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Converting a HyperCard stack to MetaCard


Table of Contents

(Partial listing:)

Importing the stack

Launch MetaCard. To open the stack in MetaCard, simply choose "Open stack" from the File menu and choose the Tech Support TimeSaver stack. Although we commonly use the word "convert" when referring to porting HyperCard stacks, in reality they are opened and read directly by MetaCard. No other "conversion" process is necessary.

Fixing the Play error

When the stack first opens, you will see an error dialog with a "bad command" error. Click the script button, which will take you to the part of the script that plays a ticking sound. MetaCard supports the play command, and the sound resource it refers to was imported into the data fork of the new stack. However, MetaCard does not support playing specific notes with a sound resource, so that is what the script has flagged.

Remove the notation parameters from the play command inside the idle handler, leaving only the command itself:

on idle
  play "Tick.rev"
  pass idle
end idle
To close and save the script, hit the Enter key, or click the OK button at the bottom of the editor.

This would be a good time to choose "Save" from the File menu and save the stack to disk. Unlike HyperCard, MetaCard does not save your work for you automatically; it works more like conventional applications. If anything should go wrong before you have saved the converted stack, all your work would be lost, so save frequently. Another advantage to saving immediately after importing is that the "Revert" menu command will work if you later need to go back to a previously-saved version. Until the stack is saved to disk, there is nothing to revert to.

Setting the stack title

In MetaCard, a stack's name is different than its title. You can give a stack a name that is easy to type and refer to in scripts, while displaying a longer or more descriptive title in the title bar. A stack without an assigned title will display the stack's name in the title bar by default, followed by an asterisk. To remove the asterisk, just give the stack a title. (If you ever want to have a title bar with no title in it at all, use a space as the stack's title.)

To add a title, choose "Stack Properties..." from the Edit menu and type a title into the Title field. We used "Tech Support TimeSaver" as the stack title, and changed the stack name to "TSTS". That gives us a short name to refer to in scripts while leaving the more descriptive name in the stack's title bar. If you prefer, it is okay to use the same name for both.

To set the properties and return to the stack, click the close box in the Stack Properties window.

Setting the idle rate

Now that we've removed the notation from the "play" command, the ticking sound on the first card is erratic. We need another way to even out the pulse.

MetaCard allows a script to set the idleRate property, which determines how often an idle message is sent. The number indicates a delay in milliseconds between idle messages and can be anything between 0 and 65535. We will use 800 to give us an even beat. Note that MetaCard supports the idle message for compatibility with HyperCard, but does not recommend its use. We will modify this script later in the Optimizing for MetaCard section of the tutorial, but for now, we will simply modify the idle handler to accomodate.

We will set the idleRate on openCard and set it back to default on closeCard. Open the script of the first card by using the same keystrokes that HyperCard uses: press Cmd-Option-C. Change the openCard handler and the closeCard handler to look like this (changes are marked in red):

on openCard
  global gShowDialog
  set the idleRate to 800
  if gShowDialog is "Yes" then
    put "No" into gShowDialog
    -- play "Bell"
    answer "This program is $5 shareware." & return & return & \
        "NOTICE: Do not distribute this stack except in its original," \
        && "unaltered form as a HyperCard file. See the About card" && \
        "for details." with "More Info" or "OK"
    if it is "More Info" then
      visual effect dissolve fast
      go next card
    end if
  end if
  pass openCard
end openCard

on idle
  play "Tick.rev"
  pass idle
end idle

on closeCard
  play stop
  set the idlerate to 60000
  pass closeCard
end closeCard

You may notice that we have also commented out the play "Bell" command in the openCard handler. MetaCard has faithfully imported this sound along with the others, but it was probably saved originally in an incompatible format, most likely as a Mac-specific compressed sound. We have commented it out to prevent the noise that occurs when MetaCard tries to reproduce it. The fix is to delete the sound from MetaCard, re-sample the original in a sound editing program, save it in ".au" format (which is the most fully cross-platform, though you can use other formats if you like) and re-import it back into MetaCard via the "Import" item under the File menu. For our purposes, we will leave this play command commented out.

If you leave the card and return, you will hear a steady ticking sound. If not, be sure the browse tool is selected. MetaCard does not send normal messages while the arrow tool is active.

The "About" card

Adjusting the graphic and button

Either type the right arrow key on your keyboard, or click the "About" button on the title card to go to the next card. This card gives some information about the stack and its author, and serves as the stack's About box.

Due to the way HyperCard stores some of its graphic information, the normally opaque graphic on this card has imported with some of its white space transparent. We will fix that by using the paint tools to re-fill the white area that is missing.

Choose "Paint Tools" from the Tools menu and click on the bucket tool in the resulting palette. Since the default fill color is white, we don't need to choose a color. Click the point of the bucket tool in the main area of the graphic which should be white, and click again in the tiny, thin area between the two black borders. Use the rectangle tool to redraw the border lines if necessary. Since the default pen color is black, there's no need to choose a color for this tool either. Close the Paint Tools palette.

The shadow button in MetaCard is drawn somewhat differently than it is in HyperCard. Since shadow is not a common button style on most platforms, let's change this button to standard style. The standard button style takes on the colors and appearance of the current operating system automatically. On Macs, a standard button will look like a round-cornered Macintosh button with Appearance Manager colors and properties. On Windows, a standard button will take on the user-selected color scheme and will be drawn as a rectangle with a focus border, according to Windows guidelines. You do not need to manage the button's appearance between platforms if you use standard buttons; MetaCard will do it for you.

To set the button style, choose "Tools Palette" from the Tools menu, and then click on the arrow tool; or alternately, you can choose the arrow tool by typing Cmd-Tab on your keyboard. Double-click the "OK" button on the About card. In the properties dialog that appears, click on the Appearance tab. Click the appropriate radio button to set the button to standard style. Close the button properties dialog to save the settings, and type Cmd-Tab again to return to the browse tool, or choose it from the Tools palette.

Save the stack to disk. The About card is done now, though we will return to it later in the Optimizing for MetaCard section of the tutorial.

It's time to move on to the main record-keeping section of the stack.



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All contents copyright (C) 1996, HyperActive Software. All rights reserved.
Revised: December 3, 2001
URL: http://www.hyperactivesw.com/mctutorial/tutorialtoc.html