Disk Image Contents

Adding files to a disk image is extremely simple using DMG Canvas. Simply drag and drop the files into the Content view to have DMG Canvas copy those files to the disk image when the disk image is built (using the Build command). To create an alias to a file or folder (such as creating an alias to the Applications folder), simply hold Control while dropping the file onto the view.

The Contents view shows the preview of what the Finder window will look like when the disk image is mounted. The window size, location, file icon sizes, and various other settings are specified using the sidebar on the right side of the window.

Disk Image Background

Creating the background of the disk image window is as easy as picking a color or setting a background image using the sidebar. But that's not where the fun has to end.

DMG Canvas also allows you to drag and drop images onto the Background view, as well as add text objects in order streamline the design process. Instead of having to switch back and forth between two different programs designing the background image and testing it in DMG Canvas, you can drop in pieces of the background and fine tune the layout right inside the Background view. DMG Canvas will automatically composite the layout from the Background view into the background image for the Finder window.

To change the font, size, and color of text objects in the Background view, double-click on it, select the text, and use the standard Font and Color panels (see the Text menu) to style the text.

Retina Background Support

Finder in OS X 10.7 Lion and later supports Retina-resolution background images in disk images. DMG Canvas supports creating these Retina backgrounds. When a dmg is created, the background image (the composited color/image of your choice with the text objects on top) is created at both a regular size and Retina-size. This multi-resolution image is set as the background image for the dmg's Finder window and the correct resolution is used when the window is displayed. To enabled Retina background creation, you must set the Build Target of the disk image to be OS X 10.7 or later. Earlier versions of OS X do not correctly handle the Retina resolution images, so if you need to build a single disk image for OS versions before and after Lion (such as for an application which runs on 10.6 through 10.8), you will unfortunately not be able to have a Retina background.

One thing you must note, however, is that if you add an image file to the dmg background (either in the Background view or setting it as the background image in the sidebar), the image files you use should be 144 dpi in order to be Retina-savvy. Otherwise, when using a standard 72 dpi image, on a Retina screen it will not be as crisp and clean as it should be. For example, if your disk image is sized 600 x 400, normally you would use a 600 x 400 72 dpi background image. To support Retina displays, you should use a 1200 x 800 144 dpi background image.

License Agreements

When a disk image is mounted, it can optionally display a window containing a localized license agreement that the user must agree to before the disk image will mount. Adding these license agreements to your disk image is done using the Licenses pane. Simply click on the Add button in the lower left corner of the window and select the language you wish to add from the list of available langauges. DMG Canavas already has localized text strings for the button labels presented along with the license agreement when mounted. Simply add your localized license agreement text and DMG Canvas will add it to the built disk image.

If the user mounting your disk image is using a language other than the ones you provided a localized license agreement for, the Disk Image Mounter will choose to show the license in a default language. This default language can be specified by clicking on the button in the lower left corner of the window with the heart-shaped icon.

Disk Image Format

Among the options for the disk image's volume inclue:

• The volume's name
• The volume's icon
• The file system format
• The capacity of the volume.
• Encryption (None, AES 128, or AES 256)
• Compression
• Internet Enabling

Making a disk image "Internet Enabled" tells web browsers like Safari that the dmg can be treated just like a .zip file would be when downloaded. When Safari has the "Open 'safe' files after downloading" option turned on, the contents of zip files and internet-enabled disk images are automatically extracted and put into the user's Downloads folder, and the zip/dmg file is deleted. Normally a dmg would mount a volume onto the desktop and the user would have to manually copy the files from the mounted volume to their hard drive.

Command Line Tool

The dmgcanvas command line tool allows you to build disk images from DMG Canvas documents using the command line. With scripting, you can use dmgcanvas to automate your disk image workflow.

To install and use dmgcanvas, select the "dmgcanvas Tool" menu item from the "DMG Canvas" application menu, then select the location from the popup below where you would like the symbolic link pointing to dmgcanvas to be created in and click the "Create Link" button.

Building Disk Images

When you add files to the document in DMG Canvas, instead of the files being copied into the document, both absolute and relative file paths to the files stored. (Relative paths use the document's parent folder as the root location.) This way, when you build a disk image using either DMG Canvas.app or the dmgcanvas command line tool, the latest versions of the files referenced are used.

When DMG Canvas looks for a file to copy into the disk image being built, it first uses the relative path to find the file. If a file does not exist at the location, it looks for it at the absolute path. By taking advantage of relative paths, you can use one set of files to create the DMG Canvas document, and move the document to another location or even another machine and use an entirely different set of files to create the disk image. As long as the relative location between the files and the document are the same, it'll work seamlessly.