) e.getKeyChar();
    if (isActive) {
        if (code == 8) {
            if (text.toString().length() >= 1) {
                text = text.toString().substring(0, text.toString().length() - 1);
            }
        } else {
            String character = "" + (char)code;
            if(acceptedCharacters.contains(character.toLowerCase()))
                text = text.toString() + (char) code;
        }
    }
}

Answer 1

How do I select text from a string using the mouse when it's rendering in Graphics?

Add a MouseListener and when it fires, check if it within the bounds of the String.

Ways to check the bounds of a String:

• FontMetrics
• GlyphVector e.g.