Setting size, scale, and orientation



The section Printing a page details the steps for a basic print job, where the output directly reflects the printed equivalent of the screen size and position of the specified sprite. However, printers use different resolutions for printing, and can have settings that adversely affect the appearance of the printed sprite.

Flash Player and AIR can read an operating system’s printing settings, but note that these properties are read-only: although you can respond to their values, you can’t set them. So, for example, you can find out the printer’s page size setting and adjust your content to fit the size. You can also determine a printer’s margin settings and page orientation. To respond to the printer settings, you may need to specify a print area, adjust for the difference between a screen’s resolution and a printer’s point measurements, or transform your content to meet the size or orientation settings of the user’s printer.

Using rectangles for the print area

The PrintJob.addPage() method allows you to specify the region of a sprite that you want printed. The second parameter, printArea, is in the form of a Rectangle object. You have three options for providing a value for this parameter:

  • Create a Rectangle object with specific properties and then use that rectangle in the addPage() call, as in the following example:

    private var rect1:Rectangle = new Rectangle(0, 0, 400, 200); 
    myPrintJob.addPage(sheet, rect1);
  • If you haven’t already specified a Rectangle object, you can do it within the call itself, as in the following example:

    myPrintJob.addPage(sheet, new Rectangle(0, 0, 100, 100));
  • If you plan to provide values for the third parameter in the addPage() call, but don’t want to specify a rectangle, you can use null for the second parameter, as in the following;

    myPrintJob.addPage(sheet, null, options);
Note: If you plan to specify a rectangle for the printing dimensions, remember to import the flash.display.Rectangle class.

Comparing points and pixels

A rectangle's width and height are pixel values. A printer uses points as print units of measurement. Points are a fixed physical size (1/72 inch), but the size of a pixel on the screen depends on the resolution of the particular screen. The conversion rate between pixels and points depends on the printer settings and whether the sprite is scaled. An unscaled sprite that is 72 pixels wide will print out one inch wide, with one point equal to one pixel, independent of screen resolution.

You can use the following equivalencies to convert inches or centimeters to twips or points (a twip is 1/20 of a point):

  • 1 point = 1/72 inch = 20 twips

  • 1 inch = 72 points = 1440 twips

  • 1 centimeter = 567 twips

If you omit the printArea parameter, or if it is passed incorrectly, the full area of the sprite is printed.

Scaling

If you want to scale a Sprite object before you print it, set the scale properties (see Manipulating size and scaling objects) before calling the PrintJob.addPage() method, and set them back to their original values after printing. The scale of a Sprite object has no relation to the printArea property. In other words, if you specify a print area that is 50 pixels by 50 pixels, 2500 pixels are printed. If you scale the Sprite object, the same 2500 pixels are printed, but the Sprite object is printed at the scaled size.

For an example, see Example: Scaling, cropping, and responding.

Printing for landscape or portrait orientation

Because Flash Player and AIR can detect the settings for orientation, you can build logic into your ActionScript to adjust the content size or rotation in response to the printer settings, as the following example illustrates:

if (myPrintJob.orientation == PrintJobOrientation.LANDSCAPE) 
{ 
    mySprite.rotation = 90; 
}
Note: If you plan to read the system setting for content orientation on the paper, remember to import the PrintJobOrientation class. The PrintJobOrientation class provides constant values that define the content orientation on the page. You import the class using the following statement:
import flash.printing.PrintJobOrientation;

Responding to page height and width

Using a strategy that is similar to handling printer orientation settings, you can read the page height and width settings and respond to them by embedding some logic into an if statement. The following code shows an example:

if (mySprite.height > myPrintJob.pageHeight) 
{ 
    mySprite.scaleY = .75; 
}

In addition, a page’s margin settings can be determined by comparing the page and paper dimensions, as the following example illustrates:

margin_height = (myPrintJob.paperHeight - myPrintJob.pageHeight) / 2; 
margin_width = (myPrintJob.paperWidth - myPrintJob.pageWidth) / 2;