CODEWITHSUNDEEP
javaswing
michael nesterenko
michael nesterenko

Reputation: 14439

wrong string width

I have following code that is used to compute dialog title width.

FontRenderContext frc = new FontRenderContext(null, true, true);
TextLayout tl = new TextLayout(getTitle(), getFont(), frc);
double w = tl.getPixelBounds(null,  0, 0).getWidth();

However for some reason text width is computed wrongly. I checked this code for computing radio button label text width and it worked correctly. My main concern is about dialog font, I am not sure if I correctly get it.

For example for title test computed width is 20 however actual width is 23. The longer string is the bigger difference between computed and actual widths.

Upvotes: 1

Views: 932

Answers (1)

Trasplazio Garzuglio
Trasplazio Garzuglio

Reputation: 3585

You're getting a wrong result because the dialog title and the font it's using are native resources.

If you're application is Windows-only, you can get the width with this code:

Font f = (Font)Toolkit.getDefaultToolkit().getDesktopProperty("win.frame.captionFont");  
Graphics gr = getGraphics();  
FontMetrics metrics = gr.getFontMetrics(f);  
int width = metrics.stringWidth(getTitle());

Otherwise try to get the FontMetrics from the title bar's font: 

Container titleBar = (Container) dialog.getLayeredPane().getComponents()[1];
FontMetrics metrics = titleBar.getFontMetrics(titleBar.getFont());
int width = metrics.stringWidth(getTitle());

If it's to dynamically set the width of the dialog, you also need to take into account the LaF spacing and the borders. Try this:

// This is the space inserted on the left of the title, 5px in Metal LaF
width += 5; 

// This is the space for the close button, LaF dependent.
width += 4;

// Add the borders
width += dialog.getWidth() - dialog.getContentPane().getWidth();

// Finally set the size
dialog.setSize(new Dimension(width, dialog.getPreferredSize().height));

Hopefully this will work. If you wonder where the numbers come from, they're in the JDK source code.

Upvotes: 5

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